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Sample records for benefits soa virtualization

  1. An Investigation of Benefits Affecting SOA Adoption in e-Banking

    OpenAIRE

    Basias, Nikolaos; Marinos, Themistocleous; Morabito, Vincenzo

    2014-01-01

    Banking is a leading industry in the development of e-business and e-banking grows rapidly due to the numerous potential benefits associated with it. E-banking brings up unique types of challenges and requires innovative integration solutions as Service Oriented Architecture (SOA). Integration is one of the most important challenges for e-banking success and many issues related to this area remain unexplored. In addressing integration issues, SOA has emerged and adopted by many banks. Neverth...

  2. Mapping SOA Artefacts onto an Enterprise Reference Architecture Framework

    Science.gov (United States)

    Noran, Ovidiu

    Currently, there is still no common agreement on the service-Oriented architecture (SOA) definition, or the types and meaning of the artefacts involved in the creation and maintenance of an SOA. Furthermore, the SOA image shift from an infrastructure solution to a business-wide change project may have promoted a perception that SOA is a parallel initiative, a competitor and perhaps a successor of enterprise architecture (EA). This chapter attempts to map several typical SOA artefacts onto an enterprise reference framework commonly used in EA. This is done in order to show that the EA framework can express and structure most of the SOA artefacts and therefore, a framework for SOA could in fact be derived from an EA framework with the ensuing SOA-EA integration benefits.

  3. SOA for the Business Developer Concepts, BPEL, and SCA

    CERN Document Server

    Margolis, Ben

    2007-01-01

    Service-Oriented Architecture (SOA) is a way of organizing software. If your company's development projects adhere to the principles of SOA, the outcome will be an inventory of modular units called "services," which allow for a quick response to change. This book tells the SOA story in a simple, straightforward manner that will help you understand not only the buzzwords and benefits, but also the technologies that underlie SOA: XML, WSDL, SOAP, XPath, BPEL, SCA, and SDO. And through it all, the authors provide business examples and illustrations, giving a practical meaning to abstract ideas

  4. Virtual Business Operating Environment in the Cloud: Conceptual Architecture and Challenges

    Science.gov (United States)

    Nezhad, Hamid R. Motahari; Stephenson, Bryan; Singhal, Sharad; Castellanos, Malu

    Advances in service oriented architecture (SOA) have brought us close to the once imaginary vision of establishing and running a virtual business, a business in which most or all of its business functions are outsourced to online services. Cloud computing offers a realization of SOA in which IT resources are offered as services that are more affordable, flexible and attractive to businesses. In this paper, we briefly study advances in cloud computing, and discuss the benefits of using cloud services for businesses and trade-offs that they have to consider. We then present 1) a layered architecture for the virtual business, and 2) a conceptual architecture for a virtual business operating environment. We discuss the opportunities and research challenges that are ahead of us in realizing the technical components of this conceptual architecture. We conclude by giving the outlook and impact of cloud services on both large and small businesses.

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

    Science.gov (United States)

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

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

  6. The Role of Fast Carrier Dynamics in SOA Based Devices

    DEFF Research Database (Denmark)

    Mørk, Jesper; Berg, Tommy Winther; Nielsen, Mads Lønstrup

    2004-01-01

    and the properties of schemes relying on cross-gain as well as cross-phase modulation are discussed. The possible benefits of using SOAs with quantum dot active regions are theoretically analyzed. The bandfilling characteristics and the presence of fast capture processes may allow to reach bitrates in excess of 100......We describe the characteristics of all-optical switching schemes based on semiconductor optical amplifiers (SOAs), with particular emphasis on the role of the fast carrier dynamics. The SOA response to a single short pulse as well as to a data-modulated pulse train is investigated...

  7. A decision making framework for SOA adoption in e-banking: a case study approach

    OpenAIRE

    Basias, Nikolaus; Themistocleous, Marinos; Morabito, Vincenzo

    2015-01-01

    E-banking grows rapidly due to the numerous potential benefits associated with it and integration is one of the most important challenges for e-banking success. In addressing integration issues, SOA has emerged and adopted by many banks. Nevertheless, numerous banks fail to achieve successful SOA adoption for various reasons. One of the main reasons is attributed to the lack of a methodological framework that would (a) explain factors affecting SOA adoption in e-banking and (b) define the SOA...

  8. Aspects of SOA: An Entry Point for Starters

    Directory of Open Access Journals (Sweden)

    Qusay F. Hassan

    2009-01-01

    Full Text Available Because Service-Oriented Architecture (SOA is one of the hottest topics that is currently gaining momentum, and the number of its adopters (both business and IT executives is increasing in a tremendous manner, it is really a must to enlist important aspects related to it in order to allow these adopters to better understand the role that it can play in both software and business markets. These aspects varies from the definition of SOA and key components of it, different forms of support given by elite software vendors to it, its evolution history, the relationship between it and web services, the future expectations about its uses and benefits in different organizations, the relationship between SOA and Enterprise Application Integration (EAI, and various applications that can use it to overcome limitations related to other traditional methods. Moreover, challenges that face SOA in software market should be addressed and discussed in order to be able to see the big picture and to look for better solutions for them.

  9. Java SOA Cookbook

    CERN Document Server

    Hewitt, Eben

    2009-01-01

    Java SOA Cookbook offers practical solutions and advice to programmers charged with implementing a service-oriented architecture (SOA) in their organization. Instead of providing another conceptual, high-level view of SOA, this cookbook shows you how to make SOA work. It's full of Java and XML code you can insert directly into your applications and recipes you can apply right away. The book focuses primarily on the use of free and open source Java Web Services technologies -- including Java SE 6 and Java EE 5 tools -- but you'll find tips for using commercially available tools as well. Jav

  10. SOA Modeling Patterns for Service Oriented Discovery and Analysis

    CERN Document Server

    Bell, Michael

    2010-01-01

    Learn the essential tools for developing a sound service-oriented architecture. SOA Modeling Patterns for Service-Oriented Discovery and Analysis introduces a universal, easy-to-use, and nimble SOA modeling language to facilitate the service identification and examination life cycle stage. This business and technological vocabulary will benefit your service development endeavors and foster organizational software asset reuse and consolidation, and reduction of expenditure. Whether you are a developer, business architect, technical architect, modeler, business analyst, team leader, or manager,

  11. SOA Pragmatism

    Science.gov (United States)

    Shan, Tony C.

    This paper presents a pragmatic approach composed of Methodology, Automation, Patterns, and Strategy (MAPS), to effectively manage the architecture design practices and solution development lifecycle of information systems in a service-oriented paradigm. The key challenges in SOA are discussed, such as architecture complexity, evolving technologies, immature governance, fragmented specification efforts, and disparate visual notations. This comprehensive framework aims to provide a mature integration of appropriate knowledge and capabilities to filter the inessential from the essential. In the Methodology dimension, a hybrid method, SOA philosophy, and a methodical approach are the key components. The Automation dimension covers tools, service lifecycle, and COTS mapping. The prominent elements of the Patterns dimension are data caching patterns, reference model, and open source reference implementation. Finally, the Strategy dimension addresses the strategy metamodel, technology architecture planning, and strategy roadmapping. In addition, a 9-point list of SOA wisdom is articulated, which gives best-practice guidelines to adopt and implement SOA pragmatically in large organizations from a practitioner's perspeoctive.

  12. Registratie van soa en HIV consulten bij GGD-en en soa-poliklinieken: Jaarverslag 2002

    NARCIS (Netherlands)

    Laar MJW van de; Veen MG van; Coenen AJJ; CIE

    2003-01-01

    Bij de GGD-en en soa-poliklinieken wordt ten behoeve van de non-curatieve soa-bestrijding een registratie bijgehouden van de bezoekers met een soa-hulpvraag of HIV-testverzoek. In 2002 registreerden 37 GGD-en en twee soa-poliklinieken in totaal 23.353 consulten (stijging van 16% t.o.v. 2001),

  13. Sensitivity analysis of simulated SOA loadings using a variance-based statistical approach: SENSITIVITY ANALYSIS OF SOA

    Energy Technology Data Exchange (ETDEWEB)

    Shrivastava, Manish [Pacific Northwest National Laboratory, Richland Washington USA; Zhao, Chun [Pacific Northwest National Laboratory, Richland Washington USA; Easter, Richard C. [Pacific Northwest National Laboratory, Richland Washington USA; Qian, Yun [Pacific Northwest National Laboratory, Richland Washington USA; Zelenyuk, Alla [Pacific Northwest National Laboratory, Richland Washington USA; Fast, Jerome D. [Pacific Northwest National Laboratory, Richland Washington USA; Liu, Ying [Pacific Northwest National Laboratory, Richland Washington USA; Zhang, Qi [Department of Environmental Toxicology, University of California Davis, California USA; Guenther, Alex [Department of Earth System Science, University of California, Irvine California USA

    2016-04-08

    We investigate the sensitivity of secondary organic aerosol (SOA) loadings simulated by a regional chemical transport model to 7 selected tunable model parameters: 4 involving emissions of anthropogenic and biogenic volatile organic compounds, anthropogenic semi-volatile and intermediate volatility organics (SIVOCs), and NOx, 2 involving dry deposition of SOA precursor gases, and one involving particle-phase transformation of SOA to low volatility. We adopt a quasi-Monte Carlo sampling approach to effectively sample the high-dimensional parameter space, and perform a 250 member ensemble of simulations using a regional model, accounting for some of the latest advances in SOA treatments based on our recent work. We then conduct a variance-based sensitivity analysis using the generalized linear model method to study the responses of simulated SOA loadings to the tunable parameters. Analysis of SOA variance from all 250 simulations shows that the volatility transformation parameter, which controls whether particle-phase transformation of SOA from semi-volatile SOA to non-volatile is on or off, is the dominant contributor to variance of simulated surface-level daytime SOA (65% domain average contribution). We also split the simulations into 2 subsets of 125 each, depending on whether the volatility transformation is turned on/off. For each subset, the SOA variances are dominated by the parameters involving biogenic VOC and anthropogenic SIVOC emissions. Furthermore, biogenic VOC emissions have a larger contribution to SOA variance when the SOA transformation to non-volatile is on, while anthropogenic SIVOC emissions have a larger contribution when the transformation is off. NOx contributes less than 4.3% to SOA variance, and this low contribution is mainly attributed to dominance of intermediate to high NOx conditions throughout the simulated domain. The two parameters related to dry deposition of SOA precursor gases also have very low contributions to SOA variance

  14. Fundamentals for the Allocation of Financial Benefits in Virtual Enterprises

    OpenAIRE

    Jähn , Hendrik; Burghardt , Thomas

    2012-01-01

    Part 18: Cost, Benefits and Performance; International audience; In the following fundamentals for the allocation of financial benefits such as profit are introduced. The content is based on the concept of value-adding process-related virtual enterprises. Before applying exact rules for the calculation and allocation of the financial benefits some initial process steps need to be completed. That is indispensable for the success of virtual enterprises because financial benefits are the main ta...

  15. A Service-Oriented Approach for Dynamic Chaining of Virtual Network Functions over Multi-Provider Software-Defined Networks

    Directory of Open Access Journals (Sweden)

    Barbara Martini

    2016-06-01

    Full Text Available Emerging technologies such as Software-Defined Networks (SDN and Network Function Virtualization (NFV promise to address cost reduction and flexibility in network operation while enabling innovative network service delivery models. However, operational network service delivery solutions still need to be developed that actually exploit these technologies, especially at the multi-provider level. Indeed, the implementation of network functions as software running over a virtualized infrastructure and provisioned on a service basis let one envisage an ecosystem of network services that are dynamically and flexibly assembled by orchestrating Virtual Network Functions even across different provider domains, thereby coping with changeable user and service requirements and context conditions. In this paper we propose an approach that adopts Service-Oriented Architecture (SOA technology-agnostic architectural guidelines in the design of a solution for orchestrating and dynamically chaining Virtual Network Functions. We discuss how SOA, NFV, and SDN may complement each other in realizing dynamic network function chaining through service composition specification, service selection, service delivery, and placement tasks. Then, we describe the architecture of a SOA-inspired NFV orchestrator, which leverages SDN-based network control capabilities to address an effective delivery of elastic chains of Virtual Network Functions. Preliminary results of prototype implementation and testing activities are also presented. The benefits for Network Service Providers are also described that derive from the adaptive network service provisioning in a multi-provider environment through the orchestration of computing and networking services to provide end users with an enhanced service experience.

  16. SOA approach to battle command: simulation interoperability

    Science.gov (United States)

    Mayott, Gregory; Self, Mid; Miller, Gordon J.; McDonnell, Joseph S.

    2010-04-01

    NVESD is developing a Sensor Data and Management Services (SDMS) Service Oriented Architecture (SOA) that provides an innovative approach to achieve seamless application functionality across simulation and battle command systems. In 2010, CERDEC will conduct a SDMS Battle Command demonstration that will highlight the SDMS SOA capability to couple simulation applications to existing Battle Command systems. The demonstration will leverage RDECOM MATREX simulation tools and TRADOC Maneuver Support Battle Laboratory Virtual Base Defense Operations Center facilities. The battle command systems are those specific to the operation of a base defense operations center in support of force protection missions. The SDMS SOA consists of four components that will be discussed. An Asset Management Service (AMS) will automatically discover the existence, state, and interface definition required to interact with a named asset (sensor or a sensor platform, a process such as level-1 fusion, or an interface to a sensor or other network endpoint). A Streaming Video Service (SVS) will automatically discover the existence, state, and interfaces required to interact with a named video stream, and abstract the consumers of the video stream from the originating device. A Task Manager Service (TMS) will be used to automatically discover the existence of a named mission task, and will interpret, translate and transmit a mission command for the blue force unit(s) described in a mission order. JC3IEDM data objects, and software development kit (SDK), will be utilized as the basic data object definition for implemented web services.

  17. Global transformation and fate of SOA: Implications of Low Volatility SOA and Gas-Phase Fragmentation Reactions

    Energy Technology Data Exchange (ETDEWEB)

    Shrivastava, ManishKumar B.; Easter, Richard C.; Liu, Xiaohong; Zelenyuk, Alla; Singh, Balwinder; Zhang, Kai; Ma, Po-Lun; Chand, Duli; Ghan, Steven J.; Jiminez, J. L.; Zhang, Qibin; Fast, Jerome D.; Rasch, Philip J.; Tiitta, P.

    2015-05-16

    Secondary organic aerosols (SOA) are large contributors to fine particle loadings and radiative forcing, but are often represented crudely in global models. We have implemented three new detailed SOA treatments within the Community Atmosphere Model version 5 (CAM5) that allow us to compare the semi-volatile versus non-volatile SOA treatments (based on some of the latest experimental findings) and also investigate the effects of gas-phase fragmentation reactions. For semi-volatile SOA treatments, fragmentation reactions decrease simulated SOA burden from 7.5 Tg to 1.8 Tg. For the non-volatile SOA treatment with fragmentation, the burden is 3.1 Tg. Larger differences between non-volatile and semi-volatile SOA (upto a factor of 5) correspond to continental outflow over the oceans. Compared to a global dataset of surface Aerosol Mass Spectrometer measurements and the US IMPROVE network measurements, the non-volatile SOA with fragmentation treatment (FragNVSOA) agrees best at rural locations. Urban SOA is under-predicted but this may be due to the coarse model resolution. All our three revised treatments show much better agreement with aircraft measurements of organic aerosols (OA) over the N. American Arctic and sub-Arctic in spring and summer, compared to the standard CAM5 formulation. This is due to treating SOA precursor gases from biomass burning, and long-range transport of biomass burning OA at elevated levels. The revised model configuration that include fragmentation (both semi-volatile and non-volatile SOA) show much better agreement with MODIS AOD data over regions dominated by biomass burning during the summer, and predict biomass burning as the largest global source of OA followed by biogenic and anthropogenic sources. The non-volatile and semi-volatile configuration predict the direct radiative forcing of SOA as -0.5 W m-2 and -0.26 W m-2 respectively, at top of the atmosphere, which are higher than previously estimated by most models, but in reasonable

  18. A lifecycle approach to SOA Governance

    NARCIS (Netherlands)

    Schepers, T.G.J.; Iacob, Maria Eugenia; van Eck, Pascal

    2008-01-01

    Due to the distributed nature of Service-Oriented Architectures (SOA), maintaining control in a SOA environment becomes more difficult as services spread over different lines-of-business. The concept of SOA governance has emerged as a way to implement control mechanisms in a SOA. In this paper we

  19. Business Process Optimization Through Soa And Cloud Integration Using Soa- Ra Model

    Directory of Open Access Journals (Sweden)

    Syed Ejaz Ali Shah

    2015-08-01

    Full Text Available Business processes workflow architecture based on agility and flexibility plays an important role in the success of any enterprise. In new era most of the processes are automated and they are supported by IT-Services in the form of Service Oriented Architecture SOA components. Due to mobility and scalability as well as high performance computing and distributed working environment it is crucial to focus on an architecture which is agile optimized cost effective and easy to implement. In this paper we have conducted a research study on layer based BPM SOA and cloud integrated architecture. The main contribution of the research study is to propose an agile cost effective and scalable solution framework based on Architectural Building Blocks ABBs following a SOA-RA layered model to integrate BPM SOA and cloud services.

  20. SOA-surveillance Nederland

    NARCIS (Netherlands)

    Rijlaarsdam J; Bosman A; Laar MJW van de; CIE

    2000-01-01

    In mei 1999 is een werkgroep gestart met de opdracht om "vanuit de bestaande situatie een voorstel te doen voor een effectief en efficient surveillancesysteem voor SOA dat inzicht geeft in de prevalentie en de incidentie van SOA in Nederland. Het systeem moet te gebruiken zijn voor directe

  1. Tutorial : service-oriented architecture (SOA) development for serious games

    NARCIS (Netherlands)

    Carvalho, M.B.; Hu, J.; Bellotti, F.; de Gloria, A.; Rauterberg, G.W.M.; Chorianopoulos, K.; Divitini, M.; Hauge, J.; Jaccheri, L.; Malaka, R.

    2015-01-01

    This tutorial aims to introduce the benefits of applying a service-oriented architecture (SOA) approach to serious games developers. For that end, we propose a hands-on session in which we will provide information on state-of-the-art services for serious games and guide developers in rethinking one

  2. Business Benefits from the Virtualization of an ICT Infrastructure

    Directory of Open Access Journals (Sweden)

    Ivan Pogarcic

    2012-11-01

    Full Text Available Virtualization is a technique that may be encountered in all parts of an ICT infrastructure. The benefits of virtualization for an infrastructure are recognized by a growing number of companies. In this way, virtualization creates prerequisites for the further improvement of the entire information system. Another reason is the growing awareness of environmental issues at the global level, which has become a large external sponsor of this technology. While virtualization technology has been known about for several decades, its hay day is yet to come. In the following years many jobs will be create because of it, from the user desktop and notebook computers, to the server in all businesses. This article examines the impact of virtualization in business enterprises, with emphasis on infrastructure costs and improved business functions. It points to the large savings that can occur even in medium‐sized enterprises. Claims are verifiable quantitative indicators, particularly in the procurement of equipment. It also demonstrates the benefits of virtualization while performing everyday tasks that take place within the IT department. We discuss the correlation of increased flexibility and convenience, and agile response to market demands, while reducing capital and operating costs, and increasing the competitiveness of companies in the market.

  3. Oracle SOA Governance 11g implementation

    CERN Document Server

    Weir, Luis Augusto

    2013-01-01

    This book is a practical tutorial, with lots of step-by-step instructions for achieving SOA Governance by implementing the component Oracle products.This book is written for SOA architects and project managers who want to learn how to implement Oracle SOA Governance.

  4. On MDA - SOA based Intercloud Interoperability framework

    Directory of Open Access Journals (Sweden)

    Tahereh Nodehi

    2013-01-01

    Full Text Available Cloud computing has been one of the latest technologies which assures reliable delivery of on - demand computing services over the Internet. Cloud service providers have established geographically distributed data centers and computing resources, which are available online as service. The clouds operated by different service providers working together in collaboration can open up lots more spaces for innovative scenarios with huge amount of resources provisioning on demand. However, current cloud systems do not support intercloud interoperability. This paper is thus motivated to address Intercloud Interoperabilityby analyzing different methodologies that have been applied to resolve various scenarios of interoperability. Model Driven Architecture (MDA and Service Oriented Architecture (SOA method have been used to address interoperability in various scenarios, which also opens up spaces to address intercloud interoperability by making use of these well accepted methodologies. The focus of this document is to show Intercloud Interoperability can be supported through a Model Driven approach and Service Oriented systems. Moreover, the current state of the art in Intercloud, concept and benefits of MDA and SOA are discussed in the paper. At the same time this paper also proposes a generic architecture for MDA - SOA based framework, which can be useful for developing applications which will require intercloud interoperability. The paper justi fies the usability of the framework by a use - case scenario for dynamic workload migration among heterogeneous clouds.

  5. Emission factor ratios, SOA mass yields, and the impact of vehicular emissions on SOA formation

    Science.gov (United States)

    Ensberg, J. J.; Hayes, P. L.; Jimenez, J. L.; Gilman, J. B.; Kuster, W. C.; de Gouw, J. A.; Holloway, J. S.; Gordon, T. D.; Jathar, S.; Robinson, A. L.; Seinfeld, J. H.

    2014-03-01

    The underprediction of ambient secondary organic aerosol (SOA) levels by current atmospheric models in urban areas is well established, yet the cause of this underprediction remains elusive. Likewise, the relative contribution of emissions from gasoline- and diesel-fueled vehicles to the formation of SOA is generally unresolved. We investigate the source of these two discrepancies using data from the 2010 CalNex experiment carried out in the Los Angeles Basin (Ryerson et al., 2013). Specifically, we use gas-phase organic mass (GPOM) and CO emission factors in conjunction with measured enhancements in oxygenated organic aerosol (OOA) relative to CO to quantify the significant lack of closure between expected and observed organic aerosol concentrations attributable to fossil-fuel emissions. Two possible conclusions emerge from the analysis to yield consistency with the ambient data: (1) vehicular emissions are not a dominant source of anthropogenic fossil SOA in the Los Angeles Basin, or (2) the ambient SOA mass yields used to determine the SOA formation potential of vehicular emissions are substantially higher than those derived from laboratory chamber studies.

  6. Psychological benefits of virtual reality for patients in rehabilitation therapy.

    Science.gov (United States)

    Chen, Chih-Hung; Jeng, Ming-Chang; Fung, Chin-Ping; Doong, Ji-Liang; Chuang, Tien-Yow

    2009-05-01

    Whether virtual rehabilitation is beneficial has not been determined. To investigate the psychological benefits of virtual reality in rehabilitation. An experimental group underwent therapy with a virtual-reality-based exercise bike, and a control group underwent the therapy without virtual-reality equipment. Hospital laboratory. 30 patients suffering from spinal-cord injury. A designed rehabilitation therapy. Endurance, Borg's rating-of-perceived-exertion scale, the Activation-Deactivation Adjective Check List (AD-ACL), and the Simulator Sickness Questionnaire. The differences between the experimental and control groups were significant for AD-ACL calmness and tension. A virtual-reality-based rehabilitation program can ease patients' tension and induce calm.

  7. Registratie van SOA en HIV consulten bij GGD's en SOA-poliklinieken: Jaarverslag 2000

    NARCIS (Netherlands)

    Laar MJW van de; Haks K; Coenen AJJ; CIE

    2001-01-01

    Bij de Gemeentelijke Gezondheidsdiensten (GGD's) wordt door sociaal-verpleegkundigen ten behoeve van de non-curatieve soa-bestrijding een registratie bijgehouden van de bezoekers ten behoeve van een SOA-hulpvraag of HIV-testverzoek. De gegevens van deze registratie worden landelijk

  8. Combining Cloud-based Workflow Management System with SOA and CEP to Create Agility in Collaborative Environment

    Directory of Open Access Journals (Sweden)

    Marian STOICA

    2017-01-01

    Full Text Available In current economy, technological solutions like cloud computing, service-oriented architecture (SOA and complex event processing (CEP are recognized as modern approaches used for increasing the business agility and achieving innovation. The complexity of collaborative business environment raises more and more the need for performant workflow management systems (WfMS that meet current requirements. Each approach has advantages, but also faces challenges. In this paper we propose a solution for integration of cloud computing with WfMS, SOA and CEP that allows these technologies to complete each other and bank on their benefits to increase agility and reduce the challenges/problems. The paper presents a short introduction in the subject, followed by an analysis of the combination between cloud computing and WfMS and the benefits of cloud based workflow management system. The paper ends with a solution for combining cloud WfMS with SOA and CEP in order to gain business agility and real time collaboration, followed by conclusions and research directions.

  9. Planning and Design Soa Architecture Blueprint

    OpenAIRE

    Tulenan, Virginia

    2013-01-01

    Service Oriented Architecture (SOA) is a framework for integrating business processes and supporting IT infrastructure as secure, standardized components-services-that can be reused and combined to address changing business priorities. Services are the building blocks of SOA and new applications can be constructed through consuming these services and orchestrating services within a business process. In SOA, services map to the business functions that are identified during business process ana...

  10. The Benefits and Risks of Virtual Bidding in Multi-Settlement Markets

    International Nuclear Information System (INIS)

    Isemonger, Alan G.

    2006-01-01

    While it is possible that multi-settlement markets can exist without virtual trading, it is equally clear that virtual trading can provide many market benefits. The main one: In the absence of explicit virtual bidding (EVB), the price arbitrage trades that are benign in other commodity markets affect the reliability of the underlying electricity markets, resulting in a situation where EVB is most useful when it neutralizes the deleterious reliability effects of implicit virtual bidding and physical arbitrage. (author)

  11. Photonic generation of ultra-wideband signals by direct current modulation on SOA section of an SOA-integrated SGDBR laser.

    Science.gov (United States)

    Lv, Hui; Yu, Yonglin; Shu, Tan; Huang, Dexiu; Jiang, Shan; Barry, Liam P

    2010-03-29

    Photonic ultra-wideband (UWB) pulses are generated by direct current modulation of a semiconductor optical amplifier (SOA) section of an SOA-integrated sampled grating distributed Bragg reflector (SGDBR) laser. Modulation responses of the SOA section of the laser are first simulated with a microwave equivalent circuit model. Simulated results show a resonance behavior indicating the possibility to generate UWB signals with complex shapes in the time domain. The UWB pulse generation is then experimentally demonstrated for different selected wavelength channels with an SOA-integrated SGDBR laser.

  12. Mechanism of SOA Formation Determines Magnitude of Radiative Effects

    Science.gov (United States)

    Zhu, J.; Penner, J.; Lin, G.; Zhou, C.

    2017-12-01

    Secondary organic aerosol (SOA) nearly always exists as an internal mixture and the distribution of this mixture depends on the formation mechanism of SOA. A model is developed to examine the influence of using an internal mixing states based on the mechanism of formation and to estimate the radiative forcing of SOA in the future. For the present day, 66 % of SOA is internally mixed with sulfate, while 34 % is internally mixed with primary soot. When compared with using an external mixture, the direct effect of SOA is decreased, due to the decrease of total aerosol surface area and the increase of absorption efficiency. Aerosol number concentrations are sharply reduced and this is responsible for a large decrease in the cloud albedo effect. In total, internal mixing suppresses the radiative effect of SOA by a factor of >4 compared to treating SOA as an external mixture. The future SOA burden increases by 24% due to CO2 increases and climate change, leading to a total (direct plus cloud albedo) radiative forcing of -0.05 W m-2. When the combined effects of changes in climate, anthropogenic emissions and land use are included, the SOA forcing is -0.07 W m-2, even though the SOA burden only increases by 6.8%. This is caused by the substantial increase of SOA associated with sulfate in the Aitken mode. The Aitken mode increase contributes to the enhancement of first indirect radiative forcing, which dominates the total radiative forcing.

  13. SOA Governance: A Critical SOA Success Factor

    Science.gov (United States)

    2010-04-01

    Software Perspective Service Consumer Service Providers Interface Optimize tomorrow today. ® Building Blocks...of a SOA Service – Software implemented capability that is well-defined, self contained and does not depend on context or state of other services ... Service Consumer – Service , application or other software component that requires a specific service . – Located through registry – Initiates service

  14. SOA in Practice The Art of Distributed System Design

    CERN Document Server

    Josuttis, Nicolai M

    2009-01-01

    Service-oriented architecture (SOA) is finally becoming a concrete discipline rather than a hopeful collection of cloud charts. This book demonstrates how SOA can simplify the creation of large-scale applications, whether your project involves a large set of Web Services-based components, or is a means to connect legacy applications to more modern business processes. SOA in Practice explains how -- and whether -- SOA fits your needs.

  15. SOA based Data Architecture for HTML5 Web Applications

    Directory of Open Access Journals (Sweden)

    Catalin STRIMBEI

    2013-01-01

    Full Text Available Web Services based architectures have already been established as the preferred way to integrate SOA specific components, from the front-end to the back-end business services. One of the key elements of such architecture are data-based or entity services. In this context, SDO standard and SDO related technologies have been confirmed as a possible approach to aggregate such enterprise-wide federation of data services, mainly backed by database servers, but not limited to them. In the followings, we will discuss an architectural purpose based on SDO approach to seamlessly integrate presentation and data services within an enterprise SOA context. This way we will outline the benefits of a common end-to-end data integration strategy. Also, we will try to argue that using HTML5 based clients as front end services in conjunction with SDO data services could be an effective strategy to adopt the mobile computing in the enterprise context.

  16. SOA formation from gasoline vehicles: from the tailpipe to the atmosphere

    Science.gov (United States)

    Robinson, A. L.; Zhao, Y.; Lambe, A. T.; Saleh, R.; Saliba, G.; Tkacik, D. S.

    2017-12-01

    Secondary organic aerosol (SOA) formation from gasoline vehicles has been indicated as an important source of atmospheric SOA, but its contribution to atmospheric SOA is loosely constrained due to the lack of measurements to link SOA formation from the tailpipe to atmospheric SOA. In this study, we determine the contribution of SOA formation based on measurements made with a Potential Aerosol Mass (PAM) oxidation flow reactor by oxidizing vehicular exhaust and ambient air. We first investigate SOA formation from dilute gasoline-vehicle exhaust during chassis dynamometer testing. The test fleet consists of both vehicles equipped with gasoline direct injection engines (GDI vehicles) and those equipped with port fuel injection engines (PFI vehicles). These vehicles span a wide range of emissions standards from Tier0 to Super Ultra-Low Emission Vehicles (SULEV). Then, we combine our measurements of SOA formation from gasoline vehicles during dynamometer testing with measurements of SOA formation using a PAM reactor conducted in a highway tunnel and in the unban atmosphere. Comparisons of SOA formation between these datasets enable us to quantitatively connect SOA formation from individual vehicles, to a large on-road fleet, and to the atmosphere. To facilitate the comparisons, we account for the effects of both the photochemical age and dilution on SOA formation. Our results show that SOA formation from gasoline vehicles can contribute over 50% of fossil fuel-related atmospheric SOA in the Los Angeles area. Furthermore, our results demonstrate that the tightening of emissions standards effectively reduces SOA formation from gasoline vehicles, including both PFI and GDI vehicles, if the atmospheric chemistry regime remains the same.

  17. Oracle SOA Suite 11g performance cookbook

    CERN Document Server

    Brasier, Matthew; Wright, Nicholas

    2013-01-01

    This is a Cookbook with interesting, hands-on recipes, giving detailed descriptions and lots of practical walkthroughs for boosting the performance of your Oracle SOA Suite.This book is for Oracle SOA Suite 11g administrators, developers, and architects who want to understand how they can maximise the performance of their SOA Suite infrastructure. The recipes contain easy to follow step-by-step instructions and include many helpful and practical tips. It is suitable for anyone with basic operating system and application server administration experience.

  18. JMS-based SOA monitors CERN particle accelerators

    CERN Multimedia

    Seeley, Rich

    2007-01-01

    "Service-oriented architecture (SOA) may not exactly be nuclear physics, but at the CERN (European Organization for Nuclear Research) physics laboratory on the border of France and Switzerland, an SOA system is watching over giant particle accelerators." (1,5 page)

  19. INTEGRATION OF VIRTUAL ENTERPRISES USING SERVICE ORIENTED ARCHITECTURE

    Directory of Open Access Journals (Sweden)

    Miladin Stefanovic

    2009-06-01

    Full Text Available Virtual enterprise integration (VEI is virtually the most critical success factor for making virtual enterprise (VE a real, competitive, and widely implemented organizational an d management concept. One of possible approaches in virtual enterprise integration is employment of web services. In this paper we will present process-oriented approach for developing an SOA for VEI. The general assumption of suggested approach is that service oriented architecture is based on business service and that business services mostly correspond to exchanged documentation in a real business system. CASE tool for web service specification is also presented.

  20. A systematic literature review on SOA migration

    NARCIS (Netherlands)

    Razavian, M.; Lago, P.

    2015-01-01

    When Service Orientation was introduced as the solution for retaining and rehabilitating legacy assets, both researchers and practitioners proposed techniques, methods, and guidelines for SOA migration. With so much hype surrounding SOA, it is not surprising that the concept was interpreted in many

  1. Model-driven Service Engineering with SoaML

    Science.gov (United States)

    Elvesæter, Brian; Carrez, Cyril; Mohagheghi, Parastoo; Berre, Arne-Jørgen; Johnsen, Svein G.; Solberg, Arnor

    This chapter presents a model-driven service engineering (MDSE) methodology that uses OMG MDA specifications such as BMM, BPMN and SoaML to identify and specify services within a service-oriented architecture. The methodology takes advantage of business modelling practices and provides a guide to service modelling with SoaML. The presentation is case-driven and illuminated using the telecommunication example. The chapter focuses in particular on the use of the SoaML modelling language as a means for expressing service specifications that are aligned with business models and can be realized in different platform technologies.

  2. Interferometric crosstalk suppression using polarization multiplexing technique and an SOA

    DEFF Research Database (Denmark)

    Liu, Fenghai; Xueyan, Zheng; Pedersen, Rune Johan Skullerud

    2000-01-01

    Interferometric crosstalk can be greatly suppressed at 10Gb/s and 20Gb/s by using a gain saturated SOA and a polarization multiplexing technique that eliminates impairments like waveform and extinction ratio degradation from the SOA.......Interferometric crosstalk can be greatly suppressed at 10Gb/s and 20Gb/s by using a gain saturated SOA and a polarization multiplexing technique that eliminates impairments like waveform and extinction ratio degradation from the SOA....

  3. The impact of SOA for achieving healthcare interoperability. An empirical investigation based on a hypothetical adoption.

    Science.gov (United States)

    Daskalakis, S; Mantas, J

    2009-01-01

    The evaluation of a service-oriented prototype implementation for healthcare interoperability. A prototype framework was developed, aiming to exploit the use of service-oriented architecture (SOA) concepts for achieving healthcare interoperability and to move towards a virtual patient record (VPR) paradigm. The prototype implementation was evaluated for its hypothetical adoption. The evaluation strategy was based on the initial proposition of the DeLone and McLean model of information systems (IS) success [1], as modeled by Iivari [2]. A set of SOA and VPR characteristics were empirically encapsulated within the dimensions of IS success model, combined with measures from previous research works. The data gathered was analyzed using partial least squares (PLS). The results highlighted that system quality is a partial predictor of system use but not of user satisfaction. On the contrary, information quality proved to be a significant predictor of user satisfaction and partially a strong significant predictor of system use. Moreover, system use did not prove to be a significant predictor of individual impact whereas the bi-directional relation between use and user satisfaction did not confirm. Additionally, user satisfaction was found to be a strong significant predictor of individual impact. Finally, individual impact proved to be a strong significant predictor of organizational impact. The empirical study attempted to obtain hypothetical, but still useful beliefs and perceptions regarding the SOA prototype implementation. The deduced observations can form the basis for further investigation regarding the adaptability of SOA implementations with VPR characteristics in the healthcare domain.

  4. Proposing and testing SOA governance process: A case study approach

    DEFF Research Database (Denmark)

    Koumaditis, Konstantinos; Themistocleous, Marinos

    2015-01-01

    Longstanding Healthcare Information Systems (HIS) integration challenges drove healthcare organisations to invest in new paradigms like Service Oriented Architecture (SOA). Yet, SOA holds challenges of its own, with SOA Governance surfacing on the top. This research depicts the development......, grounded in the normative literature and further developed to include healthcare aspects. The proposition is tested in a large Greek hospital utilising qualitative methods and the findings presented herein. This proposal aims to pinpoint attributes and guidelines for SOA Governance Process, required...

  5. Developing a More Comprehensive SOA Governance Framework by Using a Comparative Study Approach

    Directory of Open Access Journals (Sweden)

    Fazilat Hojaji

    2014-02-01

    Full Text Available Many companies have adopted Service-Oriented Architecture (SOA as an approach to improve agility and increase performance of system development.However, deploying SOA has been encountered to some challenges and problems including difficulties in designing effective decision structures and building a SOA roadmap, lack of service funding and lack of consistent governance processes. Therefore, to address SOA challenges, organizations require a comprehensive and applicable SOA governance framework to implement management and control mechanisms. Study of existing SOA governance frameworks reveals that these frameworks are not expressive enough to cover all important elements of SOA governance and also, the y have very little discussions and clarifications regarding underpinning structures such as SOA processes and activities, governance procedures and measurement metrics. In this paper, in the process of proposing a new SOA governance framework, a set of important elements for a desired SOA governance framework is proposed. Based on these elements, a more comprehensive and expressive framework is developed based on governance structure of COBIT. It focuses on covering SOA governance elements and resolving the shortcomings of the existing frameworks and can delivers an appropriate solution to help enable effective SOA governance.

  6. SOA thresholds for the perception of discrete/continuous tactile stimulation

    DEFF Research Database (Denmark)

    Eid, Mohamad; Korres, Georgios; Jensen, Camilla Birgitte Falk

    In this paper we present an experiment to measure the upper and lower thresholds of the Stimulus Onset Asynchrony (SOA) for continuous/discrete apparent haptic motion. We focus on three stimulation parameters: the burst duration, the SOA time, and the inter-actuator distance (between successive......-discrete boundary at lower SOA. Furthermore, the larger the inter-actuator distance, the more linear the relationship between the burst duration and the SOA timing. Finally, the large range between lower and upper thresholds for SOA can be utilized to create continuous movement stimulation on the skin at “varying...... speeds”. The results are discussed in reference to designing a tactile interface for providing continuous haptic motion with a desired speed of continuous tactile stimulation....

  7. The SOA/VOC/NOx system: an explicit model of secondary organic aerosol formation

    Directory of Open Access Journals (Sweden)

    S. Madronich

    2007-11-01

    Full Text Available Our current understanding of secondary organic aerosol (SOA formation is limited by our knowledge of gaseous secondary organics involved in gas/particle partitioning. The objective of this study is to explore (i the potential for products of multiple oxidation steps contributing to SOA, and (ii the evolution of the SOA/VOC/NOx system. We developed an explicit model based on the coupling of detailed gas-phase oxidation schemes with a thermodynamic condensation module. Such a model allows prediction of SOA mass and speciation on the basis of first principles. The SOA/VOC/NOx system is studied for the oxidation of 1-octene under atmospherically relevant concentrations. In this study, gaseous oxidation of octene is simulated to lead to SOA formation. Contributors to SOA formation are shown to be formed via multiple oxidation steps of the parent hydrocarbon. The behaviour of the SOA/VOC/NOx system simulated using the explicit model agrees with general tendencies observed during laboratory chamber experiments. This explicit modelling of SOA formation appears as a useful exploratory tool to (i support interpretations of SOA formation observed in laboratory chamber experiments, (ii give some insights on SOA formation under atmospherically relevant conditions and (iii investigate implications for the regional/global lifetimes of the SOA.

  8. Cloud-based Virtual Organization Engineering

    Directory of Open Access Journals (Sweden)

    Liviu Gabriel CRETU

    2012-01-01

    Full Text Available Nowadays we may notice that SOA arrived to its maturity stage and Cloud Computing brings the next paradigm-shift regarding the software delivery business model. In such a context, we consider that there is a need for frameworks to guide the creation, execution and management of virtual organizations (VO based on services from different Clouds. This paper will introduce the main components of such a framework that will innovatively combine the principles of event-driven SOA, REST and ISO/IEC 42010:2007 multiple views and viewpoints in order to provide the required methodology for Cloud-based virtual organization (Cloud-VO engi-neering. The framework will consider the resource concept found in software architectures like REST or RDF as the basic building block of Cloud-VO. and will make use of resources’ URIs to create the Cloud-VO’s resource allocation matrix. While the matrix is used to declare activity-resources relationships, the resource catalogue concept will be introduced as a way to describe the resource in one place, using as many viewpoints as needed, and then to reuse that description for the creation or simulation of different VOs.

  9. Advanced SOA tools and applications

    CERN Document Server

    Brzezinski, Jerzy; Cellary, Wojciech; Grzech, Adam; Zielinski, Krzysztof

    2014-01-01

    This book presents advanced software development tools for construction, deployment and governance of Service Oriented Architecture (SOA) applications. Novel technical concepts and paradigms, formulated during the research stage and during development of such tools are presented and illustrated by practical usage examples. Hence this book will be of interest not only to theoreticians but also to engineers who cope with real-life problems. Additionally, each chapter contains an overview of related work, enabling comparison of the proposed concepts with exiting solutions in various areas of the SOA development process. This makes the book interesting also for students and scientists who investigate similar issues.

  10. A Flexible Collaborative Innovation Model for SOA Services Providers

    OpenAIRE

    Santanna-Filho , João ,; Rabelo , Ricardo ,; Pereira-Klen , Alexandra ,

    2015-01-01

    Part 5: Innovation Networks; International audience; Software sector plays a very relevant role in current world economy. One of its characteristics is that they are mostly composed of SMEs. SMEs have been pushed to invest in innovation to keep competitive. Service Oriented Architecture (SOA) is a recent and powerful ICT paradigm for more sustainable business models. A SOA product has many differences when compared to manufacturing sector. Besides that, SOA projects are however very complex, ...

  11. An SOA model for toluene oxidation in the presence of inorganic aerosols.

    Science.gov (United States)

    Cao, Gang; Jang, Myoseon

    2010-01-15

    A predictive model for secondary organic aerosol (SOA) formation including both partitioning and heterogeneous reactions is explored for the SOA produced from the oxidation of toluene in the presence of inorganic seed aerosols. The predictive SOA model comprises the explicit gas-phase chemistry of toluene, gas-particle partitioning, and heterogeneous chemistry. The resulting products from the explicit gas phase chemistry are lumped into several classes of chemical species based on their vapor pressure and reactivity for heterogeneous reactions. Both the gas-particle partitioning coefficient and the heterogeneous reaction rate constant of each lumped gas-phase product are theoretically determined using group contribution and molecular structure-reactivity. In the SOA model, the predictive SOA mass is decoupled into partitioning (OM(P)) and heterogeneous aerosol production (OM(H)). OM(P) is estimated from the SOA partitioning model developed by Schell et al. (J. Geophys. Res. 2001, 106, 28275-28293 ) that has been used in a regional air quality model (CMAQ 4.7). OM(H) is predicted from the heterogeneous SOA model developed by Jang et al. (Environ. Sci. Technol. 2006, 40, 3013-3022 ). The SOA model is evaluated using a number of the experimental SOA data that are generated in a 2 m(3) indoor Teflon film chamber under various experimental conditions (e.g., humidity, inorganic seed compositions, NO(x) concentrations). The SOA model reasonably predicts not only the gas-phase chemistry, such as the ozone formation, the conversion of NO to NO(2), and the toluene decay, but also the SOA production. The model predicted that the OM(H) fraction of the total toluene SOA mass increases as NO(x) concentrations decrease: 0.73-0.83 at low NO(x) levels and 0.17-0.47 at middle and high NO(x) levels for SOA experiments with high initial toluene concentrations. Our study also finds a significant increase in the OM(H) mass fraction in the SOA generated with low initial toluene

  12. Who Benefits from Virtuality?

    Science.gov (United States)

    Harper, Barry; Hedberg, John G.; Wright, Rob

    2000-01-01

    Discusses the use of constructivist frameworks to develop effective and successful learning environments, including educational software. Topics include technology supporting reform; virtuality and multimedia; attributes of interactive multimedia and virtual reality; and examples of context and learner active participation. (Contains 35…

  13. Microphysical Properties of Single Secondary Organic Aerosol (SOA) Particles

    Science.gov (United States)

    Rovelli, Grazia; Song, Young-Chul; Pereira, Kelly; Hamilton, Jacqueline; Topping, David; Reid, Jonathan

    2017-04-01

    Secondary Organic Aerosols (SOA) deriving from the oxidation of volatile organic compounds (VOCs) can account for a substantial fraction of the overall atmospheric aerosol mass.[1] Therefore, the investigation of SOA microphysical properties is crucial to better comprehend their role in the atmospheric processes they are involved in. This works describes a single particle approach to accurately characterise the hygroscopic response, the optical properties and the gas-particle partitioning kinetics of water and semivolatile components for laboratory generated SOA. SOA was generated from the oxidation of different VOCs precursors (e.g. α-pinene, toluene) in a photo-chemical flow reactor, which consists of a temperature and relative humidity controlled 300 L polyvinyl fluoride bag. Known VOC, NOx and ozone concentrations are introduced in the chamber and UV irradiation is performed by means of a Hg pen-ray. SOA samples were collected with an electrical low pressure impactor, wrapped in aluminium foil and kept refrigerated at -20°C. SOA samples were extracted in a 1:1 water/methanol mixture. Single charged SOA particles were generated from the obtained solution using a microdispenser and confined within an electrodynamic balance (EDB), where they sit in a T (250-320 K) and RH (0-95%) controlled nitrogen flow. Suspended droplets are irradiated with a 532 nm laser and the evolving angularly resolved scattered light is used to keep track of changes in droplet size. One of the key features of this experimental approach is that very little SOA solution is required because of the small volumes needed to load the dispensers (evaporation kinetics experiments (CK-EDB) of suspended probe and sample droplets.[2] The variation of the refractive index of SOA droplets following to water or SVOCs evaporative loss was measured as a function of water activity by fitting the collected light scattering patterns with a generated Mie-Theory library of phase functions.[3] Long trapping

  14. Considerations Regarding Designing and Administrating SOA Solutions

    Directory of Open Access Journals (Sweden)

    Vlad DIACONITA

    2011-06-01

    Full Text Available Solutions like SOA, Cloud, SaaS, Iaas or PaaS are not only buzzwords, they became a business reality because they are relative cheap and easy to use. SOA and Cloud are tightly linked because most cloud solutions are being defined using SOA making them feasible from the business perspective, because it’s hard to move to cloud when you are using a tightly coupled architecture. Big companies such as Oracle, Microsoft, IBM or Amazon offer many commercial solutions providing software as a service, as well as hosted and managed alternatives to classical deployment. For firms that are building private clouds and for service providers that are building public clouds, diverse solutions are offered by the big players for platform as a service and infrastructure as a service.

  15. SOA formation from photooxidation of naphthalene and methylnaphthalenes with m-xylene and surrogate mixtures

    Science.gov (United States)

    Chen, Chia-Li; Li, Lijie; Tang, Ping; Cocker, David R.

    2018-05-01

    SOA formation is not well predicted in current models in urban area. The interaction among multiple anthropogenic volatile organic compounds is essential for the SOA formation in the complex urban atmosphere. Secondary organic aerosol (SOA) from the photooxidation of naphthalene, 1-methylnaphthalene, and 2-methylnaphthalene as well as individual polycyclic aromatic hydrocarbons (PAHs) mixed with m-xylene or an atmospheric surrogate mixture was explored in the UCR CE-CERT environmental chamber under urban relevant low NOx and extremely low NOx (H2O2) conditions. Addition of m-xylene suppressed SOA formation from the individual PAH precursor. A similar suppression effect on SOA formation was observed during the surrogate mixture photooxidation suggesting the importance of gas-phase chemical reactivity to SOA formation. The SOA growth rate for different PAH-m-xylene mixtures was strongly correlated with initial [HO2]/[RO2] ratio but negatively correlated with initial m-xylene/NO ratio. Decreasing SOA formation was observed for increasing m-xylene/PAHs ratios and increasing initial m-xylene/NO ratio. The SOA chemical composition characteristics such as f44 versus f43, H/C ratio, O/C ratio, and the oxidation state of the carbon OSbarc were consistent with a continuously aging with the SOA exhibiting characteristics of both individual precursors. SOA formation from PAHs was also suppressed within an atmospheric surrogate mixture compared to the SOA formed from individual PAHs, indicating that atmospheric reactivity directly influences SOA formation from PAHs.

  16. Modeling SOA formation from the oxidation of intermediate volatility n-alkanes

    Directory of Open Access Journals (Sweden)

    J. Lee-Taylor

    2012-08-01

    Full Text Available The chemical mechanism leading to SOA formation and ageing is expected to be a multigenerational process, i.e. a successive formation of organic compounds with higher oxidation degree and lower vapor pressure. This process is here investigated with the explicit oxidation model GECKO-A (Generator of Explicit Chemistry and Kinetics of Organics in the Atmosphere. Gas phase oxidation schemes are generated for the C8–C24 series of n-alkanes. Simulations are conducted to explore the time evolution of organic compounds and the behavior of secondary organic aerosol (SOA formation for various preexisting organic aerosol concentration (COA. As expected, simulation results show that (i SOA yield increases with the carbon chain length of the parent hydrocarbon, (ii SOA yield decreases with decreasing COA, (iii SOA production rates increase with increasing COA and (iv the number of oxidation steps (i.e. generations needed to describe SOA formation and evolution grows when COA decreases. The simulated oxidative trajectories are examined in a two dimensional space defined by the mean carbon oxidation state and the volatility. Most SOA contributors are not oxidized enough to be categorized as highly oxygenated organic aerosols (OOA but reduced enough to be categorized as hydrocarbon like organic aerosols (HOA, suggesting that OOA may underestimate SOA. Results show that the model is unable to produce highly oxygenated aerosols (OOA with large yields. The limitations of the model are discussed.

  17. A synthesis theory for self-oscillating adaptive systems /SOAS/

    Science.gov (United States)

    Horowitz, I.; Smay, J.; Shapiro, A.

    1974-01-01

    A quantitative synthesis theory is presented for the Self-Oscillating Adaptive System (SOAS), whose nonlinear element has a static, odd character with hard saturation. The synthesis theory is based upon the quasilinear properties of the SOAS to forced inputs, which permits the extension of quantitative linear feedback theory to the SOAS. A reasonable definition of optimum design is shown to be the minimization of the limit cycle frequency. The great advantages of the SOAS is its zero sensitivity to pure gain changes. However, quasilinearity and control of the limit cycle amplitude at the system output, impose additional constraints which partially or completely cancel this advantage, depending on the numerical values of the design parameters. By means of narrow-band filtering, an additional factor is introduced which permits trade-off between filter complexity and limit cycle frequency minimization.

  18. Research and design of logistical information system based on SOA

    Science.gov (United States)

    Zhang, Bo

    2013-03-01

    Through the study on the existing logistics information systems and SOA technology, based on the current situation of enterprise logistics management and business features, this paper puts forward a SOA-based logistics system design program. This program is made in the WCF framework, with the combination of SOA and the actual characteristics of logistics enterprises, is simple to realize, easy to operate, and has strong expansion characteristic, therefore has high practical value.

  19. Organizational structures during SOA implementation: the case of a Greek healthcare organization

    DEFF Research Database (Denmark)

    Koumaditis, Konstantinos; Themistocleous, Marinos

    2015-01-01

    The purpose of this paper is to investigate service-oriented architecture organizational studies (SOA OS) in healthcare through a rigorous literature review, development and testing in an eGovernment health-care setting. The application of SOA paradigm to integrate information systems has been...... and expand the capabilities of their health-care information system. Yet, literature indicates that eHealth government strategies, including SOA, require the support of SOA OS to be successfully implemented....

  20. SOA and Web services interface design principles, techniques, and standards

    CERN Document Server

    Bean, James

    2009-01-01

    SOA offers solutions to the most intractable business problems faced by every enterprise, but getting the SOA service interface right requires the practical design knowledge this book uniquely delivers

  1. SOA - Service Registry and Repository

    Data.gov (United States)

    Social Security Administration — SOA is an approach utilizing reusable components or services in order to build applications by plugging in the appropriate components. It utilizes COTS databases as...

  2. Humidity-dependent phase state of SOA particles from biogenic and anthropogenic precursors

    Directory of Open Access Journals (Sweden)

    E. Saukko

    2012-08-01

    Full Text Available The physical phase state (solid, semi-solid, or liquid of secondary organic aerosol (SOA particles has important implications for a number of atmospheric processes. We report the phase state of SOA particles spanning a wide range of oxygen to carbon ratios (O / C, used here as a surrogate for SOA oxidation level, produced in a flow tube reactor by photo-oxidation of various atmospherically relevant surrogate anthropogenic and biogenic volatile organic compounds (VOCs. The phase state of laboratory-generated SOA was determined by the particle bounce behavior after inertial impaction on a polished steel substrate. The measured bounce fraction was evaluated as a function of relative humidity and SOA oxidation level (O / C measured by an Aerodyne high resolution time of flight aerosol mass spectrometer (HR-ToF AMS.

    The main findings of the study are: (1 biogenic and anthropogenic SOA particles are found to be amorphous solid or semi-solid based on the measured bounced fraction (BF, which was typically higher than 0.6 on a 0 to 1 scale. A decrease in the BF is observed for most systems after the SOA is exposed to relative humidity of at least 80% RH, corresponding to a RH at impaction of 55%. (2 Long-chain alkanes have a low BF (indicating a "liquid-like", less viscous phase particles at low oxidation levels (BF < 0.2 ± 0.05 for O / C = 0.1. However, BF increases substantially upon increasing oxidation. (3 Increasing the concentration of sulphuric acid (H2SO4 in solid SOA particles (here tested for longifolene SOA causes a decrease in BF levels. (4 In the majority of cases the bounce behavior of the various SOA systems did not show correlation with the particle O / C. Rather, the molar mass of the gas-phase VOC precursor showed a positive correlation with the resistance to the RH-induced phase change of the formed SOA particles.

  3. Robustness analysis of a parallel two-box digital polynomial predistorter for an SOA-based CO-OFDM system

    Science.gov (United States)

    Diouf, C.; Younes, M.; Noaja, A.; Azou, S.; Telescu, M.; Morel, P.; Tanguy, N.

    2017-11-01

    The linearization performance of various digital baseband pre-distortion schemes is evaluated in this paper for a coherent optical OFDM (CO-OFDM) transmitter employing a semiconductor optical amplifier (SOA). In particular, the benefits of using a parallel two-box (PTB) behavioral model, combining a static nonlinear function with a memory polynomial (MP) model, is investigated for mitigating the system nonlinearities and compared to the memoryless and MP models. Moreover, the robustness of the predistorters under different operating conditions and system uncertainties is assessed based on a precise SOA physical model. The PTB scheme proves to be the most effective linearization technique for the considered setup, with an excellent performance-complexity tradeoff over a wide range of conditions.

  4. Software for virtual accelerator designing

    International Nuclear Information System (INIS)

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

    2012-01-01

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

  5. Noise properties and cascadability of SOA-EA regenerators

    DEFF Research Database (Denmark)

    Öhman, Filip; Bischoff, Svend; Tromborg, Bjarne

    2002-01-01

    We suggest and analyse a new device containing concatenated pairs of semiconductor optical amplifiers (SOAs) and electroabsorption modulators (EAs). The device has regenerative properties and improves the cascadability of optical fibre links.......We suggest and analyse a new device containing concatenated pairs of semiconductor optical amplifiers (SOAs) and electroabsorption modulators (EAs). The device has regenerative properties and improves the cascadability of optical fibre links....

  6. SOA pielietojums korporatīvo risinājumu integrācijā

    OpenAIRE

    Antuzevičs, Jānis

    2007-01-01

    SOA pielietojums korporatīvo risinājumu integrācijā” ir bakalaura darbs, kas ir veltīts korporatīvo risinājumu integrācijas problēmu risināšanai, izmantojot servisu orientētās arhitektūras (SOA) pieeju. Darba mērķis ir izpētīt SOA raksturojošās iezīmes un tās priekšrocības, kā arī apskatīt tehnoloģijas SOA realizācijai. Darba gaitā tiek apskatīta uz tīmekļa servisiem un standartiem balstīta SOA implementācija ar skaidrojošiem piemēriem, kā arī tiek sniegta kompānijas Sun Microsystems kom...

  7. An approach to SOA development methodology: SOUP comparison with RUP and XP

    Directory of Open Access Journals (Sweden)

    Sandra Svanidzaitė

    2014-08-01

    Full Text Available Service oriented architecture (SOA is an architecture for distributed applications composed of distributed services with weak coupling that are designed to meet business requirements. One of the research priorities in the field of SOA is creating such software design and development methodology (SDDM that takes into account all principles of this architecture and allows for effective and efficient application development. A lot of investigation has been carried out to find out whether can one of popular SDDM, such as agile methodologies or RUP suits, be adapted for SOA or there is a need to create some new SOA-oriented SDDM. This paper compares one of SOA-oriented SDDM – SOUP – with RUP and XP methodologies. The aim is to find out whether the SOUP methodology is already mature enough to assure successful development of SOA applications. This aim is accomplished by comparing activities, artifacts of SOUP and RUP and emphasizing which XP practices are used in SOUP.DOI: http://dx.doi.org/10.15181/csat.v2i1.77 

  8. MODEL-BASED SECURITY ENGINEERING OF SOA SYSTEM USING SECURITY INTENT DSL

    OpenAIRE

    Muhammad Qaiser Saleem; Jafreezal Jaafar; Mohd Fadzil Hassan

    2011-01-01

    Currently most of the enterprises are using SOA and web services technologies to build their web information system. They are using MDA principles for design and development of WIS and using UML as a modelling language for business process modelling. Along with the increased connectivity in SOA environment, security risks rise exponentially. Security is not defined during the early phases of development and left onto developer. Properly configuring security requirements in SOA applications is...

  9. Smart SOA platforms in cloud computing architectures

    CERN Document Server

    Exposito , Ernesto

    2014-01-01

    This book is intended to introduce the principles of the Event-Driven and Service-Oriented Architecture (SOA 2.0) and its role in the new interconnected world based on the cloud computing architecture paradigm. In this new context, the concept of "service" is widely applied to the hardware and software resources available in the new generation of the Internet. The authors focus on how current and future SOA technologies provide the basis for the smart management of the service model provided by the Platform as a Service (PaaS) layer.

  10. Concept for phase-to-intensity conversion in SOAs by facet reflections

    DEFF Research Database (Denmark)

    Blaaberg, Søren; Mørk, Jesper

    2010-01-01

    All-optical conversion from phase-modulated signals to intensity-modulated signals is theoretically demonstrated in semiconductor optical amplifiers (SOAs). Large-signal and small-signal calculations show significant conversion responses appearing as a result of even minute reflections at the end...... mirrors of the SOA. It is discussed how reflected phase-modulated signals can lead to interference resulting in intensity fluctuations that are amplified by the gain in a SOA. The effect can be utilized for deliberate conversion between optical modulation formats.......All-optical conversion from phase-modulated signals to intensity-modulated signals is theoretically demonstrated in semiconductor optical amplifiers (SOAs). Large-signal and small-signal calculations show significant conversion responses appearing as a result of even minute reflections at the end...

  11. Enterprise interoperability with SOA: a survey of service composition approaches

    NARCIS (Netherlands)

    Mantovaneli Pessoa, Rodrigo; Goncalves da Silva, Eduardo; van Sinderen, Marten J.; Quartel, Dick; Ferreira Pires, Luis

    Service-oriented architecture (SOA) claims to facilitate the construction of flexible and loosely coupled business applications, and therefore is seen as an enabling factor for enterprise interoperability. The concept of service, which is central to SOA, is very convenient to address the matching of

  12. Predicting service request rates for adaptive resource allocation in SOA

    NARCIS (Netherlands)

    Serebrenik, A.; Sidorova, N.; Barjis, J.; Kinghorn, J.; Ramaswamy, S.; Dubois, E.; Johannesson, P.

    2009-01-01

    Service orientation is rapidly becoming the common practice in the IT world. A price one often has to pay for the advantages of service oriented architectures (SOA) is performance deterioration. SOA performance heavily depends on the allocation of computational resources to services. The needs of

  13. BPM, SOA and WOA

    DEFF Research Database (Denmark)

    Christensen, Kim; Thomsen, Bent; Thomsen, Lone Leth

    This paper surveys the state-of-the art in BPM, SOA and WOA anno 2007. We argue that the vision of inter company BPM based on agile business process creation and dynamic lookup of services based on WSDL and UDDI has not materialised. Instead formalised BPM, based on BPMN and BPEL-WS, has become...

  14. An SOA-based architecture framework

    NARCIS (Netherlands)

    Aalst, van der W.M.P.; Beisiegel, M.; Hee, van K.M.; König, D.; Stahl, C.

    2007-01-01

    We present an Service-Oriented Architecture (SOA)– based architecture framework. The architecture framework is designed to be close to industry standards, especially to the Service Component Architecture (SCA). The framework is language independent and the building blocks of each system, activities

  15. Oracle SOA BPEL PM 11g R1 a hands-on tutorial

    CERN Document Server

    Saraswathi, Ravi

    2013-01-01

    This hands-on, example-driven guide is a practical getting started tutorial with plenty of step-by-step instructions for beginner to intermediate level readers working with BPEL PM in Oracle SOA SuiteWritten for SOA developers, administrators, architects, and engineers who want to get started with Oracle BPEL PM 11g. No previous experience with BPEL PM is required, but an understanding of SOA and web services is assumed

  16. SOA and BPM, a Partnership for Successful Organizations

    Directory of Open Access Journals (Sweden)

    Gheorghe MATEI

    2011-01-01

    Full Text Available In order to stay effective and competitive, companies have to be able to adapt themselves to permanent market requirements, to improve constantly their business process, to act as flexible and proactive economic agents. To achieve these goals, the IT systems within the organization have to be standardized and integrated, in order to provide fast and reliable data access to users both inside and outside the company. A proper system architecture for integrating company's IT assets is a service oriented one. A service-oriented architecture (SOA is an IT architectural style that allows integration of the company’s business as linked, repeatable tasks called services. A subject closely related to SOA is Business Process Management (BPM, an approach that aims to improve business processes. The paper also presents some aspects of this topic, as well as the relationship between SOA and BPM. They complement each other and help companies improve their business performance.

  17. Kinetic modeling studies of SOA formation from α-pinene ozonolysis

    Science.gov (United States)

    Gatzsche, Kathrin; Iinuma, Yoshiteru; Tilgner, Andreas; Mutzel, Anke; Berndt, Torsten; Wolke, Ralf

    2017-11-01

    This paper describes the implementation of a kinetic gas-particle partitioning approach used for the simulation of secondary organic aerosol (SOA) formation within the SPectral Aerosol Cloud Chemistry Interaction Model (SPACCIM). The kinetic partitioning considers the diffusion of organic compounds into aerosol particles and the subsequent chemical reactions in the particle phase. The basic kinetic partitioning approach is modified by the implementation of chemical backward reaction of the solute within the particle phase as well as a composition-dependent particle-phase bulk diffusion coefficient. The adapted gas-phase chemistry mechanism for α-pinene oxidation has been updated due to the recent findings related to the formation of highly oxidized multifunctional organic compounds (HOMs). Experimental results from a LEAK (Leipziger Aerosolkammer) chamber study for α-pinene ozonolysis were compared with the model results describing this reaction system.The performed model studies reveal that the particle-phase bulk diffusion coefficient and the particle-phase reactivity are key parameters for SOA formation. Using the same particle-phase reactivity for both cases, we find that liquid particles with higher particle-phase bulk diffusion coefficients have 310 times more organic material formed in the particle phase compared to higher viscous semi-solid particles with lower particle-phase bulk diffusion coefficients. The model results demonstrate that, even with a moderate particle-phase reactivity, about 61 % of the modeled organic mass consists of reaction products that are formed in the liquid particles. This finding emphasizes the potential role of SOA processing. Moreover, the initial organic aerosol mass concentration and the particle radius are of minor importance for the process of SOA formation in liquid particles. A sensitivity study shows that a 22-fold increase in particle size merely leads to a SOA increase of less than 10 %.Due to two additional

  18. Desiging a logical security framework for e-commerce system based on soa

    OpenAIRE

    Luhach, Ashish Kr.; Dwivedi, Sanjay K.; Jha, C. K.

    2014-01-01

    Rapid increases in information technology also changed the existing markets and transformed them into e- markets (e-commerce) from physical markets. Equally with the e-commerce evolution, enterprises have to recover a safer approach for implementing E-commerce and maintaining its logical security. SOA is one of the best techniques to fulfill these requirements. SOA holds the vantage of being easy to use, flexible, and recyclable. With the advantages, SOA is also endowed with ease for message ...

  19. MAIN CHARACTERISTICS OF COMPANIES USING SERVICE ORIENTED ARCHITECTURE (SOA AND OF THEIR OPERATION CONTEXT

    Directory of Open Access Journals (Sweden)

    Alfonso Duran Heras

    2008-12-01

    Full Text Available The aim of this article is to establish the main characteristics of the organizations that have successfully implemented information systems based on Service Oriented Architecture (SOA. Their environmental circumstances have also been studied. To achieve this objective, a SOA bibliographic review has been carried out, encompassing an analysis of 25 real cases in which different SOA applications were successfully implemented. All these cases were published between 2.001 and 2.007. The conclusions of this article can be briefly summarized as follows: SOA is well suited for organizations that rely on important legacy systems, whose performance is hindered by the lack of integration and flexibility of their computer architectures. These organizations therefore need to improve such architectures rather than replace them by new systems; SOA is being used by organizations that need to integrate their systems with those of their supply chain partners; SOA solutions provide support for the use of Web technologies.

  20. Hybrid SOA-SQP algorithm for dynamic economic dispatch with valve-point effects

    Energy Technology Data Exchange (ETDEWEB)

    Sivasubramani, S.; Swarup, K.S. [Department of Electrical Engineering, Indian Institute of Technology Madras, Chennai 600036 (India)

    2010-12-15

    This paper proposes a hybrid technique combining a new heuristic algorithm named seeker optimization algorithm (SOA) and sequential quadratic programming (SQP) method for solving dynamic economic dispatch problem with valve-point effects. The SOA is based on the concept of simulating the act of human searching, where the search direction is based on the empirical gradient (EG) by evaluating the response to the position changes and the step length is based on uncertainty reasoning by using a simple fuzzy rule. In this paper, SOA is used as a base level search, which can give a good direction to the optimal global region and SQP as a local search to fine tune the solution obtained from SOA. Thus SQP guides SOA to find optimal or near optimal solution in the complex search space. Two test systems i.e., 5 unit with losses and 10 unit without losses, have been taken to validate the efficiency of the proposed hybrid method. Simulation results clearly show that the proposed method outperforms the existing method in terms of solution quality. (author)

  1. SOA-BD: Service Oriented Architecture for Biomedical Devices

    Directory of Open Access Journals (Sweden)

    João Marcos Teixeira Lacerda

    2017-05-01

    Full Text Available Introduction: The communication of information systems with biomedical devices has become complex not only due to the existence of several private communication protocols, but also to the immutable way that software is embedded into these devices. In this sense, this paper proposes a service-oriented architecture to access biomedical devices as a way to abstract the mechanisms of writing and reading data from these devices, thus contributing to enable the focus of the development team of biomedical software to be intended for its functional requirements, i.e. business rules relevant to the problem domain. Methods The SOA-BD architecture consists of five main components: A Web Service for transport and conversion of the device data, Communication Protocols to access the devices, Data Parsers to preprocess data, a Device Repository to store data and transmitted information and Error handling, for error handling of these information. For the development of SOA-BD, technologies such as the XML language and the Java programming language were used. Besides, Software Engineering concepts such as Design Patterns were also used. For the validation of this work, data has been collected from vital sign monitors in an Intensive Care Unit using HL7 standards. Results The tests obtained a difference of about only 1 second in terms of response time with the use of SOA-BD. Conclusion SOA-BD achieves important results such as the reduction on the access protocol complexity, the opportunity for treating patients over long distances, allowing easier development of monitoring applications and interoperability with biomedical devices from diverse manufacturers.

  2. Effect of NOx level on secondary organic aerosol (SOA formation from the photooxidation of terpenes

    Directory of Open Access Journals (Sweden)

    R. C. Flagan

    2007-10-01

    Full Text Available Secondary organic aerosol (SOA formation from the photooxidation of one monoterpene (α-pinene and two sesquiterpenes (longifolene and aromadendrene is investigated in the Caltech environmental chambers. The effect of NOx on SOA formation for these biogenic hydrocarbons is evaluated by performing photooxidation experiments under varying NOx conditions. The NOx dependence of α-pinene SOA formation follows the same trend as that observed previously for a number of SOA precursors, including isoprene, in which SOA yield (defined as the ratio of the mass of organic aerosol formed to the mass of parent hydrocarbon reacted decreases as NOx level increases. The NOx dependence of SOA yield for the sesquiterpenes, longifolene and aromadendrene, however, differs from that determined for isoprene and α-pinene; the aerosol yield under high-NOx conditions substantially exceeds that under low-NOx conditions. The reversal of the NOx dependence of SOA formation for the sesquiterpenes is consistent with formation of relatively low-volatility organic nitrates, and/or the isomerization of large alkoxy radicals leading to less volatile products. Analysis of the aerosol chemical composition for longifolene confirms the presence of organic nitrates under high-NOx conditions. Consequently the formation of SOA from certain biogenic hydrocarbons such as sesquiterpenes (and possibly large anthropogenic hydrocarbons as well may be more efficient in polluted air.

  3. Explicit modelling of SOA formation from α-pinene photooxidation: sensitivity to vapour pressure estimation

    Directory of Open Access Journals (Sweden)

    R. Valorso

    2011-07-01

    Full Text Available The sensitivity of the formation of secondary organic aerosol (SOA to the estimated vapour pressures of the condensable oxidation products is explored. A highly detailed reaction scheme was generated for α-pinene photooxidation using the Generator for Explicit Chemistry and Kinetics of Organics in the Atmosphere (GECKO-A. Vapour pressures (Pvap were estimated with three commonly used structure activity relationships. The values of Pvap were compared for the set of secondary species generated by GECKO-A to describe α-pinene oxidation. Discrepancies in the predicted vapour pressures were found to increase with the number of functional groups borne by the species. For semi-volatile organic compounds (i.e. organic species of interest for SOA formation, differences in the predicted Pvap range between a factor of 5 to 200 on average. The simulated SOA concentrations were compared to SOA observations in the Caltech chamber during three experiments performed under a range of NOx conditions. While the model captures the qualitative features of SOA formation for the chamber experiments, SOA concentrations are systematically overestimated. For the conditions simulated, the modelled SOA speciation appears to be rather insensitive to the Pvap estimation method.

  4. The Staff Observation Aggression Scale - Revised (SOAS-R) - adjustment and validation for emergency primary health care.

    Science.gov (United States)

    Morken, Tone; Baste, Valborg; Johnsen, Grethe E; Rypdal, Knut; Palmstierna, Tom; Johansen, Ingrid Hjulstad

    2018-05-08

    Many emergency primary health care workers experience aggressive behaviour from patients or visitors. Simple incident-reporting procedures exist for inpatient, psychiatric care, but a similar and simple incident-report for other health care settings is lacking. The aim was to adjust a pre-existing form for reporting aggressive incidents in a psychiatric inpatient setting to the emergency primary health care settings. We also wanted to assess the validity of the severity scores in emergency primary health care. The Staff Observation Scale - Revised (SOAS-R) was adjusted to create a pilot version of the Staff Observation Scale - Revised Emergency (SOAS-RE). A Visual Analogue Scale (VAS) was added to the form to judge the severity of the incident. Data for validation of the pilot version of SOAS-RE were collected from ten casualty clinics in Norway during 12 months. Variance analysis was used to test gender and age differences. Linear regression analysis was performed to evaluate the relative impact that each of the five SOAS-RE columns had on the VAS score. The association between SOAS-RE severity score and VAS severity score was calculated by the Pearson correlation coefficient. The SOAS-R was adjusted to emergency primary health care, refined and called The Staff Observation Aggression Scale - Revised Emergency (SOAS-RE). A total of 350 SOAS-RE forms were collected from the casualty clinics, but due to missing data, 291 forms were included in the analysis. SOAS-RE scores ranged from 1 to 22. The mean total severity score of SOAS-RE was 10.0 (standard deviation (SD) =4.1) and the mean VAS score was 45.4 (SD = 26.7). We found a significant correlation of 0.45 between the SOAS-RE total severity scores and the VAS severity ratings. The linear regression analysis showed that individually each of the categories, which described the incident, had a low impact on the VAS score. The SOAS-RE seems to be a useful instrument for research, incident-recording and management

  5. Investigation of patterning effects in ultrafast SOA-based optical switches

    DEFF Research Database (Denmark)

    Xu, Jing; Zhang, Xinliang; Mørk, Jesper

    2010-01-01

    , has been proposed based on the idea of driving the SOA at two saturation extremes by two periodic pulse trains. The predictive power of the periodic method is verified by comparing its results with those obtained by using ordinary PRBS patterns. Finally, the effectiveness of the periodic method...... is exploited by analyzing in detail the performance properties of a specific type of switch over large parameter regions. Besides allowing an investigation of patterning effects, the periodic method also simultaneously provides such figures of merit as output power and pulsewidth....... that limits the ultimate speed at which SOA-based switches can be operated. In this paper, we investigate the patterning effects of SOA-based switches using a systematic approach. A simple condition for the lower bound limit of the bit pattern length that should be adopted in the performance evaluations...

  6. Virtual rehabilitation--benefits and challenges.

    Science.gov (United States)

    Burdea, G C

    2003-01-01

    To discuss the advantages and disadvantages of rehabilitation applications of virtual reality. VR can be used as an enhancement to conventional therapy for patients with conditions ranging from musculoskeletal problems, to stroke-induced paralysis, to cognitive deficits. This approach is called "VR-augmented rehabilitation." Alternately, VR can replace conventional interventions altogether, in which case the rehabilitation is "VR-based." If the intervention is done at a distance, then it is called "telerehabilitation." Simulation exercises for post-stroke patients have been developed using a "teacher object" approach or a video game approach. Simulations for musculo-skeletal patients use virtual replicas of rehabilitation devices (such as rubber ball, power putty, peg board). Phobia-inducing virtual environments are prescribed for patients with cognitive deficits. VR-augmented rehabilitation has been shown effective for stroke patients in the chronic phase of the disease. VR-based rehabilitation has been improving patients with fear of flying, Vietnam syndrome, fear of heights, and chronic stroke patients. Telerehabilitation interventions using VR have improved musculo-skeletal and post-stroke patients, however less data is available at this time. Virtual reality presents significant advantages when applied to rehabilitation of patients with varied conditions. These advantages include patient motivation, adaptability and variability based on patient baseline, transparent data storage, online remote data access, economy of scale, reduced medical costs. Challenges in VR use for rehabilitation relate to lack of computer skills on the part of therapists, lack of support infrastructure, expensive equipment (initially), inadequate communication infrastructure (for telerehabilitation in rural areas), and patient safety concerns.

  7. Dithiothreitol activity by particulate oxidizers of SOA produced from photooxidation of hydrocarbons under varied NOx levels

    Science.gov (United States)

    Jiang, Huanhuan; Jang, Myoseon; Yu, Zechen

    2017-08-01

    When hydrocarbons (HCs) are atmospherically oxidized, they form particulate oxidizers, including quinones, organic hydroperoxides, and peroxyacyl nitrates (PANs). These particulate oxidizers can modify cellular materials (e.g., proteins and enzymes) and adversely modulate cell functions. In this study, the contribution of particulate oxidizers in secondary organic aerosols (SOAs) to the oxidative potential was investigated. SOAs were generated from the photooxidation of toluene, 1,3,5-trimethylbenzene, isoprene, and α-pinene under varied NOx levels. Oxidative potential was determined from the typical mass-normalized consumption rate (reaction time t = 30 min) of dithiothreitol (DTTt), a surrogate for biological reducing agents. Under high-NOx conditions, the DTTt of toluene SOA was 2-5 times higher than that of the other types of SOA. Isoprene DTTt significantly decreased with increasing NOx (up to 69 % reduction by changing the HC / NOx ratio from 30 to 5). The DTTt of 1,3,5-trimethylbenzene and α-pinene SOA was insensitive to NOx under the experimental conditions of this study. The significance of quinones to the oxidative potential of SOA was tested through the enhancement of DTT consumption in the presence of 2,4-dimethylimidazole, a co-catalyst for the redox cycling of quinones; however, no significant effect of 2,4-dimethylimidazole on modulation of DTT consumption was observed for all SOA, suggesting that a negligible amount of quinones was present in the SOA of this study. For toluene and isoprene, mass-normalized DTT consumption (DTTm) was determined over an extended period of reaction time (t = 2 h) to quantify their maximum capacity to consume DTT. The total quantities of PANs and organic hydroperoxides in toluene SOA and isoprene SOA were also measured using the Griess assay and the 4-nitrophenylboronic acid assay, respectively. Under the NOx conditions (HC / NOx ratio: 5-36 ppbC ppb-1) applied in this study, the amount of organic hydroperoxides was

  8. Using Service Oriented Architecture in a Generic Virtual Power Plant

    DEFF Research Database (Denmark)

    Andersen, Peter Bach; Poulsen, Bjarne; Træholt, Chresten

    2009-01-01

    The purpose of this paper is to find and describe a suitable software framework that can be used to help implement the concept of a Generic Virtual Power Plant in the future power system. The Generic Virtual Power Plant concept, along with the utilization of distributed energy resources, has many...... the Generic Virtual Power Plant, an array of different software design principles, patterns and architectures must be applied. Especially Service Oriented Architecture (SOA) can aid in implementing the Generic Virtual Power Plant.......The purpose of this paper is to find and describe a suitable software framework that can be used to help implement the concept of a Generic Virtual Power Plant in the future power system. The Generic Virtual Power Plant concept, along with the utilization of distributed energy resources, has many...... interesting properties that can influence the future shape of power markets. The concept holds many promises including cheaper power to the consumer, a more flexible and responsive power production and the support of a more environment-friendly development. In order to realize a software solution supporting...

  9. A LEGO paradigm for virtual accelerator concept

    International Nuclear Information System (INIS)

    Andrianov, S.; Ivanov, A.; Podzyvalov, E.

    2012-01-01

    The paper considers basic features of a Virtual Accelerator concept based on LEGO paradigm. This concept involves three types of components: different mathematical models for accelerator design problems, integrated beam simulation packages (i. e. COSY, MAD, OptiM and others), and a special class of virtual feedback instruments similar to real control systems (EPICS). All of these components should inter-operate for more complete analysis of control systems and increased fault tolerance. The Virtual Accelerator is an information and computing environment which provides a framework for analysis based on these components that can be combined in different ways. Corresponding distributed computing services establish interaction between mathematical models and low level control system. The general idea of the software implementation is based on the Service-Oriented Architecture (SOA) that allows using cloud computing technology and enables remote access to the information and computing resources. The Virtual Accelerator allows a designer to combine powerful instruments for modeling beam dynamics in a friendly way including both self-developed and well-known packages. In the scope of this concept the following is also proposed: the control system identification, analysis and result verification, visualization as well as virtual feedback for beam line operation. The architecture of the Virtual Accelerator system itself and results of beam dynamics studies are presented. (authors)

  10. Improving the representation of secondary organic aerosol (SOA in the MOZART-4 global chemical transport model

    Directory of Open Access Journals (Sweden)

    A. Mahmud

    2013-07-01

    Full Text Available The secondary organic aerosol (SOA module in the Model for Ozone and Related Chemical Tracers, version 4 (MOZART-4 was updated by replacing existing two-product (2p parameters with those obtained from two-product volatility basis set (2p-VBS fits (MZ4-C1, and by treating SOA formation from the following additional volatile organic compounds (VOCs: isoprene, propene and lumped alkenes (MZ4-C2. Strong seasonal and spatial variations in global SOA distributions were demonstrated, with significant differences in the predicted concentrations between the base case and updated model simulations. Updates to the model resulted in significant increases in annual average SOA mass concentrations, particularly for the MZ4-C2 simulation in which the additional SOA precursor VOCs were treated. Annual average SOA concentrations predicted by the MZ4-C2 simulation were 1.00 ± 1.04 μg m−3 in South America, 1.57 ± 1.88 μg m−3 in Indonesia, 0.37 ± 0.27 μg m−3 in the USA, and 0.47 ± 0.29 μg m−3 in Europe with corresponding increases of 178, 406, 311 and 292% over the base-case simulation, respectively, primarily due to inclusion of isoprene. The increases in predicted SOA mass concentrations resulted in corresponding increases in SOA contributions to annual average total aerosol optical depth (AOD by ~ 1–6%. Estimated global SOA production was 5.8, 6.6 and 19.1 Tg yr−1 with corresponding burdens of 0.22, 0.24 and 0.59 Tg for the base-case, MZ4-C1 and MZ4-C2 simulations, respectively. The predicted SOA budgets fell well within reported ranges for comparable modeling studies, 6.7 to 96 Tg yr−1, but were lower than recently reported observationally constrained values, 50 to 380 Tg yr−1. For MZ4-C2, simulated SOA concentrations at the surface also were in reasonable agreement with comparable modeling studies and observations. Total organic aerosol (OA mass concentrations at the surface, however, were slightly over-predicted in Europe, Amazonian

  11. Flow Reactor for studying Physicochemical and aging properties of SOA

    Science.gov (United States)

    Babar, Z. B.

    2016-12-01

    Secondary organic aerosols (SOA) have importance in environmental processes such as affecting earth's radiative balance and cloud formation processes. For studying SOA formation large scale environmental batch reactors and laboratory scale flow reactors have been used. In this study application of flow reactor to study physicochemical properties of SOA is also investigated after its characterization. The flow reactor is of cylindrical design (ID 15 cm x L 70 cm) equipped with UV lamps. It is coupled with various instruments such as scanning mobility particle sizer, NOx analyzer, ozone analyzer, VOC analyzer, hygrometer, and temperature sensors for gas and particle phase measurements. OH radicals were generated by custom build ozone generator and relative humidity. The following characterizations were performed: (1) residence time distribution (RTD) measurements, (2) RH and temperature control, (3) OH radical exposure range (atmospheric aging time), (4) gas phase oxidation of SOA precursors such as α-pinene by OH radical. The flow reactor yielded narrow RTDs. In particular, RH and temperature can be controlled effectively between 0-60% and 22-43oC, respectively. OH radical exposure ranges from 6.49x1010 to 3.68x1011 molecules/cm3s (0.49 to 4.91 days). Our initial efforts on OH radical generation using hydrogen peroxide and its quantification by using flourescenet technique will be also be presented.

  12. Dithiothreitol activity by particulate oxidizers of SOA produced from photooxidation of hydrocarbons under varied NOx levels

    Directory of Open Access Journals (Sweden)

    H. Jiang

    2017-08-01

    Full Text Available When hydrocarbons (HCs are atmospherically oxidized, they form particulate oxidizers, including quinones, organic hydroperoxides, and peroxyacyl nitrates (PANs. These particulate oxidizers can modify cellular materials (e.g., proteins and enzymes and adversely modulate cell functions. In this study, the contribution of particulate oxidizers in secondary organic aerosols (SOAs to the oxidative potential was investigated. SOAs were generated from the photooxidation of toluene, 1,3,5-trimethylbenzene, isoprene, and α-pinene under varied NOx levels. Oxidative potential was determined from the typical mass-normalized consumption rate (reaction time t =  30 min of dithiothreitol (DTTt, a surrogate for biological reducing agents. Under high-NOx conditions, the DTTt of toluene SOA was 2–5 times higher than that of the other types of SOA. Isoprene DTTt significantly decreased with increasing NOx (up to 69 % reduction by changing the HC ∕ NOx ratio from 30 to 5. The DTTt of 1,3,5-trimethylbenzene and α-pinene SOA was insensitive to NOx under the experimental conditions of this study. The significance of quinones to the oxidative potential of SOA was tested through the enhancement of DTT consumption in the presence of 2,4-dimethylimidazole, a co-catalyst for the redox cycling of quinones; however, no significant effect of 2,4-dimethylimidazole on modulation of DTT consumption was observed for all SOA, suggesting that a negligible amount of quinones was present in the SOA of this study. For toluene and isoprene, mass-normalized DTT consumption (DTTm was determined over an extended period of reaction time (t =  2 h to quantify their maximum capacity to consume DTT. The total quantities of PANs and organic hydroperoxides in toluene SOA and isoprene SOA were also measured using the Griess assay and the 4-nitrophenylboronic acid assay, respectively. Under the NOx conditions (HC ∕ NOx ratio: 5–36 ppbC ppb−1 applied in

  13. Inflammatory responses to secondary organic aerosols (SOA generated from biogenic and anthropogenic precursors

    Directory of Open Access Journals (Sweden)

    W. Y. Tuet

    2017-09-01

    Full Text Available Cardiopulmonary health implications resulting from exposure to secondary organic aerosols (SOA, which comprise a significant fraction of ambient particulate matter (PM, have received increasing interest in recent years. In this study, alveolar macrophages were exposed to SOA generated from the photooxidation of biogenic and anthropogenic precursors (isoprene, α-pinene, β-caryophyllene, pentadecane, m-xylene, and naphthalene under different formation conditions (RO2 + HO2 vs. RO2 + NO dominant, dry vs. humid. Various cellular responses were measured, including reactive oxygen and nitrogen species (ROS/RNS production and secreted levels of cytokines, tumor necrosis factor-α (TNF-α and interleukin-6 (IL-6. SOA precursor identity and formation condition affected all measured responses in a hydrocarbon-specific manner. With the exception of naphthalene SOA, cellular responses followed a trend where TNF-α levels reached a plateau with increasing IL-6 levels. ROS/RNS levels were consistent with relative levels of TNF-α and IL-6, due to their respective inflammatory and anti-inflammatory effects. Exposure to naphthalene SOA, whose aromatic-ring-containing products may trigger different cellular pathways, induced higher levels of TNF-α and ROS/RNS than suggested by the trend. Distinct cellular response patterns were identified for hydrocarbons whose photooxidation products shared similar chemical functionalities and structures, which suggests that the chemical structure (carbon chain length and functionalities of photooxidation products may be important for determining cellular effects. A positive nonlinear correlation was also detected between ROS/RNS levels and previously measured DTT (dithiothreitol activities for SOA samples. In the context of ambient samples collected during summer and winter in the greater Atlanta area, all laboratory-generated SOA produced similar or higher levels of ROS/RNS and DTT activities. These results

  14. Model-driven development of smart grid services using SoaML

    DEFF Research Database (Denmark)

    Kosek, Anna Magdalena; Gehrke, Oliver

    2014-01-01

    This paper presents a model-driven software devel- opment process which can be applied to the design of smart grid services. The Service Oriented Architecture Modelling Language (SoaML) is used to describe the architecture as well as the roles and interactions between service participants....... The individual modelling steps and an example design of a SoaML model for a voltage control service are presented and explained. Finally, the paper discusses a proof-of-concept implementation of the modelled service in a smart grid testing laboratory....

  15. Analysis of the hygroscopic and volatile properties of ammonium sulphate seeded and unseeded SOA particles

    Science.gov (United States)

    Meyer, N. K.; Duplissy, J.; Gysel, M.; Metzger, A.; Dommen, J.; Weingartner, E.; Alfarra, M. R.; Prevot, A. S. H.; Fletcher, C.; Good, N.; McFiggans, G.; Jonsson, Â. M.; Hallquist, M.; Baltensperger, U.; Ristovski, Z. D.

    2009-01-01

    The volatile and hygroscopic properties of ammonium sulphate seeded and unseeded secondary organic aerosol (SOA) derived from the photo-oxidation of atmospherically relevant concentrations of α-pinene were studied. The seed particles were electrospray generated ammonium sulphate ((NH4)2SO4) having diameters of approximately 33 nm with a quasi-mono-disperse size distribution (geometric standard deviation σg=1.3). The volatile and hygroscopic properties of both seeded and unseeded SOA were simultaneously measured with a VH-TDMA (volatility - hygroscopicity tandem differential mobility analyzer). VH-TDMA measurements of unseeded SOA show a decrease in the hygroscopic growth (HGF) factor for increased volatilisation temperatures such that the more volatile compounds appear to be more hygroscopic. This is opposite to the expected preferential evaporation of more volatile but less hygroscopic material, but could also be due to enhanced oligomerisation occurring at the higher temperature in the thermodenuder. In addition, HGF measurements of seeded SOA were measured as a function of time at two relative humidities, below (RH 75%) and above (RH 85%) the deliquescence relative humidity (DRH) of the pure ammonium sulphate seeds. As these measurements were conducted during the onset phase of photo-oxidation, during particle growth, they enabled us to find the dependence of the HGF as a function of the volume fraction of the SOA coating. HGF's measured at RH of 85% showed a continuous decrease as the SOA coating thickness increased. The measured growth factors show good agreements with ZSR predictions indicating that, at these RH values, there are only minor solute-solute interactions. At 75% RH, as the SOA fraction increased, a rapid increase in the HGF was observed indicating that an increasing fraction of the (NH4)2SO4 is subject to a phase transition, going into solution, with an increasing volume fraction of SOA. To our knowledge this is the first time that SOA derived

  16. Closing the business-application gap in SOA

    NARCIS (Netherlands)

    Dietz, J.L.G.; van Sinderen, Marten J.; Filipe, J.; Helfert, M.; Shishkov, Boris

    2007-01-01

    Adequately resolving the business-software gap in the context of SOA (Service-Oriented Architecture) appears to be a non-trivial task, mainly because of the dual essence of the service concept: (i) services are inevitably business-restricted because they operate in real-life environments; (ii)

  17. Major sulfonate transporter Soa1 in Saccharomyces cerevisiae and considerable substrate diversity in its fungal family

    DEFF Research Database (Denmark)

    Holt, Sylvester; Kankipati, Harish; De Graeve, Stijn

    2017-01-01

    Sulfate is a well-established sulfur source for fungi; however, in soils sulfonates and sulfate esters, especially choline sulfate, are often much more prominent. Here we show that Saccharomyces cerevisiae YIL166C(SOA1) encodes an inorganic sulfur (sulfate, sulfite and thiosulfate) transporter...... that also catalyses sulfonate and choline sulfate uptake. Phylogenetic analysis of fungal SOA1 orthologues and expression of 20 members in the sul1 Delta sul2 Delta soa1 Delta strain, which is deficient in inorganic and organic sulfur compound uptake, reveals that these transporters have diverse substrate...... preferences for sulfur compounds. We further show that SOA2, a S. cerevisiae SOA1 paralogue found in S. uvarum, S. eubayanus and S. arboricola is likely to be an evolutionary remnant of the uncharacterized open reading frames YOL163W and YOL162W. Our work highlights the importance of sulfonates and choline...

  18. On description of contracts and agreements in the context of SOA

    Directory of Open Access Journals (Sweden)

    Laima Paliulionienė

    2013-09-01

    Full Text Available The issue of making contracts between services in Service-Oriented Architecture (SOA arises naturally, because in real life services are subjects for negotiation and contracting. The notion of contract in SOA is rather misleading, because usually means just technical specification – input and output parameters, pre- and postconditions. However, there are also other aspects of contract. Service Level Agreements (SLAs often are used together with technical contract. SLAs describes the level of service expected by a customer from a supplier, laying out the metrics by which that service is measured, the remedies or penalties in case the agreed-upon levels are not achieved. The paper aim to clear up the notions of contract and agreement in SOA, discusses the properties of languages that are used to specify contacts and agreements, paying special attention to their legal aspects and comparing contract features in WS-Agreement ir WSLA.

  19. ANALYSIS OF VIRTUAL ENVIRONMENT BENEFIT IN E-LEARNING

    Directory of Open Access Journals (Sweden)

    NOVÁK, Martin

    2013-06-01

    Full Text Available The analysis of the virtual environment assets towards the e-learning process improvements is mentioned in this article. The virtual environment was created within the solution of the project ‘Virtualization’ at the Faculty of Economics and Administration, University of Pardubice. The aim of this project was to eliminate the disproportion of free access to licensed software between groups of part-time and full-time students. The research was realized within selected subjects of the study program System Engineering and Informatics. The subjects were connected to the informatics, applied informatics, control and decision making. Student subject results, student feedback based on electronic questionnaire and data from log file of virtual server usage were compared and analysed. Based on analysis of virtualization possibilities the solution of virtual environment was implemented through Microsoft Terminal Server.

  20. Spicy Stonehenge : Proposing a SOA Case Study

    NARCIS (Netherlands)

    Espinha, T.A.; Chen, C.; Zaidman, A.E.; Gross, H.G.

    2012-01-01

    Prepint of paper published in: ICSE Workshop on Principles of Engineering Service Oriented Systems (PESOS), 4 June 2012; doi:10.1109/PESOS.2012.6225940 Maintenance research in the context of Service Oriented Architecture (SOA) is currently lacking a suitable standard case study that can be used by

  1. Analysis of the hygroscopic and volatile properties of ammonium sulphate seeded and unseeded SOA particles

    Directory of Open Access Journals (Sweden)

    N. K. Meyer

    2009-01-01

    Full Text Available The volatile and hygroscopic properties of ammonium sulphate seeded and unseeded secondary organic aerosol (SOA derived from the photo-oxidation of atmospherically relevant concentrations of α-pinene were studied. The seed particles were electrospray generated ammonium sulphate ((NH42SO4 having diameters of approximately 33 nm with a quasi-mono-disperse size distribution (geometric standard deviation σg=1.3. The volatile and hygroscopic properties of both seeded and unseeded SOA were simultaneously measured with a VH-TDMA (volatility – hygroscopicity tandem differential mobility analyzer. VH-TDMA measurements of unseeded SOA show a decrease in the hygroscopic growth (HGF factor for increased volatilisation temperatures such that the more volatile compounds appear to be more hygroscopic. This is opposite to the expected preferential evaporation of more volatile but less hygroscopic material, but could also be due to enhanced oligomerisation occurring at the higher temperature in the thermodenuder. In addition, HGF measurements of seeded SOA were measured as a function of time at two relative humidities, below (RH 75% and above (RH 85% the deliquescence relative humidity (DRH of the pure ammonium sulphate seeds. As these measurements were conducted during the onset phase of photo-oxidation, during particle growth, they enabled us to find the dependence of the HGF as a function of the volume fraction of the SOA coating. HGF's measured at RH of 85% showed a continuous decrease as the SOA coating thickness increased. The measured growth factors show good agreements with ZSR predictions indicating that, at these RH values, there are only minor solute-solute interactions. At 75% RH, as the SOA fraction increased, a rapid increase in the HGF was observed indicating that an increasing fraction of the (NH42SO4 is subject to a phase transition, going into solution, with an

  2. Novel cloud and SOA-based framework for e-health monitoring using wireless biosensors.

    Science.gov (United States)

    Benharref, Abdelghani; Serhani, Mohamed Adel

    2014-01-01

    Various and independent studies are showing that an exponential increase of chronic diseases (CDs) is exhausting governmental and private healthcare systems to an extent that some countries allocate half of their budget to healthcare systems. To benefit from the IT development, e-health monitoring and prevention approaches revealed to be among top promising solutions. In fact, well-implemented monitoring and prevention schemes have reported a decent reduction of CDs risk and have narrowed their effects, on both patients' health conditions and on government budget spent on healthcare. In this paper, we propose a framework to collect patients' data in real time, perform appropriate nonintrusive monitoring, and propose medical and/or life style engagements, whenever needed and appropriate. The framework, which relies on service-oriented architecture (SOA) and the Cloud, allows a seamless integration of different technologies, applications, and services. It also integrates mobile technologies to smoothly collect and communicate vital data from a patient's wearable biosensors while considering the mobile devices' limited capabilities and power drainage in addition to intermittent network disconnections. Then, data are stored in the Cloud and made available via SOA to allow easy access by physicians, paramedics, or any other authorized entity. A case study has been developed to evaluate the usability of the framework, and the preliminary results that have been analyzed are showing very promising results.

  3. Analysis of the hygroscopic and volatile properties of ammonium sulphate seeded and un-seeded SOA particles

    Science.gov (United States)

    Meyer, N. K.; Duplissy, J.; Gysel, M.; Metzger, A.; Dommen, J.; Weingartner, E.; Alfarra, M. R.; Fletcher, C.; Good, N.; McFiggans, G.; Jonsson, Ã. M.; Hallquist, M.; Baltensperger, U.; Ristovski, Z. D.

    2008-05-01

    The volatile and hygroscopic properties of ammonium sulphate seeded and un-seeded secondary organic aerosol (SOA) derived from the photo-oxidation of atmospherically relevant concentrations of α-pinene were studied. The seed particles were electrospray generated ammonium sulphate ((NH4)2SO4) having diameters of approximately 33 nm with a quasi-mono-disperse size distribution (geometric standard deviation σg=1.3). The volatile and hygroscopic properties of both seeded and unseeded SOA were simultaneously measured with a VH-TDMA (volatility - hygroscopicity tandem differential mobility analyzer). VH-TDMA measurements of unseeded SOA show a decrease in the hygroscopic growth (HGF) factor for increased volatilisation temperatures such that the more volatile compounds appear to be more hygroscopic. This is opposite to the expected preferential evaporation of more volatile but less hygroscopic material, but could also be due to enhanced oligomerisation occurring at the higher temperature in the thermodenuder. In addition, HGF measurements of seeded SOA were measured as a function of time at two relative humidities, below (RH 75%) and above (RH 85%) the deliquescence relative humidity (DRH) of the pure ammonium sulphate seeds. As these measurements were conducted during the onset phase of photo-oxidation, during particle growth, they enabled us to find the dependence of the HGF as a function of the volume fraction of the SOA coating. HGF's measured at RH of 85% showed a continuous decrease as the SOA coating thickness increased. The measured growth factors show good agreements with ZSR predictions indicating that, at these RH values, there are only minor solute-solute interactions. At 75% RH, as the SOA fraction increased, a rapid increase in the HGF was observed indicating that an increasing fraction of the (NH4)2SO4 is subject to a phase transition, going into solution, with an increasing volume fraction of SOA. To our knowledge this is the first time that SOA derived

  4. Volatility and lifetime against OH heterogeneous reaction of ambient isoprene-epoxydiols-derived secondary organic aerosol (IEPOX-SOA)

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Weiwei; Palm, Brett B.; Day, Douglas A.; Campuzano-Jost, Pedro; Krechmer, Jordan E.; Peng, Zhe; de Sá, Suzane S.; Martin, Scot T.; Alexander, M. Lizabeth; Baumann, Karsten; Hacker, Lina; Kiendler-Scharr, Astrid; Koss, Abigail R.; de Gouw, Joost A.; Goldstein, Allen H.; Seco, Roger; Sjostedt, Steven J.; Park, Jeong-Hoo; Guenther, Alex B.; Kim, Saewung; Canonaco, Francesco; Prévôt, André S. H.; Brune, William H.; Jimenez, Jose L.

    2016-01-01

    Isoprene-epoxydiols-derived secondary organic aerosol (IEPOX-SOA) can contribute substantially to organic aerosol (OA) concentrations in forested areas under low NO conditions, hence significantly influencing the regional and global OA budgets, accounting, for example, for 16–36 % of the submicron OA in the southeastern United States (SE US) summer. Particle evaporation measurements from a thermodenuder show that the volatility of ambient IEPOX-SOA is lower than that of bulk OA and also much lower than that of known monomer IEPOX-SOA tracer species, indicating that IEPOX-SOA likely exists mostly as oligomers in the aerosol phase. The OH aging process of ambient IEPOX-SOA was investigated with an oxidation flow reactor (OFR). New IEPOX-SOA formation in the reactor was negligible, as the OFR does not accelerate processes such as aerosol uptake and reactions that do not scale with OH. Simulation results indicate that adding ~100 µg m-3 of pure H2SO4 to the ambient air allows IEPOX-SOA to be efficiently formed in the reactor. The heterogeneous reaction rate coefficient of ambient IEPOX-SOA with OH radical (kOH) was estimated as 4.0 ± 2.0 ×10-13 cm3 molec-1 s-1, which is equivalent to more than a 2-week lifetime. A similar kOH was found for measurements of OH oxidation of ambient Amazon forest air in an OFR. At higher OH exposures in the reactor (> 1 × 1012 molec cm-3 s), the mass loss of IEPOX-SOA due to heterogeneous reaction was mainly due to revolatilization of fragmented reaction products. We report, for the first time, OH reactive uptake coefficients (γOH = 0.59±0.33 in SE US and γOH = 0.68±0.38 in Amazon) for SOA under ambient conditions. A relative humidity dependence of kOH and γOH was observed, consistent with surface-area-limited OH uptake

  5. Volatility and lifetime against OH heterogeneous reaction of ambient isoprene-epoxydiols-derived secondary organic aerosol (IEPOX-SOA

    Directory of Open Access Journals (Sweden)

    W. Hu

    2016-09-01

    Full Text Available Isoprene-epoxydiols-derived secondary organic aerosol (IEPOX-SOA can contribute substantially to organic aerosol (OA concentrations in forested areas under low NO conditions, hence significantly influencing the regional and global OA budgets, accounting, for example, for 16–36 % of the submicron OA in the southeastern United States (SE US summer. Particle evaporation measurements from a thermodenuder show that the volatility of ambient IEPOX-SOA is lower than that of bulk OA and also much lower than that of known monomer IEPOX-SOA tracer species, indicating that IEPOX-SOA likely exists mostly as oligomers in the aerosol phase. The OH aging process of ambient IEPOX-SOA was investigated with an oxidation flow reactor (OFR. New IEPOX-SOA formation in the reactor was negligible, as the OFR does not accelerate processes such as aerosol uptake and reactions that do not scale with OH. Simulation results indicate that adding  ∼  100 µg m−3 of pure H2SO4 to the ambient air allows IEPOX-SOA to be efficiently formed in the reactor. The heterogeneous reaction rate coefficient of ambient IEPOX-SOA with OH radical (kOH was estimated as 4.0 ± 2.0  ×  10−13 cm3 molec−1 s−1, which is equivalent to more than a 2-week lifetime. A similar kOH was found for measurements of OH oxidation of ambient Amazon forest air in an OFR. At higher OH exposures in the reactor (>  1  ×  1012 molec cm−3 s, the mass loss of IEPOX-SOA due to heterogeneous reaction was mainly due to revolatilization of fragmented reaction products. We report, for the first time, OH reactive uptake coefficients (γOH =  0.59 ± 0.33 in SE US and γOH =  0.68 ± 0.38 in Amazon for SOA under ambient conditions. A relative humidity dependence of kOH and γOH was observed, consistent with surface-area-limited OH uptake. No decrease of kOH was observed as OH concentrations increased. These observations of physicochemical

  6. Metadata-Driven SOA-Based Application for Facilitation of Real-Time Data Warehousing

    Science.gov (United States)

    Pintar, Damir; Vranić, Mihaela; Skočir, Zoran

    Service-oriented architecture (SOA) has already been widely recognized as an effective paradigm for achieving integration of diverse information systems. SOA-based applications can cross boundaries of platforms, operation systems and proprietary data standards, commonly through the usage of Web Services technology. On the other side, metadata is also commonly referred to as a potential integration tool given the fact that standardized metadata objects can provide useful information about specifics of unknown information systems with which one has interest in communicating with, using an approach commonly called "model-based integration". This paper presents the result of research regarding possible synergy between those two integration facilitators. This is accomplished with a vertical example of a metadata-driven SOA-based business process that provides ETL (Extraction, Transformation and Loading) and metadata services to a data warehousing system in need of a real-time ETL support.

  7. An approach to SOA development methodology: SOUP comparison with RUP and XP

    OpenAIRE

    Sandra Svanidzaitė

    2014-01-01

    Service oriented architecture (SOA) is an architecture for distributed applications composed of distributed services with weak coupling that are designed to meet business requirements. One of the research priorities in the field of SOA is creating such software design and development methodology (SDDM) that takes into account all principles of this architecture and allows for effective and efficient application development. A lot of investigation has been carried out to find out whether can o...

  8. Simultaneous wavelength and format conversion in SDN/NFV for flexible optical network based on FWM in SOA

    Science.gov (United States)

    Zhan, Yueying; Wang, Danshi; Zhang, Min

    2018-04-01

    We propose an all-optical wavelength and format conversion model (CM) for a dynamic data center interconnect node and coherent passive optical network (PON) optical network unit (ONU) in software-defined networking and network function virtualization system based on four-wave mixing in a semiconductor optical amplifier. Five wavelength converted DQPSK signals and two format converted DPSK signals are generated; the performances of the generated signals for two strategies of setting CM in the data center interconnect node and coherent PON ONU, which are over 10 km fiber transmission, have been verified. All of the converted signals are with a power penalty less than 2.2 dB at FEC threshold of 3.8 × 10 - 3, and the optimum bias current of SOA is 300 mA.

  9. Evaluation of a Generic Virtual Power Plant Framework Using Service Oriented Architecture

    DEFF Research Database (Denmark)

    Andersen, Peter Bach; Poulsen, Bjarne; Decker, Morten

    2008-01-01

    interesting properties that can influence the future shape of power markets. The concept holds many promises including cheaper power to the consumer, a more flexible and responsive power production and the support of a more environment- friendly development. In order to realize a software solution supporting...... the generic virtual power plant, an array of different software design principles, patterns and architectures must be applied. Especially Service Oriented Architecture (SOA) can aid in implementing the generic virtual power plant. An analysis of the Nordic power market has been carried out in order...... to identify potential issues and barriers, henceforth mentioned as challenges, connected with the introduction of the generic virtual power plant concept. In this paper, three use case scenarios will show how each of these challenges can be overcome by the proposed solution framework. The use case scenarios...

  10. Virtual Reality

    Science.gov (United States)

    1993-04-01

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

  11. Measuring test coverage of SoA services

    NARCIS (Netherlands)

    Sneed, Harry M.; Verhoef, Chris

    2015-01-01

    One of the challenges of testing in a SoA environment is that testers do not have access to the source code of the services they are testing. Therefore they are not able to measure test coverage at the code level, as is done in conventional white-box testing. They are compelled to measure test

  12. Suppression of interferometric crosstalk and ASE noise using a polarization multiplexing technique and an SOA

    DEFF Research Database (Denmark)

    Zheng, Xueyan; Liu, Fenghai; Wolfson, David

    2000-01-01

    Noise suppression at 10 Gbit/s and 20 Gbit/s is demonstrated using a gain saturated semiconductor optical amplifier (SOA) and a polarization multiplexing technique, where no impairments like waveform distortion and extinction ratio degradation caused by the gain saturation of the SOA appear. More...

  13. "Do You Feel in Control?": Towards Novel Approaches to Characterise, Manipulate and Measure the Sense of Agency in Virtual Environments.

    Science.gov (United States)

    Jeunet, Camille; Albert, Louis; Argelaguet, Ferran; Lecuyer, Anatole

    2018-04-01

    While the Sense of Agency (SoA) has so far been predominantly characterised in VR as a component of the Sense of Embodiment, other communities (e.g., in psychology or neurosciences) have investigated the SoA from a different perspective proposing complementary theories. Yet, despite the acknowledged potential benefits of catching up with these theories a gap remains. This paper first aims to contribute to fill this gap by introducing a theory according to which the SoA can be divided into two components, the feeling and the judgment of agency, and relies on three principles, namely the principles of priority, exclusivity and consistency. We argue that this theory could provide insights on the factors influencing the SoA in VR systems. Second, we propose novel approaches to manipulate the SoA in controlled VR experiments (based on these three principles) as well as to measure the SoA, and more specifically its two components based on neurophysiological markers, using ElectroEncephaloGraphy (EEG). We claim that these approaches would enable us to deepen our understanding of the SoA in VR contexts. Finally, we validate these approaches in an experiment. Our results (N=24) suggest that our approach was successful in manipulating the SoA as the modulation of each of the three principles induced significant decreases of the SoA (measured using questionnaires). In addition, we recorded participants' EEG signals during the VR experiment, and neurophysiological markers of the SoA, potentially reflecting the feeling and judgment of agency specifically, were revealed. Our results also suggest that users' profile, more precisely their Locus of Control (LoC), influences their level of immersion and SoA.

  14. Enterprise SOA Designing IT for Business Innovation

    CERN Document Server

    Woods, Dan

    2008-01-01

    Based on extensive research with experts from the German software company SAP, this definitive book is ideal for architects, developers, and other IT professionals who want to understand the technology and business relevance of enterprise SOA in a detailed way--especially those who want to move on the technology now, rather than in the next year or two.

  15. Medical Virtual Public Services

    Directory of Open Access Journals (Sweden)

    Iulia SURUGIU

    2008-01-01

    Full Text Available The healthcare enterprises are very disconnected. This paper intends to propose a solution that will provide citizens, businesses and medical enterprises with improved access to medical virtual public services. Referred medical services are based on existing national medical Web services and which support medically required services provided by physicians and supplementary health care practitioners, laboratory services and diagnostic procedures, clinics and hospitals’ services. Requirements and specific rules of these medical services are considered, and personalization of user preferences will to be supported. The architecture is based on adaptable process management technologies, allowing for virtual services which are dynamically combined from existing national medical services. In this way, a comprehensive workflow process is set up, allowing for service-level agreements, an audit trail and explanation of the process to the end user. The process engine operates on top of a virtual repository, providing a high-level semantic view of information retrieved from heterogeneous information sources, such as national sources of medical services. The system relies on a security framework to ensure all high-level security requirements are met. System’s architecture is business oriented: it focuses on Service Oriented Architecture - SOA concepts, asynchronously combining Web services, Business Process Management – BPM rules and BPEL standards.

  16. SOA precursors at the T0 site during the 2010 CARES campaign

    Science.gov (United States)

    Wallace, H. W.; Jobson, B. T.; Erickson, M. H.

    2010-12-01

    Continuous measurements of C5 to C12 Volatile Organic Compounds (VOC) have been made using the Washington State University Mobile Atmospheric Chemistry Laboratory (MACL), at the T0 site during the month of June 2010 Carbonaceous Aerosol Carbonaceous Aerosols and Radiative Effects Study (CARES). These measurements were made to better understand aerosol formation and growth in Sacramento, CA and the surrounding areas. Using a sorbent based preconcentration sampling technique for our quadrupole ion trap gas chromatography mass spectrometer (GCMS), we have measured anthropogenic and biogenic secondary organic aerosol (SOA) precursors. Major biogenic VOCs identified include: α-pinene, limonene, isoprene, phellanderene and β-pinene. Diurnal profiles of the concentrations will be presented. Monoterpenes were highest in the mornings while isoprene was highest in the afternoon. In addition to understanding the diurnal profiles the SOA precursors at the T0 site, the relative contributions of biogenic and anthropogenic compounds to SOA formation will be presented.

  17. Evidence for ambient dark aqueous SOA formation in the Po Valley, Italy

    Directory of Open Access Journals (Sweden)

    A. P. Sullivan

    2016-07-01

    Full Text Available Laboratory experiments suggest that water-soluble products from the gas-phase oxidation of volatile organic compounds can partition into atmospheric waters where they are further oxidized to form low volatility products, providing an alternative route for oxidation in addition to further oxidation in the gas phase. These products can remain in the particle phase after water evaporation, forming what is termed as aqueous secondary organic aerosol (aqSOA. However, few studies have attempted to observe ambient aqSOA. Therefore, a suite of measurements, including near-real-time WSOC (water-soluble organic carbon, inorganic anions/cations, organic acids, and gas-phase glyoxal, were made during the PEGASOS (Pan-European Gas-AeroSOls-climate interaction Study 2012 campaign in the Po Valley, Italy, to search for evidence of aqSOA. Our analysis focused on four periods: Period A on 19–21 June, Period B on 30 June and 1–2 July, Period C on 3–5 July, and Period D on 6–7 July to represent the first (Period A and second (Periods B, C, and D halves of the study. These periods were picked to cover varying levels of WSOC and aerosol liquid water. In addition, back trajectory analysis suggested all sites sampled similar air masses on a given day. The data collected during both periods were divided into times of increasing relative humidity (RH and decreasing RH, with the aim of diminishing the influence of dilution and mixing on SOA concentrations and other measured variables. Evidence for local aqSOA formation was only observed during Period A. When this occurred, there was a correlation of WSOC with organic aerosol (R2 = 0.84, aerosol liquid water (R2 = 0.65, RH (R2 = 0.39, and aerosol nitrate (R2 = 0.66. Additionally, this was only observed during times of increasing RH, which coincided with dark conditions. Comparisons of WSOC with oxygenated organic aerosol (OOA factors, determined from application of positive matrix

  18. The STAR Grants Contribution to the SOAS Campaign

    Science.gov (United States)

    The Southern Oxidant and Aerosol Study (SOAS) is a community-led field campaign that was part of the Southeast Atmosphere Study (SAS). As one of the largest field studies in decades to characterize air quality in the Southeastern United States, SAS is a collaborative project invo...

  19. Fuzzy-Neural Controller in Service Requests Distribution Broker for SOA-Based Systems

    Science.gov (United States)

    Fras, Mariusz; Zatwarnicka, Anna; Zatwarnicki, Krzysztof

    The evolution of software architectures led to the rising importance of the Service Oriented Architecture (SOA) concept. This architecture paradigm support building flexible distributed service systems. In the paper the architecture of service request distribution broker designed for use in SOA-based systems is proposed. The broker is built with idea of fuzzy control. The functional and non-functional request requirements in conjunction with monitoring of execution and communication links are used to distribute requests. Decisions are made with use of fuzzy-neural network.

  20. Waste Management Using Request-Based Virtual Organizations

    Science.gov (United States)

    Katriou, Stamatia Ann; Fragidis, Garyfallos; Ignatiadis, Ioannis; Tolias, Evangelos; Koumpis, Adamantios

    Waste management is on top of the political agenda globally as a high priority environmental issue, with billions spent on it each year. This paper proposes an approach for the disposal, transportation, recycling and reuse of waste. This approach incorporates the notion of Request Based Virtual Organizations (RBVOs) using a Service Oriented Architecture (SOA) and an ontology that serves the definition of waste management requirements. The populated ontology is utilized by a Multi-Agent System which performs negotiations and forms RBVOs. The proposed approach could be used by governments and companies searching for a means to perform such activities in an effective and efficient manner.

  1. Research of B2B e-Business Application and Development Technology Based on SOA

    Science.gov (United States)

    Xian, Li Liang

    Today, the B2B e-business systems in most enterprises usually have multiple heterogeneous and independent systems which are based on different platforms and operate in different functional departments. To deal with the increased services in future, an enterprise needs to expand its system continuously. This, however, will cause great inconvenience to the future system maintenance. To implement e-business successfully, a unified internal e-business integration environment must be established to integrate the internal system and thus realize a unified internal mechanism within the enterprise e-business system. The SOA (service-oriented architecture), however, can well meet the above requirements. The integration of SOA-based applications can reduce the dependency of different types of IT systems, reduce the cost of system maintenance and the complexity of the IT system operation, increase the flexibility of the system deployment, and at the same time exclude the barrier of service innovation. Research and application of SOA-based enterprise application systems has become a very important research project at present. Based on SOA, this document designs an enterprise e-business application model and realizes a flexible and expandable e-business platform.

  2. Molecular characterization and volatility evolution of α-pinene ozonolysis SOA during isothermal evaporations

    Science.gov (United States)

    D'Ambro, E.; Schobesberger, S.; Lopez-Hilfiker, F.; Shilling, J. E.; Lee, B. H.; Thornton, J. A.

    2017-12-01

    α-Pinene (C10H16), the most abundantly emitted monoterpene, is a large contributor to global biogenic secondary organic aerosol (SOA) budgets due to its high SOA yields upon oxidation. We probe the volatility and evaporation behavior upon dilution of α-pinene SOA to further our understanding of the nascent volatility distribution, viscosity, and how these evolve in time absent photochemical oxidation. We present molecular composition measurements of the gas and particle phases of α-pinene ozonolysis SOA formed at 0% and 50% relative humidity (RH), followed by room-temperature evaporation in ultra-high purity N2 humidified to 20-90% RH. Experiments were performed in the Pacific Northwest National Laboratory 10.6 m3 and the University of Washington 0.7 m3 environmental chambers utilizing a Filter Inlet for Gases and AEROsols (FIGAERO) coupled to a high-resolution time of flight chemical ionization mass spectrometer utilizing iodide adduct ionization. We present novel insights into the total mass that evaporates as a function of time from 10 min to 24 hours without heating, the molecular speciation of the evaporate, as well as the effective volatility and composition of the SOA mass remaining. Consistent with previous studies, we find two stages of evaporation: a rapid loss of a large portion of the total signal over the course of ≤3 hours, followed by a stage of much slower evaporation over the proceeding 21 hours. Varying the RH of formation effects evaporation rate on timescales ≤3 hours, however the mass fraction remaining after 24 hours converges to 30-50% under all formation and evaporation RHs. We simulate the evaporation behavior and remaining fractions desorbed via temperature programmed thermal desorption to derive effective saturation vapor concentrations, mass accommodation coefficients, and rates of chemical evolution producing both higher and lower volatility components during the evaporation time period.

  3. Virtual Reality in Psychology

    Science.gov (United States)

    Foreman, Nigel

    2009-01-01

    The benefits of using virtual environments (VEs) in psychology arise from the fact that movements in virtual space, and accompanying perceptual changes, are treated by the brain in much the same way as those in equivalent real space. The research benefits of using VEs, in areas of psychology such as spatial learning and cognition, include…

  4. REST SOA Orchestration and BPM Platforms

    Directory of Open Access Journals (Sweden)

    Octavian DOSPINESCU

    2017-01-01

    Full Text Available BPM initiatives and SOA approaches emerged and developed as distinct efforts although they could be perceived as the two sides of the same coin in the context of online business and information systems. Thus, inherently, their modeling perspectives met (or collided and generated some frameworks and languages like SOAML or SOAMF. Starting from these standards and initiatives we will propose a methodological approach that could lead to a feasible implementation of web service integration in a formal Business Process context.

  5. Secure virtualization: benefits, risks and constraints

    CSIR Research Space (South Africa)

    Carroll, M

    2011-05-01

    Full Text Available Cloud computing is changing the IT delivery model to provide on-demand self-service access to a shared pool of computing resources (physical and virtual) via broad network access to offer reduced costs, scalability, flexibility, capacity utilization...

  6. The early benefits of a problem-based approach to teaching social inclusion using an online virtual town.

    Science.gov (United States)

    Beadle, Mary; Santy, Julie

    2008-05-01

    This article describes the delivery of a core pre-registration nursing and midwifery module centred on social inclusion. The module was previously delivered using a classroom-based problem-based learning approach. Difficulties with this approach led to changes to the module and its delivery. Logistic issues encouraged the module team to implement a blended learning approach using a virtual town to facilitate online learning and discussion activities. The paper describes and discusses the use of online learning technology to support student nurses and midwives. It highlights the benefits of this approach and outlines some of the experiences of the students including their evaluation of the virtual town. There is also an examination of some of the practical and theoretical issues related to both problem-based learning, online working and using a virtual town to support learning. This article outlines the approach taken and its implications.

  7. Using SOA Patterns to promote understanding across disciplines

    Science.gov (United States)

    Patterson, A.

    2012-04-01

    The NETMAR consortium is building an open service network for marine environmental data by combining expertise from Ireland, France, the UK and Norway in disciplines such as Semantics, Software Engineering, UI Programming and Service Orchestration. Through the International Coastal Atlas Network, it engages user groups from Europe, Africa, Asia and the Americas. In doing so, it faces challenges in bringing these disciplines and groups together in a way that makes them greater than the sum of their parts. Service Oriented Architecture has been successfully applied in many cases to help build useful systems across organisational and geographic boundaries in order to expose diverse capabilities which can function together through a mutual exchange of value. This should make it ideally suited to a distributed decision making environment without centralised command and control. In theory, SOA should facilitate the building of global and complex infrastructures and the integration of information systems characterized by diverse protocols and interfaces,and with different data policies and security levels. The presentation will discuss a number of approaches used by NETMAR to bring the theory of SOA to bear in a useful way while maintaining the emphasis on keeping multi-disciplinary domain expertise as the primary driver of the project. It will discuss three approaches used: . Populating one or more standard reference models . Trade-off analysis based on business drivers and quality attributes . Documenting design reuse in the form of patterns. The three approaches will be compared in terms of how they succeed in bringing 'just enough' service architecture knowledge into the project. We discuss how the approaches can interact and complement each other. Finally, we present a number of SOA patterns identified as being relevant to NETMAR and explain why they are felt to be particularly effective in gaining consensus on how to build the NETMAR system of systems.

  8. Transforming Functional Requirements from UML into BPEL to Efficiently Develop SOA-Based Systems

    Science.gov (United States)

    Vemulapalli, Anisha; Subramanian, Nary

    The intended behavior of any system such as services, tasks or functions can be captured by functional requirements of the system. As our dependence on online services has grown steadily, the web applications are being developed employing the SOA. BPEL4WS provides a means for expressing functional requirements of an SOA-based system by providing constructs to capture business goals and objectives for the system. In this paper we propose an approach for transforming user-centered requirements captured using UML into a corresponding BPEL specification, where the business processes are captured by means of use-cases from which UML sequence diagrams and activity diagrams are extracted. Subsequently these UML models are mapped to BPEL specifications that capture the essence of the initial business requirements to develop the SOA-based system by employing CASE tools. A student housing system is used as a case study to illustrate this approach and the system is validated using NetBeans.

  9. Studi Kasus Implementasi Service Oriented Architecture (SOA di Credit Suisse

    Directory of Open Access Journals (Sweden)

    Sartika Kurniali

    2013-12-01

    Full Text Available Credit Suisse Group (CSG is a leading company engaged in global financial services. At the end of 90s IT infrastructure complexity of Credit Suisse has reached a critical situation. The existing IT infrastructure is nolonger able to support the required business functionality. This leads to the introduction of an integrated architecture based on Service-Oriented Architecture (SOA. The purpose of this study is to learn how Credit Suisse successfully implements SOA both on a technical and organizational level. Analyses were performed by processing factual and reference data acquired. From the research, the successful implementation is due to clarity of interface, clarity of process, management commitment, and solid technology. Their success does not come easily since they also face obstacles and conflicts on the implementation.

  10. Reduction of pattern effects in SOA-based all-optical switches by using cross-gain modulated holding signal

    DEFF Research Database (Denmark)

    Bischoff, Svend; Mørk, Jesper

    2002-01-01

    The effective carrier lifetime of SOAs is typically shortened by an intense Continuous Wave (CW) holding signal. However, the SOA gain is reduced by the holding signal resulting in smaller gain and refractive index changes induced by the data signal. Accordingly, an optimum exists for the CW...... and data signal power. Here, we demonstrate that the modulation bandwidth (amplitude jitter) is significantly improved (reduced) by replacing the CW holding beam with a signal, which is low-pass filtered and inverted with respect to the data signal. Such a holding beam can be generated by XGM WC in an SOA......, and reduces the fluctuations of the total energy injected into the interferometer within a bit-slot. Thus, we demonstrate a technique for reducing pattern effects in SOAs by employing a partially inverted holding beam. The method should be useful for increasing the data rates of all-optical switches....

  11. The Optimal Configuration Scheme of the Virtual Power Plant Considering Benefits and Risks of Investors

    Directory of Open Access Journals (Sweden)

    Jingmin Wang

    2017-07-01

    Full Text Available A virtual power plant (VPP is a special virtual unit that integrates various distributed energy resources (DERs distributed in the generation and consumption sides. The optimal configuration scheme of the VPP needs to break the geographical restrictions to make full use of DERs, considering the uncertainties. First, the components of the DERs and the structure of the VPP are briefly introduced. Next, the cubic exponential smoothing method is adopted to predict the VPP load requirement. Finally, the optimal configuration of the DER capacities inside the VPP is calculated by using portfolio theory and genetic algorithms (GA. The results show that the configuration scheme can optimize the DER capacities considering uncertainties, guaranteeing economic benefits of investors, and fully utilizing the DERs. Therefore, this paper provides a feasible reference for the optimal configuration scheme of the VPP from the perspective of investors.

  12. Monoterpene oxidation in an oxidative flow reactor: SOA yields and the relationship between bulk gas-phase properties and organic aerosol growth

    Science.gov (United States)

    Friedman, B.; Link, M.; Farmer, D.

    2016-12-01

    We use an oxidative flow reactor (OFR) to determine the secondary organic aerosol (SOA) yields of five monoterpenes (alpha-pinene, beta-pinene, limonene, sabinene, and terpinolene) at a range of OH exposures. These OH exposures correspond to aging timescales of a few hours to seven days. We further determine how SOA yields of beta-pinene and alpha-pinene vary as a function of seed particle type (organic vs. inorganic) and seed particle mass concentration. We hypothesize that the monoterpene structure largely accounts for the observed variance in SOA yields for the different monoterpenes. We also use high-resolution time-of-flight chemical ionization mass spectrometry to calculate the bulk gas-phase properties (O:C and H:C) of the monoterpene oxidation systems as a function of oxidant concentrations. Bulk gas-phase properties can be compared to the SOA yields to assess the capability of the precursor gas-phase species to inform the SOA yields of each monoterpene oxidation system. We find that the extent of oxygenated precursor gas-phase species corresponds to SOA yield.

  13. A collaborative computer auditing system under SOA-based conceptual model

    Science.gov (United States)

    Cong, Qiushi; Huang, Zuoming; Hu, Jibing

    2013-03-01

    Some of the current challenges of computer auditing are the obstacles to retrieving, converting and translating data from different database schema. During the last few years, there are many data exchange standards under continuous development such as Extensible Business Reporting Language (XBRL). These XML document standards can be used for data exchange among companies, financial institutions, and audit firms. However, for many companies, it is still expensive and time-consuming to translate and provide XML messages with commercial application packages, because it is complicated and laborious to search and transform data from thousands of tables in the ERP databases. How to transfer transaction documents for supporting continuous auditing or real time auditing between audit firms and their client companies is a important topic. In this paper, a collaborative computer auditing system under SOA-based conceptual model is proposed. By utilizing the widely used XML document standards and existing data transformation applications developed by different companies and software venders, we can wrap these application as commercial web services that will be easy implemented under the forthcoming application environments: service-oriented architecture (SOA). Under the SOA environments, the multiagency mechanism will help the maturity and popularity of data assurance service over the Internet. By the wrapping of data transformation components with heterogeneous databases or platforms, it will create new component markets composed by many software vendors and assurance service companies to provide data assurance services for audit firms, regulators or third parties.

  14. Maintenance Research in SOA Towards a Standard Case Study

    NARCIS (Netherlands)

    Espinha, T.; Chen, C.; Zaidman, A.E.; Gross, H.G.

    2012-01-01

    Preprint of paper published in: 16th European Conference on Software Maintenance and Reengineering (CSMR), 27-30 March 2012; doi:10.1109/CSMR.2012.49 Maintenance research in the context of Service Oriented Architecture (SOA) is currently lacking a suitable standard case study that can be used by

  15. Volatile and intermediate volatility organic compounds in suburban Paris: variability, origin and importance for SOA formation

    International Nuclear Information System (INIS)

    Ait-Helal, W.; Borbon, A.; Beekmann, M.; Doussin, J.F.; Durand-Jolibois, R.; Grand, N.; Michoud, V.; Miet, K.; Perrier, S.; Siour, G.; Zapf, P.; Sauvage, S.; Fronval, I.; Leonardis, T.; Locoge, N.; Gouw, J.A. de; Colomb, A.; Gros, V.; Lopez, M.

    2014-01-01

    Measurements of gaseous and particulate organic carbon were performed during the MEGAPOLI experiments, in July 2009 and January-February 2010, at the SIRTA observatory in suburban Paris. Measurements comprise primary and secondary volatile organic compounds (VOCs), of both anthropogenic and biogenic origins, including C12-C16 n-alkanes of intermediate volatility (IVOCs), suspected to be efficient precursors of secondary organic aerosol (SOA). The time series of gaseous carbon are generally consistent with times series of particulate organic carbon at regional scale, and are clearly affected by meteorology and air mass origin. Concentration levels of anthropogenic VOCs in urban and suburban Paris were surprisingly low (2-963 ppt) compared to other mega-cities worldwide and to rural continental sites. Urban enhancement ratios of anthropogenic VOC pairs agree well between the urban and suburban Paris sites, showing the regional extent of anthropogenic sources of similar composition. Contrary to other primary anthropogenic VOCs (aromatics and alkanes), IVOCs showed lower concentrations in winter (≤ 5 ppt) compared to summer (13-27 ppt), which cannot be explained by the gas-particle partitioning theory. Higher concentrations of most oxygenated VOCs in winter (18-5984 ppt) suggest their dominant primary anthropogenic origin. The respective role of primary anthropogenic gaseous compounds in regional SOA formation was investigated by estimating the SOA mass concentration expected from the anthropogenic VOCs and IVOCs (I/VOCs) measured at SIRTA. From an integrated approach based on emission ratios and SOA yields, 38% of the SOA measured at SIRTA is explained by the measured concentrations of I/VOCs, with a 2% contribution by C12-C16 n-alkane IVOCs. From the results of an alternative time-resolved approach, the average IVOC contribution to SOA formation is estimated to be 7 %, which is half of the average contribution of the traditional aromatic compounds (15 %). Both

  16. Novel anti-jamming technique for OCDMA network through FWM in SOA based wavelength converter

    Science.gov (United States)

    Jyoti, Vishav; Kaler, R. S.

    2013-06-01

    In this paper, we propose a novel anti-jamming technique for optical code division multiple access (OCDMA) network through four wave mixing (FWM) in semiconductor optical amplifier (SOA) based wavelength converter. OCDMA signal can be easily jammed with high power jamming signal. It is shown that wavelength conversion through four wave mixing in SOA has improved capability of jamming resistance. It is observed that jammer has no effect on OCDMA network even at high jamming powers by using the proposed technique.

  17. Indoor transient SOA formation from ozone + α-pinene reactions: Impacts of air exchange and initial product concentrations, and comparison to limonene ozonolysis

    Science.gov (United States)

    Youssefi, Somayeh; Waring, Michael S.

    2015-07-01

    The ozonolysis of reactive organic gases (ROG), e.g. terpenes, generates secondary organic aerosol (SOA) indoors. The SOA formation strength of such reactions is parameterized by the aerosol mass fraction (AMF), a.k.a. SOA yield, which is the mass ratio of generated SOA to oxidized ROG. AMFs vary in magnitude both among and for individual ROGs. Here, we quantified dynamic SOA formation from the ozonolysis of α-pinene with 'transient AMFs,' which describe SOA formation due to pulse emission of a ROG in an indoor space with air exchange, as is common when consumer products are intermittently used in ventilated buildings. We performed 19 experiments at low, moderate, and high (0.30, 0.52, and 0.94 h-1, respectively) air exchange rates (AER) at varying concentrations of initial reactants. Transient AMFs as a function of peak SOA concentrations ranged from 0.071 to 0.25, and they tended to increase as the AER and product of the initial reactant concentrations increased. Compared to our similar research on limonene ozonolysis (Youssefi and Waring, 2014), for which formation strength was driven by secondary ozone reactions, the AER impact for α-pinene was opposite in direction and weaker, while the initial reactant product impact was in the same direction but stronger for α-pinene than for limonene. Linear fits of AMFs for α-pinene ozonolysis as a function of the AER and initial reactant concentrations are provided so that future indoor models can predict SOA formation strength.

  18. SOA Formation Potential of Emissions from Soil and Leaf Litter

    Science.gov (United States)

    Faiola, C. L.; Vanderschelden, G. S.; Wen, M.; Cobos, D. R.; Jobson, B. T.; VanReken, T. M.

    2013-12-01

    In the United States, emissions of volatile organic compounds (VOCs) from natural sources exceed all anthropogenic sources combined. VOCs participate in oxidative chemistry in the atmosphere and impact the concentrations of ozone and particulate material. The formation of secondary organic aerosol (SOA) is particularly complex and is frequently underestimated using state-of-the-art modeling techniques. We present findings that suggest emissions of important SOA precursors from soil and leaf litter are higher than current inventories would suggest, particularly under conditions typical of Fall and Spring. Soil and leaf litter samples were collected at Big Meadow Creek from the University of Idaho Experimental Forest. The dominant tree species in this area of the forest are ponderosa pine, Douglas-fir, and western larch. Samples were transported to the laboratory and housed within a 0.9 cubic meter Teflon dynamic chamber where VOC emissions were continuously monitored with a GC-FID-MS and PTR-MS. Aerosol was generated from soil and leaf litter emissions by pumping the emissions into a 7 cubic meter Teflon aerosol growth chamber where they were oxidized with ozone in the absence of light. The evolution of particle microphysical and chemical characteristics was monitored over the following eight hours. Particle size distribution and chemical composition were measured with a SMPS and HR-ToF-AMS respectively. Monoterpenes dominated the emission profile with emission rates up to 283 micrograms carbon per meter squared per hour. The dominant monoterpenes emitted were beta-pinene, alpha-pinene, and delta-3-carene in descending order. The composition of the SOA produced was similar to biogenic SOA formed from oxidation of ponderosa pine emissions and alpha-pinene. Measured soil/litter monoterpene emission rates were compared with modeled canopy emissions. Results suggest that during fall and spring when tree emissions are lower, monoterpene emissions within forests may be

  19. Preparing Students to Take SOA/CAS Exam FM/2

    Science.gov (United States)

    Marchand, Richard J.

    2014-01-01

    This paper provides suggestions for preparing students to take the actuarial examination on financial mathematics, SOA/CAS Exam FM/2. It is based on current practices employed at Slippery Rock University, a small public liberal arts university. Detailed descriptions of our Theory of Interest course and subsequent Exam FM/2 prep course are provided…

  20. The Impact of Service Oriented Architecture (SOA) on IT Auditing

    NARCIS (Netherlands)

    F.S. Chotkan (Farida)

    2010-01-01

    textabstractExecutive Summary This study investigates the impact that SOA has on IT Auditing. Service-oriented architecture emerged as new technology in literature since 1996 and it has been a hype in the Netherlands between 2006 and 2007. The development of new technologies is faster than the

  1. Semivolatile POA and parameterized total combustion SOA in CMAQv5.2: impacts on source strength and partitioning

    Directory of Open Access Journals (Sweden)

    B. N. Murphy

    2017-09-01

    Full Text Available Mounting evidence from field and laboratory observations coupled with atmospheric model analyses shows that primary combustion emissions of organic compounds dynamically partition between the vapor and particulate phases, especially as near-source emissions dilute and cool to ambient conditions. The most recent version of the Community Multiscale Air Quality model version 5.2 (CMAQv5.2 accounts for the semivolatile partitioning and gas-phase aging of these primary organic aerosol (POA compounds consistent with experimentally derived parameterizations. We also include a new surrogate species, potential secondary organic aerosol from combustion emissions (pcSOA, which provides a representation of the secondary organic aerosol (SOA from anthropogenic combustion sources that could be missing from current chemical transport model predictions. The reasons for this missing mass likely include the following: (1 unspeciated semivolatile and intermediate volatility organic compound (SVOC and IVOC, respectively emissions missing from current inventories, (2 multigenerational aging of organic vapor products from known SOA precursors (e.g., toluene, alkanes, (3 underestimation of SOA yields due to vapor wall losses in smog chamber experiments, and (4 reversible organic compounds–water interactions and/or aqueous-phase processing of known organic vapor emissions. CMAQ predicts the spatially averaged contribution of pcSOA to OA surface concentrations in the continental United States to be 38.6 and 23.6 % in the 2011 winter and summer, respectively. Whereas many past modeling studies focused on a particular measurement campaign, season, location, or model configuration, we endeavor to evaluate the model and important uncertain parameters with a comprehensive set of United States-based model runs using multiple horizontal scales (4 and 12 km, gas-phase chemical mechanisms, and seasons and years. The model with representation of semivolatile POA

  2. On the Risk Management and Auditing of SOA Based Business Processes

    Science.gov (United States)

    Orriens, Bart; Heuvel, Willem-Jan V./D.; Papazoglou, Mike

    SOA-enabled business processes stretch across many cooperating and coordinated systems, possibly crossing organizational boundaries, and technologies like XML and Web services are used for making system-to-system interactions commonplace. Business processes form the foundation for all organizations, and as such, are impacted by industry regulations. This requires organizations to review their business processes and ensure that they meet the compliance standards set forth in legislation. In this paper we sketch a SOA-based service risk management and auditing methodology including a compliance enforcement and verification system that assures verifiable business process compliance. This is done on the basis of a knowledge-based system that allows integration of internal control systems into business processes conform pre-defined compliance rules, monitor both the normal process behavior and those of the control systems during process execution, and log these behaviors to facilitate retrospective auditing.

  3. VOC species and emission inventory from vehicles and their SOA formation potentials estimation in Shanghai, China

    Science.gov (United States)

    Huang, C.; Wang, H. L.; Li, L.; Wang, Q.; Lu, Q.; de Gouw, J. A.; Zhou, M.; Jing, S. A.; Lu, J.; Chen, C. H.

    2015-10-01

    Volatile organic compound (VOC) species from vehicle exhausts and gas evaporation were investigated by chassis dynamometer and on-road measurements of nine gasoline vehicles, seven diesel vehicles, five motorcycles, and four gas evaporation samples. The secondary organic aerosol (SOA) mass yields of gasoline, diesel, motorcycle exhausts, and gas evaporation were estimated based on the mixing ratio of measured C2-C12 VOC species and inferred carbon number distributions. High aromatic contents were measured in gasoline exhausts and contributed comparatively more SOA yield. A vehicular emission inventory was compiled based on a local survey of on-road traffic in Shanghai and real-world measurements of vehicle emission factors from previous studies in the cities of China. The inventory-based vehicular organic aerosol (OA) productions to total CO emissions were compared with the observed OA to CO concentrations (ΔOA / ΔCO) in the urban atmosphere. The results indicate that vehicles dominate the primary organic aerosol (POA) emissions and OA production, which contributed about 40 and 60 % of OA mass in the urban atmosphere of Shanghai. Diesel vehicles, which accounted for less than 20 % of vehicle kilometers of travel (VKT), contribute more than 90 % of vehicular POA emissions and 80-90 % of OA mass derived by vehicles in urban Shanghai. Gasoline exhaust could be an important source of SOA formation. Tightening the limit of aromatic content in gasoline fuel will be helpful to reduce its SOA contribution. Intermediate-volatile organic compounds (IVOCs) in vehicle exhausts greatly contribute to SOA formation in the urban atmosphere of China. However, more experiments need to be conducted to determine the contributions of IVOCs to OA pollution in China.

  4. Aqueous-phase mechanism for secondary organic aerosol formation from isoprene: application to the southeast United States and co-benefit of SO2 emission controls

    Directory of Open Access Journals (Sweden)

    E. A. Marais

    2016-02-01

    anthropogenic emissions of 34 % for NOx (leading to a 7 % increase in isoprene SOA and 48 % for SO2 (35 % decrease in isoprene SOA. Reducing SO2 emissions decreases sulfate and isoprene SOA by a similar magnitude, representing a factor of 2 co-benefit for PM2.5 from SO2 emission controls.

  5. VOC species and emission inventory from vehicles and their SOA formation potentials estimation in Shanghai, China

    OpenAIRE

    C. Huang; H. L. Wang; L. Li; Q. Wang; Q. Lu; J. A. de Gouw; M. Zhou; S. A. Jing; J. Lu; C. H. Chen

    2015-01-01

    VOC species from vehicle exhaust and gas evaporation were investigated by chassis dynamometer and on-road measurements of 9 gasoline vehicles, 7 diesel vehicles, 5 motorcycles, and 4 gas evaporation samples. The SOA mass yields of gasoline, diesel, motorcycle exhausts, and gas evaporation were calculated based on the mixing ratio of individual VOC species. The SOA mass yields of gasoline and motorcycle exhaust were similar to the results of the published smo...

  6. SOA from limonene: role of NO3 in its generation and degradation

    Directory of Open Access Journals (Sweden)

    R. Tillmann

    2011-04-01

    Full Text Available The formation of organic nitrates and secondary organic aerosol (SOA were monitored during the NO3 + limonene reaction in the atmosphere simulation chamber SAPHIR at Research Center Jülich. The 24-h run began in a purged, dry, particle-free chamber and comprised two injections of limonene and oxidants, such that the first experiment measured SOA yield in the absence of seed aerosol, and the second experiment yields in the presence of 10 μg m−3 seed organic aerosol. After each injection, two separate increases in aerosol mass were observed, corresponding to sequential oxidation of the two limonene double bonds. Analysis of the measured NO3, limonene, product nitrate concentrations, and aerosol properties provides mechanistic insight and constrains rate constants, branching ratios and vapor pressures of the products. The organic nitrate yield from NO3 + limonene is ≈30%. The SOA mass yield was observed to be 25–40%. The first injection is reproduced by a kinetic model. PMF analysis of the aerosol composition suggests that much of the aerosol mass results from combined oxidation by both O3 and NO3, e.g., oxidation of NO3 + limonene products by O3. Further, later aerosol nitrate mass seems to derive from heterogeneous uptake of NO3 onto unreacted aerosol alkene.

  7. Virtualization of work in global supply chains

    Directory of Open Access Journals (Sweden)

    Sabina Wyrwich-Płotka

    2016-12-01

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

  8. ROLE OF VIRTUALIZATION IN CLOUD COMPUTING

    OpenAIRE

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

    2017-01-01

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

  9. Sources, Properties, Aging, and Anthropogenic Influences on OA and SOA over the Southeast US and the Amazon duing SOAS, DC3, SEAC4RS, and GoAmazon

    Science.gov (United States)

    The SE US and the Amazon have large sources of biogenic VOCs, varying anthropogenic pollution impacts, and often poor organic aerosol (OA) model performance. Recent results on the sources, properties, aging, and impact of anthropogenic pollution on OA and secondary OA (SOA) over ...

  10. Slow and fast light in SOA-EA structures for phased-array antennas

    DEFF Research Database (Denmark)

    Sales, S.; Öhman, Filip; Bermejo, A.

    We present an SOA-EA structure for controlling the phase and amplitude of optically fed phased-array antennas. Phase shifts of 40 degrees are obtained through slow and fast light effects by changing only the reverse voltage....

  11. Virtual worlds: a new frontier for nurse education?

    Science.gov (United States)

    Green, Janet; Wyllie, Aileen; Jackson, Debra

    2014-01-01

    Virtual worlds have the potential to offer nursing students social networking and, learning, opportunities through the use of collaborative and immersive learning. If nursing educators, are to stay, abreast of contemporary learning opportunities an exploration of the potential benefits of, virtual, worlds and their possibilities is needed. Literature was sourced that explored virtual worlds, and their, use in education, but nursing education specifically. It is clear that immersive learning has, positive, benefits for nursing, however the best way to approach virtual reality in nursing education, has yet to, be ascertained.

  12. Virtual reality in pediatric psychology

    OpenAIRE

    Parsons, T. D.; Riva, G.; Parsons, S. J.; Mantovani, F.; Newbutt, N.; Lin, L.; Venturini, E.; Hall, T.

    2017-01-01

    Virtual reality technologies allow for controlled simulations of affectively engaging background narratives. These virtual environments offer promise for enhancing emotionally relevant experiences and social interactions. Within this context virtual reality can allow instructors, therapists, neuropsychologists, and service providers to offer safe, repeatable, and diversifiable interventions that can benefit assessments and learning in both typically developing children and children with disab...

  13. Secondary Organic Aerosol Formation from Acetylene (C2H2: seed effect on SOA yields due to organic photochemistry in the aerosol aqueous phase

    Directory of Open Access Journals (Sweden)

    P. J. Ziemann

    2009-03-01

    Full Text Available The lightest Non Methane HydroCarbon (NMHC, i.e., acetylene (C2H2 is found to form secondary organic aerosol (SOA. Contrary to current belief, the number of carbon atoms, n, for a NMHC to act as SOA precursor is lowered to n=2 here. The OH-radical initiated oxidation of C2H2 forms glyoxal (CHOCHO as the highest yield product, and >99% of the SOA from C2H2 is attributed to CHOCHO. SOA formation from C2H2 and CHOCHO was studied in a photochemical and a dark simulation chamber. Further, the experimental conditions were varied with respect to the chemical composition of the seed aerosols, mild acidification with sulphuric acid (SA, 3SOA source from CHOCHO, while seeds containing amino acids (AA and/or SA showed among the lowest of all YSOA values, and largely suppress the photochemical enhancement on the rate of CHOCHO uptake. Our results give first evidence for the importance of heterogeneous photochemistry of CHOCHO in SOA formation, and identify a potential bias in the currently available YSOA data for other SOA precursor NMHCs. We demonstrate that SOA formation via the aqueous phase is not limited to cloud droplets, but proceeds also in the absence of clouds, i.e., does not stop once a cloud droplet evaporates. Atmospheric models need to be expanded to include SOA formation from WSOC photochemistry of CHOCHO, and possibly other α-dicarbonyls, in aqueous aerosols.

  14. 85 km Long Reach PON System Using a Reflective SOA-EA Modulator and Distributed Raman Fiber Amplification

    DEFF Research Database (Denmark)

    Tafur Monroy, Idelfonso; Öhman, Filip; Yvind, Kresten

    2006-01-01

    We report on a bidirectional 85 km long reach PON system supported by distributed fiber Raman amplification with a record 7.5 Gb/s remote carrier modulated upstream signal by employing a reflective SOA-EA monolithically integrated circuit......We report on a bidirectional 85 km long reach PON system supported by distributed fiber Raman amplification with a record 7.5 Gb/s remote carrier modulated upstream signal by employing a reflective SOA-EA monolithically integrated circuit...

  15. The New Global Information Economy: Implications and Recommendations for Service-Oriented Architectures (SOAs)

    National Research Council Canada - National Science Library

    Bass, Tim; Donahue, William

    2005-01-01

    Service-oriented architecture (SOA), a term often used today in conjunction with net-centric operations, implies that existing and future DoD information capabilities will be engineered to publish product and/or service offerings...

  16. Experimental and theoretical investigation of semiconductor optical amplifier (SOA) based all-optical switches

    DEFF Research Database (Denmark)

    Nielsen, Mads Lønstrup

    2004-01-01

    This thesis analyzes semiconductor optical amplifier (SOA) based all-optical switches experimentally and through numerical simulations. These devices are candidates for optical signal processing functionalities such as wavelength conversion, regeneration, and logic processing in future transparent......, consisting of an SOA and an asymmetric MZI filter, is analyzed in the small-signal regime, and the obtainable modulation bandwidth is expressed analytically. A new optical spectrum approach to small signal analysis is introduced, and is used to assess the bandwidth enhancing effect of different optical...... filters, as well the impact of the filter phase response. Experiments at 40 Gb/s verify the predictions of the small-signal analysis. Wavelength conversion is demonstrated experimentally at 40 Gb/s using a simple filtering-assisted scheme with an ultra-low optical switching energy, and up to 80 Gb...

  17. Design of 10Gbps optical encoder/decoder structure for FE-OCDMA system using SOA and opto-VLSI processors.

    Science.gov (United States)

    Aljada, Muhsen; Hwang, Seow; Alameh, Kamal

    2008-01-21

    In this paper we propose and experimentally demonstrate a reconfigurable 10Gbps frequency-encoded (1D) encoder/decoder structure for optical code division multiple access (OCDMA). The encoder is constructed using a single semiconductor optical amplifier (SOA) and 1D reflective Opto-VLSI processor. The SOA generates broadband amplified spontaneous emission that is dynamically sliced using digital phase holograms loaded onto the Opto-VLSI processor to generate 1D codewords. The selected wavelengths are injected back into the same SOA for amplifications. The decoder is constructed using single Opto-VLSI processor only. The encoded signal can successfully be retrieved at the decoder side only when the digital phase holograms of the encoder and the decoder are matched. The system performance is measured in terms of the auto-correlation and cross-correlation functions as well as the eye diagram.

  18. Managing Virtual Product Development team: A Review

    Directory of Open Access Journals (Sweden)

    Amir Mohammad Colabi

    2014-05-01

    Full Text Available Although there are many potential benefits associated with the use of virtual product development teams, exploiting these benefits requires an appropriate management. Managing virtual product development team is a critical issue as many of these teams fail to accomplish their goals. Review of previous literature shows that body of knowledge in managing virtual product development teams is fragmented and inconsistent. The main objective of this paper is to categorize the previous research on the subject of virtual product development team management in order to integrate the research into a thematic model and to enable recommendations for future research. So, this study reviews and summarizes empirical research in the field, also conceptual and qualitative papers, experiences, reports and explorative case studies. Results show that there are three fields of research in this area, including: Virtual production and Virtual team in Product Development, Managing virtual team in R&D[1] and product development, Managing global virtual product development teams. In order to organize previous studies in this area, a thematic map is proposed which shows the structure and sequence of research. Finally, a comprehensive discussion on the future directions in this field is proposed.

  19. European pharmacy students' experience with virtual patient technology.

    Science.gov (United States)

    Cavaco, Afonso Miguel; Madeira, Filipe

    2012-08-10

    To describe how virtual patients are being used to simulate real-life clinical scenarios in undergraduate pharmacy education in Europe. One hundred ninety-four participants at the 2011 Congress of the European Pharmaceutical Students Association (EPSA) completed an exploratory cross-sectional survey instrument. Of the 46 universities and 23 countries represented at the EPSA Congress, only 12 students from 6 universities in 6 different countries reported having experience with virtual patient technology. The students were satisfied with the virtual patient technology and considered it more useful as a teaching and learning tool than an assessment tool. Respondents who had not used virtual patient technology expressed support regarding its potential benefits in pharmacy education. French and Dutch students were significantly less interested in virtual patient technology than were their counterparts from other European countries. The limited use of virtual patients in pharmacy education in Europe suggests the need for initiatives to increase the use of virtual patient technology and the benefits of computer-assisted learning in pharmacy education.

  20. Teleworking in South Africa: Employee benefits and challenges

    OpenAIRE

    Nicholas Baard; Adèle Thomas

    2010-01-01

    Orientation: Virtual working arrangements present possible benefits to organisations and their employees. However, in South Africa, few organisations have implemented teleworking as a specific form of virtual work. The benefits and challenges to teleworkers are therefore largely unknown. Research purpose: The present study aimed to identify employee perceptions of personal benefits and challenges of teleworking. Motivation for the study: The study sought to contribute insights for S...

  1. Aqueous-phase oxidation of green leaf volatiles by hydroxyl radical as a source of SOA: Product identification from methyl jasmonate and methyl salicylate oxidation

    Science.gov (United States)

    Hansel, Amie K.; Ehrenhauser, Franz S.; Richards-Henderson, Nicole K.; Anastasio, Cort; Valsaraj, Kalliat T.

    2015-02-01

    Green leaf volatiles (GLVs) are a group of biogenic volatile organic compounds (BVOCs) released into the atmosphere by vegetation. BVOCs produce secondary organic aerosol (SOA) via gas-phase reactions, but little is known of their aqueous-phase oxidation as a source of SOA. GLVs can partition into atmospheric water phases, e.g., fog, mist, dew or rain, and be oxidized by hydroxyl radicals (˙OH). These reactions in the liquid phase also lead to products that have higher molecular weights, increased polarity, and lower vapor pressures, ultimately forming SOA after evaporation of the droplet. To examine this process, we investigated the aqueous, ˙OH-mediated oxidation of methyl jasmonate (MeJa) and methyl salicylate (MeSa), two GLVs that produce aqueous-phase SOA. High performance liquid chromatography/electrospray ionization mass spectrometry (HPLC-ESI-MS) was used to monitor product formation. The oxidation products identified exhibit higher molecular mass than their parent GLV due to either dimerization or the addition of oxygen and hydroxyl functional groups. The proposed structures of potential products are based on mechanistic considerations combined with the HPLC/ESI-MS data. Based on the structures, the vapor pressure and the Henry's law constant were estimated with multiple methods (SPARC, SIMPOL, MPBPVP, Bond and Group Estimations). The estimated vapor pressures of the products identified are significantly (up to 7 orders of magnitude) lower than those of the associated parent compounds, and therefore, the GLV oxidation products may remain as SOA after evaporation of the water droplet. The contribution of the identified oxidation products to SOA formation is estimated based on measured HPLC-ESI/MS responses relative to previous aqueous SOA mass yield measurements.

  2. Evaluating the impact of new observational constraints on P-S/IVOC emissions, multi-generation oxidation, and chamber wall losses on SOA modeling for Los Angeles, CA

    Science.gov (United States)

    Ma, Prettiny K.; Zhao, Yunliang; Robinson, Allen L.; Worton, David R.; Goldstein, Allen H.; Ortega, Amber M.; Jimenez, Jose L.; Zotter, Peter; Prévôt, André S. H.; Szidat, Sönke; Hayes, Patrick L.

    2017-08-01

    Secondary organic aerosol (SOA) is an important contributor to fine particulate matter (PM) mass in polluted regions, and its modeling remains poorly constrained. A box model is developed that uses recently published literature parameterizations and data sets to better constrain and evaluate the formation pathways and precursors of urban SOA during the CalNex 2010 campaign in Los Angeles. When using the measurements of intermediate-volatility organic compounds (IVOCs) reported in Zhao et al. (2014) and of semi-volatile organic compounds (SVOCs) reported in Worton et al. (2014) the model is biased high at longer photochemical ages, whereas at shorter photochemical ages it is biased low, if the yields for VOC oxidation are not updated. The parameterizations using an updated version of the yields, which takes into account the effect of gas-phase wall losses in environmental chambers, show model-measurement agreement at longer photochemical ages, even though some low bias at short photochemical ages still remains. Furthermore, the fossil and non-fossil carbon split of urban SOA simulated by the model is consistent with measurements at the Pasadena ground site. Multi-generation oxidation mechanisms are often employed in SOA models to increase the SOA yields derived from environmental chamber experiments in order to obtain better model-measurement agreement. However, there are many uncertainties associated with these aging mechanisms. Thus, SOA formation in the model is compared to data from an oxidation flow reactor (OFR) in order to constrain SOA formation at longer photochemical ages than observed in urban air. The model predicts similar SOA mass at short to moderate photochemical ages when the aging mechanisms or the updated version of the yields for VOC oxidation are implemented. The latter case has SOA formation rates that are more consistent with observations from the OFR though. Aging mechanisms may still play an important role in SOA chemistry, but the

  3. Development and evaluation of SOA-based AAL services in real-life environments: a case study and lessons learned.

    Science.gov (United States)

    Stav, Erlend; Walderhaug, Ståle; Mikalsen, Marius; Hanke, Sten; Benc, Ivan

    2013-11-01

    The proper use of ICT services can support seniors in living independently longer. While such services are starting to emerge, current proprietary solutions are often expensive, covering only isolated parts of seniors' needs, and lack support for sharing information between services and between users. For developers, the challenge is that it is complex and time consuming to develop high quality, interoperable services, and new techniques are needed to simplify the development and reduce the development costs. This paper provides the complete view of the experiences gained in the MPOWER project with respect to using model-driven development (MDD) techniques for Service Oriented Architecture (SOA) system development in the Ambient Assisted Living (AAL) domain. To address this challenge, the approach of the European research project MPOWER (2006-2009) was to investigate and record the user needs, define a set of reusable software services based on these needs, and then implement pilot systems using these services. Further, a model-driven toolchain covering key development phases was developed to support software developers through this process. Evaluations were conducted both on the technical artefacts (methodology and tools), and on end user experience from using the pilot systems in trial sites. The outcome of the work on the user needs is a knowledge base recorded as a Unified Modeling Language (UML) model. This comprehensive model describes actors, use cases, and features derived from these. The model further includes the design of a set of software services, including full trace information back to the features and use cases motivating their design. Based on the model, the services were implemented for use in Service Oriented Architecture (SOA) systems, and are publicly available as open source software. The services were successfully used in the realization of two pilot applications. There is therefore a direct and traceable link from the user needs of the

  4. Virtual classroom project

    OpenAIRE

    Gmeiner, Nicholas

    2017-01-01

    This project aims to provide students with disabilities the same in class learning experience through virtual reality technology, 360-degree video capture, and the use of Arduino units. These technologies will be combined to facilitate communication between teachers in physical classrooms with students in virtual classrooms. The goal is to provide a person who is affected by a disability (which makes it hard to be in a traditional classroom) the same benefits of a safe and interactive learnin...

  5. Virtual Reality in Schools: The Ultimate Educational Technology.

    Science.gov (United States)

    Reid, Robert D.; Sykes, Wylmarie

    1999-01-01

    Discusses the use of virtual reality as an educational tool. Highlights include examples of virtual reality in public schools that lead to a more active learning process, simulated environments, integrating virtual reality into any curriculum, benefits to teachers and students, and overcoming barriers to implementation. (LRW)

  6. Simultaneous optical digital half-subtraction and -addition using SOAs and a PPLN waveguide.

    Science.gov (United States)

    McGeehan, John E; Kumar, Saurabh; Willner, Alan E

    2007-04-30

    We demonstrate an optical half-subtracter and half-adder module that performs simultaneous bit-wise subtraction and addition of two 5 Gbit/s RZ data streams. We generate Borrow (/X*Y) and Difference/Sum (X plus sign in circleY, or XOR) outputs using cross-gain modulation (XGM) in two parallel SOAs. Taking advantage of the gain saturation inherent to SOAs, we generate two signals, /X*Y, and X*/Y, and combine them using a passive optical coupler to generate the XOR Difference/Sum output. We use difference-frequency-generation-based lambda-conversion in a PPLN waveguide to generate the Carry (X*Y) output. The PPLN waveguide allows bit-synchronous wavelength shifting, is wide-bandwidth, and offers no intrinsic chirp. Our module uses three active elements to perform simultaneous half-subtraction and addition, and carries a maximum power penalty of 1.0 dB.

  7. Leveraging Virtual Reality for the Benefit of Lunar Exploration

    Science.gov (United States)

    McCandless, R. S.; Burke, E. D.; McGinley, V. T.

    2017-10-01

    Virtual reality (VR) and related technologies will assist scientists with lunar exploration and public engagement. We will present the future exponential impact of VR on lunar activities over the coming decades.

  8. S – C – L triple wavelength superluminescent source based on an ultra-wideband SOA and FBGs

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, H; Zulkifli, M Z; Hassan, N A; Muhammad, F D; Harun, S W [Photonics Research Center (Department of Physics), University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2013-10-31

    We propose and demonstrate a wide-band semiconductor optical amplifier (SOA) based triple-wavelength superluminescent source with the output in the S-, C- and L-band regions. The proposed systems uses an ultra-wideband SOA with an amplification range from 1440 to 1620 nm as the linear gain medium. Three fibre Bragg gratings (FBGs) with centre wavelengths of 1500, 1540 and 1580 nm are used to generate the lasing wavelengths in the S-, Cand L-bands respectively, while a variable optical attenuator is used to finely balance the optical powers of the lasing wavelengths. The ultra-wideband SOA generates an amplified spontaneous emission (ASE) spectrum with a peak power of -33 dBm at the highest SOA drive current, and also demonstrates a down-shift in the centre wavelength of the generated spectrum due to the spatial distribution of the carrier densities. The S-band wavelength is the dominant wavelength at high drive currents, with an output power of -6 dBm as compared to the C- and L-bands, which only have powers of -11 and -10 dBm, respectively. All wavelengths have a high average signal-to-noise ratio more than 60 dB at the highest drive current of 390 mA, and the system also shows a high degree of stability, with power fluctuations of less than 3 dB within 70 min. The proposed system can find many applications where a wide-band and stable laser source is crucial, such as in communications and sensing. (control of laser radiation parameters)

  9. S – C – L triple wavelength superluminescent source based on an ultra-wideband SOA and FBGs

    International Nuclear Information System (INIS)

    Ahmad, H; Zulkifli, M Z; Hassan, N A; Muhammad, F D; Harun, S W

    2013-01-01

    We propose and demonstrate a wide-band semiconductor optical amplifier (SOA) based triple-wavelength superluminescent source with the output in the S-, C- and L-band regions. The proposed systems uses an ultra-wideband SOA with an amplification range from 1440 to 1620 nm as the linear gain medium. Three fibre Bragg gratings (FBGs) with centre wavelengths of 1500, 1540 and 1580 nm are used to generate the lasing wavelengths in the S-, Cand L-bands respectively, while a variable optical attenuator is used to finely balance the optical powers of the lasing wavelengths. The ultra-wideband SOA generates an amplified spontaneous emission (ASE) spectrum with a peak power of -33 dBm at the highest SOA drive current, and also demonstrates a down-shift in the centre wavelength of the generated spectrum due to the spatial distribution of the carrier densities. The S-band wavelength is the dominant wavelength at high drive currents, with an output power of -6 dBm as compared to the C- and L-bands, which only have powers of -11 and -10 dBm, respectively. All wavelengths have a high average signal-to-noise ratio more than 60 dB at the highest drive current of 390 mA, and the system also shows a high degree of stability, with power fluctuations of less than 3 dB within 70 min. The proposed system can find many applications where a wide-band and stable laser source is crucial, such as in communications and sensing. (control of laser radiation parameters)

  10. Leveraging the Publish-Find-Use Paradigm of SOA -- Supporting enterprise collaboration across organisational boundaries

    NARCIS (Netherlands)

    Sapkota, Brahmananda; van Sinderen, Marten J.; Shishkov, Boris

    Service Oriented Architecture (SOA) has been widely recognized as an approach for flexible integration of enterprise applications across organisational boundaries based on service abstractions and Internet standards. Enterprise collaboration and application integration is driven by business

  11. Virtual Reality in Engineering Education: The Future of Creative Learning

    Directory of Open Access Journals (Sweden)

    Abdul-Hadi Ghazi Abulrub

    2011-12-01

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

  12. A reconfigurable all-optical VPN based on XGM effect of SOA in WDM PON

    Science.gov (United States)

    Hu, Xiaofeng; Zhang, Liang; Cao, Pan; Wang, Tao; Su, Yikai

    2010-12-01

    We propose and experimentally demonstrate a reconfigurable all-optical VPN scheme enabling intercommunications among different ONUs in a WDM PON. Reconfiguration is realized by dynamically setting wavelength conversion of optical VPN signal using a SOA in the OLT.

  13. Applications Based on Service-Oriented Architecture (SOA) in the Field of Home Healthcare.

    Science.gov (United States)

    Avila, Karen; Sanmartin, Paul; Jabba, Daladier; Jimeno, Miguel

    2017-07-25

    This article makes a literature review of applications developed in the health industry which are focused on patient care from home and implement a service-oriented (SOA) design in architecture. Throughout this work, the applicability of the concept of Internet of Things (IoT) in the field of telemedicine and health care in general is evaluated. It also performs an introduction to the concept of SOA and its main features, making a small emphasis on safety aspects. As a central theme, the description of different solutions that can be found in the health industry is developed, especially those whose goal is health care at home; the main component of these solutions are body sensor networks. Finally, an analysis of the literature from the perspectives of functionalities, security implementation and semantic interoperability is made to have a better understanding of what has been done and which are probable research paths to be studied in the future.

  14. An agent-based peer-to-peer architecture for semantic discovery of manufacturing services across virtual enterprises

    Science.gov (United States)

    Zhang, Wenyu; Zhang, Shuai; Cai, Ming; Jian, Wu

    2015-04-01

    With the development of virtual enterprise (VE) paradigm, the usage of serviceoriented architecture (SOA) is increasingly being considered for facilitating the integration and utilisation of distributed manufacturing resources. However, due to the heterogeneous nature among VEs, the dynamic nature of a VE and the autonomous nature of each VE member, the lack of both sophisticated coordination mechanism in the popular centralised infrastructure and semantic expressivity in the existing SOA standards make the current centralised, syntactic service discovery method undesirable. This motivates the proposed agent-based peer-to-peer (P2P) architecture for semantic discovery of manufacturing services across VEs. Multi-agent technology provides autonomous and flexible problemsolving capabilities in dynamic and adaptive VE environments. Peer-to-peer overlay provides highly scalable coupling across decentralised VEs, each of which exhibiting as a peer composed of multiple agents dealing with manufacturing services. The proposed architecture utilises a novel, efficient, two-stage search strategy - semantic peer discovery and semantic service discovery - to handle the complex searches of manufacturing services across VEs through fast peer filtering. The operation and experimental evaluation of the prototype system are presented to validate the implementation of the proposed approach.

  15. SOA and EDA: a comparative study - similarities, difference and conceptual guidelines on their usage

    NARCIS (Netherlands)

    Allah Bukhsh, Zaharah; van Sinderen, Marten J.; Singh, Prince Mayurank

    2015-01-01

    Changing business requirements and new technologies trigger the business stakeholders to shift their approach from many small isolated systems to a single connected system. Integration of isolated systems is partially supported by service oriented architecture (SOA) and event driven architecture

  16. Flight Hardware Virtualization for On-Board Science Data Processing

    Data.gov (United States)

    National Aeronautics and Space Administration — Utilize Hardware Virtualization technology to benefit on-board science data processing by investigating new real time embedded Hardware Virtualization solutions and...

  17. Controlling social stress in virtual reality environments

    NARCIS (Netherlands)

    Hartanto, D.; Kampmann, I.L.; Morina, N.; Emmelkamp, P.G.M.; Neerincx, M.A.; Brinkman, W.P.

    2014-01-01

    Virtual reality exposure therapy has been proposed as a viable alternative in the treatment of anxiety disorders, including social anxiety disorder. Therapists could benefit from extensive control of anxiety eliciting stimuli during virtual exposure. Two stimuli controls are studied in this study:

  18. Virtual Studio Practices: Visual Artists, Social Media and Creativity

    Directory of Open Access Journals (Sweden)

    Kylie Budge

    2013-12-01

    Full Text Available Artists’ practices are varied. Two extremes include the need for complete solitude when working and others who seek social environments such as collaborations in communal studio settings. In addition to these real life studio practices new technologies and social media have made it possible for artists to use virtual studio practices in the process of developing creative work. Working virtually offers a range of interesting benefits for creative practice. This article explores the author’s recent experiences in virtual studio practices in light of the literature on this topic and considers the implications for creativity. It highlights five specific benefits in using virtual studio practices and considers possible limitations of working in such a manner. In exploring virtual studio practices and arguing the case for such ways of working, this article contributes to research and understandings about creative practice by discussing one artist’s reflective experience of using virtual studio practices.

  19. Mechanisms leading to oligomers and SOA through aqueous photooxidation: insights from OH radical oxidation of acetic acid and methylglyoxal

    Directory of Open Access Journals (Sweden)

    Y. Tan

    2012-01-01

    Full Text Available Previous experiments have demonstrated that the aqueous OH radical oxidation of methylglyoxal produces low volatility products including pyruvate, oxalate and oligomers. These products are found predominantly in the particle phase in the atmosphere, suggesting that methylglyoxal is a precursor of secondary organic aerosol (SOA. Acetic acid plays a central role in the aqueous oxidation of methylglyoxal and it is a ubiquitous product of gas phase photochemistry, making it a potential "aqueous" SOA precursor in its own right. However, the fate of acetic acid upon aqueous-phase oxidation is not well understood. In this research, acetic acid (20 μM–10 mM was oxidized by OH radicals, and pyruvic acid and methylglyoxal experimental samples were analyzed using new analytical methods, in order to better understand the formation of SOA from acetic acid and methylglyoxal. Glyoxylic, glycolic, and oxalic acids formed from acetic acid and OH radicals. In contrast to the aqueous OH radical oxidation of methylglyoxal, the aqueous OH radical oxidation of acetic acid did not produce succinic acid and oligomers. This suggests that the methylgloxal-derived oligomers do not form through the acid catalyzed esterification pathway proposed previously. Using results from these experiments, radical mechanisms responsible for oligomer formation from methylglyoxal oxidation in clouds and wet aerosols are proposed. The importance of acetic acid/acetate as an SOA precursor is also discussed. We hypothesize that this and similar chemistry is central to the daytime formation of oligomers in wet aerosols.

  20. Laboratory studies of the chemical composition and cloud condensation nuclei (CCN activity of secondary organic aerosol (SOA and oxidized primary organic aerosol (OPOA

    Directory of Open Access Journals (Sweden)

    A. T. Lambe

    2011-09-01

    Full Text Available Secondary organic aerosol (SOA and oxidized primary organic aerosol (OPOA were produced in laboratory experiments from the oxidation of fourteen precursors representing atmospherically relevant biogenic and anthropogenic sources. The SOA and OPOA particles were generated via controlled exposure of precursors to OH radicals and/or O3 in a Potential Aerosol Mass (PAM flow reactor over timescales equivalent to 1–20 days of atmospheric aging. Aerosol mass spectra of SOA and OPOA were measured with an Aerodyne aerosol mass spectrometer (AMS. The fraction of AMS signal at m/z = 43 and m/z = 44 (f43, f44, the hydrogen-to-carbon (H/C ratio, and the oxygen-to-carbon (O/C ratio of the SOA and OPOA were obtained, which are commonly used to characterize the level of oxidation of oxygenated organic aerosol (OOA. The results show that PAM-generated SOA and OPOA can reproduce and extend the observed f44f43 composition beyond that of ambient OOA as measured by an AMS. Van Krevelen diagrams showing H/C ratio as a function of O/C ratio suggest an oxidation mechanism involving formation of carboxylic acids concurrent with fragmentation of carbon-carbon bonds. Cloud condensation nuclei (CCN activity of PAM-generated SOA and OPOA was measured as a function of OH exposure and characterized as a function of O/C ratio. CCN activity of the SOA and OPOA, which was characterized in the form of the hygroscopicity parameter κorg, ranged from 8.4×10−4 to 0.28 over measured O/C ratios ranging from 0.05 to 1.42. This range of κorg and O/C ratio is significantly wider than has been previously obtained. To first order, the κorg-to-O/C relationship is well represented by a linear function of the form κorg = (0.18±0.04 ×O/C + 0.03, suggesting that a simple, semi-empirical parameterization of OOA hygroscopicity and

  1. Getting Started With Oracle SOA Suite 11g R1 - A Hands-On Tutorial

    CERN Document Server

    Buelow, Heidi; Palvankar, Prasen

    2009-01-01

    This fully illustrated step-by-step tutorial is based on proven training material that has been highly praised by hundreds of developers in product training courses given as part of the SOA Suite 11g rollout. You will learn how to build a services-oriente

  2. Virtual Sustainability

    Directory of Open Access Journals (Sweden)

    William Sims Bainbridge

    2010-09-01

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

  3. Characterizing oxidative flow reactor SOA production and OH radical exposure from laboratory experiments of complex mixtures (engine exhaust) and simple precursors (monoterpenes)

    Science.gov (United States)

    Michael Link, M. L.; Friedman, B.; Ortega, J. V.; Son, J.; Kim, J.; Park, G.; Park, T.; Kim, K.; Lee, T.; Farmer, D.

    2016-12-01

    Recent commercialization of the Oxidative Flow Reactor (OFR, occasionally described in the literature as a "Potential Aerosol Mass") has created the opportunity for many researchers to explore the mechanisms behind OH-driven aerosol formation on a wide range of oxidative timescales (hours to weeks) in both laboratory and field measurements. These experiments have been conducted in both laboratory and field settings, including simple (i.e. single component) and complex (multi-component) precursors. Standard practices for performing OFR experiments, and interpreting data from the measurements, are still being developed. Measurement of gas and particle phase chemistry, from oxidation products generated in the OFR, through laboratory studies on single precursors and the measurement of SOA from vehicle emissions on short atmospheric timescales represent two very different experiments in which careful experimental design is essential for exploring reaction mechanisms and SOA yields. Two parameters essential in experimental design are (1) the role of seed aerosol in controlling gas-particle partitioning and SOA yields, and (2) the accurate determination of OH exposure during any one experiment. We investigated the role of seed aerosol surface area in controlling the observed SOA yields and gas/particle composition from the OH-initiated oxidation of four monoterpenes using an aerosol chemical ionization time-of-flight mass spectrometer and scanning mobility particle sizer. While the OH exposure during laboratory experiments is simple to constrain, complex mixtures such as diesel exhaust have high estimated OH reactivity values, and thus require careful consideration. We developed methods for constraining OH radical exposure in the OFR during vehicle exhaust oxidation experiments. We observe changes in O/C ratios and highly functionalized species over the temperature gradient employed in the aerosol-CIMS measurement. We relate this observed, speciated chemistry to the

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

    Science.gov (United States)

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

    2007-12-01

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

  5. Security challenges for virtualization in cloud

    International Nuclear Information System (INIS)

    Tayab, A.

    2015-01-01

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

  6. A Collaborative Semantic Annotation System in Health: Towards a SOA Design for Knowledge Sharing in Ambient Intelligence

    Directory of Open Access Journals (Sweden)

    Gabriel Guerrero-Contreras

    2017-01-01

    Full Text Available People nowadays spend more and more time performing collaborative tasks at anywhere and anytime. Specifically, professionals want to collaborate with each other by using advanced technologies for sharing knowledge in order to improve/automatize business processes. Semantic web technologies offer multiple benefits such as data integration across sources and automation enablers. The conversion of the widespread Content Management Systems into its semantic equivalent is a relevant step, as this enables the benefits of the semantic web to be extended. The FLERSA annotation tool makes it possible. In particular, it converts the Joomla! CMS into its semantic equivalent. However, this tool is highly coupled with that specific Joomla! platform. Furthermore, ambient intelligent (AmI environments can be seen as a natural way to address complex interactions between users and their environment, which could be transparently supported through distributed information systems. However, to build distributed information systems for AmI environments it is necessary to make important design decisions and apply techniques at system/software architecture level. In this paper, a SOA-based design solution consisting of two services and an underlying middleware is combined with the FLERSA tool. It allows end-users to collaborate independently of technical details and specific context conditions and in a distributed, decentralized way.

  7. Virtual Classroom

    DEFF Research Database (Denmark)

    Christensen, Ove

    2013-01-01

    In the Scandinavian countries: Sweden, Norway and Denmark, the project GNU (Grænseoverskridende Nordisk Undervisning, i.e. Transnational Nordic Teaching) is experimenting with ways of conducting teaching across the borders in the elementary schools. The cloud classes are organised with one class...... and benefits in regard to learning and pedagogy with virtual classroom....

  8. Flight Hardware Virtualization for On-Board Science Data Processing Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Utilize Hardware Virtualization technology to benefit on-board science data processing by investigating new real time embedded Hardware Virtualization solutions and...

  9. Virtual Reference, Real Money: Modeling Costs in Virtual Reference Services

    Science.gov (United States)

    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…

  10. Intermodulation and harmonic distortion in slow light Microwave Photonic phase shifters based on Coherent Population Oscillations in SOAs.

    Science.gov (United States)

    Gasulla, Ivana; Sancho, Juan; Capmany, José; Lloret, Juan; Sales, Salvador

    2010-12-06

    We theoretically and experimentally evaluate the propagation, generation and amplification of signal, harmonic and intermodulation distortion terms inside a Semiconductor Optical Amplifier (SOA) under Coherent Population Oscillation (CPO) regime. For that purpose, we present a general optical field model, valid for any arbitrarily-spaced radiofrequency tones, which is necessary to correctly describe the operation of CPO based slow light Microwave Photonic phase shifters which comprise an electrooptic modulator and a SOA followed by an optical filter and supplements another recently published for true time delay operation based on the propagation of optical intensities. The phase shifter performance has been evaluated in terms of the nonlinear distortion up to 3rd order, for a modulating signal constituted of two tones, in function of the electrooptic modulator input RF power and the SOA input optical power, obtaining a very good agreement between theoretical and experimental results. A complete theoretical spectral analysis is also presented which shows that under small signal operation conditions, the 3rd order intermodulation products at 2Ω1 + Ω2 and 2Ω2 + Ω1 experience a power dip/phase transition characteristic of the fundamental tones phase shifting operation.

  11. Identifying precursors and aqueous organic aerosol formation pathways during the SOAS campaign

    Directory of Open Access Journals (Sweden)

    N. Sareen

    2016-11-01

    Full Text Available Aqueous multiphase chemistry in the atmosphere can lead to rapid transformation of organic compounds, forming highly oxidized, low-volatility organic aerosol and, in some cases, light-absorbing (brown carbon. Because liquid water is globally abundant, this chemistry could substantially impact climate, air quality, and health. Gas-phase precursors released from biogenic and anthropogenic sources are oxidized and fragmented, forming water-soluble gases that can undergo reactions in the aqueous phase (in clouds, fogs, and wet aerosols, leading to the formation of secondary organic aerosol (SOAAQ. Recent studies have highlighted the role of certain precursors like glyoxal, methylglyoxal, glycolaldehyde, acetic acid, acetone, and epoxides in the formation of SOAAQ. The goal of this work is to identify additional precursors and products that may be atmospherically important. In this study, ambient mixtures of water-soluble gases were scrubbed from the atmosphere into water at Brent, Alabama, during the 2013 Southern Oxidant and Aerosol Study (SOAS. Hydroxyl (OH⚫ radical oxidation experiments were conducted with the aqueous mixtures collected from SOAS to better understand the formation of SOA through gas-phase followed by aqueous-phase chemistry. Total aqueous-phase organic carbon concentrations for these mixtures ranged from 92 to 179 µM-C, relevant for cloud and fog waters. Aqueous OH-reactive compounds were primarily observed as odd ions in the positive ion mode by electrospray ionization mass spectrometry (ESI-MS. Ultra high-resolution Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR-MS spectra and tandem MS (MS–MS fragmentation of these ions were consistent with the presence of carbonyls and tetrols. Products were observed in the negative ion mode and included pyruvate and oxalate, which were confirmed by ion chromatography. Pyruvate and oxalate have been found in the particle phase in many locations (as salts and

  12. Urban stress-induced biogenic VOC emissions and SOA-forming potentials in Beijing

    Directory of Open Access Journals (Sweden)

    A. Ghirardo

    2016-03-01

    Full Text Available Trees can significantly impact the urban air chemistry by the uptake and emission of reactive biogenic volatile organic compounds (BVOCs, which are involved in ozone and particle formation. Here we present the emission potentials of "constitutive" (cBVOCs and "stress-induced" BVOCs (sBVOCs from the dominant broadleaf woody plant species in the megacity of Beijing. Based on the municipal tree census and cuvette BVOC measurements on leaf level, we built an inventory of BVOC emissions, and assessed the potential impact of BVOCs on secondary organic aerosol (SOA formation in 2005 and 2010, i.e., before and after realizing the large tree-planting program for the 2008 Olympic Games. We found that sBVOCs, such as fatty acid derivatives, benzenoids, and sesquiterpenes, constituted a significant fraction ( ∼  40 % of the total annual BVOC emissions, and we estimated that the overall annual BVOC budget may have doubled from  ∼  4.8  ×  109 g C year−1 in 2005 to  ∼  10.3  ×  109 g C year−1 in 2010 due to the increase in urban greening, while at the same time the emission of anthropogenic VOCs (AVOCs decreased by 24 %. Based on the BVOC emission assessment, we estimated the biological impact on SOA mass formation potential in Beijing. Constitutive and stress-induced BVOCs might produce similar amounts of secondary aerosol in Beijing. However, the main contributors of SOA-mass formations originated from anthropogenic sources (> 90 %. This study demonstrates the general importance to include sBVOCs when studying BVOC emissions. Although the main problems regarding air quality in Beijing still originate from anthropogenic activities, the present survey suggests that in urban plantation programs, the selection of low-emitting plant species has some potential beneficial effects on urban air quality.

  13. Collaborative virtual gaming worlds in higher education

    Directory of Open Access Journals (Sweden)

    Nicola Whitton

    2008-12-01

    Full Text Available There is growing interest in the use of virtual gaming worlds in education, supported by the increased use of multi-user virtual environments (MUVEs and massively multiplayer online role-playing games (MMORPGs for collaborative learning. However, this paper argues that collaborative gaming worlds have been in use much longer and are much wider in scope; it considers the range of collaborative gaming worlds that exist and discusses their potential for learning, with particular reference to higher education. The paper discusses virtual gaming worlds from a theoretical pedagogic perspective, exploring the educational benefits of gaming environments. Then practical considerations associated with the use of virtual gaming worlds in formal settings in higher education are considered. Finally, the paper considers development options that are open to educators, and discusses the potential of Alternate Reality Games (ARGs for learning in higher education. In all, this paper hopes to provide a balanced overview of the range of virtual gaming worlds that exist, to examine some of the practical considerations associated with their use, and to consider their benefits and challenges in learning and teaching in the higher education context.

  14. Service-Oriented Architecture (SOA) Instantiation within a Hard Real-Time, Deterministic Combat System Environment

    Science.gov (United States)

    Moreland, James D., Jr

    2013-01-01

    This research investigates the instantiation of a Service-Oriented Architecture (SOA) within a hard real-time (stringent time constraints), deterministic (maximum predictability) combat system (CS) environment. There are numerous stakeholders across the U.S. Department of the Navy who are affected by this development, and therefore the system…

  15. Extended SOA to Enable Web Service Discovery on Non Functional Parameters

    OpenAIRE

    Vandan Tiwari Dr. Nirmal Dagdee Dr. Aruna Tiwari Divesh Dixit

    2012-01-01

    The current Service Oriented Architecture (SOA) standards, namely the concept of Web services and service registry lacks mechanism for managing the services’ nonfunctional properties of Web Services. Currently there is no standard that is capable of accurately representing quality of service parameters of web services. Such non functional properties are expressed by the term “Quality of Service (QoS)”. QoS for Web services is an important decisive factor for service selection. Therefore it is...

  16. Virtualization-support Cases in Engineering Education

    DEFF Research Database (Denmark)

    Soler, José

    2011-01-01

    The paper presents cases of applying hardware virtualization techniques as support for education activities in two different courses and a master thesis within the degree International MSc on Telecommunication Engineering at the Technical University of Denmark (DTU). The triggering problem...... is presented in each of the cases, together with the benefits and drawbacks of using virtualization to cope with it....

  17. Tool or Toy? Virtual Globes in Landscape Planning

    Directory of Open Access Journals (Sweden)

    Stephen R. J. Sheppard

    2011-10-01

    Full Text Available Virtual globes, i.e., geobrowsers that integrate multi-scale and temporal data from various sources and are based on a globe metaphor, have developed into serious tools that practitioners and various stakeholders in landscape and community planning have started using. Although these tools originate from Geographic Information Systems (GIS, they have become a different, potentially interactive and public tool set, with their own specific limitations and new opportunities. Expectations regarding their utility as planning and community engagement tools are high, but are tempered by both technical limitations and ethical issues [1,2]. Two grassroots campaigns and a collaborative visioning process, the Kimberley Climate Adaptation Project case study (British Columbia, illustrate and broaden our understanding of the potential benefits and limitations associated with the use of virtual globes in participatory planning initiatives. Based on observations, questionnaires and in-depth interviews with stakeholders and community members using an interactive 3D model of regional climate change vulnerabilities, potential impacts, and possible adaptation and mitigation scenarios in Kimberley, the benefits and limitations of virtual globes as a tool for participatory landscape planning are discussed. The findings suggest that virtual globes can facilitate access to geospatial information, raise awareness, and provide a more representative virtual landscape than static visualizations. However, landscape is not equally representative at all scales, and not all types of users seem to benefit equally from the tool. The risks of misinterpretation can be managed by integrating the application and interpretation of virtual globes into face-to-face planning processes.

  18. Survey on the virtual commissioning of manufacturing systems

    Directory of Open Access Journals (Sweden)

    Chi G. Lee

    2014-07-01

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

  19. SOA formation from the atmospheric oxidation of 2-methyl-3-buten-2-ol and its implications for PM2.5

    Directory of Open Access Journals (Sweden)

    W. A. Lonneman

    2012-02-01

    Full Text Available The formation of secondary organic aerosol (SOA generated by irradiating 2-methyl-3-buten-2-ol (MBO in the presence and/or absence of NOx, H2O2, and/or SO2 was examined. Experiments were conducted in smog chambers operated in either dynamic or static mode. A filter/denuder sampling system was used for simultaneously collecting gas- and particle-phase products. The structural characterization of gas and particulate products was investigated using BSTFA, BSTFA + PFBHA, and DNPH derivatization techniques followed by GC-MS and liquid chromatography analysis. This analysis showed the occurrence of more than 68 oxygenated organic compounds in the gas and particle phases, 28 of which were tentatively identified. The major components observed include 2,3-dihydroxyisopentanol (DHIP, 2-hydroxy-2-oxoisopentanol, 2,3-dihydroxy-3-methylbutanal, 2,3-dihydroxy-2-methylsuccinic acid, 2-hydroxy-2-methylpropanedioic acid, acetone, glyoxal, methylglyoxal, glycolaldehyde, and formaldehyde. Most of these oxygenated compounds were detected for the first time in this study. While measurements of the gas-phase photooxidation products have been made, the focus of this work has been an examination of the particle phase. SOA from some experiments was analyzed for the organic mass to organic carbon ratio (OM/OC, the effective enthalpy of vaporization (ΔHvapeff, and the aerosol yield. Additionally, aerosol size, volume, and number concentrations were measured by a Scanning Mobility Particle Sizer coupled to a Condensation Particle Counter system. The OM/OC ratio was 2.1 in the MBO/H2O2 system. The ΔHvapeff was 41 kJ mol−1, a value similar to that of isoprene SOA. The laboratory SOA yield measured in this study was 0.7% in MBO/H2O2 for an aerosol mass of 33 μg m−3. Secondary organic aerosol was found to be negligible under conditions with oxides of nitrogen (NOx present. Time profiles and proposed reaction schemes are provided for selected compounds. The contribution

  20. A Data Processing Middleware Based on SOA for the Internet of Things

    Directory of Open Access Journals (Sweden)

    Feng Wang

    2015-01-01

    Full Text Available The Internet of Things (IoT emphasizes on connecting every object around us by leveraging a variety of wireless communication technologies. Heterogeneous data fusion is widely considered to be a promising and urgent challenge in the data processing of the IoT. In this study, we first discuss the development of the concept of the IoT and give a detailed description of the architecture of the IoT. And then we design a middleware platform based on service-oriented architecture (SOA for integration of multisource heterogeneous information. New research angle regarding flexible heterogeneous information fusion architecture for the IoT is the theme of this paper. Experiments using environmental monitoring sensor data derived from indoor environment are performed for system validation. Through the theoretical analysis and experimental verification, the data processing middleware architecture represents better adaptation to multisensor and multistream application scenarios in the IoT, which improves heterogeneous data utilization value. The data processing middleware based on SOA for the IoT establishes a solid foundation of integration and interaction for diverse networks data among heterogeneous systems in the future, which simplifies the complexity of integration process and improves reusability of components in the system.

  1. Generating Virtual Eye Contacts Through Online Synchronous Communications in Virtual Classroom Applications

    Directory of Open Access Journals (Sweden)

    T. Volkan YUZER

    2007-01-01

    Full Text Available The Internet usage has been increasing among persons in the worldwide. This situation highlights that the number of potential distance learners has been increasing in the Internet society. Besides, the terms and concepts of the Internet environments become to be spread out in this society like virtual reality. It is also possible to explain the characters of the Internet clearly via generating relatively new terms or concepts. “Virtual eye contact” concept is one of these. In this article, this concept is considered with a specific application of synchronous internet-based e-learning environments which is virtual classroom platform application. Explanation, technological infrastructure and benefits of this concept and training of the trainers to use this nonverbal communication type more powerfully are explained and discussed.

  2. Possible Application of Virtual Reality in Geography Teaching

    OpenAIRE

    Ivan Stojšić; Anđelija Ivkov Džigurski; Olja Maričić; Ljubica Ivanović Bibić; Smiljana Đukičin Vučković

    2017-01-01

    Abstract Virtual reality represents simulated three-dimensional environment created by hardware and software, which providing realistic experience and possibility of interaction to the end-user. Benefits provided by immersive virtual reality in educational setting were recognised in the past decades, however mass application was left out due to the lack of development and high price. Intensive development of new platforms and virtual reality devices in the last few years started up with Oc...

  3. Intelligent Motion and Interaction Within Virtual Environments

    Science.gov (United States)

    Ellis, Stephen R. (Editor); Slater, Mel (Editor); Alexander, Thomas (Editor)

    2007-01-01

    What makes virtual actors and objects in virtual environments seem real? How can the illusion of their reality be supported? What sorts of training or user-interface applications benefit from realistic user-environment interactions? These are some of the central questions that designers of virtual environments face. To be sure simulation realism is not necessarily the major, or even a required goal, of a virtual environment intended to communicate specific information. But for some applications in entertainment, marketing, or aspects of vehicle simulation training, realism is essential. The following chapters will examine how a sense of truly interacting with dynamic, intelligent agents may arise in users of virtual environments. These chapters are based on presentations at the London conference on Intelligent Motion and Interaction within a Virtual Environments which was held at University College, London, U.K., 15-17 September 2003.

  4. Exposure of BALB/c mice to diesel engine exhaust origin secondary organic aer-osol (DE-SOA during the developmental stages impairs the social behavior in adult life of the males

    Directory of Open Access Journals (Sweden)

    Tin-Tin eWin-Shwe

    2016-01-01

    Full Text Available Secondary organic aerosol (SOA is a component of particulate matter (PM 2.5 and formed in the atmosphere by oxidation of volatile organic compounds. Recently, we have reported that inhalation exposure to diesel engine exhaust (DE originated SOA (DE-SOA affect novel object recognition ability and impair maternal behavior in adult mice. However, it is not clear whether early life exposure to SOA during the de-velopmental stages affect social behavior in adult life or not. In the present study, to investigate the effects of early life exposure to DE-SOA during the gestational and lactation stages on the social behavior in the adult life, BALB/c mice were exposed to clean air (control, DE, DE-SOA and gas without any particulate matter in the inhala-tion chambers from gestational day 14 to postnatal day 21 for 5 h a day and 5 days per week. Then adult mice were examined for changes in their social behavior at the age of 13 week by a sociability and social novelty preference, social interaction with a juvenile mouse and light-dark transition test, hypothalamic mRNA expression levels of social behavior-related genes, estrogen receptor-alpha and oxytocin receptor as well as of the oxidative stress marker gene, heme oxygenase (HO-1 by real-time RT-PCR method. In addition, hypothalamic level of neuronal excitatory marker, glutamate was determined by ELISA method. We observed that sociability and social novelty pref-erence as well as social interaction were remarkably impaired, expression levels of es-trogen receptor-alpha, oxytocin receptor mRNAs were significantly decreased, ex-pression levels of HO-1 mRNAs and glutamate levels were significantly increased in adult male mice exposed to DE-SOA compared to the control ones. Findings of this study indicate early life exposure of BALB/c mice to DE-SOA may affect their late-onset hypothalamic expression of social behavior related genes, trigger neurotoxi-city and impair social behavior in the males.

  5. On the Impossibility of Detecting Virtual Machine Monitors

    Science.gov (United States)

    Gueron, Shay; Seifert, Jean-Pierre

    Virtualization based upon Virtual Machines is a central building block of Trusted Computing, and it is believed to offer isolation and confinement of privileged instructions among other security benefits. However, it is not necessarily bullet-proof — some recent publications have shown that Virtual Machine technology could potentially allow the installation of undetectable malware root kits. As a result, it was suggested that such virtualization attacks could be mitigated by checking if a threatened system runs in a virtualized or in a native environment. This naturally raises the following problem: Can a program determine whether it is running in a virtualized environment, or in a native machine environment? We prove here that, under a classical VM model, this problem is not decidable. Further, although our result seems to be quite theoretic, we also show that it has practical implications on related virtualization problems.

  6. A Review on Virtual Hospital Concept and its Applications

    Directory of Open Access Journals (Sweden)

    Hadi Hassankhani

    2015-08-01

    Full Text Available Virtual hospital is an informational-interactive system that seeks to ensure that the benefits of modern medicine are available to everyone. The aim of this non-systematic narrative study was to review virtual hospital concept and its applications. Information collecting was conducted by literature review and visiting virtual hospitals' websites. Most of the already existing articles were about virtual hospitals modeling and its application in patients' management. Present data show that virtual hospitals' websites had some role in education, decreasing hospital infection rate, improving patient outcome, etc. In general, virtual hospitals have both many advantages and disadvantages. As a result, all the outcomes should be considered when modeling this new technology. ​

  7. Virtual Reality Hysteroscopy

    Science.gov (United States)

    Levy

    1996-08-01

    New interactive computer technologies are having a significant influence on medical education, training, and practice. The newest innovation in computer technology, virtual reality, allows an individual to be immersed in a dynamic computer-generated, three-dimensional environment and can provide realistic simulations of surgical procedures. A new virtual reality hysteroscope passes through a sensing device that synchronizes movements with a three-dimensional model of a uterus. Force feedback is incorporated into this model, so the user actually experiences the collision of an instrument against the uterine wall or the sensation of the resistance or drag of a resectoscope as it cuts through a myoma in a virtual environment. A variety of intrauterine pathologies and procedures are simulated, including hyperplasia, cancer, resection of a uterine septum, polyp, or myoma, and endometrial ablation. This technology will be incorporated into comprehensive training programs that will objectively assess hand-eye coordination and procedural skills. It is possible that by incorporating virtual reality into hysteroscopic training programs, a decrease in the learning curve and the number of complications presently associated with the procedures may be realized. Prospective studies are required to assess these potential benefits.

  8. Performance Evaluation of a SOA-based Rack-To-Rack Switch for Optical Interconnects Exploiting NRZ-DPSK

    DEFF Research Database (Denmark)

    Karinou, Fotini; Borkowski, Robert; Prince, Kamau

    2012-01-01

    We experimentally study the transmission performance of 10-Gb/s NRZ-DPSK through concatenated AWG MUX/DMUXs and SOAs employed in an optimized 64×64 optical supercomputer interconnect architecture. NRZ-DPSK offers 9-dB higher dynamic range compared to conventional IM/DD....

  9. 85 km long reach PON system using a reflective SOA-EA modulator and distributed Raman fiber amplification

    NARCIS (Netherlands)

    Tafur Monroy, I.; Öhman, F.; Yvind, K.; Kjaer, R.; Peucheret, C.; Koonen, A.M.J.; Jeppesen, P.

    2006-01-01

    We report on a bidirectional 85 km long reach PON system supported by distributed fiber Raman amplification with a record 7.5 Gb/s remote carrier modulated upstream signal by employing a reflective SOA-EA monolithically integrated circuit.

  10. The Changing Global Context of Virtual Workforce

    Directory of Open Access Journals (Sweden)

    James A. Ejiwale

    2012-09-01

    Full Text Available The technological revolution occurring in today’s market place has made it possible for many companies to be innovative about the way and where work is done. To get the job done, due to digital revolution, companies have turned to virtual workforce to harness the benefits of connectivity and effective information sharing among stakeholders to get the job done. More important, the success of coordinating work among a virtual workforce for profitability in a rapidly changing global environment depends on “effective indirect communication” between the leadership and the virtual workforce. This article will address the importance of effective communication as a necessary tool for the success of e-leadership, productivity improvement in virtual work environment.

  11. An Algorithm of Traffic Perception of DDoS Attacks against SOA Based on Time United Conditional Entropy

    Directory of Open Access Journals (Sweden)

    Yuntao Zhao

    2016-01-01

    Full Text Available DDoS attacks can prevent legitimate users from accessing the service by consuming resource of the target nodes, whose availability of network and service is exposed to a significant threat. Therefore, DDoS traffic perception is the premise and foundation of the whole system security. In this paper the method of DDoS traffic perception for SOA network based on time united conditional entropy was proposed. According to many-to-one relationship mapping between the source IP address and destination IP addresses of DDoS attacks, traffic characteristics of services are analyzed based on conditional entropy. The algorithm is provided with perception ability of DDoS attacks on SOA services by introducing time dimension. Simulation results show that the novel method can realize DDoS traffic perception with analyzing abrupt variation of conditional entropy in time dimension.

  12. Student eXchange Process Modelling and Implementation by Using an Integrated BMP-SOA Approach

    Directory of Open Access Journals (Sweden)

    Octavian DOSPINESCU

    2018-01-01

    Full Text Available One of the key processes of an open University Information System concerns managing the student exchange activities. In this paper we will try to address the challenges regarding modelling and implementation when integrating such a process by crossing different information systems. Our approach will leverage SOA architecture by using BPM in order to structure and build the service orchestration level.

  13. Virtual Visits in Home Health Care for Older Adults

    Directory of Open Access Journals (Sweden)

    Anne Marie Lunde Husebø

    2014-01-01

    Full Text Available Background. This review identifies the content of virtual visits in community nursing services to older adults and explores the manner in which service users and the nurses use virtual visits. Design. An integrative literature review. Method. Data collection comprised a literature search in three databases: Cinahl, Medline, and PubMed. In addition, a manual search of reference lists and expert consultation were performed. A total of 12 articles met the inclusion criteria. The articles were reviewed in terms of study characteristics, service content and utilization, and patient and health care provider experience. Results. Our review shows that in most studies the service is delivered on a daily basis and in combination with in-person visits. The findings suggest that older home-dwelling patients can benefit from virtual visits in terms of enhanced social inclusion and medication compliance. Service users and their nurses found virtual visits satisfactory and suitable for care delivery in home care to the elderly. Evidence for cost-saving benefits of virtual visits was not found. Conclusions. The findings can inform the planning of virtual visits in home health care as a complementary service to in-person visits, in order to meet the increasingly complex needs of older adults living at home.

  14. Black Carbon Aging from SOA Coatings and Coagulation with Diesel BC Emissions during SAAS at the PNNL Environmental Chamber

    Science.gov (United States)

    Aiken, A. C.; Liu, S.; Dubey, M. K.; Zaveri, R. A.; Shilling, J. E.; Gourihar, K.; Pekour, M. S.; Subramanian, R.; Zelenyuk, A.; Wilson, J. M.; Mazzoleni, C.; China, S.; Sharma, N.

    2014-12-01

    Black carbon (BC) is considered to be potentially the 2nd most important global warming factor behind CO2 (Bond et al., 2013). Uncertainties exist due to BC morphology and mixing state on the extent of the warming that it causes, e.g. Cappa et al., 2012. Core-shell BC is expected to enhance absorption by up to a factor of 2, but has yet to be observed to this extent from ambient data. Experiments were conducted during the Soot Aerosol Aging Study (SAAS) Laboratory Campaign at Pactific Northwest National Laboratory's Environmental Chamber in the winter of 2013-2014 to investigate the relationship between coatings and enhancements from diesel emissions. Direct on-line measurements were made with the single particle soot photometer (SP2) from fresh and aged BC from coating and coagulation experiments with secondary organic aerosol (SOA) formed in the chamber. BC measurements are coupled with photoactoustic measurements spanning the visible region to probe BC enhancements when mixed with SOA. Here we focus on the enhancements at 781 nm, that are tracked throughout SOA growth on BC, as determined from SP2 coating thicknesses. Thermal denuder (TD) experiments are conducted and enhancements are calculated from two different methods that agree well with each other, confirming the observed results. BC measurements are also compared with co-located measurements from SPLAT-II and filter analysis using SEM and TEM. BC coagulated with SOA produces minimal absorption enhancement values, whereas coatings are observed to have significant enhancement values at 300 degrees C, e.g. 1.3 for thickly coated BC. BC particles were coagulated with SOA in the chamber since this morphology has been observed in wildfire emissions (Sedlacek et al., 2012). Since we did not observe appreciable enhancements for the coagulated BC, we expect that ambient emissions dominated by this particle type to have enhancements due to other sources, such as brown carbon (BrC) that is often co-emitted (Saleh et

  15. Virtualization in the Operations Environments

    Science.gov (United States)

    Pitts, Lee; Lankford, Kim; Felton, Larry; Pruitt, Robert

    2010-01-01

    Virtualization provides the opportunity to continue to do "more with less"---more computing power with fewer physical boxes, thus reducing the overall hardware footprint, power and cooling requirements, software licenses, and their associated costs. This paper explores the tremendous advantages and any disadvantages of virtualization in all of the environments associated with software and systems development to operations flow. It includes the use and benefits of the Intelligent Platform Management Interface (IPMI) specification, and identifies lessons learned concerning hardware and network configurations. Using the Huntsville Operations Support Center (HOSC) at NASA Marshall Space Flight Center as an example, we demonstrate that deploying virtualized servers as a means of managing computing resources is applicable and beneficial to many areas of application, up to and including flight operations.

  16. SOA – The Link Between Modern Educational Technologies and Mobile Learning in the Higher Education Landscape

    Directory of Open Access Journals (Sweden)

    Popa Strainu Roxana Marina

    2017-06-01

    Full Text Available Modern educational technologies encompass a variety of variables such as people, processes, assets, environments, technology. These variables are part of a complex system which has some important properties and a final purpose: delivering learning material and keeping track of the recipient’s evolution and development. The purpose of this paper is to define the system of modern educational technologies with the help of its variables and internal or external processes as well as to find where mobile learning fits in this large system. From a technical point of view we want to analyze whether Service Oriented Architecture (SOA is enough or proper to integrate mobile learning in this system. At the end we should be able to decide if dedicated mobile apps, or mobile friendly sites or a combination of those two are suited to deliver the results we are looking for with the support of SOA, if we consider the variety of devices and operating systems we are trying to integrate.

  17. The TRIGA in virtual classroom for training; El TRIGA en aula virtual para entrenamiento

    Energy Technology Data Exchange (ETDEWEB)

    Plata M, A. C.; Morales S, J. B.; Salazar S, E. [UNAM, DEPFI Campus Morelos, Jiutepec Morelos 62550 (Mexico)]. e-mail: yoyuclof@hotmail.com

    2008-07-01

    The research nuclear reactors have been fundamental part in the evolution of the nuclear power plants and they have been used in the training for the obtaining of operation licenses of radioactive facilities. For purposes of training of professionals in nuclear engineering, it is interesting to know the benefit that can be obtained by means of the virtual representation of a research nuclear reactor TRIGA, with which they are possible the practice to be realized them but common that to date they are carried out in different nuclear facilities of training throughout the world. The simulation has become a valuable tool in the personal preparation, having obtained ambient and very approximate situations to the reality. The physical models of kinetics of neutrons, heat transfer, Cherenkov effect, dynamics of the xenon, as well as the virtual instrumentation is contemplated in this development. The instrumentation and control panels of a research reactor, failures waited for in the use of this equipment, physical consequences to instruments, virtual personnel and facilities, as well as the administrative and legal aspects that it requires to meet an authorized operator, must be available and they are considered in the first virtual approach. The obtaining of the reactor time constant comprises of the mathematical model that provides to the operator of a direct way the knowledge of the changes of power. The coolant and moderator are modeled as well as the retardations that appear in the measurements and controls that can be introduced from the virtual console. In the simulator the four possible states of operation of the TRIGA can be had. At the moment also the monitoring can be realized and control in remote form, thus the control and supervision interface for the remote operation will be analyzed in their benefits and possible risks in the instruction processes. (Author)

  18. Virtual Career Fairs: Perspectives from Norwegian Recruiters and Exhibitors

    Directory of Open Access Journals (Sweden)

    Ådne Stenberg Vik

    2018-02-01

    Full Text Available The present work introduces virtual fairs, particularly the perceived benefits, challenges, and relevance of such fairs for recruitment and employer branding. These aspects were explored in a semi-structured interview with an organizer of virtual fairs across Scandinavia, and a focus group composed of Norwegian recruiters and exhibitors. The results of the data collection can be summarized in the form of themes that relate to web analytics, web services and optimization. The benefits of virtual fairs pertain to the (a visibility and branding; (b costs; and (c analytics-based customization. Challenges of virtual career fairs pertain to the (a lack of online engagement, (b preparation and staffing costs; (c lack of guidelines; (d talent access and identification; (e security and infrastructure; (f long-term planning; (g and inter-dependencies. The discussion summarizes the implications of branding and recruitment and the value they add to business, also noting how context effects may come into play. The article concludes by exploring the possibility that virtual fairs will complement or become the new standard in recruitment and outlines future avenues for research and practice.

  19. The need for virtual reality simulators in dental education: A review

    OpenAIRE

    Roy, Elby; Bakr, Mahmoud M.; George, Roy

    2017-01-01

    Virtual reality simulators are becoming an essential part of modern education. The benefits of Virtual reality in dentistry is constantly being assessed as a method or an adjunct to improve fine motor skills, hand-eye coordination in pre-clinical settings and overcome the monetary and intellectual challenges involved with such training. This article, while providing an overview of the virtual reality dental simulators, also looks at the link between virtual reality simulation and current peda...

  20. Establishing a Regulatory Framework for the Development & Operations of Sub-Orbital & Orbital Aircraft (SOA) in the EU

    Science.gov (United States)

    Marciacq, Jean-Bruno; Tomasello, Filippo; Erdelyi, Zsuzsanna; Gerhard, Michael

    2013-09-01

    The Treaty of the European Union allows for the development of common policies for all sectors of transport, including aviation, and its safety. To this end, the European legislator established in 2002 the European Aviation Safety Agency (EASA), located in Cologne, Germany, and gave it responsibility for the regulation of aviation safety, successively encompassing airworthiness, air operations and Flight Crew Licensing (FCL), Air Traffic Management (ATM), Air Navigation Systems (ANS), as well as Aerodromes (ADR).The Annexes 6 and 8 of the International Civil Aviation Organization (ICAO) to the Chicago Convention define an aircraft as "any machine that can derive support in the atmosphere from the reactions of the air other than the reactions of the air against the earth's surface". The aerodynamic lift generated during the atmospheric part of the flight is commonly used to sustain and control the vehicle, that is to take-off, climb, pull-up, perform manoeuvres, fly back to the airport and land. Thus, Sub- orbital and Orbital Aircraft (SOA) are considered to be aircraft, as opposed to rockets which are symmetrical bodies not generating lift, and solely sustained by their rocket engine(s).Consequently, the regulation of SOA airworthiness, their crew, operations, insertion into the traffic and utilisation of aerodromes would in principle fall under the remit of EASA, which would have to fulfil its role of protection of the European citizens in relation to civil suborbital and orbital flights, that is to certify SOAs and their operations before they would be operated for Commercial Transport in the EU.Since EASA was first contacted by potential applicants in 2007, many projects have developed and the context has evolved. Thus, this paper intends to update the approach initially proposed at the 3rd IAASS in Rome in October 2008 and complemented at the 4th IAASS in Huntsville in May 2010 to accommodate sub-orbital and orbital aircraft into the EU regulatory system, and

  1. A manufactured past: virtual reality in archaeology

    Directory of Open Access Journals (Sweden)

    Glyn Goodrick

    2004-01-01

    Full Text Available Virtual reality and visualisation technologies developed over the past thirty years have been readily accessible to the archaeological community since the mid 1990s. Despite the high profile of virtual archaeology (Reilly 1991 both within the media and professional archaeology it has not been taken on board as a generally useful and standard technique by archaeologists. In this article we wish to discuss the technical and other issues which have resulted in a reluctance to adopt virtual archaeology and, more importantly, discuss ways forward that can enable us routinely to benefit from this technology in the diversity of archaeological practice.

  2. THE VIRTUAL UNIVERSITY MODEL AS THE MAIN PLATFORM FOR IMPLEMENTATION OF PROFESSIONAL RETRAINING PROGRAM FOR TEACHERS BY THE EXMPLE OF SYRIAN VIRTUAL UNIVERSITY

    Directory of Open Access Journals (Sweden)

    K. O. Prosyukova

    2014-09-01

    Full Text Available The interest in virtual education has recently increased in educational environment. Researchers in their scientific activity are focused on the benefits of the “virtual university” or “virtual college” models. But the range of a “virtuality” concept is too wide: some researchers recognize all information technologies in education as virtual means, while the others are looking for the ways to replace education in its general meaning with virtual educational space. The problem of virtual education is also relevant because the application area is boundless: school education, secondary professional education, higher education, training and retraining programs. Thus virtual education is able to become not only the innovative educational model, but also a possible solution to the problem of continuing education. One of the most successful examples in this field is the example of Syrian Virtual University, which has become the pioneer in virtual education in the Middle East region.

  3. PAST AND FUTURE APPLICATIONS OF 3-D (VIRTUAL REALITY) TECHNOLOGY

    OpenAIRE

    Nigel Foreman; Liliya Korallo

    2014-01-01

    Virtual Reality (virtual environment technology, VET) has been widely available for twenty years. In that time, the benefits of using virtual environments (VEs) have become clear in many areas of application, including assessment and training, education, rehabilitation and psychological research in spatial cognition. The flexibility, reproducibility and adaptability of VEs are especially important, particularly in the training and testing of navigational and way-finding skills. Transfer of tr...

  4. The need for virtual reality simulators in dental education: A review

    Directory of Open Access Journals (Sweden)

    Elby Roy

    2017-04-01

    Full Text Available Virtual reality simulators are becoming an essential part of modern education. The benefits of Virtual reality in dentistry is constantly being assessed as a method or an adjunct to improve fine motor skills, hand-eye coordination in pre-clinical settings and overcome the monetary and intellectual challenges involved with such training. This article, while providing an overview of the virtual reality dental simulators, also looks at the link between virtual reality simulation and current pedagogical knowledge.

  5. The need for virtual reality simulators in dental education: A review.

    Science.gov (United States)

    Roy, Elby; Bakr, Mahmoud M; George, Roy

    2017-04-01

    Virtual reality simulators are becoming an essential part of modern education. The benefits of Virtual reality in dentistry is constantly being assessed as a method or an adjunct to improve fine motor skills, hand-eye coordination in pre-clinical settings and overcome the monetary and intellectual challenges involved with such training. This article, while providing an overview of the virtual reality dental simulators, also looks at the link between virtual reality simulation and current pedagogical knowledge.

  6. Role of virtual reality simulation in endoscopy training.

    Science.gov (United States)

    Harpham-Lockyer, Louis; Laskaratos, Faidon-Marios; Berlingieri, Pasquale; Epstein, Owen

    2015-12-10

    Recent advancements in virtual reality graphics and models have allowed virtual reality simulators to be incorporated into a variety of endoscopic training programmes. Use of virtual reality simulators in training programmes is thought to improve skill acquisition amongst trainees which is reflected in improved patient comfort and safety. Several studies have already been carried out to ascertain the impact that usage of virtual reality simulators may have upon trainee learning curves and how this may translate to patient comfort. This article reviews the available literature in this area of medical education which is particularly relevant to all parties involved in endoscopy training and curriculum development. Assessment of the available evidence for an optimal exposure time with virtual reality simulators and the long-term benefits of their use are also discussed.

  7. Actual and Virtual Reality: Making the Most of Field Trips.

    Science.gov (United States)

    Bellan, Jennifer Marie; Scheurman, Geoffrey

    1998-01-01

    Argues that a virtual field trip can complement and enhance a real one. Discusses the benefits and pitfalls of both types of field trips. Outlines a series of student and teacher activities combining an actual field trip and a virtual one to Fort Snelling in St. Paul, Minnesota. (MJP)

  8. SQL Collaborative Learning Framework Based on SOA

    Science.gov (United States)

    Armiati, S.; Awangga, RM

    2018-04-01

    The research is focused on designing collaborative learning-oriented framework fulfilment service in teaching SQL Oracle 10g. Framework built a foundation of academic fulfilment service performed by a layer of the working unit in collaboration with Program Studi Manajemen Informatika. In the design phase defined what form of collaboration models and information technology proposed for Program Studi Manajemen Informatika by using a framework of collaboration inspired by the stages of modelling a Service Oriented Architecture (SOA). Stages begin with analyzing subsystems, this activity is used to determine subsystem involved and reliance as well as workflow between the subsystems. After the service can be identified, the second phase is designing the component specifications, which details the components that are implemented in the service to include the data, rules, services, profiles can be configured, and variations. The third stage is to allocate service, set the service to the subsystems that have been identified, and its components. Implementation framework contributes to the teaching guides and application architecture that can be used as a landing realize an increase in service by applying information technology.

  9. A Framework for Safe Composition of Heterogeneous SOA Services in a Pervasive Computing Environment with Resource Constraints

    Science.gov (United States)

    Reyes Alamo, Jose M.

    2010-01-01

    The Service Oriented Computing (SOC) paradigm, defines services as software artifacts whose implementations are separated from their specifications. Application developers rely on services to simplify the design, reduce the development time and cost. Within the SOC paradigm, different Service Oriented Architectures (SOAs) have been developed.…

  10. All-optical multi-wavelength conversion with negative power penalty by a commercial SOA-MZI for WDM wavelength multicast

    NARCIS (Netherlands)

    Yan, N.; Jung, H.D.; Tafur Monroy, I.; Waardt, de H.; Koonen, A.M.J.

    2007-01-01

    WDM wavelength multicast is demonstrated by all-optical multi-wavelength conversion at 10 Gb/s using a commercial SOA-MZI. We report for the first time simultaneous one-to-four conversion with negative power penalty of 1.84 dB.

  11. Game-Like Language Learning in 3-D Virtual Environments

    Science.gov (United States)

    Berns, Anke; Gonzalez-Pardo, Antonio; Camacho, David

    2013-01-01

    This paper presents our recent experiences with the design of game-like applications in 3-D virtual environments as well as its impact on student motivation and learning. Therefore our paper starts with a brief analysis of the motivational aspects of videogames and virtual worlds (VWs). We then go on to explore the possible benefits of both in the…

  12. Welfare Impact of Virtual Trading on Wholesale Electricity Markets

    Science.gov (United States)

    Giraldo, Juan S.

    Virtual bidding has become a standard feature of multi-settlement wholesale electricity markets in the United States. Virtual bids are financial instruments that allow market participants to take financial positions in the Day-Ahead (DA) market that are automatically reversed/closed in the Real-Time (RT) market. Most U.S. wholesale electricity markets only have two types of virtual bids: a decrement bid (DEC), which is virtual load, and an increment offer (INC), which is virtual generation. In theory, financial participants create benefits by seeking out profitable bidding opportunities through arbitrage or speculation. Benefits have been argued to take the form of increased competition, price convergence, increased market liquidity, and a more efficient dispatch of generation resources. Studies have found that price convergence between the DA and RT markets improved following the introduction of virtual bidding into wholesale electricity markets. The improvement in price convergence was taken as evidence that market efficiency had increased and many of the theoretical benefits realized. Persistent price differences between the DA and RT markets have led to calls to further expand virtual bidding as a means to address remaining market inefficiencies. However, the argument that price convergence is beneficial is extrapolated from the study of commodity and financial markets and the role of futures for increasing market efficiency in that context. This viewpoint largely ignores details that differentiate wholesale electricity markets from other commodity markets. This dissertation advances the understanding of virtual bidding by evaluating the impact of virtual bidding based on the standard definition of economic efficiency which is social welfare. In addition, an examination of the impacts of another type of virtual bid, up-to-congestion (UTC) transactions is presented. This virtual product significantly increased virtual bidding activity in the PJM interconnection

  13. Virtualization for the LHCb Online system

    International Nuclear Information System (INIS)

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

    2011-01-01

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

  14. A Survey of Technologies Supporting Virtual Project Based Learning

    DEFF Research Database (Denmark)

    Dirckinck-Holmfeld, Lone

    2002-01-01

    This paper describes a survey of technologies and to what extent they support virtual project based learning. The paper argues that a survey of learning technologies should be related to concrete learning tasks and processes. Problem oriented project pedagogy (POPP) is discussed, and a framework...... for evaluation is proposed where negotiation of meaning, coordination and resource management are identified as the key concepts in virtual project based learning. Three e-learning systems are selected for the survey, Virtual-U, Lotus Learningspace and Lotus Quickplace, as each system offers different strategies...... for e-learning. The paper concludes that virtual project based learning may benefit from facilities of all these systems....

  15. Synchronized Pair Configuration in Virtualization-Based Lab for Learning Computer Networks

    Science.gov (United States)

    Kongcharoen, Chaknarin; Hwang, Wu-Yuin; Ghinea, Gheorghita

    2017-01-01

    More studies are concentrating on using virtualization-based labs to facilitate computer or network learning concepts. Some benefits are lower hardware costs and greater flexibility in reconfiguring computer and network environments. However, few studies have investigated effective mechanisms for using virtualization fully for collaboration.…

  16. Benefitting from virtual customer environments: An empirical study of customer engagement

    NARCIS (Netherlands)

    Verhagen, T.; Swen, E; Feldberg, J.F.M.; Merikivi, J.

    2015-01-01

    Customer engagement has been labeled as a prerequisite for the success of virtual customer environments. A key challenge for organizations serving their customers via these environments is how to stimulate customer engagement. This study is among the first to shed light on this issue by examining

  17. Virtual reality solutions for the design of machine tools in practice

    OpenAIRE

    Zickner, H.; Neugebauer, Reimund; Weidlich, D.

    2006-01-01

    At the Virtual Reality Centre Production Engineering (VRCP) the Institute for Machine Tools and Production Processes (IWP) of the Chemnitz University of Technology and the Fraunhofer Institute for Machine Tools and Forming Technology (IWU) have developed several practical Virtual Reality (VR) based solutions for the industry. Some practical examples will show the benefits gained by the application of Virtual Reality techniques in the design process of machine tools and assembly lines.

  18. Dynamics of study strategies and teacher regulation in virtual patient learning activities: a cross sectional survey.

    Science.gov (United States)

    Edelbring, Samuel; Wahlström, Rolf

    2016-04-23

    Students' self-regulated learning becomes essential with increased use of exploratory web-based activities such as virtual patients (VPs). The purpose was to investigate the interplay between students' self-regulated learning strategies and perceived benefit in VP learning activities. A cross-sectional study (n = 150) comparing students' study strategies and perceived benefit of a virtual patient learning activity in a clinical clerkship preparatory course. Teacher regulation varied among three settings and was classified from shared to strong. These settings were compared regarding their respective relations between regulation strategies and perceived benefit of the virtual patient activity. Self-regulation learning strategy was generally associated with perceived benefit of the VP activities (rho 0.27, p strategies can increase the value of flexible web-based learning resources to students.

  19. On the effectiveness of virtual reality in the education of software engineering

    NARCIS (Netherlands)

    Akbulut, Akhan; Catal, Cagatay; Yildiz, Burak

    2018-01-01

    The popularity of virtual reality headsets have been rapidly increasing. With this technology, students can efficiently interact with the course content and learn the material faster than the traditional methodologies. In addition to this benefit, virtual reality devices also draw the attention

  20. Virtual Mentoring of Preservice Teachers

    Science.gov (United States)

    Reese, Jill

    2016-01-01

    The purpose of the study was to describe music teachers' perceptions of the benefits and challenges they experienced as virtual mentors of preservice music teachers. Each mentor was assigned a cohort of preservice teachers who were enrolled in an elementary general music methods course. Cohorts observed their mentor's teaching via Skype. Mentors…

  1. Virtual Reality and Engineering Education.

    Science.gov (United States)

    Pantelidis, Veronica S.

    1997-01-01

    Virtual Reality (VR) offers benefits to engineering education. This article defines VR and describes types; outlines reasons for using VR in engineering education; provides guidelines for using VR; presents a model for determining when to use VR; discusses VR applications; and describes hardware and software needed for a low-budget VR and…

  2. Volatility of methylglyoxal cloud SOA formed through OH radical oxidation and droplet evaporation

    Science.gov (United States)

    Ortiz-Montalvo, Diana L.; Schwier, Allison N.; Lim, Yong B.; McNeill, V. Faye; Turpin, Barbara J.

    2016-04-01

    The volatility of secondary organic aerosol (SOA) formed through cloud processing (aqueous hydroxyl radical (radOH) oxidation and droplet evaporation) of methylglyoxal (MGly) was studied. Effective vapor pressure and effective enthalpy of vaporization (ΔHvap,eff) were determined using 1) droplets containing MGly and its oxidation products, 2) a Vibrating Orifice Aerosol Generator (VOAG) system, and 3) Temperature Programmed Desorption Aerosol-Chemical Ionization Mass Spectrometry (TPD Aerosol-CIMS). Simulated in-cloud MGly oxidation (for 10-30 min) produces an organic mixture of higher and lower volatility components with an overall effective vapor pressure of (4 ± 7) × 10-7 atm at pH 3. The effective vapor pressure decreases by a factor of 2 with addition of ammonium hydroxide (pH 7). The fraction of organic material remaining in the particle-phase after drying was smaller than for similar experiments with glycolaldehyde and glyoxal SOA. The ΔHvap,eff of pyruvic acid and oxalic acid + methylglyoxal in the mixture (from TPD Aerosol-CIMS) were smaller than the theoretical enthalpies of the pure compounds and smaller than that estimated for the entire precursor/product mix after droplet evaporation. After 10-30 min of aqueous oxidation (one cloud cycle) the majority of the MGly + radOH precursor/product mix (even neutralized) will volatilize during droplet evaporation; neutralization and at least 80 min of oxidation at 10-12 M radOH (or >12 h at 10-14 M) is needed before low volatility ammonium oxalate exceeds pyruvate.

  3. Virtual reality and laparoscopic surgery.

    Science.gov (United States)

    Coleman, J; Nduka, C C; Darzi, A

    1994-12-01

    The nature of laparoscopic surgery makes it likely to benefit from current and future developments in virtual reality and telepresence technology. High-definition screens, three-dimensional sensory feedback and remote dextrous manipulation will be the next major developments in laparoscopic surgery. Simulators may be used in surgical training and in the evaluation of surgical capability.

  4. SOA based intensive support system for space radiation data

    International Nuclear Information System (INIS)

    Goranova, M.; Shishedjiev, B.; Genova, S.; Semkova, J.

    2013-01-01

    Modern data intensive science involves heterogeneous and structured data sets in sophisticated data formats. Scientists need access to distributed computing and data sources and support for remote access to expensive, multinational specialized instruments. Scientists need effective software for data analysis, querying, accessing and visualization. The interaction between computer science and science and engineering becomes essential for the automation of data manipulation. The key solution uses the Service-oriented Architecture (SOA) in the field of science and Grid computing. The goal of this paper is managing the scientific data received by the Lyulin-5 particle telescope used in MATROSHKA-R experiment performed at the International Space Station (ISS). The dynamics of radiation characteristics and their dependency on the time and the orbital parameters have been established. The experiment helps the accurate estimation of the impact of space radiation on human health in long-duration manned missions

  5. Special Experiences for Exceptional Students: Integrating Virtual Reality into Special Education Classrooms.

    Science.gov (United States)

    Miller, Erez Cedric

    This paper discusses some of the potential benefits and hazards that virtual reality holds for exceptional children in the special education system. Topics addressed include (1) applications of virtual reality, including developing academic skills via cyberspace, vocational training, and social learning in cyberspace; (2) telepresence and distance…

  6. Exploitation of the Virtual Worlds in Tourism and Tourism Education

    Directory of Open Access Journals (Sweden)

    Zejda Pavel

    2016-12-01

    Full Text Available Academics perceive a great potential of virtual worlds in various areas, including tourism and education. Efforts adapting the virtual worlds in practice are, however, still marginal. There is no clear definition of the virtual world. Therefore the author of this article attempts to provide one. The paper also focuses on the barriers of a wider exploitation of the virtual worlds and discusses the principles that might help to increase their potential in tourism area. One of the principles – gamification – favours a wider adaptation of the virtual worlds in tourism. Applying gamification principles provides visitors with some unique experiences while serving as a powerful marketing tool for institutions. The benefits of implementing tourism education activities based on cooperative principles set in an immersive environment of the virtual worlds are depicted afterwards. Finally, this paper includes successful case studies, which show advantages and drawbacks of some approaches in exploiting the virtual worlds in tourism and tourism education.

  7. Theoretical and experimental study of fundamental differences in the noise suppression of high-speed SOA-based all-optical switches

    DEFF Research Database (Denmark)

    Nielsen, Mads Lønstrup; Mørk, Jesper; Suzuki, R.

    2005-01-01

    We identify a fundamental difference between the ASE noise filtering properties of different all-optical SOA-based switch configurations, and divide the switches into two classes. An in-band ASE suppression ratio quantifying the difference is derived theoretically and the impact of the ASE...

  8. Two Approaches for the Management of Virtual Machines on Grid Infrastructures

    International Nuclear Information System (INIS)

    Tapiador, D.; Rubio-Montero, A. J.; Juedo, E.; Montero, R. S.; Llorente, I. M.

    2007-01-01

    Virtual machines are a promising technology to overcome some of the problems found in current Grid infrastructures, like heterogeneity, performance partitioning or application isolation. This work shows a comparison between two strategies to manage virtual machines in Globus Grids. The first alternative is a straightforward deployment that does not require additional middle ware to be installed. It is only based on standard Grid services and is not bound to a given virtualization technology. Although this option is fully functional, it is only suitable for single process batch jobs. The second solution makes use of the Virtual Workspace Service which allows a remote client to securely negotiate and manage a virtual resource. This approach better exploits the potential benefits offered by the virtualization technology and provides a wider application range. (Author)

  9. A SOA-based approach to geographical data sharing

    Science.gov (United States)

    Li, Zonghua; Peng, Mingjun; Fan, Wei

    2009-10-01

    In the last few years, large volumes of spatial data have been available in different government departments in China, but these data are mainly used within these departments. With the e-government project initiated, spatial data sharing become more and more necessary. Currently, the Web has been used not only for document searching but also for the provision and use of services, known as Web services, which are published in a directory and may be automatically discovered by software agents. Particularly in the spatial domain, the possibility of accessing these large spatial datasets via Web services has motivated research into the new field of Spatial Data Infrastructure (SDI) implemented using service-oriented architecture. In this paper a Service-Oriented Architecture (SOA) based Geographical Information Systems (GIS) is proposed, and a prototype system is deployed based on Open Geospatial Consortium (OGC) standard in Wuhan, China, thus that all the departments authorized can access the spatial data within the government intranet, and also these spatial data can be easily integrated into kinds of applications.

  10. Characterization of organic nitrate constituents of secondary organic aerosol (SOA) from nitrate-radical-initiated oxidation of limonene using high-resolution chemical ionization mass spectrometry

    Science.gov (United States)

    Faxon, Cameron; Hammes, Julia; Le Breton, Michael; Kant Pathak, Ravi; Hallquist, Mattias

    2018-04-01

    The gas-phase nitrate radical (NO3⚫) initiated oxidation of limonene can produce organic nitrate species with varying physical properties. Low-volatility products can contribute to secondary organic aerosol (SOA) formation and organic nitrates may serve as a NOx reservoir, which could be especially important in regions with high biogenic emissions. This work presents the measurement results from flow reactor studies on the reaction of NO3⚫ with limonene using a High-Resolution Time-of-Flight Chemical Ionization Mass Spectrometer (HR-ToF-CIMS) combined with a Filter Inlet for Gases and AEROsols (FIGAERO). Major condensed-phase species were compared to those in the Master Chemical Mechanism (MCM) limonene mechanism, and many non-listed species were identified. The volatility properties of the most prevalent organic nitrates in the produced SOA were determined. Analysis of multiple experiments resulted in the identification of several dominant species (including C10H15NO6, C10H17NO6, C8H11NO6, C10H17NO7, and C9H13NO7) that occurred in the SOA under all conditions considered. Additionally, the formation of dimers was consistently observed and these species resided almost completely in the particle phase. The identities of these species are discussed, and formation mechanisms are proposed. Cluster analysis of the desorption temperatures corresponding to the analyzed particle-phase species yielded at least five distinct groupings based on a combination of molecular weight and desorption profile. Overall, the results indicate that the oxidation of limonene by NO3⚫ produces a complex mixture of highly oxygenated monomer and dimer products that contribute to SOA formation.

  11. Characterization of organic nitrate constituents of secondary organic aerosol (SOA from nitrate-radical-initiated oxidation of limonene using high-resolution chemical ionization mass spectrometry

    Directory of Open Access Journals (Sweden)

    C. Faxon

    2018-04-01

    Full Text Available The gas-phase nitrate radical (NO3⚫ initiated oxidation of limonene can produce organic nitrate species with varying physical properties. Low-volatility products can contribute to secondary organic aerosol (SOA formation and organic nitrates may serve as a NOx reservoir, which could be especially important in regions with high biogenic emissions. This work presents the measurement results from flow reactor studies on the reaction of NO3⚫ with limonene using a High-Resolution Time-of-Flight Chemical Ionization Mass Spectrometer (HR-ToF-CIMS combined with a Filter Inlet for Gases and AEROsols (FIGAERO. Major condensed-phase species were compared to those in the Master Chemical Mechanism (MCM limonene mechanism, and many non-listed species were identified. The volatility properties of the most prevalent organic nitrates in the produced SOA were determined. Analysis of multiple experiments resulted in the identification of several dominant species (including C10H15NO6, C10H17NO6, C8H11NO6, C10H17NO7, and C9H13NO7 that occurred in the SOA under all conditions considered. Additionally, the formation of dimers was consistently observed and these species resided almost completely in the particle phase. The identities of these species are discussed, and formation mechanisms are proposed. Cluster analysis of the desorption temperatures corresponding to the analyzed particle-phase species yielded at least five distinct groupings based on a combination of molecular weight and desorption profile. Overall, the results indicate that the oxidation of limonene by NO3⚫ produces a complex mixture of highly oxygenated monomer and dimer products that contribute to SOA formation.

  12. Restorative effects of virtual nature settings.

    Science.gov (United States)

    Valtchanov, Deltcho; Barton, Kevin R; Ellard, Colin

    2010-10-01

    Previous research regarding the potential benefits of exposing individuals to surrogate nature (photographs and videos) has found that such immersion results in restorative effects such as increased positive affect, decreased negative affect, and decreased stress. In the current experiment, we examined whether immersion in a virtual computer-generated nature setting could produce restorative effects. Twenty-two participants were equally divided between two conditions, while controlling for gender. In each condition, participants performed a stress-induction task, and were then immersed in virtual reality (VR) for 10 minutes. The control condition featured a slide show in VR, and the nature experimental condition featured an active exploration of a virtual forest. Participants in the nature condition were found to exhibit increased positive affect and decreased stress after immersion in VR when compared to those in the control condition. The results suggest that immersion in virtual nature settings has similar beneficial effects as exposure to surrogate nature. These results also suggest that VR can be used as a tool to study and understand restorative effects.

  13. The Benefits and Barriers of Using Virtual Worlds to Engage Healthcare Professionals on Distance Learning Programmes

    Science.gov (United States)

    Hack, Catherine Jane

    2016-01-01

    Using the delivery of a large postgraduate distance learning module in bioethics to health professionals as an illustrative example, the type of learning activity that could be enhanced through delivery in an immersive virtual world (IVW) was explored. Several activities were repurposed from the "traditional" virtual learning environment…

  14. Open-Ended Behavioral Complexity for Evolved Virtual Creatures

    DEFF Research Database (Denmark)

    Lessin, Dan; Fussell, Don; Miikkulainen, Risto

    2013-01-01

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

  15. Virtually teaching virtual leadership

    DEFF Research Database (Denmark)

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

    2017-01-01

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

  16. Joint Orchestration of Cloud-Based Microservices and Virtual Network Functions

    OpenAIRE

    Kouchaksaraei, Hadi Razzaghi; Karl, Holger

    2018-01-01

    Recent studies show the increasing popularity of distributed cloud applications, which are composed of multiple microservices. Besides their known benefits, microservice architecture also enables to mix and match cloud applications and Network Function Virtualization (NFV) services (service chains), which are composed of Virtual Network Functions (VNFs). Provisioning complex services containing VNFs and microservices in a combined NFV/cloud platform can enhance service quality and optimise co...

  17. Reconfigurable virtual electrowetting channels.

    Science.gov (United States)

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

    2012-02-21

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

  18. Product Lines for Service Oriented Applications - PL for SOA

    Directory of Open Access Journals (Sweden)

    Maurice H. ter Beek

    2011-08-01

    Full Text Available PL for SOA proposes, formally, a software engineering methodology, development techniques and support tools for the provision of service product lines. We propose rigorous modeling techniques for the specification and verification of formal notations and languages for service computing with inclinations of variability. Through these cutting-edge technologies, increased levels of flexibility and adaptivity can be achieved. This will involve developing semantics of variability over behavioural models of services. Such tools will assist organizations to plan, optimize and control the quality of software service provision, both at design and at run time by making it possible to develop flexible and cost-effective software systems that support high levels of reuse. We tackle this challenge from two levels. We use feature modeling from product line engineering and, from a services point of view, the orchestration language Orc. We introduce the Smart Grid as the service product line to apply the techniques to.

  19. A Randomised Controlled Comparison of Second-Level Treatment Approaches for Treatment-Resistant Adults with Bulimia Nervosa and Binge Eating Disorder: Assessing the Benefits of Virtual Reality Cue Exposure Therapy.

    Science.gov (United States)

    Ferrer-García, Marta; Gutiérrez-Maldonado, José; Pla-Sanjuanelo, Joana; Vilalta-Abella, Ferran; Riva, Giuseppe; Clerici, Massimo; Ribas-Sabaté, Joan; Andreu-Gracia, Alexis; Fernandez-Aranda, Fernando; Forcano, Laura; Riesco, Nadine; Sánchez, Isabel; Escandón-Nagel, Neli; Gomez-Tricio, Osane; Tena, Virginia; Dakanalis, Antonios

    2017-11-01

    A question that arises from the literature on therapy is whether second-level treatment is effective for patients with recurrent binge eating who fail first-level treatment. It has been shown that subjects who do not stop binge eating after an initial structured cognitive-behavioural treatment (CBT) programme benefit from additional CBT (A-CBT) sessions; however, it has been suggested that these resistant patients would benefit even more from cue exposure therapy (CET) targeting features associated with poor response (e.g. urge to binge in response to a cue and anxiety experienced in the presence of binge-related cues). We assessed the effectiveness of virtual reality-CET as a second-level treatment strategy for 64 patients with bulimia nervosa and binge eating disorder who had been treated with limited results after using a structured CBT programme, in comparison with A-CBT. The significant differences observed between the two groups at post-treatment in dimensional (behavioural and attitudinal features, anxiety, food craving) and categorical (abstinence rates) outcomes highlighted the superiority of virtual reality-CET over A-CBT. Copyright © 2017 John Wiley & Sons, Ltd and Eating Disorders Association. Copyright © 2017 John Wiley & Sons, Ltd and Eating Disorders Association.

  20. Virtual teamwork in the context of technological and cultural transformation

    Directory of Open Access Journals (Sweden)

    Birgit FernUniversität Hagen

    2017-01-01

    Full Text Available Megatrends affect all individuals and organizations in our society. Mobility and flexibility are examples of megatrends that influence our everyday lives and also intensely alter the ways we work. The deployment of virtual teams meets the new chances emerging with these trends. Employees aspire to work virtually due to benefits, such as flexibility regarding the locations and hours for working. Organizations deploy virtual teams to remain competitive regarding new technological opportunities, employee retention and cost efficiency in an increasingly digital environment. Organizations can guide their change towards virtuality by building on the knowledge of practice as well as scientific insights regarding the deployment of virtual teams. In order to provide a holistic view on the structures and processes affected by such a change and thus provide guidance, a framework for analyzing and planning organizational change is adapted to virtual teamwork and presented in this paper. The framework shows that the deployment of virtual teams affects the whole organization. This comprehensive view on the implementation of virtual teamwork allows an integration of virtual teams and focusses on their performance. The adapted framework furthermore provides links for further in-depth research in this field.

  1. The TRIGA in virtual classroom for training

    International Nuclear Information System (INIS)

    Plata M, A. C.; Morales S, J. B.; Salazar S, E.

    2008-01-01

    The research nuclear reactors have been fundamental part in the evolution of the nuclear power plants and they have been used in the training for the obtaining of operation licenses of radioactive facilities. For purposes of training of professionals in nuclear engineering, it is interesting to know the benefit that can be obtained by means of the virtual representation of a research nuclear reactor TRIGA, with which they are possible the practice to be realized them but common that to date they are carried out in different nuclear facilities of training throughout the world. The simulation has become a valuable tool in the personal preparation, having obtained ambient and very approximate situations to the reality. The physical models of kinetics of neutrons, heat transfer, Cherenkov effect, dynamics of the xenon, as well as the virtual instrumentation is contemplated in this development. The instrumentation and control panels of a research reactor, failures waited for in the use of this equipment, physical consequences to instruments, virtual personnel and facilities, as well as the administrative and legal aspects that it requires to meet an authorized operator, must be available and they are considered in the first virtual approach. The obtaining of the reactor time constant comprises of the mathematical model that provides to the operator of a direct way the knowledge of the changes of power. The coolant and moderator are modeled as well as the retardations that appear in the measurements and controls that can be introduced from the virtual console. In the simulator the four possible states of operation of the TRIGA can be had. At the moment also the monitoring can be realized and control in remote form, thus the control and supervision interface for the remote operation will be analyzed in their benefits and possible risks in the instruction processes. (Author)

  2. Controlling social stress in virtual reality environments.

    Directory of Open Access Journals (Sweden)

    Dwi Hartanto

    Full Text Available Virtual reality exposure therapy has been proposed as a viable alternative in the treatment of anxiety disorders, including social anxiety disorder. Therapists could benefit from extensive control of anxiety eliciting stimuli during virtual exposure. Two stimuli controls are studied in this study: the social dialogue situation, and the dialogue feedback responses (negative or positive between a human and a virtual character. In the first study, 16 participants were exposed in three virtual reality scenarios: a neutral virtual world, blind date scenario, and job interview scenario. Results showed a significant difference between the three virtual scenarios in the level of self-reported anxiety and heart rate. In the second study, 24 participants were exposed to a job interview scenario in a virtual environment where the ratio between negative and positive dialogue feedback responses of a virtual character was systematically varied on-the-fly. Results yielded that within a dialogue the more positive dialogue feedback resulted in less self-reported anxiety, lower heart rate, and longer answers, while more negative dialogue feedback of the virtual character resulted in the opposite. The correlations between on the one hand the dialogue stressor ratio and on the other hand the means of SUD score, heart rate and audio length in the eight dialogue conditions showed a strong relationship: r(6 = 0.91, p = 0.002; r(6 = 0.76, p = 0.028 and r(6 = -0.94, p = 0.001 respectively. Furthermore, more anticipatory anxiety reported before exposure was found to coincide with more self-reported anxiety, and shorter answers during the virtual exposure. These results demonstrate that social dialogues in a virtual environment can be effectively manipulated for therapeutic purposes.

  3. Controlling social stress in virtual reality environments.

    Science.gov (United States)

    Hartanto, Dwi; Kampmann, Isabel L; Morina, Nexhmedin; Emmelkamp, Paul G M; Neerincx, Mark A; Brinkman, Willem-Paul

    2014-01-01

    Virtual reality exposure therapy has been proposed as a viable alternative in the treatment of anxiety disorders, including social anxiety disorder. Therapists could benefit from extensive control of anxiety eliciting stimuli during virtual exposure. Two stimuli controls are studied in this study: the social dialogue situation, and the dialogue feedback responses (negative or positive) between a human and a virtual character. In the first study, 16 participants were exposed in three virtual reality scenarios: a neutral virtual world, blind date scenario, and job interview scenario. Results showed a significant difference between the three virtual scenarios in the level of self-reported anxiety and heart rate. In the second study, 24 participants were exposed to a job interview scenario in a virtual environment where the ratio between negative and positive dialogue feedback responses of a virtual character was systematically varied on-the-fly. Results yielded that within a dialogue the more positive dialogue feedback resulted in less self-reported anxiety, lower heart rate, and longer answers, while more negative dialogue feedback of the virtual character resulted in the opposite. The correlations between on the one hand the dialogue stressor ratio and on the other hand the means of SUD score, heart rate and audio length in the eight dialogue conditions showed a strong relationship: r(6) = 0.91, p = 0.002; r(6) = 0.76, p = 0.028 and r(6) = -0.94, p = 0.001 respectively. Furthermore, more anticipatory anxiety reported before exposure was found to coincide with more self-reported anxiety, and shorter answers during the virtual exposure. These results demonstrate that social dialogues in a virtual environment can be effectively manipulated for therapeutic purposes.

  4. Controlling Social Stress in Virtual Reality Environments

    Science.gov (United States)

    Hartanto, Dwi; Kampmann, Isabel L.; Morina, Nexhmedin; Emmelkamp, Paul G. M.; Neerincx, Mark A.; Brinkman, Willem-Paul

    2014-01-01

    Virtual reality exposure therapy has been proposed as a viable alternative in the treatment of anxiety disorders, including social anxiety disorder. Therapists could benefit from extensive control of anxiety eliciting stimuli during virtual exposure. Two stimuli controls are studied in this study: the social dialogue situation, and the dialogue feedback responses (negative or positive) between a human and a virtual character. In the first study, 16 participants were exposed in three virtual reality scenarios: a neutral virtual world, blind date scenario, and job interview scenario. Results showed a significant difference between the three virtual scenarios in the level of self-reported anxiety and heart rate. In the second study, 24 participants were exposed to a job interview scenario in a virtual environment where the ratio between negative and positive dialogue feedback responses of a virtual character was systematically varied on-the-fly. Results yielded that within a dialogue the more positive dialogue feedback resulted in less self-reported anxiety, lower heart rate, and longer answers, while more negative dialogue feedback of the virtual character resulted in the opposite. The correlations between on the one hand the dialogue stressor ratio and on the other hand the means of SUD score, heart rate and audio length in the eight dialogue conditions showed a strong relationship: r(6) = 0.91, p = 0.002; r(6) = 0.76, p = 0.028 and r(6) = −0.94, p = 0.001 respectively. Furthermore, more anticipatory anxiety reported before exposure was found to coincide with more self-reported anxiety, and shorter answers during the virtual exposure. These results demonstrate that social dialogues in a virtual environment can be effectively manipulated for therapeutic purposes. PMID:24671006

  5. Possible Application of Virtual Reality in Geography Teaching

    Directory of Open Access Journals (Sweden)

    Ivan Stojšić

    2017-03-01

    Full Text Available Virtual reality represents simulated three-dimensional environment created by hardware and software, which providing realistic experience and possibility of interaction to the end-user. Benefits provided by immersive virtual reality in educational setting were recognised in the past decades, however mass application was left out due to the lack of development and high price. Intensive development of new platforms and virtual reality devices in the last few years started up with Oculus Rift, and subsequently accelerated in the year 2014 by occurrence of Google Cardboard. Nowadays, for the first time in history, immersive virtual reality is available to millions of people. In the mid 2015 Google commenced developing Expeditions Pioneer Program aiming to massively utilise the Google Cardboard platform in education. Expeditions and other VR apps can enhance geography teaching and learning. Realistic experience acquired by utilisation of virtual reality in teaching process significantly overcome possibilities provided by images and illustrations in the textbook. Besides literature review on usage of virtual reality in education this paper presents suggestion of VR mobile apps that can be used together with the Google Cardboard head mounted displays (HMDs in geography classes, thereby emphasising advantages and disadvantages as well as possible obstacles which may occur in introducing the immersive virtual reality in the educational process.

  6. Semi-Immersive Virtual Turbine Engine Simulation System

    Science.gov (United States)

    Abidi, Mustufa H.; Al-Ahmari, Abdulrahman M.; Ahmad, Ali; Darmoul, Saber; Ameen, Wadea

    2018-05-01

    The design and verification of assembly operations is essential for planning product production operations. Recently, virtual prototyping has witnessed tremendous progress, and has reached a stage where current environments enable rich and multi-modal interaction between designers and models through stereoscopic visuals, surround sound, and haptic feedback. The benefits of building and using Virtual Reality (VR) models in assembly process verification are discussed in this paper. In this paper, we present the virtual assembly (VA) of an aircraft turbine engine. The assembly parts and sequences are explained using a virtual reality design system. The system enables stereoscopic visuals, surround sounds, and ample and intuitive interaction with developed models. A special software architecture is suggested to describe the assembly parts and assembly sequence in VR. A collision detection mechanism is employed that provides visual feedback to check the interference between components. The system is tested for virtual prototype and assembly sequencing of a turbine engine. We show that the developed system is comprehensive in terms of VR feedback mechanisms, which include visual, auditory, tactile, as well as force feedback. The system is shown to be effective and efficient for validating the design of assembly, part design, and operations planning.

  7. Virtual, augmented reality and serious games for healthcare

    CERN Document Server

    Jain, Lakhmi; Anderson, Paul

    2014-01-01

    There is a tremendous interest among researchers for the development of virtual, augmented reality and games technologies due to their widespread applications in medicine and healthcare. To date the major applications of these technologies include medical simulation, telemedicine, medical and healthcare training, pain control, visualisation aid for surgery, rehabilitation in cases such as stroke, phobia, and trauma therapies. Many recent studies have identified the benefits of using Virtual Reality, Augmented Reality, or serious games in a variety of medical applications.   This research volume on Virtual, Augmented Reality and Serious Games for Healthcare 1 offers an insightful introduction to the theories, development and applications of virtual, augmented reality and digital games technologies in medical and clinical settings and healthcare in general. It is divided into six sections: section one presents a selection of applications in medical education and healthcare management; Section two relates to th...

  8. Development of a new virtual nuclear reactor laboratory

    International Nuclear Information System (INIS)

    Ahmad Abrishami; Ali Pazirandeh

    2009-01-01

    Full text: Nowadays the education industry benefits from computer programs and software in various ways as well as many other industries. Here the e-learning technology uses some forms of software platform to present its contents. Virtual laboratories are superior tools in this technology. A virtual laboratory is interactive graphical user interface software that is based on known scientific laws of its virtual elements, which responses to user acts as desired in the real case. There are some known commercial and non-commercial ones. There are also some simulation software in the field of nuclear industry that has some uses in operator learning and some other applications such as analyzing the effects of human mistakes on plant safety. In this paper we discuss more about the ways to develop a virtual nuclear reactor laboratory and propose our first release of such tool. Our target reactor is Tehran Research Reactor (TRR), which is a pool type reactor. We used WIMS and COSTANZA to develop the simulator kernel of virtual laboratory. (Author)

  9. The virtual water content of major grain crops and virtual water flows between regions in China.

    Science.gov (United States)

    Sun, Shi-Kun; Wu, Pu-Te; Wang, Yu-Bao; Zhao, Xi-Ning

    2013-04-01

    The disproportionate distribution of arable land and water resources has become a bottleneck for guaranteeing food security in China. Virtual water and virtual water trade theory have provided a potential solution to improve water resources management in agriculture and alleviate water crises in water-scarce regions. The present study evaluates the green and blue virtual water content of wheat, maize and rice at the regional scale in China. It then assesses the water-saving benefits of virtual water flows related to the transfer of the three crops between regions. The national average virtual water content of wheat, maize and rice were 1071 m(3) per ton (50.98% green water, 49.02% blue water ), 830 m(3) per ton (76.27% green water, 23.73% blue water) and 1294 m(3) per ton (61.90% green water, 38.10% blue water), respectively. With the regional transfer of wheat, maize and rice, virtual water flows reached 30.08 Gm(3) (59.91% green water, 40.09% blue water). Meanwhile, China saved 11.47 Gm(3) green water, while it consumed 7.84 Gm(3) more blue water than with a no-grain transfer scenario in 2009. In order to guarantee food security in China, the government should improve water productivity (reduce virtual water content of crops) during the grain production process. Meanwhile, under the preconditions of economic feasibility and land-water resources availability, China should guarantee the grain-sown area in southern regions for taking full advantage of green water resources and to alleviate the pressure on water resources. © 2012 Society of Chemical Industry.

  10. Virtual cascade impactors for the collection of radioactive atmospheric aerosols

    International Nuclear Information System (INIS)

    Berner, A.

    1988-01-01

    Starting from impaction theory, the properties of virtual impaction stages are discussed and compared to classical impactors. Virtual impaction stages offer the benefit of sampling coarse particles without bouncing and reentrainment, but turbulent mixing affects the performance of virtual stages. Future research should concentrate on special configurations for reducing the effects of turbulent mixing. Virtual impaction stages for sampling radioactive aerosols are to be designed in regard of the analytical requirements, the purpose of the measurements, and the aerosol. Therefore, the aerosol components expected in radioactive aerosols are discussed on the background of the multimodal model, which relates the size distribution to the genesis and the history of the aerosol. Reference is made to recent data of the radioactive atmospheric aerosol

  11. Utilization of Virtual Server Technology in Mission Operations

    Science.gov (United States)

    Felton, Larry; Lankford, Kimberly; Pitts, R. Lee; Pruitt, Robert W.

    2010-01-01

    Virtualization provides the opportunity to continue to do "more with less"---more computing power with fewer physical boxes, thus reducing the overall hardware footprint, power and cooling requirements, software licenses, and their associated costs. This paper explores the tremendous advantages and any disadvantages of virtualization in all of the environments associated with software and systems development to operations flow. It includes the use and benefits of the Intelligent Platform Management Interface (IPMI) specification, and identifies lessons learned concerning hardware and network configurations. Using the Huntsville Operations Support Center (HOSC) at NASA Marshall Space Flight Center as an example, we demonstrate that deploying virtualized servers as a means of managing computing resources is applicable and beneficial to many areas of application, up to and including flight operations.

  12. Eventedness and Disjuncture in Virtual Worlds

    Science.gov (United States)

    White, David; Le Cornu, Alison

    2010-01-01

    Background: Many of the potential benefits of using virtual worlds for teaching and learning are difficult to define and often become overly focused on the functionality of the technology or on its ability to support informal or "social" forms of learning. Purpose: The aim of the paper is to highlight the experiential nature of virtual…

  13. Cognitive training on stroke patients via virtual reality-based serious games.

    Science.gov (United States)

    Gamito, Pedro; Oliveira, Jorge; Coelho, Carla; Morais, Diogo; Lopes, Paulo; Pacheco, José; Brito, Rodrigo; Soares, Fabio; Santos, Nuno; Barata, Ana Filipa

    2017-02-01

    Use of virtual reality environments in cognitive rehabilitation offers cost benefits and other advantages. In order to test the effectiveness of a virtual reality application for neuropsychological rehabilitation, a cognitive training program using virtual reality was applied to stroke patients. A virtual reality-based serious games application for cognitive training was developed, with attention and memory tasks consisting of daily life activities. Twenty stroke patients were randomly assigned to two conditions: exposure to the intervention, and waiting list control. The results showed significant improvements in attention and memory functions in the intervention group, but not in the controls. Overall findings provide further support for the use of VR cognitive training applications in neuropsychological rehabilitation. Implications for Rehabilitation Improvements in memory and attention functions following a virtual reality-based serious games intervention. Training of daily-life activities using a virtual reality application. Accessibility to training contents.

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

    Science.gov (United States)

    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.

  15. A perspective on SOA generated in aerosol water from glyoxal and methylglyoxal and its impacts on climate-relevant aerosol properties

    Science.gov (United States)

    Sareen, N.; McNeill, V. F.

    2011-12-01

    In recent years, glyoxal and methylglyoxal have emerged to be potentially important SOA precursors with significant implications for climate-related aerosol properties. Here we will discuss how the chemistry of these and similar organic compounds in aerosol water can affect the aerosol optical and cloud formation properties. Aqueous-phase SOA production from glyoxal and methylglyoxal is a potential source of strongly light-absorbing organics, or "brown carbon". We characterized the kinetics of brown carbon formation from these precursors in mixtures of ammonium sulfate and water using UV-Vis spectrophotometry. This mechanism has been incorporated into a photochemical box model with coupled gas phase-aqueous aerosol chemistry. Methylglyoxal and related compounds also may impact an aerosol's ability to act as a cloud condensation nucleus. We recently showed via pendant drop tensiometry and aerosol chamber studies that uptake of methylglyoxal from the gas phase driven by aqueous-phase oligomerization chemistry is a potentially significant, previously unidentified source of surface-active organic material in aerosols. Results from pendant drop tensiometry showed significantly depressed surface tension in methylglyoxal-ammonium sulfate solutions. We further found that ammonium sulfate particles exposed to gas-phase methylglyoxal in a 3.5 m3 aerosol reaction chamber activate into cloud droplets at sizes up to 15% lower at a given supersaturation than do pure ammonium sulfate particles. The observed enhancement exceeds that predicted based on Henry's Law and our measurements of surface tension depression in bulk solutions, suggesting that surface adsorption of methylglyoxal plays a role in determining CCN activity. Methylglyoxal and similar gas-phase surfactants may be an important and overlooked source of enhanced CCN activity in the atmosphere. To characterize the SOA products formed in these solutions, an Aerosol Chemical Ionization Mass Spectrometer (CIMS) was used

  16. Experimental determination of the partitioning coefficient of β-pinene oxidation products in SOAs.

    Science.gov (United States)

    Hohaus, Thorsten; Gensch, Iulia; Kimmel, Joel; Worsnop, Douglas R; Kiendler-Scharr, Astrid

    2015-06-14

    The composition of secondary organic aerosols (SOAs) formed by β-pinene ozonolysis was experimentally investigated in the Juelich aerosol chamber. Partitioning of oxidation products between gas and particles was measured through concurrent concentration measurements in both phases. Partitioning coefficients (Kp) of 2.23 × 10(-5) ± 3.20 × 10(-6) m(3) μg(-1) for nopinone, 4.86 × 10(-4) ± 1.80 × 10(-4) m(3) μg(-1) for apoverbenone, 6.84 × 10(-4) ± 1.52 × 10(-4) m(3) μg(-1) for oxonopinone and 2.00 × 10(-3) ± 1.13 × 10(-3) m(3) μg(-1) for hydroxynopinone were derived, showing higher values for more oxygenated species. The observed Kp values were compared with values predicted using two different semi-empirical approaches. Both methods led to an underestimation of the partitioning coefficients with systematic differences between the methods. Assuming that the deviation between the experiment and the model is due to non-ideality of the mixed solution in particles, activity coefficients of 4.82 × 10(-2) for nopinone, 2.17 × 10(-3) for apoverbenone, 3.09 × 10(-1) for oxonopinone and 7.74 × 10(-1) for hydroxynopinone would result using the vapour pressure estimation technique that leads to higher Kp. We discuss that such large non-ideality for nopinone could arise due to particle phase processes lowering the effective nopinone vapour pressure such as diol- or dimer formation. The observed high partitioning coefficients compared to modelled results imply an underestimation of SOA mass by applying equilibrium conditions.

  17. Stereopsis, Visuospatial Ability, and Virtual Reality in Anatomy Learning

    OpenAIRE

    Luursema, Jan-Maarten; Vorstenbosch, Marc; Kooloos, Jan

    2017-01-01

    A new wave of virtual reality headsets has become available. A potential benefit for the study of human anatomy is the reintroduction of stereopsis and absolute size. We report a randomized controlled trial to assess the contribution of stereopsis to anatomy learning, for students of different visuospatial ability. Sixty-three participants engaged in a one-hour session including a study phase and posttest. One group studied 3D models of the anatomy of the deep neck in full stereoptic virtual ...

  18. Virtual building environments (VBE) - Applying information modeling to buildings

    Energy Technology Data Exchange (ETDEWEB)

    Bazjanac, Vladimir

    2004-06-21

    A Virtual Building Environment (VBE) is a ''place'' where building industry project staffs can get help in creating Building Information Models (BIM) and in the use of virtual buildings. It consists of a group of industry software that is operated by industry experts who are also experts in the use of that software. The purpose of a VBE is to facilitate expert use of appropriate software applications in conjunction with each other to efficiently support multidisciplinary work. This paper defines BIM and virtual buildings, and describes VBE objectives, set-up and characteristics of operation. It informs about the VBE Initiative and the benefits from a couple of early VBE projects.

  19. Hybrid Feedforward-Feedback Noise Control Using Virtual Sensors

    Science.gov (United States)

    Bean, Jacob; Fuller, Chris; Schiller, Noah

    2016-01-01

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

  20. Virtual reality simulators for gastrointestinal endoscopy training.

    Science.gov (United States)

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

    2014-01-16

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

  1. Towards the development of run times leveraging virtualization for high performance computing

    International Nuclear Information System (INIS)

    Diakhate, F.

    2010-12-01

    In recent years, there has been a growing interest in using virtualization to improve the efficiency of data centers. This success is rooted in virtualization's excellent fault tolerance and isolation properties, in the overall flexibility it brings, and in its ability to exploit multi-core architectures efficiently. These characteristics also make virtualization an ideal candidate to tackle issues found in new compute cluster architectures. However, in spite of recent improvements in virtualization technology, overheads in the execution of parallel applications remain, which prevent its use in the field of high performance computing. In this thesis, we propose a virtual device dedicated to message passing between virtual machines, so as to improve the performance of parallel applications executed in a cluster of virtual machines. We also introduce a set of techniques facilitating the deployment of virtualized parallel applications. These functionalities have been implemented as part of a runtime system which allows to benefit from virtualization's properties in a way that is as transparent as possible to the user while minimizing performance overheads. (author)

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

    Science.gov (United States)

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

    2015-10-01

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

  3. Virtual endoscopy in neurosurgery: a review.

    Science.gov (United States)

    Neubauer, André; Wolfsberger, Stefan

    2013-01-01

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

  4. Virtual goods recommendations in virtual worlds.

    Science.gov (United States)

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

    2015-01-01

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

  5. Physico-chemical characterization of SOA derived from catechol and guaiacol – a model substance for the aromatic fraction of atmospheric HULIS

    Directory of Open Access Journals (Sweden)

    K. Whitmore

    2011-01-01

    Full Text Available Secondary organic aerosol (SOA was produced from the aromatic precursors catechol and guaiacol by reaction with ozone in the presence and absence of simulated sunlight and humidity and investigated for its properties as a proxy for HUmic-LIke Substances (HULIS. Beside a small particle size, a relatively low molecular weight and typical optical features in the UV/VIS spectral range, HULIS contain a typical aromatic and/or olefinic chemical structure and highly oxidized functional groups within a high chemical diversity. Various methods were used to characterize the secondary organic aerosols obtained: Fourier transform infrared spectroscopy (FTIR demonstrated the formation of several carbonyl containing functional groups as well as structural and functional differences between aerosols formed at different environmental conditions. UV/VIS spectroscopy of filter samples showed that the particulate matter absorbs far into the visible range up to more than 500 nm. Ultrahigh resolved mass spectroscopy (ICR-FT/MS determined O/C-ratios between 0.3 and 1 and observed m/z ratios between 200 and 450 to be most abundant. Temperature-programmed-pyrolysis mass spectroscopy (TPP-MS identified carboxylic acids and lactones/esters as major functional groups. Particle sizing using a condensation-nucleus-counter and differential-mobility-particle-sizer (CNC/DMPS monitored the formation of small particles during the SOA formation process. Particle imaging, using field-emission-gun scanning electron microscopy (FEG-SEM, showed spherical particles, forming clusters and chains. We conclude that catechol and guaiacol are appropriate precursors for studies of the processing of aromatic SOA with atmospheric HULIS properties on the laboratory scale.

  6. Benefits of virtual reality based cognitive rehabilitation through simulated activities of daily living: a randomized controlled trial with stroke patients.

    Science.gov (United States)

    Faria, Ana Lúcia; Andrade, Andreia; Soares, Luísa; I Badia, Sergi Bermúdez

    2016-11-02

    Stroke is one of the most common causes of acquired disability, leaving numerous adults with cognitive and motor impairments, and affecting patients' capability to live independently. There is substancial evidence on post-stroke cognitive rehabilitation benefits, but its implementation is generally limited by the use of paper-and-pencil methods, insufficient personalization, and suboptimal intensity. Virtual reality tools have shown potential for improving cognitive rehabilitation by supporting carefully personalized, ecologically valid tasks through accessible technologies. Notwithstanding important progress in VR-based cognitive rehabilitation systems, specially with Activities of Daily Living (ADL's) simulations, there is still a need of more clinical trials for its validation. In this work we present a one-month randomized controlled trial with 18 stroke in and outpatients from two rehabilitation units: 9 performing a VR-based intervention and 9 performing conventional rehabilitation. The VR-based intervention involved a virtual simulation of a city - Reh@City - where memory, attention, visuo-spatial abilities and executive functions tasks are integrated in the performance of several daily routines. The intervention had levels of difficulty progression through a method of fading cues. There was a pre and post-intervention assessment in both groups with the Addenbrooke Cognitive Examination (primary outcome) and the Trail Making Test A and B, Picture Arrangement from WAIS III and Stroke Impact Scale 3.0 (secondary outcomes). A within groups analysis revealed significant improvements in global cognitive functioning, attention, memory, visuo-spatial abilities, executive functions, emotion and overall recovery in the VR group. The control group only improved in self-reported memory and social participation. A between groups analysis, showed significantly greater improvements in global cognitive functioning, attention and executive functions when comparing VR to

  7. PAST AND FUTURE APPLICATIONS OF 3-D (VIRTUAL REALITY TECHNOLOGY

    Directory of Open Access Journals (Sweden)

    Nigel Foreman

    2014-11-01

    Full Text Available Virtual Reality (virtual environment technology, VET has been widely available for twenty years. In that time, the benefits of using virtual environments (VEs have become clear in many areas of application, including assessment and training, education, rehabilitation and psychological research in spatial cognition. The flexibility, reproducibility and adaptability of VEs are especially important, particularly in the training and testing of navigational and way-finding skills. Transfer of training between real and virtual environments has been found to be reliable. However, input device usage can compromise spatial information acquisition from VEs, and distances in VEs are invariably underestimated. The present review traces the evolution of VET, anticipates future areas in which developments are likely to occur, and highlights areas in which research is needed to optimise usage.

  8. Virtual marketing in virtual enterprises

    OpenAIRE

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

    2008-01-01

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

  9. Estudio Comparativo de Plataformas Cloud Computing para Arquitecturas SOA

    Directory of Open Access Journals (Sweden)

    Franco Bocchio

    2013-10-01

    Full Text Available Las plataformas Cloud Computing están fundadas en un paradigma tecnológico moderno que ofrece nuevas alternativas a empresas de diversas envergaduras para implementar modelos de negocios innovadores. Con estos nuevos modelos de negocio las empresas pequeñas pueden hacer uso de las plataformas Cloud Computing disponiendo de la posibilidad de incrementar, tanto progresiva como abruptamente, su capacidad de cómputo y almacenamiento de datos en función de las necesidades y en tiempo real, implicando una oportunidad singular para la competencia de mercado. En adición, las arquitecturas orientadas a servicios otorgan características de grandes beneficios para los sistemas modernos, permitiendo altos niveles de reutilización de funcionalidades, encapsulamiento y nuevas oportunidades para sociedades entre proveedores y consumidores de servicios. En este trabajo se propone, entonces, analizar y comparar las plataformas de los principales proveedores de servicios Cloud Computing, alineados a los distintos modelos arquitectónicos SOA que de las plataformas antedichas se desprenden con el objetivo de encontrar similitudes y diferencias, así como también faltantes.

  10. Virtual Realities: A School Leader's Guide to Online Education. A Technology Leadership Network Special Report.

    Science.gov (United States)

    Abdal-Haqq, Ismat, Ed.

    This book is designed to provide practical information about planning and operating virtual, or online, schools. It discusses and illustrates promising practices and successful models and approaches; provides planning resources for implementation; presents costs and benefits of launching virtual schools; offers preventive strategies that help…

  11. Virtual Presenters: Towards Interactive Virtual Presentations

    NARCIS (Netherlands)

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

    2005-01-01

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

  12. World Wind: NASA's Virtual Globe

    Science.gov (United States)

    Hogan, P.

    2007-12-01

    Virtual globes have set the standard for information exchange. Once you've experienced the visually rich and highly compelling nature of data delivered via virtual globes with their highly engaging context of 3D, it's hard to go back to a flat 2D world. Just as the sawbones of not-too-long-ago have given way to sophisticated surgical operating theater, today's medium for information exchange is just beginning to leap from the staid chalkboards and remote libraries to fingertip navigable 3D worlds. How we harness this technology to serve a world inundated with information will describe the quality of our future. Our instincts for discovery and entertainment urge us on. There's so much we could know if the world's knowledge was presented to us in its natural context. Virtual globes are almost magical in their ability to reveal natural wonders. Anyone flying along a chain of volcanoes, a mid-ocean ridge or deep ocean trench, while simultaneously seeing the different depths to the history of earthquakes in those areas, will be delighted to sense Earth's dynamic nature in a way that would otherwise take several paragraphs of "boring" text. The sophisticated concepts related to global climate change would be far more comprehensible when experienced via a virtual globe. There is a large universe of public and private geospatial data sets that virtual globes can bring to light. The benefit derived from access to this data within virtual globes represents a significant return on investment for government, industry, the general public, and especially in the realm of education. Data access remains a key issue. Just as the highway infrastructure allows unimpeded access from point A to point B, an open standards-based infrastructure for data access allows virtual globes to exchange data in the most efficient manner possible. This data can be either free or proprietary. The Open Geospatial Consortium is providing the leadership necessary for this open standards-based data access

  13. Virtual Worlds for Virtual Organizing

    Science.gov (United States)

    Rhoten, Diana; Lutters, Wayne

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

  14. Are Learning Styles Relevant to Virtual Reality?

    Science.gov (United States)

    Chen, Chwen Jen; Toh, Seong Chong; Ismail, Wan Mohd Fauzy Wan

    2005-01-01

    This study aims to investigate the effects of a virtual reality (VR)-based learning environment on learners with different learning styles. The findings of the aptitude-by-treatment interaction study have shown that learners benefit most from the VR (guided exploration) mode, irrespective of their learning styles. This shows that the VR-based…

  15. Enhancing Student Collaboration in Global Virtual Teams

    Science.gov (United States)

    Kohut, Gary F.

    2012-01-01

    With the growth in the global economy and the rapid development of communication and information technologies, global virtual teams are quickly becoming the norm in the workplace. Research indicates, however, that many students have little or no experience working in such teams. Students who learn through these experiences benefit from higher task…

  16. All-Optical flip-flop operation using a SOA and DFB laser diode optical feedback combination

    DEFF Research Database (Denmark)

    D'Oosterlinck, W.; Öhman, Filip; Buron, Jakob Due

    2007-01-01

    We report on the switching of an all-optical flip-flop consisting of a semiconductor optical amplifier (SOA) and a distributed feedback laser diode (DFB), bidirectionally coupled to each other. Both simulation and experimental results are presented. Switching times as low as 50ps, minimal required...... switch pulse energies below lpJ and a repetition rate of 1.25GHz have been measured. Contrast ratios over 25dB have been obtained. The dependence on the pulse length and CW input power of the minimal required switch energy is investigated....

  17. Visualizing learner activities with a virtual learning environment

    DEFF Research Database (Denmark)

    Eskildsen, Søren; Rodil, Kasper; Rehm, Matthias

    2012-01-01

    This paper presents how to gain insights into children’s navigation of an interactive virtual learning environment and how that would benefit their educators. A prototype for logging user information as quantifiable data has been developed and deployed in an in-situ evaluation of the system...

  18. The Benefits of Third-Person Perspective in Virtual and Augmented Reality?

    OpenAIRE

    Salamin, P.; Vexo, F.; Thalmann, D.

    2006-01-01

    Instead of the reality in which you can see your own limbs, in virtual reality simulations it is sometimes disturbing not to be able to see your own body. It seems to create an issue in the proprioperception of the user who does not completely feel integrated in the environment. This perspective should be beneficial for the users. We propose to give the possibility to the people to use the first and the third-person perspective like in video games (e.g. GTA). As the gamers prefer to use the t...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-07-01

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

  20. Knowledge translation in eHealth: building a virtual community.

    Science.gov (United States)

    Bassi, Jesdeep; Lau, Francis; Hagens, Simon; Leaver, Chad; Price, Morgan

    2013-01-01

    Knowledge can be powerful in eliciting positive change when it is put into action. This is the belief that drives knowledge translation. The University of Victoria (UVic) eHealth Observatory is focused on deriving knowledge from health information system (HIS) evaluation, which needs to be shared with HIS practitioners. Through an application of the Knowledge-to-Action Framework and the concept of a virtual community, we have established the virtual eHealth Benefits Evaluation Knowledge Translation (KT) Community. This paper describes the foundational elements of the KT Community and our overall KT strategy.

  1. The Break of High Voltage IGBT and Diode SOA Performance——SSCM%高压IGBT和二极管SOA性能的突破——SSCM

    Institute of Scientific and Technical Information of China (English)

    M Rahimo; A Kopta; S Eicher; U Schlapbach

    2008-01-01

    介绍了一种新型高压IGBT和二极管设计平台,它展现出目前安全工作区域SOA(Safe Operation Area,简称SOA)所能达到的最高极限.首次展示了一种额定电压3.3~6.5kV、能够同时承受动态雪崩和开关自箝位模式(SwitchSelf Clamp Mode,简称SSCM)、低损耗的IGBT和二极管芯片组.这项成果将促成高压器件SOA能力的全新突破.

  2. A Virtual Approach to Teaching Safety Skills to Children with Autism Spectrum Disorder

    Science.gov (United States)

    Self, Trisha; Scudder, Rosalind R.; Weheba, Gamal; Crumrine, Daiquirie

    2007-01-01

    Recent advancements in the development of hardware/software configurations for delivering virtual reality (VR) environments to individuals with disabilities have included approaches for children with autism spectrum disorder (ASD). This article describes a study comparing benefits of using VR to benefits of an integrated/visual treatment model…

  3. Virtual Laboratories in Science Education: Students' Motivation and Experiences in Two Tertiary Biology Courses

    Science.gov (United States)

    Dyrberg, Nadia Rahbek; Treusch, Alexander H.; Wiegand, Claudia

    2017-01-01

    Potential benefits of simulations and virtual laboratory exercises in natural sciences have been both theorised and studied recently. This study reports findings from a pilot study on student attitude, motivation and self-efficacy when using the virtual laboratory programme Labster. The programme allows interactive learning about the workflows and…

  4. Virtual Environments and Autism: A Developmental Psychopathological Approach

    Science.gov (United States)

    Rajendran, G.

    2013-01-01

    Individuals with autism spectrum disorders supposedly have an affinity with information and communication technology (ICT), making it an ideally suited media for this population. Virtual environments (VEs)--both two-dimensional and immersive--represent a particular kind of ICT that might be of special benefit. Specifically, this paper discusses…

  5. Adaptive UIX Layer for University Information SOA-BUS

    Directory of Open Access Journals (Sweden)

    Octavian DOSPINESCU

    2017-01-01

    Full Text Available The user interface (UI layer is considered one of the key components of software applications since it connects their end-users to functionalities. Well-engineered and robust software applications could eventually fail to be adopted due to a weak UI layer. In the current market, when creating sites, UI designers have to determine how to plan the best interface according to the devices of the users, namely desktops, laptops, tablets or smartphones. Having this in mind, the current paper aims to present the adaptive UIX Layer for a University Information SOA-Bus (UISB – a topic discussed in previous works [1], [2]. In this respect, we reviewed the literature on responsive and adaptive web design in order to identify the best front-end approach to the UISB. According to our findings, there is a strong debate in the academic field as well in the IT business in what concerns UI design. Recent interests have shown that the new trend in drafting the front-end layer is choosing between a responsive and an adaptive design. While arguments provided by both sides have failed to ease the decision makers’ choices on what type of design to choose, we aim to bring some light on the subject by proposing different layers for the UISB.

  6. Investigating the Impact of Virtual Communities on Furtherance of Customers’ Buying Behavior

    Directory of Open Access Journals (Sweden)

    Mohammad Fathian

    2014-09-01

    Full Text Available In recent years, virtual communities have been significantly popular and almost all of them are targeted for business profitability. In our study, the profitability of these communities for businesses has been analyzed from a commercial perspective. The study considers virtual community as a business model which can have a great impact on consumer purchase decision process. With respect to reference groups and word-of-mouth recommendations in virtual communities, contributing factors have been detected and a model of impacts and relationships between these factors has been presented. Hypotheses of the mentioned model are evaluated by making use of a questionnaire completed by 110 members of virtual communities. Using AMOS program and path analysis method, statistical analysis of received responses showed that factors such as virtual community's information quality, trust between people, sense of belonging, virtual community members’ perceived benefit and members’ permeability are effective to different degrees, and there is no significant relationship between social identity of members and their permeability.

  7. Sensorial Virtualization: Coupling Gaming and Virtual Environment

    NARCIS (Netherlands)

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

    2014-01-01

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

  8. Ecological validity of virtual environments to assess human navigation ability

    Directory of Open Access Journals (Sweden)

    Ineke eVan Der Ham

    2015-05-01

    Full Text Available Route memory is frequently assessed in virtual environments. These environments can be presented in a fully controlled manner and are easy to use. Yet they lack the physical involvement that participants have when navigating real environments. For some aspects of route memory this may result in reduced performance in virtual environments. We assessed route memory performance in four different environments: real, virtual, virtual with directional information (compass, and hybrid. In the hybrid environment, participants walked the route outside on an open field, while all route information (i.e. path, landmarks was shown simultaneously on a handheld tablet computer. Results indicate that performance in the real life environment was better than in the virtual conditions for tasks relying on survey knowledge, like pointing to start and end point, and map drawing. Performance in the hybrid condition however, hardly differed from real life performance. Performance in the virtual environment did not benefit from directional information. Given these findings, the hybrid condition may offer the best of both worlds: the performance level is comparable to that of real life for route memory, yet it offers full control of visual input during route learning.

  9. Operating Room Performance Improves after Proficiency-Based Virtual Reality Cataract Surgery Training

    DEFF Research Database (Denmark)

    Thomsen, Ann Sofia Skou; Bach-Holm, Daniella; Kjærbo, Hadi

    2017-01-01

    PURPOSE: To investigate the effect of virtual reality proficiency-based training on actual cataract surgery performance. The secondary purpose of the study was to define which surgeons benefit from virtual reality training. DESIGN: Multicenter masked clinical trial. PARTICIPANTS: Eighteen cataract...... surgeons with different levels of experience. METHODS: Cataract surgical training on a virtual reality simulator (EyeSi) until a proficiency-based test was passed. MAIN OUTCOME MEASURES: Technical performance in the operating room (OR) assessed by 3 independent, masked raters using a previously validated...... task-specific assessment tool for cataract surgery (Objective Structured Assessment of Cataract Surgical Skill). Three surgeries before and 3 surgeries after the virtual reality training were video-recorded, anonymized, and presented to the raters in random order. RESULTS: Novices (non...

  10. Are Spatial Visualization Abilities Relevant to Virtual Reality?

    Science.gov (United States)

    Chen, Chwen Jen

    2006-01-01

    This study aims to investigate the effects of virtual reality (VR)-based learning environment on learners of different spatial visualization abilities. The findings of the aptitude-by-treatment interaction study have shown that learners benefit most from the Guided VR mode, irrespective of their spatial visualization abilities. This indicates that…

  11. Virtual Class Support at the Virtual Machine Level

    DEFF Research Database (Denmark)

    Nielsen, Anders Bach; Ernst, Erik

    2009-01-01

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

  12. Training of Perceptual Motor Skills in Multimodal Virtual Environments

    Directory of Open Access Journals (Sweden)

    Gopher Daniel

    2011-12-01

    Full Text Available Multimodal, immersive, virtual reality (VR techniques open new perspectives for perceptualmotor skill trainers. They also introduce new risks and dangers. This paper describes the benefits and pitfalls of multimodal training and the cognitive building blocks of a multimodal, VR training simulators.

  13. Virtual CT-colonoscopy. Examination technique, limitations, and prospects

    International Nuclear Information System (INIS)

    Springer, P.; Dessl, A.; Giacomuzzi, S.M.; Stoehr, B.; Stoeger, A.; Bodner, G.; Buchberger, W.

    1997-01-01

    Virtual CT-colonoscopy is a post-processing method which allows for reconstruction of inner bowel surface structures from helical CT datasets. The reconstructed images simulate the views which are known from fiberoptic endoscopy. Since colorectal cancer is the second main cause of death in USA and Europe today and since recent screening recommendations are often ignored by the public, a non-invasive or minimal-invasive procedure for colonic evaluation would offer some benefits. Virtual CT-colonoscopy generally involves three essential steps: patient preparation with cleansing of the bowel and administration of an air enema, helical CT-examination by using appropriate scan parameters, and interactive 3D rendering of the volume dataset. Although recent studies have demonstrated that polypoid lesions of about 5 mm size are well detectable and although virtual colonoscopy offers many advantages over fiberoptic endoscopy, some technical and clinical limitations must still be noted. Thus, the current inability of virtual colonoscopy to provide texture and color leads to problems in identifying flat lesions; the presence of retained or adherent fecal matter may result to false positive diagnosis and collapsed segments of bowel may cause problems as they cannot subsequently be evaluated during image reconstruction. Virtual endoscopy is still in its infancy and further technical and clinical development are necessary. (orig./AJ) [de

  14. Establishing a Virtual Community of Practice in Simulation: The Value of Social Media.

    Science.gov (United States)

    Thoma, Brent; Brazil, Victoria; Spurr, Jesse; Palaganas, Janice; Eppich, Walter; Grant, Vincent; Cheng, Adam

    2018-04-01

    Professional development opportunities are not readily accessible for most simulation educators, who may only connect with simulation experts at periodic and costly conferences. Virtual communities of practice consist of individuals with a shared passion who communicate via virtual media to advance their own learning and that of others. A nascent virtual community of practice is developing online for healthcare simulation on social media platforms. Simulation educators should consider engaging on these platforms for their own benefit and to help develop healthcare simulation educators around the world. Herein, we describe this developing virtual community of practice and offer guidance to assist educators to engage, learn, and contribute to the growth of the community.

  15. Stereopsis, Visuospatial Ability, and Virtual Reality in Anatomy Learning.

    Science.gov (United States)

    Luursema, Jan-Maarten; Vorstenbosch, Marc; Kooloos, Jan

    2017-01-01

    A new wave of virtual reality headsets has become available. A potential benefit for the study of human anatomy is the reintroduction of stereopsis and absolute size. We report a randomized controlled trial to assess the contribution of stereopsis to anatomy learning, for students of different visuospatial ability. Sixty-three participants engaged in a one-hour session including a study phase and posttest. One group studied 3D models of the anatomy of the deep neck in full stereoptic virtual reality; one group studied those structures in virtual reality without stereoptic depth. The control group experienced an unrelated virtual reality environment. A post hoc questionnaire explored cognitive load and problem solving strategies of the participants. We found no effect of condition on learning. Visuospatial ability however did impact correct answers at F (1) = 5.63 and p = .02. No evidence was found for an impact of cognitive load on performance. Possibly, participants were able to solve the posttest items based on visuospatial information contained in the test items themselves. Additionally, the virtual anatomy may have been complex enough to discourage memory based strategies. It is important to control the amount of visuospatial information present in test items.

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

    CERN Document Server

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

    2010-01-01

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

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

    Directory of Open Access Journals (Sweden)

    América Valdés

    2002-06-01

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

  18. Utilization of virtual learning environments in the allied health professions.

    Science.gov (United States)

    Butina, Michelle; Brooks, Donna; Dominguez, Paul J; Mahon, Gwendolyn M

    2013-01-01

    Multiple technology based tools have been used to enhance skill development in allied health education, which now includes virtual learning environments. The purpose of this study was to explore whether, and how, this latest instructional technology is being adapted in allied health education. An online survey was circulated to all Association of Schools of Allied Health Professions (ASAHP) member institutions and focused on three broad areas of virtual learning environments: the uses of, the perceived pros and cons of, and the outcomes of utilizing them. Results show 40% (17 of 42) of the respondent use some form of the technology. The use of virtual learning technology in other healthcare professions (e.g., medicine) demonstrates the potential benefits to allied health education.

  19. Variable Delay With Directly-Modulated R-SOA and Optical Filters for Adaptive Antenna Radio-Fiber Access

    DEFF Research Database (Denmark)

    Prince, Kamau; Presi, Marco; Chiuchiarelli, Andrea

    2009-01-01

    types of signals defined in IEEE 802.16 (WiMAX) standard for wireless networks: a 90 Mbps single-carrier signal (64-QAM at 2.4 GHz) and a 78 Mbps multitone orthogonal frequency-division multiple access (OFDMA) signal. The power budget of this configuration supports a 4-element antenna array....... on a directly-modulated reflective emiconductor amplifier (R-SOA) and exploits the interplay between transmission-line dispersion and tunable optical filtering to achieve flexible true time delay, with $2pi$ beam steering at the different antennas. The system was characterized, then successfully tested with two...

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

    International Nuclear Information System (INIS)

    Smartt, Heidi Anne

    2001-01-01

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

  1. Stereopsis, Visuospatial Ability, and Virtual Reality in Anatomy Learning

    NARCIS (Netherlands)

    Luursema, J.M.; Vorstenbosch, M.A.; Kooloos, J.G.M.

    2017-01-01

    A new wave of virtual reality headsets has become available. A potential benefit for the study of human anatomy is the reintroduction of stereopsis and absolute size. We report a randomized controlled trial to assess the contribution of stereopsis to anatomy learning, for students of different

  2. Constructing service-oriented architecture adoption maturity matrix using Kano model

    Science.gov (United States)

    Hamzah, Mohd Hamdi Irwan; Baharom, Fauziah; Mohd, Haslina

    2017-10-01

    Commonly, organizations adopted Service-Oriented Architecture (SOA) because it can provide a flexible reconfiguration and can reduce the development time and cost. In order to guide the SOA adoption, previous industry and academia have constructed SOA maturity model. However, there is a limited number of works on how to construct the matrix in the previous SOA maturity model. Therefore, this study is going to provide a method that can be used in order to construct the matrix in the SOA maturity model. This study adapts Kano Model to construct the cross evaluation matrix focused on SOA adoption IT and business benefits. This study found that Kano Model can provide a suitable and appropriate method for constructing the cross evaluation matrix in SOA maturity model. Kano model also can be used to plot, organize and better represent the evaluation dimension for evaluating the SOA adoption.

  3. Virtual Library: An essential component of virtual education

    Directory of Open Access Journals (Sweden)

    M zarghani

    2015-06-01

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

  4. Human Factors Virtual Analysis Techniques for NASA's Space Launch System Ground Support using MSFC's Virtual Environments Lab (VEL)

    Science.gov (United States)

    Searcy, Brittani

    2017-01-01

    Using virtual environments to assess complex large scale human tasks provides timely and cost effective results to evaluate designs and to reduce operational risks during assembly and integration of the Space Launch System (SLS). NASA's Marshall Space Flight Center (MSFC) uses a suite of tools to conduct integrated virtual analysis during the design phase of the SLS Program. Siemens Jack is a simulation tool that allows engineers to analyze human interaction with CAD designs by placing a digital human model into the environment to test different scenarios and assess the design's compliance to human factors requirements. Engineers at MSFC are using Jack in conjunction with motion capture and virtual reality systems in MSFC's Virtual Environments Lab (VEL). The VEL provides additional capability beyond standalone Jack to record and analyze a person performing a planned task to assemble the SLS at Kennedy Space Center (KSC). The VEL integrates Vicon Blade motion capture system, Siemens Jack, Oculus Rift, and other virtual tools to perform human factors assessments. By using motion capture and virtual reality, a more accurate breakdown and understanding of how an operator will perform a task can be gained. By virtual analysis, engineers are able to determine if a specific task is capable of being safely performed by both a 5% (approx. 5ft) female and a 95% (approx. 6'1) male. In addition, the analysis will help identify any tools or other accommodations that may to help complete the task. These assessments are critical for the safety of ground support engineers and keeping launch operations on schedule. Motion capture allows engineers to save and examine human movements on a frame by frame basis, while virtual reality gives the actor (person performing a task in the VEL) an immersive view of the task environment. This presentation will discuss the need of human factors for SLS and the benefits of analyzing tasks in NASA MSFC's VEL.

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

    Science.gov (United States)

    Parmar, Dhaval

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

  6. Virtual Reality and the Virtual Library.

    Science.gov (United States)

    Oppenheim, Charles

    1993-01-01

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

  7. From virtual environment to virtual community

    NARCIS (Netherlands)

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

    2001-01-01

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

  8. Validation of virtual reality as a tool to understand and prevent child pedestrian injury.

    Science.gov (United States)

    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.

  9. Virtual Sensor Test Instrumentation

    Science.gov (United States)

    Wang, Roy

    2011-01-01

    Virtual Sensor Test Instrumentation is based on the concept of smart sensor technology for testing with intelligence needed to perform sell-diagnosis of health, and to participate in a hierarchy of health determination at sensor, process, and system levels. A virtual sensor test instrumentation consists of five elements: (1) a common sensor interface, (2) microprocessor, (3) wireless interface, (4) signal conditioning and ADC/DAC (analog-to-digital conversion/ digital-to-analog conversion), and (5) onboard EEPROM (electrically erasable programmable read-only memory) for metadata storage and executable software to create powerful, scalable, reconfigurable, and reliable embedded and distributed test instruments. In order to maximize the efficient data conversion through the smart sensor node, plug-and-play functionality is required to interface with traditional sensors to enhance their identity and capabilities for data processing and communications. Virtual sensor test instrumentation can be accessible wirelessly via a Network Capable Application Processor (NCAP) or a Smart Transducer Interlace Module (STIM) that may be managed under real-time rule engines for mission-critical applications. The transducer senses the physical quantity being measured and converts it into an electrical signal. The signal is fed to an A/D converter, and is ready for use by the processor to execute functional transformation based on the sensor characteristics stored in a Transducer Electronic Data Sheet (TEDS). Virtual sensor test instrumentation is built upon an open-system architecture with standardized protocol modules/stacks to interface with industry standards and commonly used software. One major benefit for deploying the virtual sensor test instrumentation is the ability, through a plug-and-play common interface, to convert raw sensor data in either analog or digital form, to an IEEE 1451 standard-based smart sensor, which has instructions to program sensors for a wide variety of

  10. The ALIVE Project: Astronomy Learning in Immersive Virtual Environments

    Science.gov (United States)

    Yu, K. C.; Sahami, K.; Denn, G.

    2008-06-01

    The Astronomy Learning in Immersive Virtual Environments (ALIVE) project seeks to discover learning modes and optimal teaching strategies using immersive virtual environments (VEs). VEs are computer-generated, three-dimensional environments that can be navigated to provide multiple perspectives. Immersive VEs provide the additional benefit of surrounding a viewer with the simulated reality. ALIVE evaluates the incorporation of an interactive, real-time ``virtual universe'' into formal college astronomy education. In the experiment, pre-course, post-course, and curriculum tests will be used to determine the efficacy of immersive visualizations presented in a digital planetarium versus the same visual simulations in the non-immersive setting of a normal classroom, as well as a control case using traditional classroom multimedia. To normalize for inter-instructor variability, each ALIVE instructor will teach at least one of each class in each of the three test groups.

  11. Virtual surgery in a (tele-)radiology framework.

    Science.gov (United States)

    Glombitza, G; Evers, H; Hassfeld, S; Engelmann, U; Meinzer, H P

    1999-09-01

    This paper presents telemedicine as an extension of a teleradiology framework through tools for virtual surgery. To classify the described methods and applications, the research field of virtual reality (VR) is broadly reviewed. Differences with respect to technical equipment, methodological requirements and areas of application are pointed out. Desktop VR, augmented reality, and virtual reality are differentiated and discussed in some typical contexts of diagnostic support, surgical planning, therapeutic procedures, simulation and training. Visualization techniques are compared as a prerequisite for virtual reality and assigned to distinct levels of immersion. The advantage of a hybrid visualization kernel is emphasized with respect to the desktop VR applications that are subsequently shown. Moreover, software design aspects are considered by outlining functional openness in the architecture of the host system. Here, a teleradiology workstation was extended by dedicated tools for surgical planning through a plug-in mechanism. Examples of recent areas of application are introduced such as liver tumor resection planning, diagnostic support in heart surgery, and craniofacial surgery planning. In the future, surgical planning systems will become more important. They will benefit from improvements in image acquisition and communication, new image processing approaches, and techniques for data presentation. This will facilitate preoperative planning and intraoperative applications.

  12. Virtual Reality: Developing a VR space for Academic activities

    Science.gov (United States)

    Kaimaris, D.; Stylianidis, E.; Karanikolas, N.

    2014-05-01

    Virtual reality (VR) is extensively used in various applications; in industry, in academia, in business, and is becoming more and more affordable for end users from the financial point of view. At the same time, in academia and higher education more and more applications are developed, like in medicine, engineering, etc. and students are inquiring to be well-prepared for their professional life after their educational life cycle. Moreover, VR is providing the benefits having the possibility to improve skills but also to understand space as well. This paper presents the methodology used during a course, namely "Geoinformatics applications" at the School of Spatial Planning and Development (Eng.), Aristotle University of Thessaloniki, to create a virtual School space. The course design focuses on the methods and techniques to be used in order to develop the virtual environment. In addition the project aspires to become more and more effective for the students and provide a real virtual environment with useful information not only for the students but also for any citizen interested in the academic life at the School.

  13. Designing 3 Dimensional Virtual Reality Using Panoramic Image

    Science.gov (United States)

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

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

  14. MIDDIS: ARQUITECTURA DE REFERENCIA PARA LA INTERACCIÓN DE SERVICIOS BASADOS EN SOA E IMS

    Directory of Open Access Journals (Sweden)

    Ximena Velasco Melo

    2010-01-01

    Full Text Available En telecomunicaciones la tendencia actual está dirigida hacia una búsqueda de la convergencia de redes fijas y móviles, y por lo tanto, las redes que se diseñan son más complejas. Así mismo, se presentan nuevos retos en el campo de la interconexión e integración de servicios a través de múltiples redes, tecnologías y áreas de negocio, lo cual hace imprescindible interoperar los servicios de las Tecnologías de Información (Information Technologies, IT , con los de telecomunicaciones. Para aportar en la solución de estos retos y debido además, a la ausencia de un entorno de telecomunicaciones convergente y completamente adecuado para la prestación de servicios tradicionales y nuevos, en este artículo se presenta una arquitectura de referencia que permite la habilitación y entrega rápida de servicios convergentes para el mundo IT y el mundo de las Telecomunicaciones, con la mediación en la interacción de servicios basados en la Arquitectura Orientada a Servicios (Service Oriented Architecture, SOA, y el Subsistema Multimedia IP (IP Multimedia Subsystem, IMS . La característica esencial del middleware, implementado en un Entorno de Ejecución de Lógica de Servicio (Service Logic Execution Environment, SLEE, consiste en que IMS utiliza a SOA para integrar sus propios elementos software con componentes externos y de esta manera, se logra la combinación de las facilidades de la Web y de IMS para exponer un conjunto de servicios enriquecidos para ambos mundos.

  15. A virtual radiation therapy workflow training simulation

    International Nuclear Information System (INIS)

    Bridge, P.; Crowe, S.B.; Gibson, G.; Ellemor, N.J.; Hargrave, C.; Carmichael, M.

    2016-01-01

    Aim: Simulation forms an increasingly vital component of clinical skills development in a wide range of professional disciplines. Simulation of clinical techniques and equipment is designed to better prepare students for placement by providing an opportunity to learn technical skills in a “safe” academic environment. In radiotherapy training over the last decade or so this has predominantly comprised treatment planning software and small ancillary equipment such as mould room apparatus. Recent virtual reality developments have dramatically changed this approach. Innovative new simulation applications and file processing and interrogation software have helped to fill in the gaps to provide a streamlined virtual workflow solution. This paper outlines the innovations that have enabled this, along with an evaluation of the impact on students and educators. Method: Virtual reality software and workflow applications have been developed to enable the following steps of radiation therapy to be simulated in an academic environment: CT scanning using a 3D virtual CT scanner simulation; batch CT duplication; treatment planning; 3D plan evaluation using a virtual linear accelerator; quantitative plan assessment, patient setup with lasers; and image guided radiotherapy software. Results: Evaluation of the impact of the virtual reality workflow system highlighted substantial time saving for academic staff as well as positive feedback from students relating to preparation for clinical placements. Students valued practice in the “safe” environment and the opportunity to understand the clinical workflow ahead of clinical department experience. Conclusion: Simulation of most of the radiation therapy workflow and tasks is feasible using a raft of virtual reality simulation applications and supporting software. Benefits of this approach include time-saving, embedding of a case-study based approach, increased student confidence, and optimal use of the clinical environment

  16. Use of Virtual Reality Tools for Vestibular Disorders Rehabilitation: A Comprehensive Analysis.

    Science.gov (United States)

    Bergeron, Mathieu; Lortie, Catherine L; Guitton, Matthieu J

    2015-01-01

    Classical peripheral vestibular disorders rehabilitation is a long and costly process. While virtual reality settings have been repeatedly suggested to represent possible tools to help the rehabilitation process, no systematic study had been conducted so far. We systematically reviewed the current literature to analyze the published protocols documenting the use of virtual reality settings for peripheral vestibular disorders rehabilitation. There is an important diversity of settings and protocols involving virtual reality settings for the treatment of this pathology. Evaluation of the symptoms is often not standardized. However, our results unveil a clear effect of virtual reality settings-based rehabilitation of the patients' symptoms, assessed by objectives tools such as the DHI (mean decrease of 27 points), changing symptoms handicap perception from moderate to mild impact on life. Furthermore, we detected a relationship between the duration of the exposure to virtual reality environments and the magnitude of the therapeutic effects, suggesting that virtual reality treatments should last at least 150 minutes of cumulated exposure to ensure positive outcomes. Virtual reality offers a pleasant and safe environment for the patient. Future studies should standardize evaluation tools, document putative side effects further, compare virtual reality to conventional physical therapy, and evaluate economical costs/benefits of such strategies.

  17. Use of Virtual Reality Tools for Vestibular Disorders Rehabilitation: A Comprehensive Analysis

    Directory of Open Access Journals (Sweden)

    Mathieu Bergeron

    2015-01-01

    Full Text Available Classical peripheral vestibular disorders rehabilitation is a long and costly process. While virtual reality settings have been repeatedly suggested to represent possible tools to help the rehabilitation process, no systematic study had been conducted so far. We systematically reviewed the current literature to analyze the published protocols documenting the use of virtual reality settings for peripheral vestibular disorders rehabilitation. There is an important diversity of settings and protocols involving virtual reality settings for the treatment of this pathology. Evaluation of the symptoms is often not standardized. However, our results unveil a clear effect of virtual reality settings-based rehabilitation of the patients’ symptoms, assessed by objectives tools such as the DHI (mean decrease of 27 points, changing symptoms handicap perception from moderate to mild impact on life. Furthermore, we detected a relationship between the duration of the exposure to virtual reality environments and the magnitude of the therapeutic effects, suggesting that virtual reality treatments should last at least 150 minutes of cumulated exposure to ensure positive outcomes. Virtual reality offers a pleasant and safe environment for the patient. Future studies should standardize evaluation tools, document putative side effects further, compare virtual reality to conventional physical therapy, and evaluate economical costs/benefits of such strategies.

  18. Comparison of three aerosol chemical characterization techniques utilizing PTR-ToF-MS: a study on freshly formed and aged biogenic SOA

    Science.gov (United States)

    Gkatzelis, Georgios I.; Tillmann, Ralf; Hohaus, Thorsten; Müller, Markus; Eichler, Philipp; Xu, Kang-Ming; Schlag, Patrick; Schmitt, Sebastian H.; Wegener, Robert; Kaminski, Martin; Holzinger, Rupert; Wisthaler, Armin; Kiendler-Scharr, Astrid

    2018-03-01

    An intercomparison of different aerosol chemical characterization techniques has been performed as part of a chamber study of biogenic secondary organic aerosol (BSOA) formation and aging at the atmosphere simulation chamber SAPHIR (Simulation of Atmospheric PHotochemistry In a large Reaction chamber). Three different aerosol sampling techniques - the aerosol collection module (ACM), the chemical analysis of aerosol online (CHARON) and the collection thermal-desorption unit (TD) were connected to proton transfer reaction time-of-flight mass spectrometers (PTR-ToF-MSs) to provide chemical characterization of the SOA. The techniques were compared among each other and to results from an aerosol mass spectrometer (AMS) and a scanning mobility particle sizer (SMPS). The experiments investigated SOA formation from the ozonolysis of β-pinene, limonene, a β-pinene-limonene mix and real plant emissions from Pinus sylvestris L. (Scots pine). The SOA was subsequently aged by photo-oxidation, except for limonene SOA, which was aged by NO3 oxidation. Despite significant differences in the aerosol collection and desorption methods of the PTR-based techniques, the determined chemical composition, i.e. the same major contributing signals, was found by all instruments for the different chemical systems studied. These signals could be attributed to known products expected from the oxidation of the examined monoterpenes. The sampling and desorption method of ACM and TD provided additional information on the volatility of individual compounds and showed relatively good agreement. Averaged over all experiments, the total aerosol mass recovery compared to an SMPS varied within 80 ± 10, 51 ± 5 and 27 ± 3 % for CHARON, ACM and TD, respectively. Comparison to the oxygen-to-carbon ratios (O : C) obtained by AMS showed that all PTR-based techniques observed lower O : C ratios, indicating a loss of molecular oxygen either during aerosol sampling or detection. The differences in total

  19. A virtual power plant model for time-driven power flow calculations

    Directory of Open Access Journals (Sweden)

    Gerardo Guerra

    2017-11-01

    Full Text Available This paper presents the implementation of a custom-made virtual power plant model in OpenDSS. The goal is to develop a model adequate for time-driven power flow calculations in distribution systems. The virtual power plant is modeled as the aggregation of renewable generation and energy storage connected to the distribution system through an inverter. The implemented operation mode allows the virtual power plant to act as a single dispatchable generation unit. The case studies presented in the paper demonstrate that the model behaves according to the specified control algorithm and show how it can be incorporated into the solution scheme of a general parallel genetic algorithm in order to obtain the optimal day-ahead dispatch. Simulation results exhibit a clear benefit from the deployment of a virtual power plant when compared to distributed generation based only on renewable intermittent generation.

  20. US-CERN Virtual Visits: Building Transcontinental Connections for High Energy Physics

    CERN Document Server

    Gonski, Julia; The ATLAS collaboration

    2017-01-01

    For nearly fifteen years, Virtual Visits at CERN have been bringing high-energy physics research directly to the public, through the use of videoconferencing systems at both ATLAS and CMS experimental sites. Over 30,000 people from all seven continents have participated in Virtual Visits to date, engaging students, teachers, artists, and general enthusiasts alike. While these connections often take place in science festivals or classrooms, the versatility of the medium allows the visit to be customized for any audience. In particular, Virtual Visit connections to the United States can integrate a population for which distance from the experiment may hinder education and awareness. Examples of such targeted audiences include US Congressional offices and other governmental institutions, to enhance dialogue about the benefits of global basic research, and historically underrepresented or underserved minority groups. Both the foundational work and future possibilities of US Virtual Visit connections is discussed.

  1. Immersive Training Systems: Virtual Reality and Education and Training.

    Science.gov (United States)

    Psotka, Joseph

    1995-01-01

    Describes virtual reality (VR) technology and VR research on education and training. Focuses on immersion as the key added value of VR, analyzes cognitive variables connected to immersion, how it is generated in synthetic environments and its benefits. Discusses value of tracked, immersive visual displays over nonimmersive simulations. Contains 78…

  2. The Impact of Virtual Reality on Chronic Pain.

    Science.gov (United States)

    Jones, Ted; Moore, Todd; Choo, James

    2016-01-01

    The treatment of chronic pain could benefit from additional non-opioid interventions. Virtual reality (VR) has been shown to be effective in decreasing pain for procedural or acute pain but to date there have been few studies on its use in chronic pain. The present study was an investigation of the impact of a virtual reality application for chronic pain. Thirty (30) participants with various chronic pain conditions were offered a five-minute session using a virtual reality application called Cool! Participants were asked about their pain using a 0-10 visual analog scale rating before the VR session, during the session and immediately after the session. They were also asked about immersion into the VR world and about possible side effects. Pain was reduced from pre-session to post-session by 33%. Pain was reduced from pre-session during the VR session by 60%. These changes were both statistically significant at the p virtual reality session. All participants (100%) reported a decrease in pain to some degree between pre-session pain and during-session pain. The virtual reality experience was found here to provide a significant amount of pain relief. A head mounted display (HMD) was used with all subjects and no discomfort was experienced. Only one participant noted any side effects. VR seems to have promise as a non-opioid treatment for chronic pain and further investigation is warranted.

  3. Virtual geotechnical laboratory experiments using a simulator

    Science.gov (United States)

    Penumadu, Dayakar; Zhao, Rongda; Frost, David

    2000-04-01

    The details of a test simulator that provides a realistic environment for performing virtual laboratory experimentals in soil mechanics is presented. A computer program Geo-Sim that can be used to perform virtual experiments, and allow for real-time observations of material response is presented. The results of experiments, for a given set of input parameters, are obtained with the test simulator using well-trained artificial neural-network-based soil models for different soil types and stress paths. Multimedia capabilities are integrated in Geo-Sim, using software that links and controls a laser disc player with a real-time parallel processing ability. During the simulation of a virtual experiment, relevant portions of the video image of a previously recorded test on an actual soil specimen are dispalyed along with the graphical presentation of response from the feedforward ANN model predictions. The pilot simulator developed to date includes all aspects related to performing a triaxial test on cohesionless soil under undrained and drained conditions. The benefits of the test simulator are also presented.

  4. Performance Analysis of Ivshmem for High-Performance Computing in Virtual Machines

    Science.gov (United States)

    Ivanovic, Pavle; Richter, Harald

    2018-01-01

    High-Performance computing (HPC) is rarely accomplished via virtual machines (VMs). In this paper, we present a remake of ivshmem which can change this. Ivshmem was a shared memory (SHM) between virtual machines on the same server, with SHM-access synchronization included, until about 5 years ago when newer versions of Linux and its virtualization library libvirt evolved. We restored that SHM-access synchronization feature because it is indispensable for HPC and made ivshmem runnable with contemporary versions of Linux, libvirt, KVM, QEMU and especially MPICH, which is an implementation of MPI - the standard HPC communication library. Additionally, MPICH was transparently modified by us to get ivshmem included, resulting in a three to ten times performance improvement compared to TCP/IP. Furthermore, we have transparently replaced MPI_PUT, a single-side MPICH communication mechanism, by an own MPI_PUT wrapper. As a result, our ivshmem even surpasses non-virtualized SHM data transfers for block lengths greater than 512 KBytes, showing the benefits of virtualization. All improvements were possible without using SR-IOV.

  5. Virtual Reality in Pediatric Psychology.

    Science.gov (United States)

    Parsons, Thomas D; Riva, Giuseppe; Parsons, Sarah; Mantovani, Fabrizia; Newbutt, Nigel; Lin, Lin; Venturini, Eva; Hall, Trevor

    2017-11-01

    Virtual reality (VR) technologies allow for controlled simulations of affectively engaging background narratives. These virtual environments offer promise for enhancing emotionally relevant experiences and social interactions. Within this context, VR can allow instructors, therapists, neuropsychologists, and service providers to offer safe, repeatable, and diversifiable interventions that can benefit assessments and learning in both typically developing children and children with disabilities. Research has also pointed to VR's capacity to reduce children's experience of aversive stimuli and reduce anxiety levels. Although there are a number of purported advantages of VR technologies, challenges have emerged. One challenge for this field of study is the lack of consensus on how to do trials. A related issue is the need for establishing the psychometric properties of VR assessments and interventions. This review investigates the advantages and challenges inherent in the application of VR technologies to pediatric assessments and interventions. Copyright © 2017 by the American Academy of Pediatrics.

  6. Stereopsis, Visuospatial Ability, and Virtual Reality in Anatomy Learning

    Directory of Open Access Journals (Sweden)

    Jan-Maarten Luursema

    2017-01-01

    Full Text Available A new wave of virtual reality headsets has become available. A potential benefit for the study of human anatomy is the reintroduction of stereopsis and absolute size. We report a randomized controlled trial to assess the contribution of stereopsis to anatomy learning, for students of different visuospatial ability. Sixty-three participants engaged in a one-hour session including a study phase and posttest. One group studied 3D models of the anatomy of the deep neck in full stereoptic virtual reality; one group studied those structures in virtual reality without stereoptic depth. The control group experienced an unrelated virtual reality environment. A post hoc questionnaire explored cognitive load and problem solving strategies of the participants. We found no effect of condition on learning. Visuospatial ability however did impact correct answers at F(1=5.63 and p=.02. No evidence was found for an impact of cognitive load on performance. Possibly, participants were able to solve the posttest items based on visuospatial information contained in the test items themselves. Additionally, the virtual anatomy may have been complex enough to discourage memory based strategies. It is important to control the amount of visuospatial information present in test items.

  7. Alleviating travel anxiety through virtual reality and narrated video technology.

    Science.gov (United States)

    Ahn, J C; Lee, O

    2013-01-01

    This study presents an empirical evidence of benefit of narrative video clips in embedded virtual reality websites of hotels for relieving travel anxiety. Even though it was proven that virtual reality functions do provide some relief in travel anxiety, a stronger virtual reality website can be built when narrative video clips that show video clips with narration about important aspects of the hotel. We posit that these important aspects are 1. Escape route and 2. Surrounding neighborhood information, which are derived from the existing research on anxiety disorder as well as travel anxiety. Thus we created a video clip that showed and narrated about the escape route from the hotel room, another video clip that showed and narrated about surrounding neighborhood. We then conducted experiments with this enhanced virtual reality website of a hotel by having human subjects play with the website and fill out a questionnaire. The result confirms our hypothesis that there is a statistically significant relationship between the degree of travel anxiety and psychological relief caused by the use of embedded virtual reality functions with narrative video clips of a hotel website (Tab. 2, Fig. 3, Ref. 26).

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

    Science.gov (United States)

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

    2017-01-01

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

  9. [Self-regulation and virtual reality in forensic psychiatry: An emphasis on theoretical underpinnings].

    Science.gov (United States)

    Benbouriche, M; Renaud, P; Pelletier, J-F; De Loor, P

    2016-12-01

    Forensic psychiatry is the field whose expertise is the assessment and treatment of offending behaviours, in particular when offenses are related to mental illness. An underlying question for all etiological models concerns the manner in which an individual's behaviours are organized. Specifically, it becomes crucial to understand how certain individuals come to display maladaptive behaviours in a given environment, especially when considering issues such as offenders' responsibility and their ability to change their behaviours. Thanks to its ability to generate specific environments, associated with a high experimental control on generated simulations, virtual reality is gaining recognition in forensic psychiatry. Virtual reality has generated promising research data and may turn out to be a remarkable clinical tool in the near future. While research has increased, a conceptual work about its theoretical underpinnings is still lacking. However, no important benefit should be expected from the introduction of a new tool (as innovative as virtual reality) without an explicit and heuristic theoretical framework capable of clarifying its benefits in forensic psychiatry. Our paper introduces self-regulation perspective as the most suitable theoretical framework for virtual reality in forensic psychiatry. It will be argued that virtual reality does not solely help to increase ecological validity. However, it does allow one to grant access to an improved understanding of violent offending behaviours by probing into the underlying mechanisms involved in the self-regulation of behaviours in a dynamical environment. Illustrations are given as well as a discussion regarding perspectives in the use of virtual reality in forensic psychiatry. Copyright © 2015 L’Encéphale, Paris. Published by Elsevier Masson SAS. All rights reserved.

  10. Virtual Reality in Neurorehabilitation

    Directory of Open Access Journals (Sweden)

    Stasieńko Agnieszka

    2016-12-01

    Full Text Available This article includes current information on the use of modern IT solutions and virtual-reality (VR-based technologies in medical rehabilitation. A review of current literature on VR-based interventions and their indications, benefits and limitations in patients with nervous system diseases was conducted. The popularity of VR-based training as a tool used for rehabilitation of patients with acute and chronic deficits in both sensory-motor and cognitive disorders is increasing. Still, there is a need for large randomized trials to evaluate the efficacy and safety of VR-based rehabilitation techniques in different disease entities. .

  11. 3D Technology Selection for a Virtual Learning Environment by Blending ISO 9126 Standard and AHP

    Science.gov (United States)

    Cetin, Aydin; Guler, Inan

    2011-01-01

    Web3D presents many opportunities for learners in a virtual world or virtual environment over the web. This is a great opportunity for open-distance education institutions to benefit from web3d technologies to create courses with interactive 3d materials. There are many open source and commercial products offering 3d technologies over the web…

  12. Design of Electric Power Management System in Jilin Province based on SOA

    Directory of Open Access Journals (Sweden)

    Ren Shou Ze

    2016-01-01

    Full Text Available Aiming at the problem of electric power data integration and sharing in Jilin Province, China, this paper proposed a method based on SOA which has high scalability, flexibility in strong power data and application integration. This approach establishes a web service-oriented system architecture, using SQL Server 2012 as its backend database and using C# as the programming language. And this approach has developed three kinds of terminal applications namely C/S(Client/Server, B/S(Browser /Server and M/S(Mobile/Server. Client applications send all kinds of request to the electric power cloud computing centre, meanwhile web service components receive the requests and call corresponding functions to compute, and then return the results to the original app through the internet. The results show that system achieved the target we expected and successfully realized electric power information data integration, release and sharing.

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

    Science.gov (United States)

    Zhan, Yihong; Bai, Yu; Liu, Ziheng

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

  14. Addressing security issues related to virtual institute distributed activities

    Science.gov (United States)

    Stytz, Martin R.; Banks, Sheila B.

    2008-03-01

    One issue confounding the development and experimentation of distributed modeling and simulation environments is the inability of the project team to identify and collaborate with resources, both human and technical, from outside the United States. This limitation is especially significant within the human behavior representation area where areas such as cultural effects research and joint command team behavior modeling require the participation of various cultural and national representatives. To address this limitation, as well as other human behavior representation research issues, NATO Research and Technology Organization initiated a project to develop a NATO virtual institute that enables more effective and more collaborative research into human behavior representation. However, in building and operating a virtual institute one of the chief concerns must be the cyber security of the institute. Because the institute "exists" in cyberspace, all of its activities are susceptible to cyberattacks, subterfuge, denial of service and all of the vulnerabilities that networked computers must face. In our opinion, for the concept of virtual institutes to be successful and useful, their operations and services must be protected from the threats in the cyber environment. A key to developing the required protection is the development and promulgation of standards for cyber security. In this paper, we discuss the types of cyber standards that are required, how new internet technologies can be exploited and can benefit the promulgation, development, maintenance, and robustness of the standards. This paper is organized as follows. Section One introduces the concept of the virtual institutes, the expected benefits, and the motivation for our research and for research in this area. Section Two presents background material and a discussion of topics related to VIs, uman behavior and cultural modeling, and network-centric warfare. Section Three contains a discussion of the

  15. Virtual Reality and Learning: Where Is the Pedagogy?

    Science.gov (United States)

    Fowler, Chris

    2015-01-01

    The aim of this paper was to build upon Dalgarno and Lee's model or framework of learning in three-dimensional (3-D) virtual learning environments (VLEs) and to extend their road map for further research in this area. The enhanced model shares the common goal with Dalgarno and Lee of identifying the learning benefits from using 3-D VLEs. The…

  16. Virtual health platform for medical tourism purposes.

    Science.gov (United States)

    Martinez, Debora; Ferriol, Pedro; Tous, Xisco; Cabrer, Miguel; Prats, Mercedes

    2008-01-01

    This paper introduces an overview of the Virtual Health Platform (VHP), an alternative approach to create a functional PHR system in a medical tourism environment. The proposed platform has been designed in order to be integrated with EHR infrastructures and in this way it expects to be useful and more advantageous to the patient or tourist. Use cases of the VHP and its potential benefits summarize the analysis.

  17. A review of virtual cutting methods and technology in deformable objects.

    Science.gov (United States)

    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.

  18. Uses of virtual reality in clinical training: developing the spatial skills of children with mobility impairments.

    Science.gov (United States)

    Stanton, D; Foreman, N; Wilson, P N

    1998-01-01

    In this chapter we review some of the ways in which the skills learned in virtual environments (VEs) transfer to real situations, and in particular how information about the spatial layouts of virtual buildings acquired from the exploration of three-dimensional computer-simulations transfers to their real equivalents. Four experiments are briefly described which examined VR use by disabled children. We conclude that spatial information of the kind required for navigation transfers effectively from virtual to real situations. Spatial skills in disabled children showed progressive improvement with repeated exploration of virtual environments. The results are discussed in relation to the potential future benefits of VR in special needs education and training.

  19. Polarization encoded all-optical quaternary successor with the help of SOA assisted Sagnac switch

    Science.gov (United States)

    Chattopadhyay, Tanay; Roy, Jitendra Nath

    2011-06-01

    The application of multi-valued (non-binary) signals can provide a considerable relief in transmission, storage and processing of large amount of information in digital signal processing. Optical multi-valued logical operation is an interesting challenge for future optical signal processing where we can expect much innovation. A novel all-optical quaternary successor (QSUC) circuit with the help of semiconductor optical amplifier (SOA)-assisted Sagnac switch is proposed and described. This circuit exploits the polarization properties of light. Different logical states are represented by different polarization state of light. Simulation result confirming described method is given in this paper. Proposed all-optical successor circuit can take an important and significant role in designing of all-optical quaternary universal inverter and modulo arithmetic unit (addition and multiplication).

  20. Virtual network topology reconfiguration based on big data analytics for traffic prediction

    OpenAIRE

    Morales Alcaide, Fernando; Ruiz Ramírez, Marc; Velasco Esteban, Luis Domingo

    2016-01-01

    Big data analytics is applied for IP traffic prediction. When the virtual topology needs to be reconfigured, predicted and current traffic matrices are used to find the optimal topology. Exhaustive simulation results reveal large benefits. Peer Reviewed

  1. Best Practices and Provisional Guidelines for Integrating Mobile, Virtual, and Videogame-Based Training and Assessments

    Science.gov (United States)

    2014-01-01

    videogame -based platforms, 2) role of assessments and how they can be implemented within these platforms, or 3) benefits or challenges of the...Technical Report 1334 Best Practices and Provisional Guidelines for Integrating Mobile, Virtual, and Videogame -Based Training and...Virtual, and Videogame -Based Training and Assessments 5a. CONTRACT OR GRANT NUMBER W5J9CQ-11-D-0002 5b. PROGRAM ELEMENT NUMBER 622785

  2. Multi-agent: a technique to implement geo-visualization of networked virtual reality

    Science.gov (United States)

    Lin, Zhiyong; Li, Wenjing; Meng, Lingkui

    2007-06-01

    Networked Virtual Reality (NVR) is a system based on net connected and spatial information shared, whose demands cannot be fully meet by the existing architectures and application patterns of VR to some extent. In this paper, we propose a new architecture of NVR based on Multi-Agent framework. which includes the detailed definition of various agents and their functions and full description of the collaboration mechanism, Through the prototype system test with DEM Data and 3D Models Data, the advantages of Multi-Agent based Networked Virtual Reality System in terms of the data loading time, user response time and scene construction time etc. are verified. First, we introduce the characters of Networked Virtual Realty and the characters of Multi-Agent technique in Section 1. Then we give the architecture design of Networked Virtual Realty based on Multi-Agent in Section 2.The Section 2 content includes the rule of task division, the multi-agent architecture design to implement Networked Virtual Realty and the function of agents. Section 3 shows the prototype implementation according to the design. Finally, Section 4 discusses the benefits of using Multi-Agent to implement geovisualization of Networked Virtual Realty.

  3. Innovative application of virtual display technique in virtual museum

    Science.gov (United States)

    Zhang, Jiankang

    2017-09-01

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

  4. Realistic Visualization of Virtual Views and Virtual Cinema

    DEFF Research Database (Denmark)

    Livatino, Salvatore

    2005-01-01

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

  5. Virtual Trondheim: A Virtual Environment for Tourism and Education

    OpenAIRE

    Jose, Dawn Alphonse

    2015-01-01

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

  6. Super-virtual refraction interferometry: Theory

    KAUST Repository

    Bharadwaj, Pawan

    2011-01-01

    Inverting for the subsurface velocity distribution by refraction traveltime tomography is a well-accepted imaging method by both the exploration and earthquake seismology communities. A significant drawback, however, is that the recorded traces become noisier with increasing offset from the source position, and so prevents accurate picking of traveltimes in far-offset traces. To enhance the signal-to-noise ratio of the far-offset traces, we present the theory of super-virtual refraction interferometry where the signal-to-noise ratio (SNR) of far-offset head-wave arrivals can be theoretically increased by a factor proportional to N; here, N is the number of receiver and source positions associated with the recording and generation of the head-wave arrival. There are two steps to this methodology: correlation and summation of the data to generate traces with virtual head-wave arrivals, followed by the convolution of the data with the virtual traces to create traces with super-virtual head-wave arrivals. This method is valid for any medium that generates head-wave arrivals. There are at least three significant benefits to this methodology: 1). enhanced SNR of far-offset traces so the first-arrival traveltimes of the noisy far-offset traces can be more reliably picked to extend the useful aperture of data, 2). the SNR of head waves in a trace that arrive after the first arrival can be enhanced for accurate traveltime picking and subsequent inversion by traveltime tomography, and 3). common receiver-pair gathers can be analyzed to detect the presence of diving waves in the first arrivals, which can be used to assess the nature of the refracting boundary. © 2011 Society of Exploration Geophysicists.

  7. Economic and social effects of novel supply chain concepts and virtual enterprises

    Directory of Open Access Journals (Sweden)

    György Kovács

    2017-05-01

    Full Text Available Growing market globalization, increasing global competition, more complex products results in application of new technologies, methods and business processes – due to the abovementioned tendencies novel supply chain strategies (Lean, Agile and Leagile Supply Chains are established. In this study these supply chain concepts are being described and compared. Virtual enterprise is a temporary alliance of enterprises that come together to share their skills, core competencies, costs and resources in order to better respond to rapidly changing market environment and dynamic customer demands. Economic and social benefits and effects of virtual enterprises for customers and production companies and service providers are also described. Optimization software has been developed for optimal formation of virtual enterprise networks and is also introduced in this study. The aim of this software application is to define virtual enterprise as the optimal combination of supply chain members.

  8. Virtualizing Resources for the Application Services and Framework Team

    Science.gov (United States)

    Varner, Justin T.; Crawford, Linda K.

    2010-01-01

    Virtualization is an emerging technology that will undoubtedly have a major impact on the future of Information Technology. It allows for the centralization of resources in an enterprise system without the need to make any changes to the host operating system, file system, or registry. In turn, this significantly reduces cost and administration, and provides a much greater level of security, compatibility, and efficiency. This experiment examined the practicality, methodology, challenges, and benefits of implementing the technology for the Launch Control System (LCS), and more specifically the Application Services (AS) group of the National Aeronautics and Space Administration (NASA) at the Kennedy Space Center (KSC). In order to carry out this experiment, I used several tools from the virtualization company known as VMWare; these programs included VMWare ThinApp, VMWare Workstation, and VMWare ACE. Used in conjunction, these utilities provided the engine necessary to virtualize and deploy applications in a desktop environment on any Windows platform available. The results clearly show that virtualization is a viable technology that can, when implemented properly, dramatically cut costs, enhance stability and security, and provide easier management for administrators.

  9. Virtual Trackballs Revisited

    DEFF Research Database (Denmark)

    Henriksen, Knud; Sporring, Jon; Hornbæk, Kasper

    2004-01-01

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

  10. Augmented-Virtual Reality: How to improve education systems

    Directory of Open Access Journals (Sweden)

    Manuel Fernandez

    2017-06-01

    Full Text Available This essay presents and discusses the developing role of virtual and augmented reality technologies in education. Addressing the challenges in adapting such technologies to focus on improving students’ learning outcomes, the author discusses the inclusion of experiential modes as a vehicle for improving students’ knowledge acquisition. Stakeholders in the educational role of technology include students, faculty members, institutions, and manufacturers. While the benefits of such technologies are still under investigation, the technology landscape offers opportunities to enhance face-to-face and online teaching, including contributions in the understanding of abstract concepts and training in real environments and situations. Barriers to technology use involve limited adoption of augmented and virtual reality technologies, and, more directly, necessary training of teachers in using such technologies within meaningful educational contexts. The author proposes a six-step methodology to aid adoption of these technologies as basic elements within the regular education: training teachers; developing conceptual prototypes; teamwork involving the teacher, a technical programmer, and an educational architect; and producing the experience, which then provides results in the subsequent two phases wherein teachers are trained to apply augmented- and virtual-reality solutions within their teaching methodology using an available subject-specific experience and then finally implementing the use of the experience in a regular subject with students. The essay concludes with discussion of the business opportunities facing virtual reality in face-to-face education as well as augmented and virtual reality in online education.

  11. Motor learning from virtual reality to natural environments in individuals with Duchenne muscular dystrophy.

    Science.gov (United States)

    Quadrado, Virgínia Helena; Silva, Talita Dias da; Favero, Francis Meire; Tonks, James; Massetti, Thais; Monteiro, Carlos Bandeira de Mello

    2017-11-10

    To examine whether performance improvements in the virtual environment generalize to the natural environment. we had 64 individuals, 32 of which were individuals with DMD and 32 were typically developing individuals. The groups practiced two coincidence timing tasks. In the more tangible button-press task, the individuals were required to 'intercept' a falling virtual object at the moment it reached the interception point by pressing a key on the computer. In the more abstract task, they were instructed to 'intercept' the virtual object by making a hand movement in a virtual environment using a webcam. For individuals with DMD, conducting a coincidence timing task in a virtual environment facilitated transfer to the real environment. However, we emphasize that a task practiced in a virtual environment should have higher rates of difficulties than a task practiced in a real environment. IMPLICATIONS FOR REHABILITATION Virtual environments can be used to promote improved performance in ?real-world? environments. Virtual environments offer the opportunity to create paradigms similar ?real-life? tasks, however task complexity and difficulty levels can be manipulated, graded and enhanced to increase likelihood of success in transfer of learning and performance. Individuals with DMD, in particular, showed immediate performance benefits after using virtual reality.

  12. Personal Virtual Libraries

    Science.gov (United States)

    Pappas, Marjorie L.

    2004-01-01

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

  13. Extinction ratio enhancement of SOA-based delayed-interference signal converter using detuned filtering

    Science.gov (United States)

    Zhang, B.; Kumar, S.; Yan, L.-S.; Willner, A. E.

    2007-12-01

    We demonstrate experimentally >3 dB extinction ratio improvement at the output of SOA-based delayed-interference signal converter (DISC) using optical off-centered filtering. Through careful modeling of the carrier and the phase dynamics, we explain in detail the origin of sub-pulses in the wavelength converted output, with an emphasis on the time-resolved frequency chirping of the output signal. Through our simulations we conclude that the sub-pulses and the main-pulses are oppositely chirped, which is also verified experimentally by analyzing the output with a chirp form analyzer. We propose and demonstrate an optical off-center filtering technique which effectively suppresses these sub-pulses. The effects of filter detuning and phase bias adjustment in the delayed-interferometer are experimentally characterized and optimized, leading to a >3 dB extinction ratio enhancement of the output signal.

  14. Does virtual reality simulation have a role in training trauma and orthopaedic surgeons?

    Science.gov (United States)

    Bartlett, J D; Lawrence, J E; Stewart, M E; Nakano, N; Khanduja, V

    2018-05-01

    Aims The aim of this study was to assess the current evidence relating to the benefits of virtual reality (VR) simulation in orthopaedic surgical training, and to identify areas of future research. Materials and Methods A literature search using the MEDLINE, Embase, and Google Scholar databases was performed. The results' titles, abstracts, and references were examined for relevance. Results A total of 31 articles published between 2004 and 2016 and relating to the objective validity and efficacy of specific virtual reality orthopaedic surgical simulators were identified. We found 18 studies demonstrating the construct validity of 16 different orthopaedic virtual reality simulators by comparing expert and novice performance. Eight studies have demonstrated skill acquisition on a simulator by showing improvements in performance with repeated use. A further five studies have demonstrated measurable improvements in operating theatre performance following a period of virtual reality simulator training. Conclusion The demonstration of 'real-world' benefits from the use of VR simulation in knee and shoulder arthroscopy is promising. However, evidence supporting its utility in other forms of orthopaedic surgery is lacking. Further studies of validity and utility should be combined with robust analyses of the cost efficiency of validated simulators to justify the financial investment required for their use in orthopaedic training. Cite this article: Bone Joint J 2018;100-B:559-65.

  15. A web-based virtual laboratory workbench for electrical circuits with ...

    African Journals Online (AJOL)

    A distinguishing feature of this Virtual Laboratory Workbench is that it allows the instructor flexibility in designing laboratory exercises so as to integrate specific knowledge objectives, outcome concepts and pre-requisites with the activity instructions. Another important benefit is that it has a watch-dog monitor that keeps a log ...

  16. Wireless virtualization

    CERN Document Server

    Wen, Heming; Le-Ngoc, Tho

    2013-01-01

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

  17. Bringing Agility to Business Process Management: Rules Deployment in an SOA

    Science.gov (United States)

    El Kharbili, Marwane; Keil, Tobias

    Business process management (BPM) has emerged as paradigm for integrating business strategies and enterprise architecture (EA). In this context, BPM implementation on top of web-service-based service oriented architectures is an accepted approach as shown by great amount of literature. One concern in this regard is how-to make BPs reactive to change. Our approach to the problem is the integration of business rule management (BRM) and BPM by allowing modeling of decisions hard-coded in BPs as separate business rules (BRs). These BRs become EA assets and need to be exploited when executing BPs. We motivate why BPM needs agility and discuss what requirements on BPM this poses. This paper presents prototyping work conducted at a BP modeling and analysis vendor which weeks to showcase how using business rule management (BRM) as a mean for modeling decisions can help achieve a much sought-after agility to BPM. This prototype relies on the integrated modeling of business rules (BRs) and BPs, and rule deployment as web services part of an SOA.

  18. Comparison of three aerosol chemical characterization techniques utilizing PTR-ToF-MS: a study on freshly formed and aged biogenic SOA

    Directory of Open Access Journals (Sweden)

    G. I. Gkatzelis

    2018-03-01

    Full Text Available An intercomparison of different aerosol chemical characterization techniques has been performed as part of a chamber study of biogenic secondary organic aerosol (BSOA formation and aging at the atmosphere simulation chamber SAPHIR (Simulation of Atmospheric PHotochemistry In a large Reaction chamber. Three different aerosol sampling techniques – the aerosol collection module (ACM, the chemical analysis of aerosol online (CHARON and the collection thermal-desorption unit (TD were connected to proton transfer reaction time-of-flight mass spectrometers (PTR-ToF-MSs to provide chemical characterization of the SOA. The techniques were compared among each other and to results from an aerosol mass spectrometer (AMS and a scanning mobility particle sizer (SMPS. The experiments investigated SOA formation from the ozonolysis of β-pinene, limonene, a β-pinene–limonene mix and real plant emissions from Pinus sylvestris L. (Scots pine. The SOA was subsequently aged by photo-oxidation, except for limonene SOA, which was aged by NO3 oxidation. Despite significant differences in the aerosol collection and desorption methods of the PTR-based techniques, the determined chemical composition, i.e. the same major contributing signals, was found by all instruments for the different chemical systems studied. These signals could be attributed to known products expected from the oxidation of the examined monoterpenes. The sampling and desorption method of ACM and TD provided additional information on the volatility of individual compounds and showed relatively good agreement. Averaged over all experiments, the total aerosol mass recovery compared to an SMPS varied within 80 ± 10, 51 ± 5 and 27 ± 3 % for CHARON, ACM and TD, respectively. Comparison to the oxygen-to-carbon ratios (O : C obtained by AMS showed that all PTR-based techniques observed lower O : C ratios, indicating a loss of molecular oxygen either during aerosol sampling or

  19. Virtual reality in surgery and medicine.

    Science.gov (United States)

    Chinnock, C

    1994-01-01

    . Surgical robots are likely to be deployed for specific tasks in the operating room (OR) and to support telesurgery applications. Technical developments in robotics and motion control are key components of many virtual reality systems. Since almost all of the virtual reality and enhanced reality systems will be digitally based, they are also capable of being put "on-line" for tele-training, consulting, and even surgery. Advancements in virtual and enhanced reality systems will be driven in part by consumer applications of this technology. Many of the companies that will supply systems for medical applications are also working on commercial products. A big consumer hit can benefit the entire industry by increasing volumes and bringing down costs.(ABSTRACT TRUNCATED AT 400 WORDS)

  20. Augmented Virtual Reality: How to Improve Education Systems

    OpenAIRE

    Fernández-Utrilla Miguel, Manuel

    2017-01-01

    This essay presents and discusses the developing role of virtual and augmented reality technologies in education. Addressing the challenges in adapting such technologies to focus on improving students’ learning outcomes, the author discusses the inclusion of experiential modes as a vehicle for improving students’ knowledge acquisition. Stakeholders in the educational role of technology include students, faculty members, institutions, and manufacturers. While the benefits of suc...

  1. People management implications of virtual workplace arrangements

    OpenAIRE

    K. Ortlepp; X. Hloma

    2006-01-01

    Purpose: The purpose of this paper is to investigate the factors that led to an organisation implementing a particular form of virtual workplace arrangement, namely, home-based work. The benefits and disadvantages associated with this form of work arrangement are explored from both the managers' and home-based employees' perspectives. Design/Methodology/Approach: Given the exploratory nature of the empirical study on which this paper is based, a qualitative research design was adopt...

  2. Virtual colonoscopy

    Science.gov (United States)

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

  3. AN EVALUATION ON THE USE OF VIRTUAL REALITY ADMINISTRATION IN PUBLIC RELATIONS AND ADVERTISING EDUCATION

    OpenAIRE

    Gürcan, Halil İbrahim; Coşkun, Engin; Sever, Necip Serdar; Başer, Emrah; Ataizi, Murat; Öztürk, Mesude Canan; Bical, Adil

    2018-01-01

    Especiallyin the early 2000s, the concept of virtual reality, which evolved as a resultof major changes in communication, was first used in 1977. When it comes today,it is obvious that many areas (medicine, pilotage, communication, education,simulation, production, marketing, advertising, etc.) are benefited fromvirtual reality applications and virtual worlds. These applications offer arange of possibilities for individual users or consumers and also provide someopportunities for enterprise u...

  4. Virtual Exploratories

    DEFF Research Database (Denmark)

    Jensen, Sisse Siggaard

    2006-01-01

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

  5. The Virtual Maternity Clinic: a teaching and learning innovation for midwifery education.

    Science.gov (United States)

    Phillips, Diane; Duke, Maxine; Nagle, Cate; Macfarlane, Susie; Karantzas, Gery; Patterson, Denise

    2013-10-01

    There are challenges for midwifery students in developing skill and competency due to limited placements in antenatal clinics. The Virtual Maternity Clinic, an online resource, was developed to support student learning in professional midwifery practice. Identifying students' perceptions of the Virtual Maternity Clinic; learning about the impact of the Virtual Maternity Clinic on the students' experience of its use and access; and learning about the level of student satisfaction of the Virtual Maternity Clinic. Two interventions were used including pre and post evaluations of the online learning resource with data obtained from questionnaires using open ended and dichotomous responses and rating scales. The pre-Virtual Maternity Clinic intervention used a qualitative design and the post-Virtual Maternity Clinic intervention applied both qualitative and quantitative approaches. Three campuses of Deakin University, located in Victoria, Australia. Midwifery students enrolled in the Bachelor of Nursing/Bachelor of Midwifery and Graduate Diploma of Midwifery were recruited across three campuses of Deakin University (n=140). Thematic analysis of the pre-Virtual Maternity Clinic intervention (return rate n=119) related to students' expectations of this resource. The data for the post-Virtual Maternity Clinic intervention (return rate n=42) including open-ended responses were thematically analysed; dichotomous data examined in the form of frequencies and percentages of agreement and disagreement; and 5-rating scales were analysed using Pearson's correlations (α=.05, two-tailed). Results showed from the pre-Virtual Maternity Clinic intervention that students previously had placements in antenatal clinics were optimistic about the online learning resource. The post-Virtual Maternity Clinic intervention results indicated that students were satisfied with the Virtual Maternity Clinic as a learning resource despite some technological issues. The Virtual Maternity Clinic

  6. Virtual reality training for health-care professionals.

    Science.gov (United States)

    Mantovani, Fabrizia; Castelnuovo, Gianluca; Gaggioli, Andrea; Riva, Giuseppe

    2003-08-01

    Emerging changes in health-care delivery are having a significant impact on the structure of health-care professionals' education. Today it is recognized that medical knowledge doubles every 6-8 years, with new medical procedures emerging everyday. While the half-life of medical information is so short, the average physician practices 30 years and the average nurse 40 years. Continuing education thus represents an important challenge to face. Recent advances in educational technology are offering an increasing number of innovative learning tools. Among these, Virtual Reality represents a promising area with high potential of enhancing the training of health-care professionals. Virtual Reality Training can provide a rich, interactive, engaging educational context, thus supporting experiential learning-by-doing; it can, in fact, contribute to raise interest and motivation in trainees and to effectively support skills acquisition and transfer, since the learning process can be settled within an experiential framework. Current virtual training applications for health-care differ a lot as to both their technological/multimedia sophistication and to the types of skills trained, varying for example from telesurgical applications to interactive simulations of human body and brain, to virtual worlds for emergency training. Other interesting applications include the development of immersive 3D environments for training psychiatrists and psychologists in the treatment of mental disorders. This paper has the main aim of discussing the rationale and main benefits for the use of virtual reality in health-care education and training. Significant research and projects carried out in this field will also be presented, followed by discussion on key issues concerning current limitations and future development directions.

  7. 4 × 10 Gb s−1 wavelength multicasting with tunable NRZ-to-RZ format conversion using nonlinear polarization rotation in an SOA

    International Nuclear Information System (INIS)

    Liu, S; Fu, S; Tang, M; Shum, P; Liu, D

    2013-01-01

    We experimentally demonstrate simultaneous 4 × 10 Gb s −1 all-optical wavelength multicasting and non-return-to-zero (NRZ)-on-off-keying (OOK) to return-to-zero (RZ)-OOK format conversion with a tunable duty cycle using nonlinear polarization rotation in a semiconductor optical amplifier (SOA). The experimental results show that the duty cycle of four converted RZ-OOK signals can be tuned by adjusting the orientation of a polarizer placed at the SOA output. Four-channel NRZ-OOK-to-RZ-OOK conversion with a full width at half maximum of 33–67 ps can be simultaneously obtained with an extinction ratio over 10 dB. Moreover, it is experimentally verified that such a wavelength multicasting scheme with simultaneous NRZ-OOK-to-RZ-OOK conversion is insensitive to the wavelength of the input signal, indicating that such a scheme can be operated in the whole C-band with less than 0.18 dB power penalty at a bit error ratio level of 10 −9 . The device can facilitate the cross-connection between optical transmission networks employing different modulation formats. (paper)

  8. Modeling biogenic secondary organic aerosol (BSOA) formation from monoterpene reactions with NO3: A case study of the SOAS campaign using CMAQ

    Science.gov (United States)

    Qin, Momei; Hu, Yongtao; Wang, Xuesong; Vasilakos, Petros; Boyd, Christopher M.; Xu, Lu; Song, Yu; Ng, Nga Lee; Nenes, Athanasios; Russell, Armistead G.

    2018-07-01

    Monoterpenes react with nitrate radicals (NO3), contributing substantially to nighttime organic aerosol (OA) production. In this study, the role of reactions of monoterpenes + NO3 in forming biogenic secondary organic aerosol (BSOA) was examined using the Community Multiscale Air Quality (CMAQ) model, with extended emission profiles of biogenic volatile organic compounds (BVOCs), species-specific representations of BSOA production from individual monoterpenes and updated aerosol yields for monoterpene + NO3. The model results were compared to detailed measurements from the Southern Oxidants and Aerosol Study (SOAS) at Centreville, Alabama. With the more detailed model, monoterpene-derived BSOA increased by ∼1 μg m-3 at night, accounting for one-third of observed less-oxidized oxygenated OA (LO-OOA), more closely agreeing with observations (lower error, stronger correlation). Implementation of a multigenerational oxidation approach resulted in the model capturing elevated OA episodes. With the aging model, aged semi-volatile organic compounds (ASVOCs) contributed over 60% of the monoterpene-derived BSOA, followed by SOA formation via nitrate radical chemistry, making up to 34% of that formed at night. Among individual monoterpenes, β-pinene and limonene contributed most to the monoterpene-derived BSOA from nighttime reactions.

  9. A framework for Service-oriented Architecture adoption in e-banking: the case of banks from a transition and a developed economy

    OpenAIRE

    Themistocleous, Marinos; Nikolaos, Basias; Morabito, Vincenzo

    2015-01-01

    Integration is considered as an important challenge for electronic banking (e-banking) success and many issues related to it remain unexplored. In addressing integration issues, Service Oriented Architecture (SOA) has emerged and been adopted by banks but many of them have failed to achieve significant SOA benefits. An important reason for this failure is attributed to the absence of a methodological framework that explains factors influencing SOA adoption in e-banking. In addition to this, t...

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

    Science.gov (United States)

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

    2017-09-01

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

  11. On virtual displacement and virtual work in Lagrangian dynamics

    International Nuclear Information System (INIS)

    Ray, Subhankar; Shamanna, J

    2006-01-01

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

  12. Framework for Virtual Cognitive Experiment in Virtual Geographic Environments

    Directory of Open Access Journals (Sweden)

    Fan Zhang

    2018-01-01

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

  13. Undergraduate Student Self-Efficacy and Perceptions of Virtual World Learning Experience

    Science.gov (United States)

    Stanton, Lorraine May

    2017-01-01

    Virtual worlds are innovative teaching and learning methods that can provide immersive and engaging learning experiences (Lu, 2010). Though they have potential benefits, students sometimes experience a steep learning curve and discomfort with the technology (Warburton, 2009). This study explored how students in two American Studies classes using…

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

    Science.gov (United States)

    Kay, Robin; Goulding, Helene; Li, Jia

    2018-01-01

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

  15. Adaptive Soa Stack-Based Business Process Monitoring Platform

    Directory of Open Access Journals (Sweden)

    Przemysław Dadel

    2014-01-01

    Full Text Available Executable business processes that formally describe company activities are well placed in the SOA environment as they allow for declarative organization of high-level system logic.However, for both technical and non-technical users, to fully benet from that element of abstractionappropriate business process monitoring systems are required and existing solutions remain unsatisfactory.The paper discusses the problem of business process monitoring in the context of the service orientation paradigm in order to propose an architectural solution and provide implementation of a system for business process monitoring that alleviates the shortcomings of the existing solutions.Various platforms are investigated to obtain a broader view of the monitoring problem and to gather functional and non-functional requirements. These requirements constitute input forthe further analysis and the system design. The monitoring software is then implemented and evaluated according to the specied criteria.An extensible business process monitoring system was designed and built on top of OSGiMM - a dynamic, event-driven, congurable communications layer that provides real-time monitoring capabilities for various types of resources. The system was tested against the stated functional requirements and its implementation provides a starting point for the further work.It is concluded that providing a uniform business process monitoring solution that satises a wide range of users and business process platform vendors is a dicult endeavor. It is furthermore reasoned that only an extensible, open-source, monitoring platform built on top of a scalablecommunication core has a chance to address all the stated and future requirements.

  16. Effects of Unaugmented Periphery and Vibrotactile Feedback on Proxemics with Virtual Humans in AR.

    Science.gov (United States)

    Lee, Myungho; Bruder, Gerd; Hollerer, Tobias; Welch, Greg

    2018-04-01

    In this paper, we investigate factors and issues related to human locomotion behavior and proxemics in the presence of a real or virtual human in augmented reality (AR). First, we discuss a unique issue with current-state optical see-through head-mounted displays, namely the mismatch between a small augmented visual field and a large unaugmented periphery, and its potential impact on locomotion behavior in close proximity of virtual content. We discuss a potential simple solution based on restricting the field of view to the central region, and we present the results of a controlled human-subject study. The study results show objective benefits for this approach in producing behaviors that more closely match those that occur when seeing a real human, but also some drawbacks in overall acceptance of the restricted field of view. Second, we discuss the limited multimodal feedback provided by virtual humans in AR, present a potential improvement based on vibrotactile feedback induced via the floor to compensate for the limited augmented visual field, and report results showing that benefits of such vibrations are less visible in objective locomotion behavior than in subjective estimates of co-presence. Third, we investigate and document significant differences in the effects that real and virtual humans have on locomotion behavior in AR with respect to clearance distances, walking speed, and head motions. We discuss potential explanations for these effects related to social expectations, and analyze effects of different types of behaviors including idle standing, jumping, and walking that such real or virtual humans may exhibit in the presence of an observer.

  17. Curating and nudging in virtual CLIL environments

    Directory of Open Access Journals (Sweden)

    Helle Lykke Nielsen

    2014-03-01

    Full Text Available Foreign language teachers can benefit substantially from the notions of curation and nudging when scaffolding CLIL activities on the internet. This article shows how these principles can be integrated into CLILstore, a free multimedia-rich learning tool with seamless access to online dictionaries, and presents feedback from first and second year university students of Arabic as a second language to inform foreign language teachers about students’ needs and preferences in virtual learning environments.

  18. A study of factors affecting the adoption of server virtualization technology

    Science.gov (United States)

    Lu, Hsin-Ke; Lin, Peng-Chun; Chiang, Chang-Heng; Cho, Chien-An

    2018-04-01

    It has become a trend that worldwide enterprises and organizations apply new technologies to improve their operations; besides, it has higher cost and less flexibility to construct and manage traditional servers, therefore the current mainstream is to use server virtualization technology. However, from these new technology organizations will not necessarily get the expected benefits because each one has its own level of organizational complexity and abilities to accept changes. The researcher investigated key factors affecting the adoption of virtualization technology through two phases. In phase I, the researcher reviewed literature and then applied the dimensions of "Information Systems Success Model" (ISSM) to generalize the factors affecting the adoption of virtualization technology to be the preliminary theoretical framework and develop a questionnaire; in phase II, a three-round Delphi Method was used to integrate the opinions of experts from related fields which were then gradually converged in order to obtain a stable and objective questionnaire of key factors so that these results were expected to provide references for organizations' adoption of server virtualization technology and future studies.

  19. Machine learning in virtual screening.

    Science.gov (United States)

    Melville, James L; Burke, Edmund K; Hirst, Jonathan D

    2009-05-01

    In this review, we highlight recent applications of machine learning to virtual screening, focusing on the use of supervised techniques to train statistical learning algorithms to prioritize databases of molecules as active against a particular protein target. Both ligand-based similarity searching and structure-based docking have benefited from machine learning algorithms, including naïve Bayesian classifiers, support vector machines, neural networks, and decision trees, as well as more traditional regression techniques. Effective application of these methodologies requires an appreciation of data preparation, validation, optimization, and search methodologies, and we also survey developments in these areas.

  20. Virtualization Security Combining Mandatory Access Control and Virtual Machine Introspection

    OpenAIRE

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

    2014-01-01

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

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

    Science.gov (United States)

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

    2017-01-01

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

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

    Directory of Open Access Journals (Sweden)

    María V Navarro-Haro

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

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

    Science.gov (United States)

    Valdés, América

    2002-01-01

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

  4. A Second Chance at Health: How a 3D Virtual World Can Improve Health Self-Efficacy for Weight Loss Management Among Adults.

    Science.gov (United States)

    Behm-Morawitz, Elizabeth; Lewallen, Jennifer; Choi, Grace

    2016-02-01

    Health self-efficacy, or the beliefs in one's capabilities to perform health behaviors, is a significant factor in eliciting health behavior change, such as weight loss. Research has demonstrated that virtual embodiment has the potential to alter one's psychology and physicality, particularly in health contexts; however, little is known about the impacts embodiment in a virtual world has on health self-efficacy. The present research is a randomized controlled trial (N = 90) examining the effectiveness of virtual embodiment and play in a social virtual world (Second Life [SL]) for increasing health self-efficacy (exercise and nutrition efficacy) among overweight adults. Participants were randomly assigned to a 3D social virtual world (avatar virtual interaction experimental condition), 2D social networking site (no avatar virtual interaction control condition), or no intervention (no virtual interaction control condition). The findings of this study provide initial evidence for the use of SL to improve exercise efficacy and to support weight loss. Results also suggest that individuals who have higher self-presence with their avatar reap more benefits. Finally, quantitative findings are triangulated with qualitative data to increase confidence in the results and provide richer insight into the perceived effectiveness and limitations of SL for meeting weight loss goals. Themes resulting from the qualitative analysis indicate that participation in SL can improve motivation and efficacy to try new physical activities; however, individuals who have a dislike for video games may not be benefitted by avatar-based virtual interventions. Implications for research on the transformative potential of virtual embodiment and self-presence in general are discussed.

  5. Surgical approaches to complex vascular lesions: the use of virtual reality and stereoscopic analysis as a tool for resident and student education.

    Science.gov (United States)

    Agarwal, Nitin; Schmitt, Paul J; Sukul, Vishad; Prestigiacomo, Charles J

    2012-08-01

    Virtual reality training for complex tasks has been shown to be of benefit in fields involving highly technical and demanding skill sets. The use of a stereoscopic three-dimensional (3D) virtual reality environment to teach a patient-specific analysis of the microsurgical treatment modalities of a complex basilar aneurysm is presented. Three different surgical approaches were evaluated in a virtual environment and then compared to elucidate the best surgical approach. These approaches were assessed with regard to the line-of-sight, skull base anatomy and visualisation of the relevant anatomy at the level of the basilar artery and surrounding structures. Overall, the stereoscopic 3D virtual reality environment with fusion of multimodality imaging affords an excellent teaching tool for residents and medical students to learn surgical approaches to vascular lesions. Future studies will assess the educational benefits of this modality and develop a series of metrics for student assessments.

  6. Virtual reality for the treatment of autism.

    Science.gov (United States)

    Strickland, D

    1997-01-01

    Autism is a mental disorder which has received attention in several unrelated studies using virtual reality. One of the first attempts was to diagnose children with special needs at Tokyo University using a sandbox playing technique. Although operating the computer controls proved to be too difficult for the individuals with autism in the Tokyo study, research at the University of Nottingham, UK, is successful in using VR as a learning aid for children with a variety of disorders including autism. Both centers used flat screen computer systems with virtual scenes. Another study which concentrated on using VR as a learning aid with an immersive headset system is described in detail in this chapter. Perhaps because of the seriousness of the disorder and the lack of effective treatments, autism has received more study than attention deficit disorders, although both would appear to benefit from many of the same technology features.

  7. Virtual Box

    DEFF Research Database (Denmark)

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

    2007-01-01

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

  8. Development of a Virtual Reality Solution for End User Involvement in Interior Design

    DEFF Research Database (Denmark)

    Svidt, Kjeld; Sørensen, Jesper Bendix

    2016-01-01

    This paper describes development and test of a prototype Virtual Reality system aimed at user involvement in hospital design. User needs and functional requirements are captured by interviews and observations in three case studies of ongoing projects in Denmark. Based on the identified requirements......, a prototype is developed based on a multitouch display for manipulating room layout in a floor plan view and a set of Oculus Rift glasses for experiencing the design in Virtual Reality. Together with users from the studied cases, test scenarios were performed to identify possible benefits, challenges...

  9. Virtual socialization in adults with spina bifida.

    Science.gov (United States)

    Chan, Wendy M; Dicianno, Brad E

    2011-03-01

    -term social avoidance. Users of the most immersive forms of virtual socialization, have more real world friends than both semi-users and nonusers. Any form of VS, whether immersive or real time, may improve the opportunity for meaningful social encounters. Prospective intervention studies are needed to elucidate whether a causal positive relationship between virtual socialization and friendships exists. Further research is needed to clarify virtual socialization's impact on QOL; however, the upward trend in all 4 domains of QOL across user groups suggests similar potential benefits. Copyright © 2011 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

  10. Collaborative Learning in Architectural Education: Benefits of Combining Conventional Studio, Virtual Design Studio and Live Projects

    Science.gov (United States)

    Rodriguez, Carolina; Hudson, Roland; Niblock, Chantelle

    2018-01-01

    Combinations of Conventional Studio and Virtual Design Studio (VDS) have created valuable learning environments that take advantage of different instruments of communication and interaction. However, past experiences have reported limitations in regards to student engagement and motivation, especially when the studio projects encourage abstraction…

  11. Realidad virtual y materialidad

    OpenAIRE

    Pérez Herranz, Fernando Miguel

    2009-01-01

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

  12. A virtual network computer's optical storage virtualization scheme

    Science.gov (United States)

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

    2008-12-01

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

  13. Virtual bronchoscopy

    International Nuclear Information System (INIS)

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

    2001-01-01

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

  14. Evaluation of Binocular Eye Trackers and Algorithms for 3D Gaze Interaction in Virtual Reality Environments

    OpenAIRE

    Thies Pfeiffer; Ipke Wachsmuth; Marc E. Latoschik

    2009-01-01

    Tracking user's visual attention is a fundamental aspect in novel human-computer interaction paradigms found in Virtual Reality. For example, multimodal interfaces or dialogue-based communications with virtual and real agents greatly benefit from the analysis of the user's visual attention as a vital source for deictic references or turn-taking signals. Current approaches to determine visual attention rely primarily on monocular eye trackers. Hence they are restricted to the interpretation of...

  15. Virtual button interface

    Science.gov (United States)

    Jones, J.S.

    1999-01-12

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

  16. Online International Learning: Internationalising the Curriculum through Virtual Mobility at Coventry University

    Science.gov (United States)

    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…

  17. The Design, Development and Evaluation of a Virtual Reality Based Learning Environment

    Science.gov (United States)

    Chen, Chwen Jen

    2006-01-01

    Many researchers and instructional designers increasingly recognise the benefits of utilising three dimensional virtual reality (VR) technology in instruction. In general, there are two types of VR system, the immersive system and the non-immersive system. This article focuses on the latter system that merely uses the conventional personal…

  18. Virtual Web Services

    OpenAIRE

    Rykowski, Jarogniew

    2007-01-01

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

  19. An analytical solution for stationary distribution of photon density in traveling-wave and reflective SOAs

    International Nuclear Information System (INIS)

    Totović, A R; Crnjanski, J V; Krstić, M M; Gvozdić, D M

    2014-01-01

    In this paper, we analyze two semiconductor optical amplifier (SOA) structures, traveling-wave and reflective, with the active region made of the bulk material. The model is based on the stationary traveling-wave equations for forward and backward propagating photon densities of the signal and the amplified spontaneous emission, along with the stationary carrier rate equation. We start by introducing linear approximation of the carrier density spatial distribution, which enables us to find solutions for the photon densities in a closed analytical form. An analytical approach ensures a low computational resource occupation and an easy analysis of the parameters influencing the SOA’s response. The comparison of the analytical and numerical results shows high agreement for a wide range of the input optical powers and bias currents. (paper)

  20. Making the most of mobility: virtual mentoring and education practitioner professional development

    Directory of Open Access Journals (Sweden)

    Hazel D. Owen

    2015-09-01

    Full Text Available Learning provision, including professional learning, needs to embrace mobility (of knowledge, cultures and contexts – physical and cerebral to enable education practitioners to interact locally and globally, engage with new literacies, access rich contexts, and to question, co-construct and collaborate. Virtual mentoring, also known as distance, remote, tele-, cyber- and eMentoring, offers a level of flexibility that enables mentors and mentees to maximise these concepts of mobility. There are Professional Learning and Development (PLD initiatives that offer contextualised, individualised learning experiences via mentoring partnerships and Communities of Practice (CoPs, but not so many that have focussed on virtual mentoring and online CoPs. This article describes a Virtual PLD programme that has been offered in Aotearoa New Zealand from 2009 to date and discusses findings from the associated research study, including benefits that can be specifically equated to the virtual nature of the mentoring and access to the online CoP. Also reported are shifts in mentees’ self-efficacy and perceptions of changes in professional practice.

  1. Structure functions of longitudinal virtual photons at low virtualities

    International Nuclear Information System (INIS)

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

    1996-01-01

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

  2. Virtual hand: a 3D tactile interface to virtual environments

    Science.gov (United States)

    Rogowitz, Bernice E.; Borrel, Paul

    2008-02-01

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

  3. Teachers' perceptions of virtual worlds as a medium for social inclusion for adults with intellectual disability.

    Science.gov (United States)

    Balandin, Susan; Molka-Danielsen, Judith

    2015-01-01

    The aim of this research was to explore educators' perceptions of a virtual world Second Life TM as an environment for social interaction and social inclusion for the Norwegian adult students with intellectual disability that they supported. Five educators who supported a total of 10 adult students with intellectual disability in computer classes in community Adult Education Centres participated in individual in-depth interviews. The interviews were transcribed verbatim and analysed using a content analysis. Participants were positive about Second Life although they did not perceive that it offered a successful context for social interaction or inclusion. They identified a number of benefits to using a virtual world and for students participating in virtual world research. Barriers identified included language, literacy, and technology issues along with the complexity of participating independently in a virtual world. Some people with intellectual disability can use virtual worlds but the skills required need additional research. Virtual worlds may provide a stimulating, safe, and exciting context for a range of activities but the level of support required by many people is high and consequently expensive.

  4. Interactive Character as a Virtual Tour Guide to an Online Museum Exhibition.

    Science.gov (United States)

    de Almeida, Pilar; Yokoi, Shigeki

    Online museums could benefit from digital "lifelike" characters in order to guide users to virtual tours and to customize the tour information to users' interests. Digital characters have been explored in online museum web sites with different degrees of interaction and modes of communication. Such research, however, does not explore…

  5. Virtual Learning Communities as a Vehicle for Workforce Development: A Case Study

    Science.gov (United States)

    Allan, Barbara; Lewis, Dina

    2006-01-01

    Purpose: The purpose of this paper is to explore the benefits and challenges of using a virtual learning community (VLC) as a vehicle for workforce development. This paper argues that VLCs provide a flexible vehicle for workforce development. However, workplace realities may lead to unexpected challenges for participants wanting exploit the…

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

    CERN Document Server

    Marshall, David; McCrory, Dave

    2006-01-01

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

  7. A Virtual Class Calculus

    DEFF Research Database (Denmark)

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

    2006-01-01

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

  8. The Virtual Tablet: Virtual Reality as a Control System

    Science.gov (United States)

    Chronister, Andrew

    2016-01-01

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

  9. SDN-enabled OPS with QoS guarantee for reconfigurable virtual data center networks

    NARCIS (Netherlands)

    Miao, W.; Agraz, F.; Peng, S.; Spadaro, S.; Bernini, G.; Perelló, J.; Zervas, G.; Nejabati, R.; Ciulli, Nicola; Simeonidou, D.; Dorren, H.; Calabretta, N.

    2015-01-01

    Optical packet switching (OPS) can enhance the performance of data center networks (DCNs)by providing fast and large-capacity switching capability. Benefiting from the software-defined networking (SDN) control plane, which could update the look-up-table (LUT) of the OPS, virtual DCNs can be flexibly

  10. Virtual projects

    DEFF Research Database (Denmark)

    Svejvig, Per; Commisso, Trine Hald

    2012-01-01

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

  11. Neurocognitive Treatment for a Patient with Alzheimer's Disease Using a Virtual Reality Navigational Environment

    Directory of Open Access Journals (Sweden)

    Paul J.F. White

    2016-01-01

    Full Text Available In this case study, a man at the onset of Alzheimer's disease (AD was enrolled in a cognitive treatment program based upon spatial navigation in a virtual reality (VR environment. We trained him to navigate to targets in a symmetric, landmark-less virtual building. Our research goals were to determine whether an individual with AD could learn to navigate in a simple VR navigation (VRN environment and whether that training could also bring real-life cognitive benefits. The results show that our participant learned to perfectly navigate to desired targets in the VRN environment over the course of the training program. Furthermore, subjective feedback from his primary caregiver (his wife indicated that his skill at navigating while driving improved noticeably and that he enjoyed cognitive improvement in his daily life at home. These results suggest that VRN treatments might benefit other people with AD.

  12. Transforming Virtual Teams

    DEFF Research Database (Denmark)

    Bjørn, Pernille

    2005-01-01

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

  13. Trust and virtual worlds

    DEFF Research Database (Denmark)

    Ess, Charles; Thorseth, May

    2011-01-01

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

  14. Pengaruh Latihan Lari Zig-Zag, Lari Bolak-Balik, Push-Up dengan Pola Circuit Training Terhadap Kesegaran Jasmani Siswa Ekstrakurikuler Sepak Bola SMAN I Soa Tahun Ajaran 2015/2016

    Directory of Open Access Journals (Sweden)

    Wiljiwianus Primus Wio Bei

    2017-11-01

    Full Text Available Tujuan penelitian ini adalah untuk mengetahui pengaruh latihan lari zig-zag,  lari bolak-balik, push-up dengan pola circuit training studi pada siswa ekstrakurikuler sepak bola SMAN 1 Soa. Penelitian ini adalah penelitian eksperimen dengan desain the static –group pretest – posttest design. Sampel penelitian ini sebanyak 40 orang terdiri atas 20 orang adalah kelompok eksperimen dan 20 orang kelompok kontrol yang diambil secara random. Untuk mengumpulkan data peningkatan Kesegaran Jasmani digunakan TKJI, kemudian data dianalisis dengan t-test. Hasil analisis menunjukan bahwa nilai thitung sebesar 3,5 lebih besar dari nilai ttabel 2,042 pada taraf signifikasi 5 % (α=0,05. Ini berarti ada perbedaan yang signifikan Kesegaran Jasmani antara kelompok eksperimen dan kelompok kontrol. Dengan demikian dapat disimpulkan bahwa latihan lari zig-zag, lari bolak-balik, push up dengan pola circuit training berpengaruh terhadap kesegaran jasmani pada siswa peserta ektrakurikuler sepak bola SMAN 1 Soa.

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

    NARCIS (Netherlands)

    Roth, D.; Warner, J.F.

    2008-01-01

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

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

    Science.gov (United States)

    Chang, Chia-Hu; Wu, Ja-Ling

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

  17. Virtual reality therapy for adults post-stroke: a systematic review and meta-analysis exploring virtual environments and commercial games in therapy.

    Science.gov (United States)

    Lohse, Keith R; Hilderman, Courtney G E; Cheung, Katharine L; Tatla, Sandy; Van der Loos, H F Machiel

    2014-01-01

    The objective of this analysis was to systematically review the evidence for virtual reality (VR) therapy in an adult post-stroke population in both custom built virtual environments (VE) and commercially available gaming systems (CG). MEDLINE, CINAHL, EMBASE, ERIC, PSYCInfo, DARE, PEDro, Cochrane Central Register of Controlled Trials, and Cochrane Database of Systematic Reviews were systematically searched from the earliest available date until April 4, 2013. Controlled trials that compared VR to conventional therapy were included. Population criteria included adults (>18) post-stroke, excluding children, cerebral palsy, and other neurological disorders. Included studies were reported in English. Quality of studies was assessed with the Physiotherapy Evidence Database Scale (PEDro). Twenty-six studies met the inclusion criteria. For body function outcomes, there was a significant benefit of VR therapy compared to conventional therapy controls, G = 0.48, 95% CI = [0.27, 0.70], and no significant difference between VE and CG interventions (P = 0.38). For activity outcomes, there was a significant benefit of VR therapy, G = 0.58, 95% CI = [0.32, 0.85], and no significant difference between VE and CG interventions (P = 0.66). For participation outcomes, the overall effect size was G = 0.56, 95% CI = [0.02, 1.10]. All participation outcomes came from VE studies. VR rehabilitation moderately improves outcomes compared to conventional therapy in adults post-stroke. Current CG interventions have been too few and too small to assess potential benefits of CG. Future research in this area should aim to clearly define conventional therapy, report on participation measures, consider motivational components of therapy, and investigate commercially available systems in larger RCTs. Prospero CRD42013004338.

  18. Theft of Virtual Property — Towards Security Requirements for Virtual Worlds

    Science.gov (United States)

    Beyer, Anja

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

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

    OpenAIRE

    Kyriakou, Marios; Pan, Xueni; Chrysanthou, Yiorgos

    2016-01-01

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

  20. Low-Cost Solutions Using the Infrastructure as a Service with High Availability and Virtualization Model

    Directory of Open Access Journals (Sweden)

    Cesar Armando Moreira Zambrano

    2017-02-01

    Full Text Available This paper presents the results obtained from the implementation of an infrastructure to improve technological services of email, virtual learning environment, digital repository and virtual library at the Polytechnic Agricultural Higher School of Manabí (Polytechnic School of Agriculture of Manabí, ESPAM, through the use of high availability and virtualization mechanisms to provide more reliable resources. Virtualization is an empowering and cutting-edge technology that is transforming the operation of technological services, but it involves a paradigm shift in serviceoriented information technologies and cloud computing. To execute each of the processes the V-cycle methodology was used as a strategy. Virtualization services empowers companies and institutions by transforming how they operate to be at the forefront of innovation in their services as a technological solution. So the implementation of redundant technology in the ESPAM, has allowed its technological services are always operative, for the benefit of the university community, because if there were failures in the main system or services, the backups will be enabled quickly allowing the systems come into operation immediately.

  1. Use of Signaling to Integrate Desktop Virtual Reality and Online Learning Management Systems

    Science.gov (United States)

    Dodd, Bucky J.; Antonenko, Pavlo D.

    2012-01-01

    Desktop virtual reality is an emerging educational technology that offers many potential benefits for learners in online learning contexts; however, a limited body of research is available that connects current multimedia learning techniques with these new forms of media. Because most formal online learning is delivered using learning management…

  2. Validity of assessing child feeding with virtual reality.

    Science.gov (United States)

    Persky, Susan; Goldring, Megan R; Turner, Sara A; Cohen, Rachel W; Kistler, William D

    2018-04-01

    Assessment of parents' child feeding behavior is challenging, and there is need for additional methodological approaches. Virtual reality technology allows for the creation of behavioral measures, and its implementation overcomes several limitations of existing methods. This report evaluates the validity and usability of the Virtual Reality (VR) Buffet among a sample of 52 parents of children aged 3-7. Participants served a meal of pasta and apple juice in both a virtual setting and real-world setting (counterbalanced and separated by a distractor task). They then created another meal for their child, this time choosing from the full set of food options in the VR Buffet. Finally, participants completed a food estimation task followed by a questionnaire, which assessed their perceptions of the VR Buffet. Results revealed that the amount of virtual pasta served by parents correlated significantly with the amount of real pasta they served, r s  = 0.613, p < .0001, as did served amounts of virtual and real apple juice, r s  = 0.822, p < .0001. Furthermore, parents' perception of the calorie content of chosen foods was significantly correlated with observed calorie content (r s  = 0.438, p = .002), and parents agreed that they would feed the meal they created to their child (M = 4.43, SD = 0.82 on a 1-5 scale). The data presented here demonstrate that parent behavior in the VR Buffet is highly related to real-world behavior, and that the tool is well-rated by parents. Given the data presented and the potential benefits of the abundant behavioral data the VR Buffet can provide, we conclude that it is a valid and needed addition to the array of tools for assessing feeding behavior. Published by Elsevier Ltd.

  3. Virtual Reference Services: Connecting Users with Experts and Supporting the Development of Skills

    Directory of Open Access Journals (Sweden)

    Trix Bakker

    2002-04-01

    Full Text Available Virtual reference - a service that allows librarians and patrons to communicate with each other in real time through the Internet by e-mail, chat or instant messaging - is currently a hot topic in libraries. In a way the commercial sector has challenged the reference function by offering Question & Answer services. To librarians this represents a threat and an opportunity. They can benefit from technologies and service models developed for the commercial arena by adapting these to virtual reference applications that will more effectively meet the needs of libraries on the Web. The literature provides many examples of pilots and experiments in taking reference into cyberspace. After an introduction to the in-and-outs of virtual reference, follows a short exposition of a virtual tour in the Netherlands where 7 of the 13 university libraries and the Royal Library have a basic ‚virtual helpdesk’. One thing is clear: virtual reference services are definitely put high on the agenda of the Dutch libraries. The Royal Library is one of the Dutch libraries, which is going to participate with QuestionPoint, formerly called Collaborative Digital Reference Service (CDRS, jointly developed by the Library of Congress and OCLC, which will provide web-based reference service to researchers anytime, anywhere, through an international, online network of member libraries.

  4. People management implications of virtual workplace arrangements

    Directory of Open Access Journals (Sweden)

    K. Ortlepp

    2006-12-01

    Full Text Available Purpose: The purpose of this paper is to investigate the factors that led to an organisation implementing a particular form of virtual workplace arrangement, namely, home-based work. The benefits and disadvantages associated with this form of work arrangement are explored from both the managers' and home-based employees' perspectives. Design/Methodology/Approach: Given the exploratory nature of the empirical study on which this paper is based, a qualitative research design was adopted so as to ensure that the data collection process was dynamic and probing in nature. Semi-structured in-depth interviews were therefore used as instruments for data collection. Findings: The research findings indicate that virtual work arrangements such as home-based work arrangements have advantages for both employers and employees. For instance, reduction of costs associated with office space and facilities, decrease in absenteeism rates, increased employee job satisfaction and improvements in employees' general quality of life. However, a number of negative experiences related to this form of virtual work arrangement are also evident, for example, feelings of isolation as well as stress related to the inability to have firm boundaries between work and family responsibilities. Implications: Based on the insights gained from the findings in the empirical study, a number of areas that need to be given specific attention when organisations are introducing virtual workplace arrangements of this nature are identified. Recommendations made in this article are important for human resource management specialists as well as core business policy makers considering different forms of organisational design. Originality/Value: Maximising the quality of production and service provided has become the prime objective in most organisations in the 21st century. Technology has made it possible for some jobs to be performed at any place at any time and has facilitated the

  5. Designing Virtual Worlds

    DEFF Research Database (Denmark)

    Gürsimsek, Remzi Ates

    2014-01-01

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

  6. Feasibility Pilot Study: Training Soft Skills in Virtual Worlds.

    Science.gov (United States)

    Abshier, Patricia

    2012-04-01

    In a world where funding is limited, training for healthcare professionals is turning more and more to distance learning in an effort to maintain a knowledgeable and skilled work force. In 2010, Cicatelli Associates, Inc. began exploring the feasibility of using games and virtual worlds as an alternative means to teach skills-training in a distance-learning environment. The pilot study was conducted with six individuals familiar with general counseling and communication skills used by the healthcare industry to promote behavior change. Participants reported that the venue, although challenging at first, showed great potential for use with healthcare providers, as it allowed for more interaction and activities than traditional Webinars. However, there are significant limitations that must be overcome in order for this healthcare training modality to be utilized on a large scale. These limitations included a lack of microgestures and issues regarding the technology being used. In spite of the limitations, however, the potential use of virtual worlds for the training of healthcare providers exists and should be researched further. This article discusses the need and intended benefits of virtual world training as well as the results and conclusions of the pilot study.

  7. Server virtualization solutions

    OpenAIRE

    Jonasts, Gusts

    2012-01-01

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

  8. Virtual Trackballs Revisited

    OpenAIRE

    Henriksen, Knud; Sporring, Jon; Hornbæk, Kasper

    2004-01-01

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

  9. Interactive Virtual Cinematography

    OpenAIRE

    Burelli, Paolo

    2012-01-01

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

  10. Virtual reality: Avatars in human spaceflight training

    Science.gov (United States)

    Osterlund, Jeffrey; Lawrence, Brad

    2012-02-01

    With the advancements in high spatial and temporal resolution graphics, along with advancements in 3D display capabilities to model, simulate, and analyze human-to-machine interfaces and interactions, the world of virtual environments is being used to develop everything from gaming, movie special affects and animations to the design of automobiles. The use of multiple object motion capture technology and digital human tools in aerospace has demonstrated to be a more cost effective alternative to the cost of physical prototypes, provides a more efficient, flexible and responsive environment to changes in the design and training, and provides early human factors considerations concerning the operation of a complex launch vehicle or spacecraft. United Space Alliance (USA) has deployed this technique and tool under Research and Development (R&D) activities on both spacecraft assembly and ground processing operations design and training on the Orion Crew Module. USA utilizes specialized products that were chosen based on functionality, including software and fixed based hardware (e.g., infrared and visible red cameras), along with cyber gloves to ensure fine motor dexterity of the hands. The key findings of the R&D were: mock-ups should be built to not obstruct cameras from markers being tracked; a mock-up toolkit be assembled to facilitate dynamic design changes; markers should be placed in accurate positions on humans and flight hardware to help with tracking; 3D models used in the virtual environment be striped of non-essential data; high computational capable workstations are required to handle the large model data sets; and Technology Interchange Meetings with vendors and other industries also utilizing virtual reality applications need to occur on a continual basis enabling USA to maintain its leading edge within this technology. Parameters of interest and benefit in human spaceflight simulation training that utilizes virtual reality technologies are to

  11. Virtual Laboratory Enabling Collaborative Research in Applied Vehicle Technologies

    Science.gov (United States)

    Lamar, John E.; Cronin, Catherine K.; Scott, Laura E.

    2005-01-01

    The virtual laboratory is a new technology, based on the internet, that has had wide usage in a variety of technical fields because of its inherent ability to allow many users to participate simultaneously in instruction (education) or in the collaborative study of a common problem (real-world application). The leadership in the Applied Vehicle Technology panel has encouraged the utilization of this technology in its task groups for some time and its parent organization, the Research and Technology Agency, has done the same for its own administrative use. This paper outlines the application of the virtual laboratory to those fields important to applied vehicle technologies, gives the status of the effort, and identifies the benefit it can have on collaborative research. The latter is done, in part, through a specific example, i.e. the experience of one task group.

  12. Virtual Reflexes

    OpenAIRE

    Jonker, Catholijn; Broekens, Joost; Plaat, Aske

    2014-01-01

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

  13. Online Measurements of Highly Oxidized Organics in the Gas and Particle phase during SOAS and SENEX

    Science.gov (United States)

    Lopez-Hilfiker, F.; Lee, B. H.; Mohr, C.; Ehn, M.; Rubach, F.; Mentel, T. F.; Kleist, E.; Thornton, J. A.

    2014-12-01

    We present measurements of a large suite of gas and particle phase organic compounds made with a Filter Inlet for Gas and AEROsol (FIGAERO) coupled to a high resolution time of flight chemical ionization mass spectrometer (HR-ToF-CIMS) developed at the University of Washington and with airborne HR-ToF-CIMS measurements. The FIGAERO instrument was deployed on the Jülich Plant Atmosphere Chamber to study α-pinene oxidation, and subsequently at the SMEAR II forest station in Hyytiälä, Finland and the SOAS ground site, in Brent Alabama. During the Southern Atmosphere Study, a gas-phase only version of the HR-ToF-CIMS was deployed on the NOAA WP-3 aircraft as part of SENEX. We focus here on highly oxygenated organic compounds derived from monoterpene oxidation detected both aloft during SENEX and at the ground-based site during SOAS. In both chamber and the atmosphere, many highly oxidized, low volatility compounds were observed in the gas and particles and many of the same compositions detected in the gas-phase were detected in the particles upon temperature programmed thermal desorption. The fraction of a given compound measured in the particle phase follows expected trends with elemental composition such as O/C ratios, but many compounds would not be well described by an absorptive partitioning model assuming unity activity coefficients. The detailed structure in the thermograms reveals a significant contribution from large molecular weight organics and/or oligomers in both chamber and ambient aerosol samples. Approximately 50% of the measured organics in the particle phase are associated with compounds having effective vapour pressures 4 or more orders of magnitude lower than commonly measured monoterpene oxidation products. We discuss the implications of these findings for measurements of gas-particle partitioning and for evaluating the contribution of monoterpene oxidation to organic aerosol formation and growth. We also use the aircraft measurements and a

  14. Beyond xMOOCs in healthcare education: study of the feasibility in integrating virtual patient systems and MOOC platforms.

    Science.gov (United States)

    Stathakarou, Natalia; Zary, Nabil; Kononowicz, Andrzej A

    2014-01-01

    Background. Massive Open Online Courses (MOOCs) are an emerging trend in online learning. However, their technology is not yet completely adjusted to the needs of healthcare education. Integration of Virtual Patients within MOOCs to increase interactivity and foster clinical reasoning skills training, has been discussed in the past, but not verified by a practical implementation. Objective. To investigate the technical feasibility of integrating MOOCs with Virtual Patients for the purpose of enabling further research into the potential pedagogical benefits of this approach. Methods. We selected OpenEdx and Open Labyrinth as representative constituents of a MOOC platform and Virtual Patient system integration. Based upon our prior experience we selected the most fundamental technical requirement to address. Grounded in the available literature we identified an e-learning standard to guide the integration. We attempted to demonstrate the feasibility of the integration by designing a "proof-of-concept" prototype. The resulting pilot implementation was subject of verification by two test cases. Results. A Single Sign-On mechanism connecting Open Labyrinth with OpenEdx and based on the IMS LTI standard was successfully implemented and verified. Conclusion. We investigated the technical perspective of integrating Virtual Patients with MOOCs. By addressing this crucial technical requirement we set a base for future research on the educational benefits of using virtual patients in MOOCs. This provides new opportunities for integrating specialized software in healthcare education at massive scale.

  15. Beyond xMOOCs in healthcare education: study of the feasibility in integrating virtual patient systems and MOOC platforms

    Directory of Open Access Journals (Sweden)

    Natalia Stathakarou

    2014-11-01

    Full Text Available Background. Massive Open Online Courses (MOOCs are an emerging trend in online learning. However, their technology is not yet completely adjusted to the needs of healthcare education. Integration of Virtual Patients within MOOCs to increase interactivity and foster clinical reasoning skills training, has been discussed in the past, but not verified by a practical implementation.Objective. To investigate the technical feasibility of integrating MOOCs with Virtual Patients for the purpose of enabling further research into the potential pedagogical benefits of this approach.Methods. We selected OpenEdx and Open Labyrinth as representative constituents of a MOOC platform and Virtual Patient system integration. Based upon our prior experience we selected the most fundamental technical requirement to address. Grounded in the available literature we identified an e-learning standard to guide the integration. We attempted to demonstrate the feasibility of the integration by designing a “proof-of-concept” prototype. The resulting pilot implementation was subject of verification by two test cases.Results. A Single Sign-On mechanism connecting Open Labyrinth with OpenEdx and based on the IMS LTI standard was successfully implemented and verified.Conclusion. We investigated the technical perspective of integrating Virtual Patients with MOOCs. By addressing this crucial technical requirement we set a base for future research on the educational benefits of using virtual patients in MOOCs. This provides new opportunities for integrating specialized software in healthcare education at massive scale.

  16. A virtual pointer to support the adoption of professional vision in laparoscopic training.

    Science.gov (United States)

    Feng, Yuanyuan; McGowan, Hannah; Semsar, Azin; Zahiri, Hamid R; George, Ivan M; Turner, Timothy; Park, Adrian; Kleinsmith, Andrea; Mentis, Helena M

    2018-05-23

    To assess a virtual pointer in supporting surgical trainees' development of professional vision in laparoscopic surgery. We developed a virtual pointing and telestration system utilizing the Microsoft Kinect movement sensor as an overlay for any imagine system. Training with the application was compared to a standard condition, i.e., verbal instruction with un-mediated gestures, in a laparoscopic training environment. Seven trainees performed four simulated laparoscopic tasks guided by an experienced surgeon as the trainer. Trainee performance was subjectively assessed by the trainee and trainer, and objectively measured by number of errors, time to task completion, and economy of movement. No significant differences in errors and time to task completion were obtained between virtual pointer and standard conditions. Economy of movement in the non-dominant hand was significantly improved when using virtual pointer ([Formula: see text]). The trainers perceived a significant improvement in trainee performance in virtual pointer condition ([Formula: see text]), while the trainees perceived no difference. The trainers' perception of economy of movement was similar between the two conditions in the initial three runs and became significantly improved in virtual pointer condition in the fourth run ([Formula: see text]). Results show that the virtual pointer system improves the trainer's perception of trainee's performance and this is reflected in the objective performance measures in the third and fourth training runs. The benefit of a virtual pointing and telestration system may be perceived by the trainers early on in training, but this is not evident in objective trainee performance until further mastery has been attained. In addition, the performance improvement of economy of motion specifically shows that the virtual pointer improves the adoption of professional vision- improved ability to see and use laparoscopic video results in more direct instrument movement.

  17. Using ESB and BPEL for Evolving Healthcare Systems Towards Pervasive, Grid-Enabled SOA

    Science.gov (United States)

    Koufi, V.; Malamateniou, F.; Papakonstantinou, D.; Vassilacopoulos, G.

    Healthcare organizations often face the challenge of integrating diverse and geographically disparate information technology systems to respond to changing requirements and to exploit the capabilities of modern technologies. Hence, systems evolution, through modification and extension of the existing information technology infrastructure, becomes a necessity. Moreover, the availability of these systems at the point of care when needed is a vital issue for the quality of healthcare provided to patients. This chapter takes a process perspective of healthcare delivery within and across organizational boundaries and presents a disciplined approach for evolving healthcare systems towards a pervasive, grid-enabled service-oriented architecture using the enterprise system bus middleware technology for resolving integration issues, the business process execution language for supporting collaboration requirements and grid middleware technology for both addressing common SOA scalability requirements and complementing existing system functionality. In such an environment, appropriate security mechanisms must ensure authorized access to integrated healthcare services and data. To this end, a security framework addressing security aspects such as authorization and access control is also presented.

  18. Pure Play vs. Bricks-and-Clicks: Who Reaps the Benefits of Virtual Retailing?

    OpenAIRE

    Youlong Zhuang; Albert L. Lederer

    2006-01-01

    Pure play and bricks-and-clicks represent today’s two major retailing models. The current study answers four questions comparing the two models in terms of the e-commerce benefits achieved and information systems management practices used to achieve them. It applies a Web-based survey to compare 69 pure plays to 348 bricks-and-clicks retailers in terms of the market expansion, customer service, back-end efficiency, inventory management, and cost reduction benefits reaped, as well as in term...

  19. [Virtual + 1] * Reality

    Science.gov (United States)

    Beckhaus, Steffi

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

  20. Virtual Vision

    Science.gov (United States)

    Terzopoulos, Demetri; Qureshi, Faisal Z.

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

  1. Novel Optical Header Extraction Based-on SOA and M-Z Interferometer%基于SOA和改进M-Z干涉仪的光分组头提取方案

    Institute of Scientific and Technical Information of China (English)

    刘焕淋; 潘英俊

    2007-01-01

    提出了一种基于半导体光放大器(SOA)和改进的马赫一曾德尔(M-Z)干涉仪的全光分组交换的分组头提取结构和方案.通过讨论SOA-改进的M-Z干涉仪参数对系统性能的影响,从而得到使性能优化的系统参数.数值分析和仿真结果表明,系统在分组头和净荷速率分别为2.5 Gb/s和40 Gb/s时,系统提取分组头的对比度达到15 dB以上.另外,该系统还具有结构简单、可扩展性好和易于集成的优点.

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

    Science.gov (United States)

    Watanuki, Keiichi; Kojima, Kazuyuki

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-07-01

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

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

    International Nuclear Information System (INIS)

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

    2015-01-01

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

  5. The Role of Virtual Learning Environment in Improving Information and Communication Technology Adoption in Teaching Exploring How Virtual Learning Environments Improve University Teacher's Attitudes about the Use of Information and Communication Technology

    Science.gov (United States)

    Ageel, Mohammed

    2012-01-01

    The adoption of ICT-enabled teaching in contemporary schools has largely lagged behind despite its obvious and many benefits, mainly because teachers still hold ignorant, misinformed and highly negative attitudes towards ICT-enabled teaching. This article aimed at investigating the effect of Virtual Learning Environments (VLE) on university…

  6. Integration of aquifer thermal energy systems (ATES) into virtual powerplant as a source of flexibility

    NARCIS (Netherlands)

    Bozkaya, B.; Zeiler, W.; Boxem, G.; Treeck, van C.; Müller, D.

    2014-01-01

    Rapid deployment of distributed energy resources (DER) has changed traditional billing system into dynamic pricing due to the fluctuations in power generation. Virtual power plant (VPP) concept has emerged to take full economic benefit of electricity market and enhancing reliability of electricity

  7. Using a vision cognitive algorithm to schedule virtual machines

    Directory of Open Access Journals (Sweden)

    Zhao Jiaqi

    2014-09-01

    Full Text Available Scheduling virtual machines is a major research topic for cloud computing, because it directly influences the performance, the operation cost and the quality of services. A large cloud center is normally equipped with several hundred thousand physical machines. The mission of the scheduler is to select the best one to host a virtual machine. This is an NPhard global optimization problem with grand challenges for researchers. This work studies the Virtual Machine (VM scheduling problem on the cloud. Our primary concern with VM scheduling is the energy consumption, because the largest part of a cloud center operation cost goes to the kilowatts used. We designed a scheduling algorithm that allocates an incoming virtual machine instance on the host machine, which results in the lowest energy consumption of the entire system. More specifically, we developed a new algorithm, called vision cognition, to solve the global optimization problem. This algorithm is inspired by the observation of how human eyes see directly the smallest/largest item without comparing them pairwisely. We theoretically proved that the algorithm works correctly and converges fast. Practically, we validated the novel algorithm, together with the scheduling concept, using a simulation approach. The adopted cloud simulator models different cloud infrastructures with various properties and detailed runtime information that can usually not be acquired from real clouds. The experimental results demonstrate the benefit of our approach in terms of reducing the cloud center energy consumption

  8. Performance verification of network function virtualization in software defined optical transport networks

    Science.gov (United States)

    Zhao, Yongli; Hu, Liyazhou; Wang, Wei; Li, Yajie; Zhang, Jie

    2017-01-01

    With the continuous opening of resource acquisition and application, there are a large variety of network hardware appliances deployed as the communication infrastructure. To lunch a new network application always implies to replace the obsolete devices and needs the related space and power to accommodate it, which will increase the energy and capital investment. Network function virtualization1 (NFV) aims to address these problems by consolidating many network equipment onto industry standard elements such as servers, switches and storage. Many types of IT resources have been deployed to run Virtual Network Functions (vNFs), such as virtual switches and routers. Then how to deploy NFV in optical transport networks is a of great importance problem. This paper focuses on this problem, and gives an implementation architecture of NFV-enabled optical transport networks based on Software Defined Optical Networking (SDON) with the procedure of vNFs call and return. Especially, an implementation solution of NFV-enabled optical transport node is designed, and a parallel processing method for NFV-enabled OTN nodes is proposed. To verify the performance of NFV-enabled SDON, the protocol interaction procedures of control function virtualization and node function virtualization are demonstrated on SDON testbed. Finally, the benefits and challenges of the parallel processing method for NFV-enabled OTN nodes are simulated and analyzed.

  9. All-optical SR flip-flop based on SOA-MZI switches monolithically integrated on a generic InP platform

    Science.gov (United States)

    Pitris, St.; Vagionas, Ch.; Kanellos, G. T.; Kisacik, R.; Tekin, T.; Broeke, R.; Pleros, N.

    2016-03-01

    At the dawning of the exaflop era, High Performance Computers are foreseen to exploit integrated all-optical elements, to overcome the speed limitations imposed by electronic counterparts. Drawing from the well-known Memory Wall limitation, imposing a performance gap between processor and memory speeds, research has focused on developing ultra-fast latching devices and all-optical memory elements capable of delivering buffering and switching functionalities at unprecedented bit-rates. Following the master-slave configuration of electronic Flip-Flops, coupled SOA-MZI based switches have been theoretically investigated to exceed 40 Gb/s operation, provided a short coupling waveguide. However, this flip-flop architecture has been only hybridly integrated with silica-on-silicon integration technology exhibiting a total footprint of 45x12 mm2 and intra-Flip-Flop coupling waveguide of 2.5cm, limited at 5 Gb/s operation. Monolithic integration offers the possibility to fabricate multiple active and passive photonic components on a single chip at a close proximity towards, bearing promises for fast all-optical memories. Here, we present for the first time a monolithically integrated all-optical SR Flip-Flop with coupled master-slave SOA-MZI switches. The photonic chip is integrated on a 6x2 mm2 die as a part of a multi-project wafer run using library based components of a generic InP platform, fiber-pigtailed and fully packaged on a temperature controlled ceramic submount module with electrical contacts. The intra Flip-Flop coupling waveguide is 5 mm long, reducing the total footprint by two orders of magnitude. Successful flip flop functionality is evaluated at 10 Gb/s with clear open eye diagram, achieving error free operation with a power penalty of 4dB.

  10. Virtual volatility

    Science.gov (United States)

    Silva, A. Christian; Prange, Richard E.

    2007-03-01

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

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

    NARCIS (Netherlands)

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

    2003-01-01

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

  12. Characteristics of aggression among psychiatric inpatients by ward type in Japan: Using the Staff Observation Aggression Scale - Revised (SOAS-R).

    Science.gov (United States)

    Sato, Makiko; Noda, Toshie; Sugiyama, Naoya; Yoshihama, Fumihiro; Miyake, Michi; Ito, Hiroto

    2017-12-01

    Aggressive behaviour by psychiatric patients is a serious issue in clinical practice, and adequate management of such behaviour is required, with careful evaluation of the factors causing the aggression. To examine the characteristics of aggressive incidents by ward type, a cross-sectional descriptive study was conducted for 6 months between April 2012 and June 2013 using the Staff Observation Aggression Scale - Revised, Japanese version (SOAS-R) in 30 wards across 20 Japanese psychiatric hospitals. Participating wards were categorized into three types based on the Japanese medical reimbursement system: emergency psychiatric, acute psychiatric, and standard wards (common in Japan, mostly treating non-acute patients). On analyzing the 443 incidents reported, results showed significant differences in SOAS-R responses by ward type. In acute and emergency psychiatric wards, staff members were the most common target of aggression. In acute psychiatric wards, staff requiring patients to take medication was the most common provocation, and verbal aggression was the most commonly used means. In emergency psychiatric wards, victims felt threatened. In contrast, in standard wards, both the target and provocation of aggression were most commonly other patients, hands were used, victims reported experiencing physical pain, and seclusion was applied to stop their behaviour. These findings suggest that ward environment was an important factor influencing aggressive behaviour. Ensuring the quality and safety of psychiatric care requires understanding the characteristics of incidents that staff are likely to encounter in each ward type, as well as implementing efforts to deal with the incidents adequately and improve the treatment environment. © 2016 Australian College of Mental Health Nurses Inc.

  13. Study on generation and sharing of on-demand global seamless data—Taking MODIS NDVI as an example

    Science.gov (United States)

    Shen, Dayong; Deng, Meixia; Di, Liping; Han, Weiguo; Peng, Chunming; Yagci, Ali Levent; Yu, Genong; Chen, Zeqiang

    2013-04-01

    By applying advanced Geospatial Data Abstraction Library (GDAL) and BigTIFF technology in a Geographical Information System (GIS) with Service Oriented Architecture (SOA), this study has derived global datasets using tile-based input data and implemented Virtual Web Map Service (VWMS) and Virtual Web Coverage Service (VWCS) to provide software tools for visualization and acquisition of global data. Taking MODIS Normalized Difference Vegetation Index (NDVI) as an example, this study proves the feasibility, efficiency and features of the proposed approach.

  14. High availability using virtualization

    International Nuclear Information System (INIS)

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

    2010-01-01

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

  15. Virtual reality in education

    OpenAIRE

    Minocha, Shailey; Tudor, Ana-Despina

    2017-01-01

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

  16. The Elderly Perceived Meanings and Values of Virtual Reality Leisure Activities: A Means-End Chain Approach

    Directory of Open Access Journals (Sweden)

    Cheng-Shih Lin

    2018-04-01

    Full Text Available This study uses means-end chain (MEC techniques to examine the awareness, decision-making procedure, and personal values of the elderly with regard to virtual reality leisure activities. The results of the study show that elderly respondents value virtual reality leisure activities that are fun, safe, and easy. In terms of outcome benefits, elderly respondents value feeling physically and mentally healthy, firsthand experience, and satisfied curiosity. In value terms, elderly respondents hope that their chosen virtual reality leisure activities improve not only their relationships with others, but also their enjoyment, quality of life, and sense of belonging. The results show that, while consumers with different awarenesses of virtual reality leisure activities have different decision-making processes, they share creating “good memories” as the terminal value with the most significant effect. This presents a potential opportunity to promote virtual reality leisure activities. Relevant bodies or enterprises can seek to create good memories in consumers by developing activities that are safe and fun, promote good health, and provide good service, thereby attracting the interest of elderly consumers.

  17. The Elderly Perceived Meanings and Values of Virtual Reality Leisure Activities: A Means-End Chain Approach

    Science.gov (United States)

    Lin, Cheng-Shih; Jeng, Mei-Yuan

    2018-01-01

    This study uses means-end chain (MEC) techniques to examine the awareness, decision-making procedure, and personal values of the elderly with regard to virtual reality leisure activities. The results of the study show that elderly respondents value virtual reality leisure activities that are fun, safe, and easy. In terms of outcome benefits, elderly respondents value feeling physically and mentally healthy, firsthand experience, and satisfied curiosity. In value terms, elderly respondents hope that their chosen virtual reality leisure activities improve not only their relationships with others, but also their enjoyment, quality of life, and sense of belonging. The results show that, while consumers with different awarenesses of virtual reality leisure activities have different decision-making processes, they share creating “good memories” as the terminal value with the most significant effect. This presents a potential opportunity to promote virtual reality leisure activities. Relevant bodies or enterprises can seek to create good memories in consumers by developing activities that are safe and fun, promote good health, and provide good service, thereby attracting the interest of elderly consumers. PMID:29614012

  18. The Elderly Perceived Meanings and Values of Virtual Reality Leisure Activities: A Means-End Chain Approach.

    Science.gov (United States)

    Lin, Cheng-Shih; Jeng, Mei-Yuan; Yeh, Tsu-Ming

    2018-04-03

    This study uses means-end chain (MEC) techniques to examine the awareness, decision-making procedure, and personal values of the elderly with regard to virtual reality leisure activities. The results of the study show that elderly respondents value virtual reality leisure activities that are fun, safe, and easy. In terms of outcome benefits, elderly respondents value feeling physically and mentally healthy, firsthand experience, and satisfied curiosity. In value terms, elderly respondents hope that their chosen virtual reality leisure activities improve not only their relationships with others, but also their enjoyment, quality of life, and sense of belonging. The results show that, while consumers with different awarenesses of virtual reality leisure activities have different decision-making processes, they share creating "good memories" as the terminal value with the most significant effect. This presents a potential opportunity to promote virtual reality leisure activities. Relevant bodies or enterprises can seek to create good memories in consumers by developing activities that are safe and fun, promote good health, and provide good service, thereby attracting the interest of elderly consumers.

  19. Virtual Reality: Principles and Applications

    OpenAIRE

    MÉRIENNE , Frédéric

    2017-01-01

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

  20. Virtual Organizations: Beyond Network Organization

    Directory of Open Access Journals (Sweden)

    Liviu Gabriel CRETU

    2006-01-01

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

  1. Virtual Reference Services.

    Science.gov (United States)

    Brewer, Sally

    2003-01-01

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

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

    Science.gov (United States)

    Scacchi, Walt

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

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

    Science.gov (United States)

    Pritt, Stacy L; Mackta, Jayne

    2010-05-01

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

  4. Measuring sense of presence and user characteristics to predict effective training in an online simulated virtual environment.

    Science.gov (United States)

    De Leo, Gianluca; Diggs, Leigh A; Radici, Elena; Mastaglio, Thomas W

    2014-02-01

    Virtual-reality solutions have successfully been used to train distributed teams. This study aimed to investigate the correlation between user characteristics and sense of presence in an online virtual-reality environment where distributed teams are trained. A greater sense of presence has the potential to make training in the virtual environment more effective, leading to the formation of teams that perform better in a real environment. Being able to identify, before starting online training, those user characteristics that are predictors of a greater sense of presence can lead to the selection of trainees who would benefit most from the online simulated training. This is an observational study with a retrospective postsurvey of participants' user characteristics and degree of sense of presence. Twenty-nine members from 3 Air Force National Guard Medical Service expeditionary medical support teams participated in an online virtual environment training exercise and completed the Independent Television Commission-Sense of Presence Inventory survey, which measures sense of presence and user characteristics. Nonparametric statistics were applied to determine the statistical significance of user characteristics to sense of presence. Comparing user characteristics to the 4 scales of the Independent Television Commission-Sense of Presence Inventory using Kendall τ test gave the following results: the user characteristics "how often you play video games" (τ(26)=-0.458, Pvirtual environment experience such as dizziness, nausea, headache, and eyestrain. The user characteristic "knowledge of virtual reality" was significantly related to engagement (τ(26)=0.463, Pvirtual environments and experience with gaming environments report a higher sense of presence that indicates that they will likely benefit more from online virtual training. Future research studies could include a larger population of expeditionary medical support, and the results obtained could be used to create

  5. Virtualization A Manager's Guide

    CERN Document Server

    Kusnetzky, Dan

    2011-01-01

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

  6. Virtual reality - aesthetic consequences

    OpenAIRE

    Benda, Lubor

    2014-01-01

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

  7. Virtual reality therapy for adults post-stroke: a systematic review and meta-analysis exploring virtual environments and commercial games in therapy.

    Directory of Open Access Journals (Sweden)

    Keith R Lohse

    Full Text Available The objective of this analysis was to systematically review the evidence for virtual reality (VR therapy in an adult post-stroke population in both custom built virtual environments (VE and commercially available gaming systems (CG.MEDLINE, CINAHL, EMBASE, ERIC, PSYCInfo, DARE, PEDro, Cochrane Central Register of Controlled Trials, and Cochrane Database of Systematic Reviews were systematically searched from the earliest available date until April 4, 2013. Controlled trials that compared VR to conventional therapy were included. Population criteria included adults (>18 post-stroke, excluding children, cerebral palsy, and other neurological disorders. Included studies were reported in English. Quality of studies was assessed with the Physiotherapy Evidence Database Scale (PEDro.Twenty-six studies met the inclusion criteria. For body function outcomes, there was a significant benefit of VR therapy compared to conventional therapy controls, G = 0.48, 95% CI = [0.27, 0.70], and no significant difference between VE and CG interventions (P = 0.38. For activity outcomes, there was a significant benefit of VR therapy, G = 0.58, 95% CI = [0.32, 0.85], and no significant difference between VE and CG interventions (P = 0.66. For participation outcomes, the overall effect size was G = 0.56, 95% CI = [0.02, 1.10]. All participation outcomes came from VE studies.VR rehabilitation moderately improves outcomes compared to conventional therapy in adults post-stroke. Current CG interventions have been too few and too small to assess potential benefits of CG. Future research in this area should aim to clearly define conventional therapy, report on participation measures, consider motivational components of therapy, and investigate commercially available systems in larger RCTs.Prospero CRD42013004338.

  8. Simulation-based Education for Endoscopic Third Ventriculostomy : A Comparison Between Virtual and Physical Training Models

    NARCIS (Netherlands)

    Breimer, Gerben E.; Haji, Faizal A.; Bodani, Vivek; Cunningham, Melissa S.; Lopez-Rios, Adriana-Lucia; Okrainec, Allan; Drake, James M.

    BACKGROUND: The relative educational benefits of virtual reality (VR) and physical simulation models for endoscopic third ventriculostomy (ETV) have not been evaluated "head to head." OBJECTIVE: To compare and identify the relative utility of a physical and VR ETV simulation model for use in

  9. Incidental memory and navigation in panoramic virtual reality for electronic commerce.

    Science.gov (United States)

    Howes, A; Miles, G E; Payne, S J; Mitchell, C D; Davies, A J

    2001-01-01

    Recently much effort has been dedicated to designing and implementing World Wide Web sites for virtual shopping and e-commerce. Despite this effort, relatively little empirical work has been done to determine the effectiveness with which different site designs sell products. We report three experiments in which participants were asked to search for products in various experimental e-commerce sites. Across the experiments participants were asked to search in either QTVR (QuickTime Virtual Reality), hypertext, or pictorially rich hypertext environments; they were then tested for their ability to recall the products seen and to recognize product locations. The experiments demonstrated that when using QTVR (Experiments 1, 2, and 3) or pictorial environments (Experiment 2), participants retained more information about products that were incidental to their goals. In two of the experiments it was shown that participants navigated more efficiently when using a QTVR environment. The costs and benefits of using 3D virtual environments for on-line shops are discussed. Actual or potential applications of this research include support for the development of e-commerce design guidelines.

  10. User-centered virtual environment design for virtual rehabilitation

    Directory of Open Access Journals (Sweden)

    Rizzo Albert A

    2010-02-01

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

  11. User-centered virtual environment design for virtual rehabilitation.

    Science.gov (United States)

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

    2010-02-19

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

  12. Trends in Virtualized User Environments

    Directory of Open Access Journals (Sweden)

    Diane Barrett

    2008-06-01

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

  13. Supporting virtual enterprise design by a web-based information model

    Science.gov (United States)

    Li, Dong; Barn, Balbir; McKay, Alison; de Pennington, Alan

    2001-10-01

    Development of IT and its applications have led to significant changes in business processes. To pursue agility, flexibility and best service to customers, enterprises focus on their core competence and dynamically build relationships with partners to form virtual enterprises as customer driven temporary demand chains/networks. Building the networked enterprise needs responsively interactive decisions instead of a single-direction partner selection process. Benefits and risks in the combination should be systematically analysed, and aggregated information about value-adding abilities and risks of networks needs to be derived from interactions of all partners. In this research, a hierarchical information model to assess partnerships for designing virtual enterprises was developed. Internet technique has been applied to the evaluation process so that interactive decisions can be visualised and made responsively during the design process. The assessment is based on the process which allows each partner responds to requirements of the virtual enterprise by planning its operational process as a bidder. The assessment is then produced by making an aggregated value to represent prospect of the combination of partners given current bidding. Final design is a combination of partners with the greatest total value-adding capability and lowest risk.

  14. Second Life in Education: The Case of Commercial Online Virtual Reality Applied to Teaching and Learning

    OpenAIRE

    Abbie Brown; William Sugar

    2009-01-01

    Second Life is a three-dimensional, multi-user virtual environment that has attracted particularattention for its instructional potential in professional development and higher educationsettings. This article describes Second Life in general and explores the benefits and challengesof using it for teaching and learning.

  15. Contract-oriented software development for internet services

    DEFF Research Database (Denmark)

    Giambiagi, Pablo; Owe, Olaf; Ravn, Anders Peter

    2008-01-01

    COSoDIS (Contract-Oriented Software Development for Internet Services) develops novel approaches to implement and reason about contracts in service oriented architectures (SOA). The rationale is that system developers benefit from abstraction mechanisms to work with these architectures. Therefore...... the goal is to design and test system modeling and programming language tools to empower SOA developers to deploy highly dynamic, negotiable and monitorable Internet services....

  16. Getting with the times: a narrative review of the literature on group decision making in virtual environments and implications for promotions committees.

    Science.gov (United States)

    Acai, Anita; Sonnadara, Ranil R; O'Neill, Thomas A

    2018-05-24

    Concerns around the time and administrative burden of trainee promotion processes have been reported, making virtual meetings an attractive option for promotions committees in undergraduate and postgraduate medicine. However, whether such meetings can uphold the integrity of decision-making processes has yet to be explored. This narrative review aimed to summarize the literature on decision making in virtual teams, discuss ways to improve the effectiveness of virtual teams, and explore their implications for practice. In August 2017, the Web of Science platform was searched with the terms 'decision making' AND 'virtual teams' for articles published within the last 20 years. The search yielded 336 articles, which was narrowed down to a final set of 188 articles. A subset of these, subjectively deemed to be of high-quality and relevant to the work of promotions committees, was included in this review. Virtual team functioning was explored with respect to team composition and development, idea generation and selection, group memory, and communication. While virtual teams were found to potentially offer a number of key benefits over face-to-face meetings including convenience and scheduling flexibility, inclusion of members at remote sites, and enhanced idea generation and external storage, these benefits must be carefully weighed against potential challenges involving planning and coordination, integration of perspectives, and relational conflict among members, all of which can potentially reduce decision-making quality. Avenues to address these issues and maximize the outcomes of virtual promotions meetings are offered in light of the evidence.

  17. Does Narrative Feedback Enhance Children's Motor Learning in a Virtual Environment?

    Science.gov (United States)

    Levac, Danielle E; Lu, Amy S

    2018-04-30

    Augmented feedback has motivational and informational functions in motor learning, and is a key feature of practice in a virtual environment (VE). This study evaluated the impact of narrative (story-based) feedback as compared to standard feedback during practice of a novel task in a VE on typically developing children's motor learning, motivation and engagement. Thirty-eight children practiced navigating through a virtual path, receiving narrative or non-narrative feedback following each trial. All participants improved their performance on retention but not transfer, with no significant differences between groups. Self-reported engagement was associated with acquisition, retention and transfer for both groups. A narrative approach to feedback delivery did not offer an additive benefit; additional affective advantages of augmented feedback for motor learning in VEs should be explored.

  18. Outcomes of a virtual-reality simulator-training programme on basic surgical skills in robot-assisted laparoscopic surgery.

    Science.gov (United States)

    Phé, Véronique; Cattarino, Susanna; Parra, Jérôme; Bitker, Marc-Olivier; Ambrogi, Vanina; Vaessen, Christophe; Rouprêt, Morgan

    2017-06-01

    The utility of the virtual-reality robotic simulator in training programmes has not been clearly evaluated. Our aim was to evaluate the impact of a virtual-reality robotic simulator-training programme on basic surgical skills. A simulator-training programme in robotic surgery, using the da Vinci Skills Simulator, was evaluated in a population including junior and seasoned surgeons, and non-physicians. Their performances on robotic dots and suturing-skin pod platforms before and after virtual-simulation training were rated anonymously by surgeons experienced in robotics. 39 participants were enrolled: 14 medical students and residents in surgery, 14 seasoned surgeons, 11 non-physicians. Junior and seasoned surgeons' performances on platforms were not significantly improved after virtual-reality robotic simulation in any of the skill domains, in contrast to non-physicians. The benefits of virtual-reality simulator training on several tasks to basic skills in robotic surgery were not obvious among surgeons in our initial and early experience with the simulator. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  19. Virtual Workshop

    DEFF Research Database (Denmark)

    Buus, Lillian; Bygholm, Ann

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

  20. A Load Balancing Scheme Using Federate Migration Based on Virtual Machines for Cloud Simulations

    Directory of Open Access Journals (Sweden)

    Xiao Song

    2015-01-01

    Full Text Available A maturing and promising technology, Cloud computing can benefit large-scale simulations by providing on-demand, anywhere simulation services to users. In order to enable multitask and multiuser simulation systems with Cloud computing, Cloud simulation platform (CSP was proposed and developed. To use key techniques of Cloud computing such as virtualization to promote the running efficiency of large-scale military HLA systems, this paper proposes a new type of federate container, virtual machine (VM, and its dynamic migration algorithm considering both computation and communication cost. Experiments show that the migration scheme effectively improves the running efficiency of HLA system when the distributed system is not saturated.