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Sample records for benefits soa virtualization

  1. Virtualization as a key component for SOA enabling

    OpenAIRE

    Skage, Robert

    2008-01-01

    OBJECTIVES Service oriented architecture (SOA) is frequently recognized as an approach to enhance the business value of IT, in particular for its potential to enable more flexible IT infrastructures and organizational interoperability. Traditionally SOA has been subjected to misconceptions, hence has yet to fulfill its potential in large scale. Change management and security has proven to be among the most significant challenges related to SOA enabling of IT infrastructures. Virtualization te...

  2. An architecture based on SOA and virtual enterprise principles: OpenNebula for cloud deployment

    CSIR Research Space (South Africa)

    Mvelase, P

    2012-04-01

    Full Text Available by established legacy infrastructures, thus reducing the complexity of deploying cloud solutions. The author envisions a cloud-based system built on service oriented architecture (SOA) principles and virtual enterprise (VE) principles as a solution to enhancing...

  3. 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...

  4. 增强计算系统可信赖性:融合虚拟化和SOA%Enhance the Dependability of Computing Systems: Integration of Virtualization and SOA

    Institute of Scientific and Technical Information of China (English)

    林闯; 孔祥震; 周寰

    2009-01-01

    随着计算机软、硬件技术的不断进步和应用需求的日益增长,以计算机为中心的计算系统的应用范围越来越广,其复杂程度也在迅速提高,人们对如何评估和提高计算系统的可信赖性的需求日益迫切.首先给出了计算系统的可信赖性的定义,并系统地定义了一整套量化评价指标;同时,对计算系统面临的各种可信赖性威胁进行了详细的归类分析.传统的方法难以应对复杂系统面临的各种可信赖性问题,人们仍在不断地寻求新的技术.虚拟化技术在这种应用背景下走向复兴,成为一大研究热点.介绍了已有的虚拟化技术在增强系统可信赖性上相关的研究成果,并且总结了虚拟化技术在增强系统可信赖性方面的各种特性和机制.然而由于现有的计算系统体系结构的限制,难以将虚拟化技术在增强系统可信赖性方面的优势充分地发挥出来.面向服务的体系结构(service oriented architecture,简称SOA)以其松散耦合、平台无关性等特点很好地适应了虚拟化技术的需求.因此,最后将SOA和虚拟化技术相结合,提出了一种增强计算系统可信赖性的系统架构,即面向服务的虚拟化SOV(service oriented virtualization),并且分析了SOV系统如何在遭受各种可信赖性威胁时,运用体系结构优势和虚拟化技术的各种机制保证系统可信赖性.%With the advance of computer hardware and software techniques and the continuous growth of application requirements, the computing systems, which have computers as their centers, have increasingly broadened the scope of application, while the complexity is also growing quickly. The demand for evaluating and improving the dependability of computing systems is more and more urgent. This paper gives the definition of computing systems' dependability, and a series of quantitative indicators are presented to evaluate the dependability. At the same time, the threats to

  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. 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.

  7. On the Benefit of Virtualization: Strategies for Flexible Server Allocation

    CERN Document Server

    Arora, Dushyant; Schaffrath, Gregor; Schmid, Stefan

    2010-01-01

    Virtualization technology facilitates a dynamic, demand-driven allocation and migration of servers. This paper studies how the flexibility offered by network virtualization can be used to improve Quality-of-Service parameters such as latency, while taking into account allocation costs. A generic use case is considered where both the overall demand issued for a certain service (for example, an SAP application in the cloud, or a gaming application accessed) as well as the origins of the requests change over time (e.g., due to time zone effects or due to user mobility), and we present online and optimal offline strategies to compute the number and location of the servers implementing this service. These algorithms also allow us to study the fundamental benefits of dynamic resource allocation compared to static systems. Our simulation results confirm our expectations that the gain of flexible server allocation is particularly high in scenarios with moderate dynamics.

  8. 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

  9. 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

  10. 基于SOA的虚拟研发组织协同管理平台设分%SOA-based Management Collaboration Platform for Virtual R&D Organization

    Institute of Scientific and Technical Information of China (English)

    陈鑫铭; 熊曙初

    2011-01-01

    针对虚拟研发组织的特点和需求,采用工作流与Web服务技术,设计了一个基于SOA的协同管理平台,分离了研发管理的核心业务逻辑和流程控制逻辑,采用面向语义的流程服务模型构建了Web服务的执行环境,以提高业务服务和流程服务的动态发现和建模能力。%Based on work flow and web services, a SOA-based collaboration platform is designed for virtual R&D organizations, kernel business logic and flow control logic are separated, the semantics-oriented service model was applied to set up execution environment for Web service to improve the ability of dynamical finding and modeling for business services and process services. Finally, a collaboration case among virtual R&D organizations is demonstrated to validate the production of the thesis.

  11. SOA: A Quality Attribute Perspective

    Science.gov (United States)

    2011-06-23

    JMS) – CORBA … • Infrastructure services available to service providers and/or service consumers to perform common tasks or satisfy QoS requirements...Services is one technology for SOA implementation SOA and Quality Attributes SOA WS* Web Services CORBA REST Services and POX Key Class Realization

  12. Collaborative Virtual Queue: Fair Management of Congested Departure Operations and Benefit Analysis

    CERN Document Server

    Burgain, Pierrick; Clarke, John-Paul

    2008-01-01

    Due to the stochastic nature of departure operations, working at full capacity makes major US airports very sensitive to uncertainties. Consequently, airport ground operations face critically congested taxiways and long runway queues. In this report, we show how improved management of departure operations from the ready-to-push-back time to the wheels-off time can potentially yield significant benefits to airlines and air traffic services. We develop a Collaborative Virtual Queue to enable better optimization capabilities during congested situations while taking into account the laissez-faire competitive environment. Results are evaluated using a departure system model, validated using current statistics and previous studies. First, the Collaborative Virtual Queue enables keeping aircraft away from runway queues, which increases wheels-off time predictability. Second, holding aircraft enables last-minute intra-airline flight switching. This creates new optimization capabilities for airlines i.e. it gives airl...

  13. 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.

  14. A Design Science Approach to Develop a New Comprehensive SOA Governance Framework

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Ayatollahzadeh Shirazi

    2012-09-01

    Full Text Available SOA governance has a critical role in achieving success and realizing the benefits of SOA. Without effective SOA governance, organizations will experience some significant challenges including difficultiesin designing effective decision structures and managing services. To address SOA challenges, organizations require a comprehensive SOA governance framework to implement management and control mechanisms. Study of existing frameworks reveals that these frameworks are not expressive enough to cover all elements of SOA governance and also, they do not completely document underpinning structuressuch as processes, procedures, responsibilities and measurement metrics. In this paper, we propose a new SOA governance framework that is more comprehensive and expressive than its counterparts. In the process of developing the framework, a set of important elements for a desired SOA governance framework is proposed. Based on these elements, a new SOA governance framework is developed. The proposed framework is obtained by extending characteristics of COBIT and applying ITIL service lifecycle activitiesto support the SOA governance principles and requirements. It is a perceptible framework that clarifies all processes, activities, metrics and other related elements in a logical structure. Also, to simplify the application of the framework, an implementation process is proposed.

  15. 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

  16. Knowledge representation with SOA

    Directory of Open Access Journals (Sweden)

    Daniela Gotseva

    2013-01-01

    Full Text Available This paper addresses the problem of supporting the software development process through the artificial intelligence. The expert systems could advise the Domain Engineer in programming without the detailed experience in programming languages. He will use and integrate, with the help of deductive database and domain knowledge, the previously developed software components to new complex functionalities. The objective of this document is to provide the knowledge representation about atomic Web Services which will be registered as the facts in the deductive database. The author proposes to use the decision rules in decision tables for representing the service model which consists of semantic specification, interface description, service quality (QoS, non-functional properties. Also the use of Domain Specific Languages (DSL for modeling Domain Engineers re-quests to the expert system will be considered within this document. As the illustrative use case for described knowledge representation the author proposes the domain of SOA-based geographic information systems (GIS which represent a new branch of information and communication technologies.

  17. 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.

  18. 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.

  19. 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.

  20. Graphically E-Learning introduction and its benefits in Virtual Learning

    CERN Document Server

    Malayeri, A Daneshmand; Rezaei, R

    2010-01-01

    E-learning with using multimedia and graphical interfaces is now fashionable in some virtual learning environments. Especially, in open colleges, universities and E-learning databases, using these interfaces can improve quality of educating by increasing attraction of educational subjects. In this paper, we introduce this technology and its aspects by defining some Graphical User Interfaces (GUI). Improving some indexes in E-learning environments can be measured by using GUI. Adding some plug-ins in E-learning softwares and environments like relative sound, electronic noting paper and virtual classrooms can be created by E-learning GUI (ELGUI) as explain in this paper.

  1. On the Benefits of Stereo Graphics in Virtual Obstacle Avoidance Tasks

    DEFF Research Database (Denmark)

    Bærentzen, Jakob Andreas; Stenholt, Rasmus

    2014-01-01

    of an experiment to see if stereo makes any quantifiable, statistically significant difference in the ability to avoid collisions with virtual obstacles while navigating a 3-D space under constant acceleration. Our results indicate that for this particular application scenario, stereo does provide a significant......In virtual reality, stereo graphics is a very common way of increasing the level of perceptual realism in the visual part of the experience. However, stereo graphics comes at cost, both in technical terms and from a user perspective. In this paper, we present the preliminary results...

  2. 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...

  3. 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.

  4. Benefits of using virtual energy storage system for power system frequency response

    OpenAIRE

    Cheng, Meng; Sami, Saif Sabah; Wu, Jianzhong

    2016-01-01

    This paper forms a Virtual Energy Storage System (VESS) and validates that VESS is an innovative and cost-effective way to provide the function of conventional Energy Storage Systems (ESSs) through the utilization of the present network assets represented by the flexible demand. The VESS is a solution to convert to a low carbon power system and in this paper, is modelled to store and release energy in response to regulation signals by coordinating the Demand Response (DR) from domestic refrig...

  5. Customising virtual globe tours to enhance community awareness of local landscape benefits

    OpenAIRE

    Harwood, Amii R.; Lovett, Andrew A.; Turner, Jenni A.

    2015-01-01

    Our wellbeing depends upon the services provided by ecosystems and their components. Despite recent advances in academic understanding of ecosystem services, and consideration in UK national environmental policy, a greater awareness is needed at community and individual levels. Dynamic features of virtual globe applications have considerable potential for helping convey the multi-dimensional context of ecosystem services and promoting general awareness. In a case study targeting residents in ...

  6. 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.

  7. 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...

  8. 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.

  9. NASA'S Solar System Exploration Research Virtual Institute: An international approach toward bringing science and human exploration together for mutual benefit

    Science.gov (United States)

    Schmidt, Gregory

    2016-07-01

    The NASA Solar System Exploration Research Virtual Institute (SSERVI) is a virtual institute focused on research at the intersection of science and explora-tion, training the next generation of lunar scientists, and community development. The institute is a hub for opportunities that engage the larger scientific and exploration communities in order to form new interdis-ciplinary, research-focused collaborations. Its relative-ly large domestic teams work together along with in-ternational partners in both traditional and virtual set-tings to bring disparate approaches together for mutual benefit. This talk will describe the research efforts of the nine domestic teams that constitute the U.S. com-plement of the Institute and how it is engaging the in-ternational science and exploration communities through workshops, conferences, online seminars and classes, student exchange programs and internships. The Institute is centered on the scientific aspects of exploration as they pertain to the Moon, Near Earth Asteroids (NEAs) and the moons of Mars. It focuses on interdisciplinary, exploration-related science cen-tered around all airless bodies targeted as potential human destinations. Areas of study reported here will represent the broad spectrum of lunar, NEA, and Mar-tian moon sciences encompassing investigations of the surface, interior, exosphere, and near-space environ-ments as well as science uniquely enabled from these bodies. The technical focus ranges from investigations of plasma physics, geology/geochemistry, technology integration, solar system origins/evolution, regolith geotechnical properties, analogues, volatiles, ISRU and exploration potential of the target bodies. SSERVI enhances the widening knowledgebase of planetary research by acting as a bridge between several differ-ent groups and bringing together researchers from the scientific and exploration communities, multiple disci-plines across the full range of planetary sciences, and domestic and

  10. Collaborative software design in an SOA environment

    Institute of Scientific and Technical Information of China (English)

    W.T. TSAI; Bingnan XIAO; Qian HUANG; Yinong CHEN

    2006-01-01

    Based on the current Service-Oriented Architecture (SOA), this paper proposes a new collaborative software design methodology in an SOA Environment: the Global Software Enterprise (GSE). The current SOA is producer-centric, in which the service providers publish services that they produce and let the consumers to search available services to compose their applications. GSE is build on top of Consumer-Centric SOA (CCSOA), in which the application builders publish their application requirements for the service providers to follow when producing or customizing services to support the application. This new methodology reduces the workload and improves the application description capability of the service consumers. It also extends the capacity of design and code sharing, and thus further improves the software productivity. This paper presents the concepts, architecture, enabling techniques, and illustrative examples of collaborative software design in GSE.

  11. REST SOA Orchestration and BPM Platforms

    National Research Council Canada - National Science Library

    Octavian Dospinescu; Catalin Strîmbei; Roxana-Marina Strainu; Alexandra Nistor

    2017-01-01

      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...

  12. Evolvability Characterization in the Context of SOA

    Science.gov (United States)

    Arciniegas H., Jose L.; Dueñas L., Juan C.

    Service-Oriented Architecture (SOA) is an architectural style which promotes reuse of self-contained services. These self-contained services allow a better consideration of software quality characteristics as they can be independently analyzed. In our work, the evolvability quality characteristic has been considered, due to its impact in the stages of Maintenance and Evolution (M&E) for the software enterprises. Three goals are underlined in this paper: first, the relationship between SOA and quality characteristics focusing on a precise definition of evolvability of a software product from the SOA perspective, second a M&E model for SOA, and finally, some experiences are presented in order to assess evolvability in real software products. Two case studies have been executed: the first one analyzing the evolvability of the OSGi framework. And in the second case, the model is used in local Small and Medium Enterprises (SMEs), where an improvement process has been executed.

  13. Vision and benefits of a virtual radiology environment for the U.S. Army

    Science.gov (United States)

    Chacko, Anna K.; Griffin, Robert; Cook, Jay F.; Martinez, Ralph; Lollar, H. William; Perez, Guadalupe

    1998-07-01

    The changes that have overtaken the U.S. healthcare industry in the last five years could be best characterized as tectonic shifts. Every aspect of the healthcare market has been affected by the changes in Government policy and the attitude of society to issues in Healthcare. Most of these changes have been viewed as adversarial both to the health care provider and to the consumer. Healthcare reform was to have made healthcare more affordable and more available. Although healthcare reform was not passed, attempts have been made nationwide to address the ills of the system. These attempts have been largely half-hearted and weak-kneed. In most instances, only half a solution has been provided. There has been no improvement in the quality of care. In fact, in many instances, there has been degradation in quality and it has not become more available. We are faced with seemingly conflicting mandates -- providing quality care making it more available working under severe capitation constraints and attracting and retaining a quality workforce. How do we address these problems? We have to change. We have to adopt the military paradigm of agility, adaptability and flexibility applicable to military science to our field of endeavor. We have to consider achieving all our goals without sacrificing any aspect. The most obvious step is to improve efficiency. This can be done best by incorporating the advantages that information technology has bestowed on other fields of endeavor. Properly applied information technology will provide the answer to improving efficiency in the Healthcare field. In the Department of Defense (DoD), we are now embarking on an extremely exciting new idea -- rendering the entire Virtual Radiology Environment (VRE). The business of radiology in the military therefore, is being re-engineered on several fronts. This is achieved in several sequential steps: (1) Equipping every radiology department to become digital and PACS-network capable. (2) Information

  14. Linearity enhancement of EA modulator using SOA

    Science.gov (United States)

    Han, Sang-Kook; Lee, Chang-Hyun; Sohn, Sung-Il

    2000-03-01

    Nonlinearity of Electroabsorption modulator (EAM) resulting from its near exponential transfer function decreases SNR in analog optical transmission. Since the transfer function of semiconductor optical amplifier (SOA) is inverse to that of EAM, the intermodulation distortion of EAM can be reduced by using SOA that connect with EAM in series and operating in gain saturation region. To improve the nonlinearity compensation of EAM, the increased gain of SOA is required and the slope of giant saturation, the ratio of gain to input SOA power, needs to be steep. However, the signal- spontaneous beat noise that is the dominant system noise increase in proportion to the gain. Thus, the noise power level of system is increased and the spurious free dynamic range (SFDR) of EAM is reduced. We have analyzed the SFDR variation of EAM including SOA gain and ASE noise. An enhancement of 9dB in SFDR was theoretically obtained and the gain of SOA for an optimum operation is mentioned. The proposed scheme is easy to implement and can be monolithically integrated with other optical devices useful for an efficient linear analog optical transmitter.

  15. Apertium goes SOA: an efficient and scalable service based on the Apertium rule-based machine translation platform

    OpenAIRE

    Minervini, Pasquale

    2009-01-01

    Service Oriented Architecture (SOA) is a paradigm for organising and using distributed services that may be under the control of different ownership domains and implemented using various technology stacks. In some contexts, an organisation using an IT infrastructure implementing the SOA paradigm can take a great benefit from the integration, in its business processes, of efficient machine translation (MT) services to overcome language barriers. This paper describes the architecture and the de...

  16. 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

  17. 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.

  18. The STAR Grants Contribution to the SOAS Campaign

    Science.gov (United States)

    Hunt, S.

    2013-12-01

    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 involving the US Environmental Protection Agency (EPA), the National Science Foundation (NSF), the National Oceanic and Atmospheric Administration (NOAA), the Electric Power Research Institute (EPRI) and dozens of domestic and international research institutions. In 2013, the EPA's Science to Achieve Results (STAR) grants program funded fourteen projects, resulting in a research portfolio addressing a number of scientific needs outlined in the solicitation. These projects fall into two categories: field measurements of key chemical species and supporting laboratory experiments and model development. Awardees participating in the SOAS campaign are studying key chemical species (including volatile organic compounds, formaldehyde, reactive nitrogen species, reactive oxidant species, organonitrates and organosulfates) for understanding the interactions between anthropogenic and biogenic emissions. Measurements were made by instruments both on the ground and from aircrafts. Additionally, projects characterized and investigated the climatically-relevant properties of aerosol from the field site. Work also includes several chamber experiments that will result in a detailed analysis of secondary organic aerosol components and precursors. Certain species measured in the field campaign will be analyzed and characterized in a laboratory setting. Finally, three projects focus on improving air quality and climate models, particularly in areas dealing with cloud droplets, aqueous chemistry, and organic aerosol mixtures. This poster will provide an overview of the STAR grants program's contribution to the SAS and SOAS campaign and highlight some of the challenges and benefits of leveraging funds in this way.

  19. An Interface using SOA Framework For Mediclaim Provider

    OpenAIRE

    Rajini, S. Nirmala Sugirtha; T Bhuvaneswari

    2012-01-01

    SOA brought new opportunities for the long expected agility, reuse and the adaptive capability of information technology to the ever changing business requirements and environments. The purpose of this paper is to describe the implementation of Medical Insurance Claim Process Model using SOA. We adopt Service Oriented Architecture (SOA) to reduce the complexity among systems and solve data consistency problems among services. We choose n-tier and Service-Oriented Architecture (SOA) as our sys...

  20. 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.

  1. 大师眼中SOA

    Institute of Scientific and Technical Information of China (English)

    李楠

    2007-01-01

    国内第一本详细论述SOA的专业著作,《Understanding SOA With Web Services》经过编译终于出版了。作者Eric Newcomer之前也如约来到国内进行签售,希望借此书推动国内SOA的发展。

  2. Adaptive SOA Infrastructure Based on Variability Management

    OpenAIRE

    Graubmann, Peter; Roshchin, Mikhail

    2008-01-01

    In order to exploit the adaptability of a SOA infrastructure, it becomes necessary to provide platform mechanisms that support a mapping of the variability in the applications to the variability provided by the infrastructure. The approach focuses on the configuration of the needed infrastructure mechanisms including support for the derivation of the infrastructure variability model.

  3. 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.

  4. Review on SOA-MZl-based photonic add/drop and switching operations

    Institute of Scientific and Technical Information of China (English)

    Claudio PORZI; Giovanni SERAFINO; Sergio PINNA; An NGUYEN; Giampiero CONTESTABILE; Antonclla BOGONI

    2013-01-01

    Semiconductor optical amplifier-Mach-Zehnder interferometer (SOA-MZI) is a technologically mature optical device that can be exploited for a wide range of operations on both amplitude and phase modulated signals, with performance limited by the carrier lifetime in the SOAs. Recent advances on SOA structures have demonstrated their suitability for high quality, ultra-fast photonic signal processing, making SOA-MZI a good candidate for elaborating signals in new generation high-capacity optical networks. Dynamic wavelength switching/routing and add/drop operations are expected to bring benefits in future optical networks in terms of improved system flexibility and efficiency. The capability of performing such operations directly in the optical domain can significantly reduce the number of opto/electrical and electro/optical conversions in the routing nodes, reducing their power consumption and their latency time. Moreover, since phase-shift keying (PSK) formats or other advanced modulation formats involving both amplitude and phase modulation, start to coexist in optical communication systems with the conventional on-off keying (OOK) modulation format, the availability of a single device, suitable for processing all these different signals, is mandatory. The SOA-MZI fits all these requirements for both OOK and constant-envelope phase-modulated signals, providing a compact and flexible solution. Here we review on the use of the SOA-MZI for carrying out all- optical switching operations, by realizing wavelength conversion and add/drop functionalities, both for OOK and differential binary phase shift keying (DPSK) signals up to 40Gb/s. Power penalties lower than 2 dB are demonstrated in all cases.

  5. Virtual colonoscopy.

    Science.gov (United States)

    Vining, D J

    1997-04-01

    A new method for colon examination, virtual colonoscopy, has been created by combining spiral computed tomography and virtual reality computer technology. If virtual colonoscopy proves equal to or superior to traditional colonoscopy in sensitivity and specificity for cancer screening, it would yield significant clinical and public health benefits because of its potential for increased acceptance among patients as well as its considerably lower cost and risks.

  6. Leveraging SOA for Distributed Test and Evaluation: To SOA or Not to SOA, That Is the Question

    Science.gov (United States)

    2008-09-01

    Point Mugu, California Gil Torres Naval Air System Command (NAVAIR), Point Mugu, California Ken Thomas TSAE, Sierra Vista, Arizona James Buscemi GBL ... GBL Systems Corporation, Camarillo, Califor- nia. He is the principle investigator for ‘‘Applicability of Service-Oriented Architecture (SOA) to...of New York at Stony Brook. KENNETH THOMAS is the GBL lead system architect for the Science and Technology NST Focus Area and NST T&E Reference

  7. 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.

  8. How the Cloud Stretches the SOA Scope

    Directory of Open Access Journals (Sweden)

    Lakshmanan G

    2012-09-01

    Full Text Available In this article, we will describe how the enterprise serviceoriented-architecture (SOA scope is stretched with the advent of cloud computing. With the help of the case study of a fictitious global retailer, we will demonstrate the process for identifying cloud scenarios. Also, we will come across an emerging breed of distributed applications—both on-premise and in the Cloud—and discuss the integration considerations for building them.

  9. An Approach for Agile SOA Development using Agile Principals

    CERN Document Server

    Shahrbanoo, Majlesi; Mehran, Mohsenzadeh

    2012-01-01

    In dynamic and turbulent business environment, the need for success and survival of any organization is the ability of adapting to changes efficiently and cost-effectively. So, for developing software applications, one of the methods is Service Oriented Architecture (SOA) methodology and other is Agile Methodology. Since embracing changes is the indispensable concept of SOA development as well as Agile Development, using an appropriate SOA methodology able to adapt changes even during system development with the preservation of software quality is necessary. In this paper, a new approach consisted of five steps is presented to add agility to SOA methodologies. This approach, before any SOA-based development, helps architect(s) to determine Core Business Processes (CBPs) by using agile principals for establishing Core Architecture. The most important advantage of this approach according to the results of case study is possibility of embracing changes with the preservation of software quality in SOA development...

  10. A Scenario-Based Technique for Developing SOA Technical Governance

    Science.gov (United States)

    2009-06-01

    18  Figure 5:  CBDi-SAE SOA Governance Framework 19  Figure 6:  IBM SOA Governance and Management Method 20  Figure 7:  ITIL Core Framework 21...organizations, even if they are not SOA specific, such as the Information Technol- ogy Infrastructure Library ( ITIL ) [10] These frameworks can be very...based on a standard or a widely recommended approach such as ITIL , one custom-built for the organization, or a hybrid of all of the preceding. For

  11. 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.

  12. 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

  13. Mapping of SOA and RUP: DOA as Case Study

    CERN Document Server

    Hussain, Shahid; Ahmad, Bashir; Ahmed, Shakeel

    2010-01-01

    SOA (Service Oriented Architecture) is a new trend towards increasing the profit margins in an organization due to incorporating business services to business practices. Rational Unified Process (RUP) is a unified method planning form for large business applications that provides a language for describing method content and processes. The well defined mapping of SOA and RUP leads to successful completion of RUP software projects to provide services to their users. DOA (Digital Office Assistant) is a multi user SOA type application that provides appropriate viewer for each user to assist him through services. In this paper authors proposed the mapping strategy of SOA with RUP by considering DOA as case study.

  14. A model for service oriented architecture (SOA governance maturity

    Directory of Open Access Journals (Sweden)

    Alireza Hasanzadeh

    2012-07-01

    Full Text Available Today, SOA has created the opportunities to improve agility and speed in matching business needs with information technology infrastructure. Since the organization in the process of using this technology faces many challenges and may spend a lot of energy and despite huge investments, failure, therefore need to implement a model for SOA governance that based on a gradual approach and SOA maturity of the organization determine what actions they do to move toward SOA. Therefore, this study was following present such a model. Data gathering tool was questionnaire. In order to confirm the model of study, sample included 16 academic experts. The results confirmed the model of this study.

  15. An Interface using SOA Framework For Mediclaim Provider

    CERN Document Server

    Rajini, S Nirmala Sugirtha

    2012-01-01

    SOA brought new opportunities for the long expected agility, reuse and the adaptive capability of information technology to the ever changing business requirements and environments. The purpose of this paper is to describe the implementation of Medical Insurance Claim Process Model using SOA. We adopt Service Oriented Architecture (SOA) to reduce the complexity among systems and solve data consistency problems among services. We choose n-tier and Service-Oriented Architecture (SOA) as our system environment. This model can also establish a potentially new innovative market branch for the insurance industry.

  16. 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

    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 and the propert......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...

  17. Virtual Reality in Psychology

    National Research Council Canada - National Science Library

    Nigel Foreman

    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...

  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. The online appeal of the physical shop: How a physical store can benefit from a virtual representation.

    Science.gov (United States)

    Moes, Anne; Vliet, Harry van

    2017-06-01

    Consumer behaviour in 2016 shows that (r)etailers need online/offline integration to better serve their clients. An important distinguishing feature of the physical shop is how it can offer consumers a shopping experience. This study uses two experiments to research the extent a fashion store's shopping experience can be presented to consumers via visual material (a regular photo, a 360-degree photo and a virtual reality photo of the shop) without the consumers being in the shop itself. The effects of these visual materials will also be measured in (among others) terms of purchase intention, visiting intention to the physical shop and online visit satisfaction. A theoretical framework is used to substantiate how the three types of pictures can be classified in terms of medium richness. The completed experiments show, among other outcomes, that consumers who saw the virtual reality photo of the shop have a more positive shopping experience, a higher purchase intention, a higher intention to visit the physical shop and more online visit satisfaction than people who have only seen the regular photo or the 360-degree photo of the shop. Enjoyment and novelty seem to partly explain these found effects.

  20. The online appeal of the physical shop: How a physical store can benefit from a virtual representation

    Directory of Open Access Journals (Sweden)

    Anne Moes

    2017-06-01

    Full Text Available Consumer behaviour in 2016 shows that (retailers need online/offline integration to better serve their clients. An important distinguishing feature of the physical shop is how it can offer consumers a shopping experience. This study uses two experiments to research the extent a fashion store’s shopping experience can be presented to consumers via visual material (a regular photo, a 360-degree photo and a virtual reality photo of the shop without the consumers being in the shop itself. The effects of these visual materials will also be measured in (among others terms of purchase intention, visiting intention to the physical shop and online visit satisfaction. A theoretical framework is used to substantiate how the three types of pictures can be classified in terms of medium richness. The completed experiments show, among other outcomes, that consumers who saw the virtual reality photo of the shop have a more positive shopping experience, a higher purchase intention, a higher intention to visit the physical shop and more online visit satisfaction than people who have only seen the regular photo or the 360-degree photo of the shop. Enjoyment and novelty seem to partly explain these found effects.

  1. A Novel Technique of Measuring SOA Differential Carrier Lifetime and a -Factor Using SOA Optical Modulation Response

    Institute of Scientific and Technical Information of China (English)

    Ki-Hyuk Lee; Woo-Young Choi

    2003-01-01

    We demonstrate a new technique of measuring differential carrier lifetime and linewidth enhancement factor in a semiconductor optical amplifier. In our method, the optical responses and fiber transfer functions of a self-gain modulated SOA are measured and, from these, values of carrier lifetimes and linewidth enhancement factors are determined for various SOA input optical powers.

  2. SOA-based security governance middleware

    CERN Document Server

    de Leusse, Pierre; 10.1109/SECURWARE.2010.17

    2012-01-01

    Business requirements for rapid operational efficiency, customer responsiveness as well as rapid adaptability are actively driving the need for ever increasing communication and integration apabilities of software assets. In this context, security, although acknowledged as being a necessity, is often perceived as a hindrance. Indeed, dynamic environments require flexible and understandable security that can be customized, adapted and reconfigured dynamically to face changing requirements. In this paper, the authors propose SOA based security governance middleware that handles security requirements on behalf of a resource exposed through it. The middleware aims at providing different security settings through the use of managed compositions of security services called profiles. The main added value of this work compared to existing handlers or centralized approaches lies in its enhanced flexibility and transparency.

  3. Teamcenter2007起舞SOA

    Institute of Scientific and Technical Information of China (English)

    穆清

    2008-01-01

    @@ 在Siemens A&D集团收购了UGS 5个月后,Siemens PLM Software宣布其新一代PLM产品Teamcenter2007使用了最新的IT标准,是建立在一个完整的面向服务架构(SOA)基础上、集成的PLM平台.Teamcenter产品行销部高级总监BillBoswe]l表示Siemens PLM Soft w&re因此成为首家产品具有完整SOA体系架构的PLM厂商,并将引领PLM下一个可能的发展方向.

  4. SOA approach for integration of departmental systems.

    Science.gov (United States)

    Itälä, Timo; Ukkola, Jari; Virtanen, Aino; Mykkänen, Juha

    2008-01-01

    In this paper a unified method for integration of departmental systems into the main systems of a healthcare organization is described. The approach is based on combining Business Process Modeling (BPM) and Service Oriented Architecture (SOA) methods and technologies. A top-down approach is used for modeling the care process and supporting care services which in turn are decomposed down to such a level of granularity that they can be described and implemented as web services described with Web Services Description Language (WSDL) documents. Then a bottom-up approach is used for wrapping the existing departmental systems and their interfaces into web services using Enterprise Service Bus (ESB). Finally the orchestration of the services is described using executable Business Process Execution Language (BPEL) code.

  5. 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....

  6. SOA FROM ISOPRENE OXIDATION PRODUCTS: MODEL SIMULATION OF CLOUD CHEMISTRY

    Science.gov (United States)

    Recent laboratory evidence supports the hypothesis that secondary organic aerosol (SOA) is formed in the atmosphere through aqueous-phase reactions in clouds. The results of batch photochemical reactions of glyoxal, methylglyoxal and hydrogen peroxide are presented. These labor...

  7. 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....

  8. Formation of anthropogenic secondary organic aerosol (SOA and its influence on biogenic SOA properties

    Directory of Open Access Journals (Sweden)

    E. U. Emanuelsson

    2013-03-01

    Full Text Available Secondary organic aerosol (SOA formation from mixed anthropogenic and biogenic precursors has been studied exposing reaction mixtures to natural sunlight in the SAPHIR chamber in Jülich, Germany. In this study aromatic compounds served as examples of anthropogenic volatile organic compound (VOC and a mixture of α-pinene and limonene as an example for biogenic VOC. Several experiments with exclusively aromatic precursors were performed to establish a relationship between yield and organic aerosol mass loading for the atmospheric relevant range of aerosol loads of 0.01 to 10 μg m−3. The yields (0.5 to 9% were comparable to previous data and further used for the detailed evaluation of the mixed biogenic and anthropogenic experiments. For the mixed experiments a number of different oxidation schemes were addressed. The reactivity, the sequence of addition, and the amount of the precursors influenced the SOA properties. Monoterpene oxidation products, including carboxylic acids and dimer esters were identified in the aged aerosol at levels comparable to ambient air. OH radicals were measured by Laser Induced Fluorescence, which allowed for establishing relations of aerosol properties and composition to the experimental OH dose. Furthermore, the OH measurements in combination with the derived yields for aromatic SOA enabled application of a simplified model to calculate the chemical turnover of the aromatic precursor and corresponding anthropogenic contribution to the mixed aerosol. The estimated anthropogenic contributions were ranging from small (≈8% up to significant fraction (>50% providing a suitable range to study the effect of aerosol composition on the aerosol volatility (volume fraction remaining (VFR at 343 K: 0.86–0.94. The aromatic aerosol had higher oxygen to carbon ratio O/C and was less volatile than the biogenic fraction. However, in order to produce significant amount of aromatic SOA the reaction mixtures needed a higher

  9. Formation of anthropogenic secondary organic aerosol (SOA) and its influence on biogenic SOA properties

    Science.gov (United States)

    Emanuelsson, E. U.; Hallquist, M.; Kristensen, K.; Glasius, M.; Bohn, B.; Fuchs, H.; Kammer, B.; Kiendler-Scharr, A.; Nehr, S.; Rubach, F.; Tillmann, R.; Wahner, A.; Wu, H.-C.; Mentel, Th. F.

    2013-03-01

    Secondary organic aerosol (SOA) formation from mixed anthropogenic and biogenic precursors has been studied exposing reaction mixtures to natural sunlight in the SAPHIR chamber in Jülich, Germany. In this study aromatic compounds served as examples of anthropogenic volatile organic compound (VOC) and a mixture of α-pinene and limonene as an example for biogenic VOC. Several experiments with exclusively aromatic precursors were performed to establish a relationship between yield and organic aerosol mass loading for the atmospheric relevant range of aerosol loads of 0.01 to 10 μg m-3. The yields (0.5 to 9%) were comparable to previous data and further used for the detailed evaluation of the mixed biogenic and anthropogenic experiments. For the mixed experiments a number of different oxidation schemes were addressed. The reactivity, the sequence of addition, and the amount of the precursors influenced the SOA properties. Monoterpene oxidation products, including carboxylic acids and dimer esters were identified in the aged aerosol at levels comparable to ambient air. OH radicals were measured by Laser Induced Fluorescence, which allowed for establishing relations of aerosol properties and composition to the experimental OH dose. Furthermore, the OH measurements in combination with the derived yields for aromatic SOA enabled application of a simplified model to calculate the chemical turnover of the aromatic precursor and corresponding anthropogenic contribution to the mixed aerosol. The estimated anthropogenic contributions were ranging from small (≈8%) up to significant fraction (>50%) providing a suitable range to study the effect of aerosol composition on the aerosol volatility (volume fraction remaining (VFR) at 343 K: 0.86-0.94). The aromatic aerosol had higher oxygen to carbon ratio O/C and was less volatile than the biogenic fraction. However, in order to produce significant amount of aromatic SOA the reaction mixtures needed a higher OH dose that also

  10. PDM based I-SOAS Data Warehouse Design

    CERN Document Server

    Ahmed, Zeeshan

    2010-01-01

    This research paper briefly describes the industrial contributions of Product Data Management in any organization's technical and managerial data management. Then focusing on some current major PDM based problems i.e. Static and Unintelligent Search, Platform Independent System and Successful PDM System Implementation, briefly presents a semantic based solution i.e. I-SOAS. Majorly this research paper is about to present and discuss the contributions of I-SOAS in any organization's technical and system data management.

  11. 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…

  12. Anthropogenic influence on SOA and the resulting radiative forcing

    Directory of Open Access Journals (Sweden)

    C. R. Hoyle

    2009-04-01

    Full Text Available The effect of chemical changes in the atmosphere since the pre-industrial period on the distributions and burdens of Secondary Organic Aerosol (SOA has been calculated using the off-line aerosol chemistry transport model Oslo CTM2. The production of SOA was found to have increased from about 35 Tg yr−1 to 53 Tg yr−1 since pre-industrial times, leading to an increase in the global annual mean SOA burden from 0.33 Tg to 0.50 Tg, or about 51%. The effect of allowing semi-volatile species to partition to sulphate aerosol was also tested, leading to an increase in SOA production from about 43 Tg yr−1 to 69 Tg yr−1 since pre-industrial times, while the annual mean SOA burden increased from 0.44 Tg to 0.70 Tg, or about 59%. The increases were greatest over industrialised areas, especially when partitioning to sulphate aerosol was allowed, as well as over regions with high biogenic precursor emissions. The contribution of emissions from different sources to the larger SOA burdens has been calculated. The results suggest that the majority of the increase was caused by emissions of primary organic aerosols (POA, from fossil fuel and bio fuel combustion. As yet, very few radiative forcing estimates of SOA exist, and no such estimates were provided in the latest IPCC report. In this study, we found that the change in SOA burden caused a radiative forcing (defined here as the difference between the pre-industrial and the present day run of −0.09 W m−2, when SOA was allowed to partition to both organic and sulphate aerosols, and −0.06 W m−2 when only partitioning to organic aerosols was assumed. Therefore, the radiative forcing of SOA was found to be stronger than the best estimate for POA in the latest IPCC assessment.

  13. The Virtual Reference Librarian's Handbook.

    Science.gov (United States)

    Lipow, Anne Grodzins

    This book is a practical guide to librarians and their administrators who are thinking about or in the early stages of providing virtual reference service. Part 1, "The Decision to Go Virtual," provides a context for thinking about virtual reference, including the benefits and problems, getting in the virtual frame of mind, and shopping…

  14. 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 (trapping experiments (up to >20000 s) allow the observation of slow SVOCs evaporation kinetics at different T and RH conditions. Water condensation/evaporation kinetics experiments onto/from trapped SOA droplets following fast RH step changes (<0.5 s) were also performed in order to evaluate possible kinetics limitations to water diffusion in the

  15. 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.

  16. A Novel Testing Model for SOA based Services

    Directory of Open Access Journals (Sweden)

    Abhishek Kumar

    2015-01-01

    Full Text Available SOA (Service-Oriented Architecture filled the gap between software and commercial enterprise. SOA integrates multiple web services. We bear to secure the caliber of web services that gives guarantee about what network services work and their output results. There is close to work has to be performed for an automatic test case generation for SOA based services. But, full coverage of XML elements is missing. To the best of our knowledge this all works do not attempt to cover all possible elements of the XML schema presents in the WSDL file. There is also a need to apply different assertions on each service operation for generating the test cases. To overcome this problem we proposed a novel testing model for SOA based application. This new testing model helps us to get the automatic test cases of SOA based application. We build up our new test model with the aid of our proposed test case generation algorithm and test case selection algorithm. In the end, we generate the test suite execution results and find the coverage of XML schema elements present in the WSDL file.

  17. The Research and Design of SOA-Based Systems

    Institute of Scientific and Technical Information of China (English)

    王晶晶

    2014-01-01

    According to the traditional IT system to integrated the parts and brings much repetition and high cost is insufficient,service oriented architecture is put forward solutions.Further introduces the service oriented architecture theory knowledge,transverse relative to the traditional development advantages,fully demonstrates the main trend of the service oriented architecture that drive.Discusses in detail the service oriented architecture(SOA),the core concept and design principles,and security measures to IBM led the company put forward using the service oriented architecture modeling,and to service the abstract concept to carry on the analysis.The core of service oriented is the component architecture and service data object,combining components and data on the part of the object oriented service principle.And Web services and SOA are compared to further understanding the connotation of SOA,and can support is given based on SOA application system of the specific technology,finally,the paper discusses the SOA further research direction.

  18. An improved method for the quantification of SOA bound peroxides

    Science.gov (United States)

    Mutzel, Anke; Rodigast, Maria; Iinuma, Yoshiteru; Böge, Olaf; Herrmann, Hartmut

    2013-03-01

    An improvement is made to a method for the quantification of SOA-bound peroxides. The procedure is based on an iodometric-spectrophotometric method that has been commonly used for the determination of peroxides in a wide range of biological and environmental samples. The improved method was applied to determine the peroxide content of laboratory-generated SOA from α-pinene ozonolysis. Besides main improvements for the detection conditions, the use of more environmentally sound solvents is considered instead of carcinogenic solvents. In addition to the improved method for peroxide determination, the present study provides evidence for artefact formation caused by ultrasonic agitation for the extraction of organic compounds in SOA filter samples. The concentration of SOA-bound peroxides in the extracts from ultrasonic agitation were up to three times higher than those from a laboratory orbital shaker under the same extraction conditions, indicating peroxide formation caused by acoustic cavitation during extraction. In contrast, pinic acid, terebic acid and terpenylic acid showed significantly lower concentrations in the sample extract prepared using ultrasonic agitation, indicating that these compounds react with OH radicals that are formed from acoustic cavitation. Great care should be taken when extracting SOA samples and the use of ultrasound should be avoided.

  19. 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.

  20. Comparison of affective and semantic priming in different SOA.

    Science.gov (United States)

    Jiang, Zhongqing; Qu, Yuhong; Xiao, Yanli; Wu, Qi; Xia, Likun; Li, Wenhui; Liu, Ying

    2016-11-01

    Researchers have been at odds on whether affective or semantic priming is faster or stronger. The present study selects a series of facial expression photos and words, which have definite emotional meaning or gender meaning, to set up experiment including both affective and semantic priming. The intensity of emotion and gender information in the prime as well as the strength of emotional or semantic (in gender) relationship between the prime and the target is matched. Three groups of participants are employed separately in our experiment varied with stimulus onset asynchrony (SOA) as 50, 250 or 500 ms. The results show that the difference between two types of priming effect is revealed when the SOA is at 50 ms, in which the affective priming effect is presented when the prime has negative emotion. It indicates that SOA can affect the comparison between the affective and semantic priming, and the former takes the priority in the automatic processing level.

  1. Virtual Specimens

    Science.gov (United States)

    de Paor, D. G.

    2009-12-01

    new possibilities for distance learning, where design of effective lab exercises has long been an issue, and they permit independent evaluation of published field research by reviewers who do not have access to the physical field area. Although their creation can be labor intensive, the benefits of virtual specimens for education and research are potentially great. Interactive 3D Specimen of Sierra Granodiorite at Outcrop Location

  2. A security framework for SOA applications in mobile environment

    CERN Document Server

    Fonseca, Johnneth; Lopes, Denivaldo; Labidi, Sofiane

    2010-01-01

    A Rapid evolution of mobile technologies has led to the development of more sophisticated mobile devices with better storage, processing and transmission power. These factors enable support to many types of application but also give rise to a necessity to find a model of service development. Actually, SOA (Service Oriented Architecture) is a good option to support application development. This paper presents a framework that allows the development of SOA based application in mobile environment. The objective of the framework is to give developers with tools for provision of services in this environment with the necessary security characteristics.

  3. 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.

  4. Study on Importing Benefits of Virtual Water in China’ s Main Agricultural Products%中国主要农产品的虚拟水进口效益分析

    Institute of Scientific and Technical Information of China (English)

    井璐; 黄德春

    2016-01-01

    Through calculation and trend analysis , it was pointed that the import quantum of virtual water in China ’ s main agricultural products ( especially grain crops and edible vegetable oil) was on the rise.Through analyzing the importing benefits of virtual water in China’ s main agricultural products, this paper evaluated the economic benefits and social benefits produced by re-placing with virtual water.In the end, some suggestions on the international trade of China’s agricultural products were put for-ward:adjusting the import and export structure of agricultural products , enriching the kinds of imported and exported agricultural products, and achieving the optimization of importing benefits of virtual water .%通过对我国主要农产品的虚拟水含量进行计算及趋势分析,得出主要农产品虚拟水进口量呈上升趋势,以粮食作物和食用植物油为主;通过分析虚拟水的进口效益,测算了虚拟水替代效益而产生的经济收益和社会收益。最后,对我国对外农产品贸易提出了调整农产品进出口结构、丰富进出口产品结构、实现虚拟水进口效益最优化等对策建议。

  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. 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…

  7. 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...

  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

    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....

  9. Regional modeling of SOA formation under consideration of HOMs

    Science.gov (United States)

    Gatzsche, Kathrin; Iinuma, Yoshiteru; Tilgner, Andreas; Berndt, Torsten; Poulain, Laurent; Wolke, Ralf

    2017-04-01

    Secondary organic aerosol (SOA) is the major burden of the atmospheric organic particulate matter with about 140 - 910 TgC/yr (Hallquist et al., 2009). SOA particles are formed via the oxidation of volatile organic carbons (VOCs), where the volatility of the VOCs is lowered. Therefore, gaseous compounds can either nucleate to form new particles or condense on existing particles. The framework of SOA formation under natural conditions is very complex, because there are a variety of gas-phase precursors, atmospheric degradation pathways and formed oxidation products. Up to now, atmospheric models underpredict the SOA mass. Therefore, improved regional scale model implementations are necessary to achieve a better agreement between model predictions and field measurements. Recently, highly oxidized multifunctional organic compounds (HOMs) were found in the gas phase from laboratory and field studies (Jokinen et al., 2015, Mutzel et al., 2015, Berndt et al., 2016a,b). From box model studies, it is known that HOMs are important for the early aerosol growth, however they are not yet considered in mechanisms applied in regional models. The present study utilizes the state-of-the-art multiscale model system COSMO-MUSCAT (Wolke et al., 2012), which is qualified for process studies in local and regional areas. The established model system was enhanced by a kinetic partitioning approach (Zaveri et al., 2014) for the gas-to-particle transfer of oxidized VOCs. The framework of the partitioning approach and the gas-phase mechanism were tested in a box model and evaluated with chamber studies, before implementing in the 3D model system COSMO-MUSCAT. Moreover, HOMs are implemented in the same way for the regional SOA modeling. 3D simulations were performed with an equilibrium partitioning and diffusion dependent partitioning approach, respectively. The presentation will provide first 3D simulation results including comparisons with field measurements from the TROPOS field site

  10. Molecular formula composition of β-caryophyllene ozonolysis SOA formed in humid and dry conditions

    Science.gov (United States)

    Kundu, Shuvashish; Fisseha, Rebeka; Putman, Annie L.; Rahn, Thom A.; Mazzoleni, Lynn R.

    2017-04-01

    We studied the molecular formula composition of six β-caryophyllene SOA samples using ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry under various reaction conditions. The SOA samples were generated in dry or low relative humidity (RH) chamber conditions with or without cyclohexane. All of the studied SOA mass spectra have three distinct clusters of hundreds of negative ions referred to as Group I (100 molecular formulas with higher average carbon numbers were observed in humid SOA than in dry SOA in the absence of cyclohexane, suggesting a decrease of cleavage reactions in humid condition. This study characterizes β-caryophyllene ozonolysis SOA based on ultrahigh mass resolution and demonstrates the significance of humidity in terms of the molecular distributions and relative abundances of the analytes. We also discuss the possible mechanism for the formation of Group I-III compounds based on the current understanding of SOA formation in the atmosphere.

  11. Role of glyoxal in SOA formation from aromatic hydrocarbons: gas-phase reaction trumps reactive uptake

    Directory of Open Access Journals (Sweden)

    S. Nakao

    2011-11-01

    Full Text Available This study evaluates the significance of glyoxal acting as an intermediate species leading to SOA formation from aromatic hydrocarbon photooxidation under humid conditions. Rapid SOA formation from glyoxal uptake onto aqueous (NH42SO4 seed particles is observed; however, glyoxal did not partition to SOA or SOA coated aqueous seed during all aromatic hydrocarbon experiments (RH up to 80%. Glyoxal is found to only influence SOA formation by raising hydroxyl (OH radical concentrations. Four experimental approaches supporting this conclusion are presented in this paper: (1 increased SOA formation and decreased SOA volatility in the toluene + NOx photooxidation system with additional glyoxal was reproduced by matching OH radical concentrations through H2O2 addition; (2 glyoxal addition to SOA seed formed from toluene + NOx photooxidation did not increase observed SOA volume; (3 SOA formation from toluene + NOx photooxidation with and without deliquesced (NH42SO4 seed resulted in similar SOA growth, consistent with a coating of SOA preventing glyoxal uptake onto deliquesced (NH42SO4 seed; and (4 the fraction of a C4H9+ fragment (observed by Aerodyne High Resolution Time-of-Flight Aerosol Mass Spectrometer, HR-ToF-AMS from SOA formed by 2-tert-butylphenol (BP oxidation was unchanged in the presence of additional glyoxal despite enhanced SOA formation. This study suggests that glyoxal uptake onto aerosol is minor when the surface (and near-surface of aerosols are primarily composed of secondary organic compounds.

  12. 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.

  13. 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.

  14. An SOA-based Noise Mapping Platform for Urban Traffics

    Directory of Open Access Journals (Sweden)

    Wensheng Xu

    2013-05-01

    Full Text Available Traffic noise is a major environmental problem in many urban areas and frequently causes complaints from urban residents. An accurate traffic noise map of urban areas can facilitate noise monitoring, traffic strategic planning, street planning, residential area planning and noise prevention or reduction. An SOA based platform for urban traffic strategic noise mapping is proposed in this paper. Service Oriented Computing Environment (SORCER is adopted to build the highly flexible distributed platform for noise monitoring and noise mapping. The platform architecture and the hierarchical services structure based on SOA are presented. The major services in the platform, including the task scheduler service, prediction service and noise propagation calculation service are analyzed in details. To demonstrate the function and mechanism of the platform, a real traffic noise mapping project for a Beijing area is presented.

  15. Role of ozone in SOA formation from alkane photooxidation

    Directory of Open Access Journals (Sweden)

    X. Zhang

    2013-09-01

    Full Text Available Long-chain alkanes, which can be categorized as intermediate volatile organic compounds (IVOCs, are an important source of secondary organic aerosol (SOA. Mechanisms for the gas-phase OH-initiated oxidation of long-chain alkanes have been well documented; particle-phase chemistry, however, has received less attention. The δ-hydroxycarbonyl, which is generated from the isomerization of alkoxy radicals, can undergo heterogeneous cyclization to form substituted dihydrofuran. Due to the presence of C=C bonds, the substituted dihydrofuran is predicted to be highly reactive with OH, and even more so with O3 and NO3, thus opening a reaction pathway that is not usually accessible to alkanes. This work focuses on the role of substituted dihydrofuran formation and its subsequent reaction with OH, and more importantly ozone, in SOA formation from the photooxidation of long-chain alkanes. Experiments were carried out in the Caltech Environmental Chamber using dodecane as a representative alkane to investigate the difference in aerosol composition generated from "OH-oxidation dominating" vs. "ozonolysis dominating" environments. A detailed mechanism incorporating the specific gas-phase photochemistry, together with the heterogeneous formation of substituted dihydrofuran and its subsequent gas-phase OH/O3 oxidation, is presented to evaluate the importance of this reaction channel in the dodecane SOA formation. We conclude that: (1 the formation of δ-hydroxycarbonyl and its subsequent heterogeneous conversion to substituted dihydrofuran is significant in the presence of NOx; (2 the ozonolysis of substituted dihydrofuran dominates over the OH-initiated oxidation under conditions prevalent in urban and rural air; and (3 a spectrum of highly-oxygenated products with carboxylic acid, ester, and ether functional groups are produced from the substituted dihydrofuran chemistry, thereby affecting the average oxidation state of the SOA.

  16. Organizaciones Virtuales Organizaciones Virtuales

    Directory of Open Access Journals (Sweden)

    Gladis Cecilia Villegas Arias

    2003-06-01

    Full Text Available Virtual Organizations are new organizational forms originated from both the replacementof face to face communications by remote communications supported by electronic means,and from the accesibility of real time information about the operation of the company, forall employees.This article pursues the following goals: 1 To define virtual organization, review its sociotechnical antecedents and propose a preliminary classification into inter-organizationaland intra-organizational forms.  2 To discuss the characteristics of virtual organizationsand their impact on organizational design, and 3 To compare virtual organizations toother organizational forms.Las organizaciones virtuales son formas organizativas nuevas, que resultan de: primero, reemplazar las interacciones cara a cara con interacciones remotas, soportadas por comunicaciones electrónicas y segundo,  proveer acceso en tiempo real a toda la información de la empresa para todos los trabajadores.En este artículo se busca: 1 Definir organización virtual, revisar sus antecedentes y proponeruna clasificación básica preliminar de las mismas  2 Discutir las características de las organizaciones virtuales y sus implicaciones para el diseño organizativo 3 Comparar estaforma organizativa a las formas organizativas no virtuales.

  17. 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 phenomen...

  18. Using SOA and WEB Services for an Electricity Distribution Enterprise

    Directory of Open Access Journals (Sweden)

    Radu-Ştefan MOLEAVIN

    2012-01-01

    Full Text Available A viable enterprise today must adapt continously to the requirements of the market. The adaptation of a company to the market requirements means also changes of business processes within IT systems. In any enterprise there is a strong link between business processes and IT applications IT and a business process modification will determine a modification in the IT applications. In order to increase the alignment between business and IT and achieve business agility – the ability to respond to changes quickly and efficiency – we have to create a flexible mechanism between IT applications and business processes which will make that the adaptation to the market changes will be made quickly and with low consumption of either human or material resources. Therefore, enterprises need agility to maintain strategic advantages in operating businesses. Service Oriented Architecture (SOA represents an architectural design which provide agility and satisfies the business processes in order to achieve business agility. In the IT area, SOA promises to reduce application development and maintenance costs through service reuse. A service may be considered as a set of components and software operations which are built in a way that permit them to be flexibly and dynamically integrated to cover both IT and business needs. SOA offers capabilities for the services to be combined together, to support and create a flexible and agile enterprise.

  19. Virtual reality for engineering

    CERN Document Server

    De Gennaro, Silvano; CERN. Geneva

    1996-01-01

    Virtual Reality for Engineers. Virtual Reality is a very powerful visualization technique for 3D data, which can bring enormous benefits to engineering design. CAD models can be exported to a VR application and used as "Virtual Prototypes". Virtual Prototypes are an ideal replacement for wooden models as they can be generated automatically from most CAD products. They are totally reliable, they can be updated in a matter of minutes, and they allow designers to explore them from inside, on a one-to-one scale and using a 3D-stereo vision. Navigation can be performed using a number of instinctive tools, such as joysticks, spaceballs, VR helmets and 3D mice. The lectures will cover today's Virtual Reality products and methods, and describe how to transform CAD models into Virtual Prototypes. A "hands on" VR experience featuring the LHC detectors models can be organized for people interested.

  20. 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 pu...... 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....... pursued mainly by private organizations. However, SOA starts to appear in the public agenda and specifically in health-care reengineering, as well. Recently, government strategies for eHealth have been slowly incorporating the SOA paradigm to integrate isolated systems, provide cost-effective solutions...

  1. 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.

  2. fMRI Study Revealing Neural Mechanisms of the Functions of SOA in Spatial Orienting

    Institute of Scientific and Technical Information of China (English)

    Yin Tian; Qian Zhang; De-Zhong Yao

    2009-01-01

    It is well documented that orienting attention plays an important role in visual search. However, it remains unclear how the executive brain regions will act when two different stimulus onset asynchrony (SOA) are used in visual search. In this work, event-related fMRI was used to investigate neural mechanisms on the functions of SOA in endogenous and exogenous orienting. The results showed that in the endogenous orienting, long SOA versus short SOA resulted in widespread cortical activation mainly including right medial frontal gyrus and bilateral middle frontal gyri. Conversely, in exogenous orienting, long SOA compared to short SOA resulted in only activations in bilateral middle frontal gyri. These findings indicated that these two spatial orienting involved different brain areas and neural mechanisms.

  3. Analysis of the benefits of designing and implementing a virtual didactic model of multiple choice exam and problem-solving heuristic report, for first year engineering students

    CERN Document Server

    Bennun, Leonardo

    2015-01-01

    Improvements in performance and approval obtained by first year engineering students from University of Concepcion, Chile, were studied, once a virtual didactic model of multiple-choice exam, was implemented. This virtual learning resource was implemented in the Web ARCO platform and allows training, by facing test models comparable in both time and difficulty to those that they will have to solve during the course. It also provides a feedback mechanism for both: 1) The students, since they can verify the level of their knowledge. Once they have finished the simulations, they can access a complete problem-solving heuristic report of each problem; 2) The teachers, since they can obtain information about the habits of the students in their strategies of preparation; and they also can diagnose the weaknesses of the students prior to the exam. This study indicates how this kind of preparation generates substantial improvements on the approval rates by allowing the students: 1) A more structured and oriented syste...

  4. Research-Grade 3D Virtual Astromaterials Samples: Novel Visualization of NASA's Apollo Lunar Samples and Antarctic Meteorite Samples to Benefit Curation, Research, and Education

    Science.gov (United States)

    Blumenfeld, E. H.; Evans, C. A.; Oshel, E. R.; Liddle, D. A.; Beaulieu, K. R.; Zeigler, R. A.; Righter, K.; Hanna, R. D.; Ketcham, R. A.

    2017-01-01

    NASA's vast and growing collections of astromaterials are both scientifically and culturally significant, requiring unique preservation strategies that need to be recurrently updated to contemporary technological capabilities and increasing accessibility demands. New technologies have made it possible to advance documentation and visualization practices that can enhance conservation and curation protocols for NASA's Astromaterials Collections. Our interdisciplinary team has developed a method to create 3D Virtual Astromaterials Samples (VAS) of the existing collections of Apollo Lunar Samples and Antarctic Meteorites. Research-grade 3D VAS will virtually put these samples in the hands of researchers and educators worldwide, increasing accessibility and visibility of these significant collections. With new sample return missions on the horizon, it is of primary importance to develop advanced curation standards for documentation and visualization methodologies.

  5. Semantic priming in schizophrenia: an examination of spreading activation using word pronunciation and multiple SOAs.

    Science.gov (United States)

    Barch, D M; Cohen, J D; Servan-Schreiber, D; Steingard, S; Cohen, J D; Steinhauer, S S; van Kammen, D P

    1996-11-01

    Semantic priming in word pronunciation was examined at 5 stimulus onset asynchronies (SOAs) in 75 medicated and 25 unmedicated people with schizophrenia (SCZ) and in 10 depressed and 28 normal controls. At SOAs problems and that automatic priming processes operate normally in SCZ. The failure of SCZ to display significant priming at the 950-ms SOA is consistent with a hypothesized disturbance in higher level processes.

  6. 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

  7. 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

  8. 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 ...

  9. 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

    2017-08-14

    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.

  10. 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.

  11. Clock recovery from NRZ data at 10 Gb/s using SOA loop mirror and mode-locked fiber ring laser based on SOA

    Institute of Scientific and Technical Information of China (English)

    Lina Yin; Guoming Liu; Jian Wu; Jintong Lin

    2006-01-01

    @@ All-optical clock recovery from non-return-to-zero (NRZ) data using an semiconductor optical amplifier(SOA) loop mirror and a mode-locked SOA fiber laser is firstly schematically explained and experimentally demonstrated at 10 Gb/s. Furthermore, the pulse quality of the recovered clock is effectively improved by using a continuous-wave (CW) assist light in the gain region of SOA, through which the amplitude modulation is reduced from 57.2% to 8.47%. This scheme is a promising method for clock recovery from NRZ data in the future all-optical communication networks.

  12. 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

  13. Service Registry: A Key Piece for Enhancing Reuse in SOA

    Directory of Open Access Journals (Sweden)

    Juan Pablo García-González

    2013-01-01

    Full Text Available One of the promises of adopting a service-oriented approach in organizations is the potential cost savings that result from the reuse of existing services. A service registry is one of the fundamental pieces of service oriented architecture (SOA for achieving reuse. It refers to a place in which service providers can impart information about their offered services and potential clients can search for services. In this article, we provide advice for implementing an enterprise-wide service registry. We also discuss open issues in industry and academia that affect the management of service- repository information.

  14. Communications Solutions for Heterogeneous Systems Based on SOA

    Science.gov (United States)

    Wei, Xianmin

    In order to address the gaps which widely used in business application architecture and problems of heterogeneous system communication, this paper provides a standardized framework of SOA, built in the application of a loose coupling between systems "server + proxy" data exchange platform, to achieve heterogeneous data exchange and data sharing, and developed a business based on Web services platform, making full use of the Web service, which makes the system has good scalability and maintainability, to solve the problem of heterogeneous system communication and widely used to make up for the current architecture lack of business applications.

  15. A Low Cost Tax SOA Infrastructure in Grid Applications

    Institute of Scientific and Technical Information of China (English)

    HE Hong; XU Baowen

    2006-01-01

    Many high performance database servers are becoming idle with the tax data being integrated to country tax data centers.We make use of the idle servers to set up a provincial tax Grid based on open Grid service architecture (OGSA).We put forward practical methods to integrate databases, to define and create basic modular Grid services and apply agent to manage Grid services.This technical innovation scheme is of a service-oriented architecture (SOA) and succeeds in averting resources waste.Tests proved that it greatly improves the quality of tax services.

  16. 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...

  17. 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...

  18. All optical wavelength conversion by SOA's in a Mach-Zehnder configuration

    DEFF Research Database (Denmark)

    Durhuus, T.; Jørgensen, C.; Mikkelsen, Benny

    1994-01-01

    Penalty free wavelength conversion is demonstrated at 2.5 Gbit/s over a wavelength span of 12 nm by the use of semiconductor optical amplifier (SOA)'s in a Mach-Zehnder configuration. An increase in the extinction ratio is measured for the converted signal compared to the input signal implying si...... signal regeneration as well as wavelength conversion...

  19. Reduction of nonlinear patterning effects in SOA-based All-optical Switches using Optical filtering

    DEFF Research Database (Denmark)

    Nielsen, Mads Lønstrup; Mørk, Jesper; Skaguchi, J.

    2005-01-01

    We explain theoretically, and demonstrate and quantify experimentally, how appropriate filtering can reduce the dominant nonlinear patterning effect, which limits the performance of differential-mode SOA-based switches.......We explain theoretically, and demonstrate and quantify experimentally, how appropriate filtering can reduce the dominant nonlinear patterning effect, which limits the performance of differential-mode SOA-based switches....

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

    Directory of Open Access Journals (Sweden)

    J. Lee-Taylor

    2012-06-01

    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.

  1. 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.

  2. Wavelength and NOx dependent complex refractive index of SOAs generated from the photooxidation of toluene

    Directory of Open Access Journals (Sweden)

    A. Yamazaki

    2012-06-01

    Full Text Available Recently, secondary organic aerosols (SOAs generated from anthropogenic volatile organic compounds have been proposed as a possible source of lightabsorbing organic compounds "brown carbon" in the urban atmosphere. However, the atmospheric importance of these SOAs remains unclear due to limited information about their optical properties. In this study, the complex refractive index (RI, m=n − ki values at 405, 532, and 781 nm of the SOAs generated during the photooxidation of toluene (toluene-SOAs under a variety of initial nitrogen oxide (NOx= NO + NO2 conditions were examined by photoacoustic spectroscopy (PAS and cavity ring down spectroscopy (CRDS. The complex RI values obtained in the present study and reported in the literature indicate that the k value, which represents the light absorption of the toluene-SOAs steeply increased to shorter wavelengths at n value gradually increased to shorter wavelengths from 781 to 355 nm. The k values at 405 nm were found to increase from 1.8 × 10−3 to 7.2 × 10−3 with increasing initial NOx concentration from 109 to 571 ppbv. The nitrate to organics ratio of the SOAs determined using a highresolution time-of-flight aerosol mass spectrometer (H-ToF-AMS also increased with increasing initial NOx concentration. The RI values of the SOAs generated during the photooxidation of 1,3,5-trimethylbenzene in the presence of NOx (1,3,5-TMB-SOAs were also determined to investigate the influence of the chemical structure of the precursor on the optical properties of the SOAs, and it was found that the light absorption of the 1,3,5-TMB-SOAs is negligible at all of the wavelengths investigated (405, 532, and 781 nm. These results can be reasonably explained by the hypothesis that nitro-aromatic compounds such as nitro-cresols are the major contributors to the light absorption of the toluene-SOAs. Using the obtained RI values, mass absorption cross sections of the toluene-SOAs at 405 and 532 nm were estimated to

  3. A Service Composition Approach Based on Sequence Mining for Migrating E-learning Legacy System to SOA

    Institute of Scientific and Technical Information of China (English)

    Zhuo Zhang; Dong-Dai Zhou; Hong-Ji Yang; Shao-Chun Zhong

    2010-01-01

    With the fast development of business logic and information technology, today's best solutions are tomorrow's legacy systems. In China, the situation in the education domain follows the same path. Currently, there exists a number of e-learning legacy assets with accumulated practical business experience, such as program resource, usage behaviour data resource, and so on. In order to use these legacy assets adequately and efficiently, we should not only utilize the explicit assets but also discover the hidden assets. The usage behaviour data resource is the set of practical operation sequences requested by all users. The hidden patterns in this data resource will provide users' practical experiences, which can benefit the service composition in service-oriented architecture (SOA) migration. Namely, these discovered patterns will be the candidate composite services (coarse-grained) in SOA systems. Although data mining techniques have been used for software engineering tasks, little is known about how they can be used for service composition of migrating an e-learning legacy system (MELS) to SOA. In this paper, we propose a service composition approach based on sequence mining techniques for MELS. Composite services found by this approach will be the complementation of business logic analysis results of MELS. The core of this approach is to develop an appropriate sequence mining algorithm for mining related data collected from an e-leaxning legacy system. According to the features of execution trace data on usage behaviour from this e-learning legacy system and needs of further pattern analysis, we propose a sequential mining algorithm to mine this kind of data of the legacy system. For validation, this approach has been applied to the corresponding real data, which was collected from the e-learning legacy system;meanwhile, some investigation questionnaires were set up to collect satisfaction data. The investigation result is 90 % the same with the result obtained

  4. Effect of Vapor Pressure Scheme on Multiday Evolution of SOA in an Explicit Model

    Science.gov (United States)

    Lee-Taylor, J.; Madronich, S.; Aumont, B.; Camredon, M.; Emmons, L. K.; Tyndall, G. S.; Valorso, R.

    2011-12-01

    Recent modeling of the evolution of Secondary Organic Aerosol (SOA) has led to the critically important prediction that SOA mass continues to increase for several days after emission of primary pollutants. This growth of organic aerosol in dispersing plumes originating from urban point sources has direct implications for regional aerosol radiative forcing. We investigate the robustness of predicted SOA mass growth downwind of Mexico City in the model GECKO-A (Generator of Explicit Chemistry and Kinetics of Organics in the Atmosphere), by assessing its sensitivity to the choice of vapor pressure prediction scheme. We also explore the implications for multi-day SOA mass growth of glassification / solidification of SOA constituents during aging. Finally we use output from the MOZART-4 chemical transport model to evaluate our results in the regional and global context.

  5. Designing A Logical Security Framework for E-Commerce System Based on SOA

    Directory of Open Access Journals (Sweden)

    Ashish Kr. Luhach

    2014-08-01

    Full Text Available 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 tampering and unauthorized access. This causes the security technology implementation of E - commerce very difficult at other engineering sciences. This paper discusses the importance of using SOA in E - commerce and identif ies the flaws in the existing security analysis of E - commerce platforms. On the foundation of identifying defects, this editorial also suggested an implementation design of the logical security framework for SOA supported E - commerce system

  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. Virtual Worlds

    OpenAIRE

    Novák, František

    2009-01-01

    The bachelor's thesis is focused on highlighting the development of virtual worlds. The paper summarizes the evolution of virtual reality. Current virtual worlds are compared in fundamental aspects, such as sociology, economics and education. Social sphere describes the interaction in virtual reality and its specialities. Economical sphere is focused on comparison of real and virtual economies, including their economic indicators. Educational sphere describes the sciences, which are best usea...

  8. Desktop Virtualization Solutions-A Comprehensive Survey

    Directory of Open Access Journals (Sweden)

    Vasuprada Vijayakumar

    2013-09-01

    Full Text Available Virtualization has become apparent in the 1960s as a practice to enhance the use of expensive computing hardware. Virtualization targets to reduce the complexity associated with deployment and maintenance of client devices, which eventually helps IT Companies to reduce system management costs. In this paper, we propose the virtualization concept expanding into many aspects of IT world. There are various virtualization technologies which include storage, desktop virtual platforms, server consolidation, virtual desktop infrastructure and application virtualization. This is the basic prerequisite for cloud computing and its applications. This paper highlights the benefits of virtualization and provides a comparative study on the various products that have been derived from it. This paper also describes how to create a virtualization strategy introducing comprehensive desktop-virtualization solutions, thereby providing a high-level guidance to help develop a desktop-virtualization strategy.

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

    Directory of Open Access Journals (Sweden)

    E. Saukko

    2012-02-01

    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 solid or semi-solid until a relative humidity of at least 50 % RH at impaction is reached. (2 Long-chain alkanes produce liquid SOA particles when generated at low oxidation level of O/C<0.2, but at higher oxidation levels they solidify. (3 Increasing sulphuric acid (H2SO4 within the SOA particles reduces the threshold of humidity-induced phase changes. (4 The bounce behavior of the various SOA systems did not show a consistent linear relationship 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.

  10. Virtual screening of virtual libraries.

    Science.gov (United States)

    Green, Darren V S

    2003-01-01

    methods, algorithms that manage the combinatorial explosion, high throughput crystallography and ADME measurements and the massive increase in computational horsepower from distributed computing. The author is confident that the synergy of these technologies will bring great benefit to the industry, with more efficient production of higher quality clinical candidates. The future is bright. The future is virtual!

  11. Mastering Microsoft Virtualization Using Hyper-V, Terminal Services, and SoftGrid

    CERN Document Server

    Cerling, Tim

    2009-01-01

    The first in-depth, comprehensive guide to Microsoft's suite of virtualization products. Virtualization is a hot topic for IT because of the potential it offers for serious economic benefits. While other books treat server virtualization alone, this comprehensive guide provides a complete virtual strategy. You will learn how to deploy a complete virtualization stack with Microsoft's offerings in server virtualization, application virtualization, presentation virtualization, and desktop virtualization. Written by Microsoft technology product specialists, this guide provides real-world focus, en

  12. Reformulating the atmospheric lifecycle of SOA based on new field and laboratory data

    Directory of Open Access Journals (Sweden)

    M. Shrivastava

    2011-07-01

    Full Text Available Atmospheric loadings of secondary organic aerosols (SOA are significantly under-predicted by climate models. In these models, SOA particles are assumed liquid-like droplets at equilibrium with the gas-phase. In sharp contrast, our recent laboratory and field measurements show that SOA particles are non-rigid, highly viscous, spherical, quasi-solids, and do not behave like liquid droplets. They evaporate at rates much lower than predicted by models, and are consequently not at equilibrium with the gas phase. In addition, our data show that SOA particles trap hydrophobic organics, whose presence further reduces evaporation rates, and that aging these particles nearly stops evaporation. Measurements of the evaporation kinetics of ambient SOA particles under vapor-free conditions at room temperature showed that less than 20 % of particle mass evaporates in 4 h.

    In this study, we examine, for the first time, these groundbreaking observations to present a new, experimentally based picture of the phase and evaporation behavior of SOA particles. We conclude that to first order SOA can be reasonably approximated to be non-evaporating. We use a simplified approach to investigate the implications of this near-irreversible gas-particle partitioning behavior in a box model and a 3-D chemical transport model, both of which, for the first time, include multi-generational gas-phase chemistry with functionalization and fragmentation reactions, and compare them to traditional reversible partitioning models. Results indicate that the revised irreversible partitioning approach yields slightly higher SOA loadings than traditional reversible partitioning approach when functionalization reactions, pushing SOA species to lower volatility bins are dominant. However, when fragmentation reactions play a major role, the revised irreversible partitioning approach predicts significantly higher SOA than the traditional approach. In addition to irreversibility

  13. Rapid SOA Frontend Design and Prototyping for LINC-NIRVANA

    Science.gov (United States)

    Berwein, J.; Briegel, F.; Kittmann, F.; Pavlov, A.; Gaessler, W.; Kittmann, F.

    2010-12-01

    LINC-NIRVANA is a German-Italian Fizeau (imaging) interferometer for the Large Binocular Telescope (LBT) on Mt. Graham in Arizona, USA. For laboratory testing and integration, a large number of engineering applications are needed. The process of engineering, testing and integration has to go hand in hand with an agile software development for data display and configuration frontends. Therefore we implemented software packages, which enable a rapid design and prototyping of engineering applications within an SOA oriented environment. Due to the usage of only pre-compiled software and the easy to handle workflow neither compilation nor programming knowledge is require. We will present the current development status, usage and advantages of our software, which was realized at the Max Planck Institute for Astronomy in Heidelberg, Germany.

  14. Access to a simulator is not enough: the benefits of virtual reality training based on peer-group-derived benchmarks--a randomized controlled trial.

    Science.gov (United States)

    von Websky, Martin W; Raptis, Dimitri A; Vitz, Martina; Rosenthal, Rachel; Clavien, P A; Hahnloser, Dieter

    2013-11-01

    Virtual reality (VR) simulators are widely used to familiarize surgical novices with laparoscopy, but VR training methods differ in efficacy. In the present trial, self-controlled basic VR training (SC-training) was tested against training based on peer-group-derived benchmarks (PGD-training). First, novice laparoscopic residents were randomized into a SC group (n = 34), and a group using PGD-benchmarks (n = 34) for basic laparoscopic training. After completing basic training, both groups performed 60 VR laparoscopic cholecystectomies for performance analysis. Primary endpoints were simulator metrics; secondary endpoints were program adherence, trainee motivation, and training efficacy. Altogether, 66 residents completed basic training, and 3,837 of 3,960 (96.8 %) cholecystectomies were available for analysis. Course adherence was good, with only two dropouts, both in the SC-group. The PGD-group spent more time and repetitions in basic training until the benchmarks were reached and subsequently showed better performance in the readout cholecystectomies: Median time (gallbladder extraction) showed significant differences of 520 s (IQR 354-738 s) in SC-training versus 390 s (IQR 278-536 s) in the PGD-group (p training group being more efficient. Basic VR laparoscopic training based on PGD benchmarks with external assessment is superior to SC training, resulting in higher trainee motivation and better performance in simulated laparoscopic cholecystectomies. We recommend such a basic course based on PGD benchmarks before advancing to more elaborate VR training.

  15. The Virtual Intercultural Team Tool

    Science.gov (United States)

    Rus, Calin

    2010-01-01

    This article describes the Virtual Intercultural Team Tool (VITT) and discusses its processes and benefits. VIIT is a virtual platform designed with the aim of assisting European project teams to improve intercultural communication and build on their cultural diversity for effective implementation of their projects. It is a process-focused tool,…

  16. Uncertainties in SOA simulations due to meteorological uncertainties in Mexico City during MILAGRO-2006 field campaign

    Science.gov (United States)

    Bei, N.; Li, G.; Molina, L. T.

    2013-05-01

    The purpose of the present study is to investigate the uncertainties in simulating secondary organic aerosol (SOA) in Mexico City metropolitan area (MCMA) due to meteorological initial uncertainties using the WRF-CHEM model through ensemble simulations. The simulated periods (24 and 29 March 2006) represent two typical meteorological episodes ("Convection-South" and "Convection-North", respectively) in the Mexico City basin during the MILAGRO-2006 field campaign. The organic aerosols are simulated using a non-traditional SOA model including the volatility basis-set modeling method and the contributions from glyoxal and methylglyoxal. Model results demonstrate that uncertainties in meteorological initial conditions have significant impacts on SOA simulations, including the peak time concentrations, the horizontal distributions, and the temporal variations. The ensemble spread of the simulated peak SOA at T0 can reach up to 4.0 μg m-3 during the daytime, which is around 35% of the ensemble mean. Both the basin wide wind speed and the convergence area affect the magnitude and the location of the simulated SOA concentrations inside the Mexico City basin. The wind speed, especially during the previous midnight and the following early morning, influences the magnitude of the peak SOA concentration through ventilation. The surface horizontal convergence zone generally determines the area with high SOA concentrations. The magnitude of the ensemble spreads may vary with different meteorological episodes but the ratio of the ensemble spread to mean does not change significantly.

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

    Directory of Open Access Journals (Sweden)

    J. H. Seinfeld

    2011-03-01

    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 in 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.

  18. 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.

  19. VIRTUALIZATION TECHNOLOGY FOR SMB

    Directory of Open Access Journals (Sweden)

    Adriana BARNOSCHI

    2009-10-01

    Full Text Available Data is growing at an alarming rate. Storage administrators are struggling to handle a spiraling volume of documents, images, audio and video files and large emails. Virtualization is a general term that could be applied to: storage systems, databases and networks. In this article, I present an overview of server virtualization architecture. I also specify the goals and benefits of virtualization for a SMB. The article points out some issues about server virtualization: definition, implementing problems and security features. In case of major calamity, you need a disaster recovery plan. The article lists a series of differences and similar parts of DR planning and business continuity plan. I give some ideas that guide you to protect yourself against disaster, what to back up and how backups should work.

  20. A new look at the Effect of NOx on Biogenic SOA Yields

    Science.gov (United States)

    Shilling, J.; Liu, J.; Zaveri, R. A.; Zelenyuk, A.; Bell, D.; Guenther, A. B.; Thornton, J. A.; D'Ambro, E.; Schobesberger, S.; Gaston, C.; Lee, B. H.; Ehn, M.; Perakyla, O.; Yan, C.; Cappa, C. D.; Helgestad, T.; Li, Z.; Wise, M.; Wang, J.; Thalman, R.; Surratt, J. D.; Zhang, Z.; Riedel, T.; Gold, A.

    2016-12-01

    Secondary organic aerosol is a large fraction of the total aerosol mass and is thought to be responsible for growth of many particles from the Aitken to accumulation mode. However, gaps still exist in the scientific understanding of the basic chemical and physical properties of SOA, its formation mechanisms, volatility, and atmospheric lifecycle. To address these knowledge gaps, we recently conducted a collaborative study (SOAFFEE) involving seven institutions, hosted at PNNL in a continuous-flow environmental chamber, in which oxidation of several biogenic hydrocarbons and their oxidation products were investigated as a function of seed particle concentration, NOx concentration, oxidant identity, relative humidity, and aging time. We will discuss results from this study, focusing on a subset of these experiments investigating the role of precursor VOC, oxidant, and NO concentration on the yield and chemical composition of SOA from biogenic VOCs. When investigating α-pinene and isoprene photooxidation, we found that addition of progressively larger amounts of NO to the system had a complex, but relatively muted effect on SOA yield. When α-pinene was oxidized by ozone, addition of NO to the system also had a negligible effect on SOA yield, but substantially changed the condensed phase chemical composition, generating a significant mass of organic nitrates. Photooxidation of Δ-carene generated SOA in higher yield than α-pinene under similar conditions, despite their similar molecular structure. A general anti-correlation was observed between SOA yield and SOA volatility with more volatile SOA systems displaying lower yield. These results indicate that the role of monoterpene structure and NOx in determining SOA yield is more complex than typically represented in models.

  1. Rethinking the global secondary organic aerosol (SOA) budget: stronger production, faster removal, shorter lifetime

    Science.gov (United States)

    Hodzic, Alma; Kasibhatla, Prasad S.; Jo, Duseong S.; Cappa, Christopher D.; Jimenez, Jose L.; Madronich, Sasha; Park, Rokjin J.

    2016-06-01

    Recent laboratory studies suggest that secondary organic aerosol (SOA) formation rates are higher than assumed in current models. There is also evidence that SOA removal by dry and wet deposition occurs more efficiently than some current models suggest and that photolysis and heterogeneous oxidation may be important (but currently ignored) SOA sinks. Here, we have updated the global GEOS-Chem model to include this new information on formation (i.e., wall-corrected yields and emissions of semi-volatile and intermediate volatility organic compounds) and on removal processes (photolysis and heterogeneous oxidation). We compare simulated SOA from various model configurations against ground, aircraft and satellite measurements to assess the extent to which these improved representations of SOA formation and removal processes are consistent with observed characteristics of the SOA distribution. The updated model presents a more dynamic picture of the life cycle of atmospheric SOA, with production rates 3.9 times higher and sinks a factor of 3.6 more efficient than in the base model. In particular, the updated model predicts larger SOA concentrations in the boundary layer and lower concentrations in the upper troposphere, leading to better agreement with surface and aircraft measurements of organic aerosol compared to the base model. Our analysis thus suggests that the long-standing discrepancy in model predictions of the vertical SOA distribution can now be resolved, at least in part, by a stronger source and stronger sinks leading to a shorter lifetime. The predicted global SOA burden in the updated model is 0.88 Tg and the corresponding direct radiative effect at top of the atmosphere is -0.33 W m-2, which is comparable to recent model estimates constrained by observations. The updated model predicts a population-weighed global mean surface SOA concentration that is a factor of 2 higher than in the base model, suggesting the need for a reanalysis of the contribution of

  2. Increasing input power dynamic range of SOA by shifting the transparent wavelength of tunable optical filter

    DEFF Research Database (Denmark)

    Yu, Jianjun; Jeppesen, Palle

    2001-01-01

    Gain-saturation-induced self-phase modulation (SPM) leading to pulse distortion in a semiconductor optical amplifier (SOA) is overcome by shifting a tunable optical filter (TOF). A recovered or broadened pulse can be obtained after filtering the amplified pulse in the SOA even if the short pulse...... to a longer wavelength for RZ signals and to a shorter for NRZ signals. 80-Gb/s optical time division multiplexing (OTDM) signal amplification in the SOA is demonstrated for the first time. We also demonstrate that a large IPDR for the 80-Gb/s OTDM signal can be obtained by shifting the TOF....

  3. Virtual box

    DEFF Research Database (Denmark)

    Stougaard, Malthe Kirkhoff

    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...

  4. 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

  5. Benefit-Aware On-Demand Provisioning Approach for Virtual Resources%一种收益敏感的虚拟资源按需提供方法

    Institute of Scientific and Technical Information of China (English)

    吴恒; 张文博; 张建华; 魏峻; 黄涛

    2013-01-01

    It is a challenging problem to provide QoS (quality of service) in the virtualization-based cloud computing environment. Existing efforts have addressed this challenge based on either Cost-Oblivious approaches, or Cost-Aware approaches. However, both approaches may suffer frequent QoS violations under typical flash crowd workload. For instance, both approaches ignore the benefit gained after configuration changes. In this paper, a benefit-aware approach according to the profit rate maximization principle is introduced to address this problem. Here, the benefit means the satisfaction percept of the duration that application continuously guarantees the QoS in the new configuration. Experimental results based on TPC-W benchmark show that this benefit-aware approach can save the costs of VM resources as much as 25%and can effectively reduce the QoS violations compared through a cost-aware approach.%  基于虚拟机的资源重配置操作具有耗时长并伴随性能衰减的特点。已有的 Cost-Oblivious 和 Cost-Aware方法在面对Internet突变负载时存在因经常执行资源重配置操作而导致频繁QoS违约的不足。提出了一种收益敏感(benefit-aware)的资源按需提供方法。该方法首先考虑了 Web 应用在配置稳定期内的 QoS 获益,并以此构建收益函数;然后,以收益率最大化原则作为资源重配置策略选择的依据。实验结果表明,该方法与Cost-Oblivious方法相比最多能节约25%的资源成本,而与Cost-Aware方法相比则能有效减少Web应用在突变负载下的QoS违约次数。

  6. Frequency unlimited optical delay lines based on slow and fast light in SOAs

    DEFF Research Database (Denmark)

    Berger, Perrine; Bourderionnet, Jérôme; Pu, Minhao

    2011-01-01

    We experimentally demonstrate that up-converted coherent population oscillations (CPO) in SOA open the possibility to conceive integrated optical tunable delay lines beyond the carrier lifetime limit, up to THz frequencies....

  7. SOA - NOLM in Reflective Configuration for Optical Regeneration in High Bit Rate Transmission Systems

    CERN Document Server

    Roncin, Vincent; Gay, Mathilde; Bramerie, Laurent; Simon, Jean-Claude

    2014-01-01

    This paper presents a theoretical and experimental investigation of optical signal regeneration properties of a non-linear optical loop mirror using a semiconductor optical amplifier as the active element (SOA-NOLM). While this device has been extensively studied for optical time division demultiplexing (OTDM) and wavelength conversion applications, our proposed approach, based on a reflective configuration, has not yet been investigated, particularly in the light of signal regeneration. The impact on the transfer function shape of different parameters, like SOA position in the interferometer and SOA input optical powers, are numerically studied to appreciate the regenerative capabilities of the device.Regenerative performances in association with a dual stage of SOA to create a 3R regenerator which preserves the data polarity and the wavelength are experimentally assessed. Thanks to this complete regenerative function, a 100.000 km error free transmission has experimentally been achieved at 10 Gb/s in a reci...

  8. 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.

  9. 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

  10. 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.

  11. Controlling Social Stress in Virtual Reality Environments

    OpenAIRE

    Hartanto, Dwi; Kampmann, Isabel L.; Morina, Nexhmedin; Paul G M Emmelkamp; 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 r...

  12. Controlling social stress in virtual reality environments

    OpenAIRE

    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: 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 r...

  13. Controlling social stress in virtual reality environments

    OpenAIRE

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

    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 r...

  14. Frequency unlimited optical delay lines based on slow and fast light in SOAs

    DEFF Research Database (Denmark)

    Berger, Perrine; Bourderionnet, Jérôme; Pu, Minhao

    2011-01-01

    We experimentally demonstrate that up-converted coherent population oscillations (CPO) in SOA open the possibility to conceive integrated optical tunable delay lines beyond the carrier lifetime limit, up to THz frequencies.......We experimentally demonstrate that up-converted coherent population oscillations (CPO) in SOA open the possibility to conceive integrated optical tunable delay lines beyond the carrier lifetime limit, up to THz frequencies....

  15. All-optical D and T flip-flops based on polarization switch of SOA

    Science.gov (United States)

    Wang, Lina; Wang, Yongjun; Wu, Chen

    2016-11-01

    The semiconductor optical amplifier (SOA) plays an important role in the development of the all-optical signal processing because of the advantages of simple structure, easy integration and strong non-linearity. Especially the nonlinear polarization rotation effect of SOA is receiving considerable interest by many researchers nowadays. The all-optical flip-flop using the properties of SOA also obtains widespread attention by researchers, as all-optical flip-flop is an important part in the field of all-optical signal processing. In this paper, a new all-optical flip-flop structure using polarization switch (PSW) based on polarization rotation effect of SOA is presented. The main work of the paper is the simulation of all-optical logic gates and optical SR latch. The logic gate setup only uses one SOA, but it can get two different logic gates through a simulation. The extinction ratio of the logic gate is about 30dB. The structure of optical SR latch utilizes the two coupled polarization rotation switch of SOA. The structure of the flip-flop is based on these two parts. To demonstrate the feasibility of the structure, we analyze two types of flip-flops, including all-optical D and T flip-flops, whose clock pulse repetition rate is 1GHz with the pulse width of 0.3ns. The quality of all-optical flip-flop in this paper is measured by the falling and rising edge time. In the simulation, the falling edge time is about 50ps, while the rising edge time is higher than the falling edge time, because the gain increases slowly to the recovery time after the decrease of the gain of SOA. The results are useful for the development of all-optical flip-flop based on SOA.

  16. Metamodel-based Editor for Service Oriented Architecture(MED4SOA)

    OpenAIRE

    Gjataj, Rudin

    2007-01-01

    In software development tool support is essential. Since the standardization of UML and Model Driven Architecture (MDA), new approaches in the design and implementation of software systems have flourished. These approaches are specific architectures like Service Oriented Architecture (SOA) or specialised MDA flavours, like Model Driven Software Development (MDSD). In this thesis we provide a Metamodel-based Editor for Service Oriented Architecture(MED4SOA). It is a graphical modeling e...

  17. Investigation of patterning effect in ultrafast SOA-based optical switches

    DEFF Research Database (Denmark)

    Xu, Jing; Zhang, Xinliang; Mørk, Jesper

    2009-01-01

    A lower bound of PRBS length is derived considering patterning effects in ultrafast SOA-based switches. An effective method for simulating patterning effects is proposed, validated and applied to characterize the switches in large parameter regions.......A lower bound of PRBS length is derived considering patterning effects in ultrafast SOA-based switches. An effective method for simulating patterning effects is proposed, validated and applied to characterize the switches in large parameter regions....

  18. 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.......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....

  19. Ice Formation Potential of Laboratory Generated Biogenic and Anthropogenic-Biogenic SOA Particles

    Science.gov (United States)

    Knopf, D. A.; Alpert, P. A.; Charnawskas, J. C.; Lambe, A. T.; Massoli, P.; Onasch, T. B.; Davidovits, P.; Worsnop, D. R.

    2014-12-01

    Secondary organic aerosol (SOA) is ubiquitous in the atmosphere and may play an important role in cloud glaciation processes. We investigated several laboratory generated SOA particles systems for their initial water uptake and ice formation propensity as a function of temperature, T, relative humidity with respect to water, RH, relative humidity with respect to ice, RHice, and for different humidification rates, cRHice. This includes pure SOA particles formed from α-pinene, isoprene, and longifolene volatile organic compound precursors with and without the presence of sulfate seed particles as well as oxidized soot and soot-coated α-pinene and naphthalene SOA with varying O/C ratios and coating thicknesses. Micro-spectroscopic chemical imaging using scanning transmission X-ray microscopy with near edge X-ray absorption fine structure spectroscopy (STXM/NEXAFS) is used to characterize SOA, SOA-sulfate, SOA-soot particles generated in the Boston College potential aerosol mass (PAM) flow reactor in relation to their ice nucleation behavior. Water uptake is consistently observed on SOA particles at RH=75% and 95% for 262 and 228 K, respectively, followed by homogeneous ice nucleation applying atmospherically relevant cRHice=1 % min-1. When cRHice=25 % min-1, ice nucleation is delayed by about 30-40% RHice and cannot be explained by homogeneous ice nucleation. This implies diffusion limitation of water into these potentially glassy or semi-solid organic particles resulting in non-equilibrium between ambient RH and particle water activity. These data will aid in our understanding of the role of organic particle phase states in response to changes in T and RH which is crucial information for prediction of atmospheric ice nucleation.

  20. A functional group oxidation model (FGOM for SOA formation and aging

    Directory of Open Access Journals (Sweden)

    X. Zhang

    2013-06-01

    Full Text Available Secondary organic aerosol (SOA formation from a volatile organic compound (VOC involves multiple generations of oxidation that include functionalization and fragmentation of the parent carbon backbone and likely particle-phase oxidation and/or accretion reactions. Despite the typical complexity of the detailed molecular mechanism of SOA formation and aging, a relatively small number of functional groups characterize the oxidized molecules that constitute SOA. Given the carbon number and set of functional groups, the volatility of the molecule can be estimated. We present here a functional group oxidation model (FGOM that represents the process of SOA formation and aging. The FGOM contains a set of parameters that are to be determined by fitting of the model to laboratory chamber data: total organic aerosol concentration, and O : C and H : C atomic ratios. The sensitivity of the model prediction to variation of the adjustable parameters allows one to assess the relative importance of various pathways involved in SOA formation. An analysis of SOA formation from the high- and low-NOx photooxidation of four C12 alkanes (n-dodecane, 2-methylundecane, hexylcyclohexane, and cyclododecane using the FGOM is presented, and comparison with the statistical oxidation model (SOM of Cappa et al. (2013 is discussed.

  1. A Functional Group Oxidation Model (FGOM for SOA formation and aging

    Directory of Open Access Journals (Sweden)

    X. Zhang

    2012-12-01

    Full Text Available Secondary organic aerosol (SOA formation from a volatile organic compound (VOC involves multiple generations of oxidation that include functionalization and fragmentation of the parent carbon backbone and, likely, particle-phase oxidation and/or accretion reactions. Despite the typical complexity of the detailed molecular mechanism of SOA formation and aging, a relatively small number of functional groups characterize the oxidized molecules that constitute SOA. Given the carbon number and set of functional groups, the volatility of the molecule can be estimated. We present here a Functional Group Oxidation Model (FGOM that represents the process of SOA formation and aging. The FGOM contains a set of parameters that are to be determined by fitting of the model to laboratory chamber data: total organic aerosol concentration, and O:C and H:C atomic ratios. The sensitivity of the model prediction to variation of the adjustable parameters allows one to assess the relative importance of various pathways involved in SOA formation. An analysis of SOA formation from the high- and low-NOx photooxidation of four C12 alkanes (n-dodecane, 2-methylundecane, hexylcyclohexane, and cyclododecane using the FGOM is presented, and comparison with the Statistical Oxidation Model (SOM of Cappa et al. (2012 is discussed.

  2. 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 

  3. Research of marine sensor web based on SOA and EDA

    Science.gov (United States)

    Jiang, Yongguo; Dou, Jinfeng; Guo, Zhongwen; Hu, Keyong

    2015-04-01

    A great deal of ocean sensor observation data exists, for a wide range of marine disciplines, derived from in situ and remote observing platforms, in real-time, near-real-time and delayed mode. Ocean monitoring is routinely completed using sensors and instruments. Standardization is the key requirement for exchanging information about ocean sensors and sensor data and for comparing and combining information from different sensor networks. One or more sensors are often physically integrated into a single ocean `instrument' device, which often brings in many challenges related to diverse sensor data formats, parameters units, different spatiotemporal resolution, application domains, data quality and sensors protocols. To face these challenges requires the standardization efforts aiming at facilitating the so-called Sensor Web, which making it easy to provide public access to sensor data and metadata information. In this paper, a Marine Sensor Web, based on SOA and EDA and integrating the MBARI's PUCK protocol, IEEE 1451 and OGC SWE 2.0, is illustrated with a five-layer architecture. The Web Service layer and Event Process layer are illustrated in detail with an actual example. The demo study has demonstrated that a standard-based system can be built to access sensors and marine instruments distributed globally using common Web browsers for monitoring the environment and oceanic conditions besides marine sensor data on the Web, this framework of Marine Sensor Web can also play an important role in many other domains' information integration.

  4. 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.

  5. 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

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

    Science.gov (United States)

    Mahmud, A.; Barsanti, K.

    2013-07-01

    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 regions and Malaysian Borneo

  7. 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.

  8. 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.

  9. Virtual volatility

    OpenAIRE

    A. Christian Silva; Prange, Richard E.

    2006-01-01

    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 st...

  10. Virtual Reflexes

    OpenAIRE

    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...

  11. Virtual reality

    OpenAIRE

    Zheng, JM; Chan, KW; Gibson, I.

    1998-01-01

    Virtual reality is still in its infancy. However, many contemporary applications already have proven virtual reality to be indispensable to everyday life. For instance, the technology of virtual product design and manufacturing makes the new products better and cheaper. The applications of VR in medicine allow doctors to diagnose a disease more accurately. Without a doubt, it has and will foster more innovative research and applications. High-resolution, low-lag and low-price systems will be ...

  12. 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......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...

  13. 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

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

    Directory of Open Access Journals (Sweden)

    A. Mahmud

    2012-12-01

    Full Text Available The secondary organic aerosol (SOA module in the Model for Ozone and Related chemical Tracers, version 4 (MOZART-4 has been updated by replacing existing two-product (2p parameters with those obtained from two-product volatility basis set (2p-VBS fits, and by treating SOA formation from the following volatile organic compounds (VOCs: isoprene, propene and lumped alkenes. 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 versions. The base-case MOZART-4 predicted annual average SOA of 0.36 ± 0.50 μg m−3 in South America, 0.31 ± 0.38 μg m−3 in Indonesia, 0.09 ± 0.05 μg m−3 in the USA, and 0.12 ± 0.07 μg m−3 in Europe. Concentrations from the updated versions of the model showed a~marked increase in annual average SOA. Using the updated set of parameters alone (MZ4-v1 increased annual average SOA by ~8%, ~16%, ~56%, and ~108% from the base-case in South America, Indonesia, USA, and Europe, respectively. Treatment of additional parent VOCs (MZ4-v2 resulted in an even more dramatic increase of ~178–406% in annual average SOA for these regions over the base-case. The increases in predicted SOA concentrations further resulted in increases in corresponding SOA contributions to annual average total aerosol optical depth (AOD by <1% for MZ4-v1 and ~1–6% for MZ4-v2. Estimated global SOA production was ~6.6 Tg yr−1 and ~19.1 Tg yr−1 with corresponding burdens of ~0.24 Tg and ~0.59 Tg using MZ4-v1 and MZ4-v2, respectively. The SOA budgets predicted in the current study fall well within reported ranges for similar modeling studies, 6.7 to 96 Tg yr−1, but are lower than recently reported observationally-constrained values, 50 to 380 Tg yr−1. With MZ4-v2, simulated SOA concentrations at the surface were also in

  15. Virtual Laboratories and Virtual Worlds

    CERN Document Server

    Hut, Piet

    2007-01-01

    Since we cannot put stars in a laboratory, astrophysicists had to wait till the invention of computers before becoming laboratory scientists. For half a century now, we have been conducting experiments in our virtual laboratories. However, we ourselves have remained behind the keyboard, with the screen of the monitor separating us from the world we are simulating. Recently, 3D on-line technology, developed first for games but now deployed in virtual worlds like Second Life, is beginning to make it possible for astrophysicists to enter their virtual labs themselves, in virtual form as avatars. This has several advantages, from new possibilities to explore the results of the simulations to a shared presence in a virtual lab with remote collaborators on different continents. I will report my experiences with the use of Qwaq Forums, a virtual world developed by a new company (see http://www.qwaq.com)

  16. 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.

  17. Global mechanistic model of SOA formation: effects of different chemical mechanisms

    Directory of Open Access Journals (Sweden)

    G. Lin

    2011-09-01

    Full Text Available Recent experimental findings indicate that Secondary Organic Aerosol (SOA represents an important and, under many circumstances, the major fraction of the organic aerosol burden. Here, we use a global 3-d model (IMPACT to test the results of different mechanisms for the production of SOA. The basic mechanism includes SOA formation from organic nitrates and peroxides produced from an explicit chemical formulation, using partition coefficients based on thermodynamic principles. We also include the formation of non-evaporative SOA from the reaction of glyoxal and methylglyoxal on aqueous aerosols and cloud droplets as well as from the reaction of epoxides on aqueous aerosols. A model simulation including these SOA formation mechanisms gives an annual global SOA production of 113.5 Tg. The global production of SOA is substantially decreased to 85.0 Tg yr−1 if the HOx regeneration mechanism proposed by Peeters et al. (2009 is used. Model predictions with and without this HOx regeneration scheme are compared with multiple surface observation datasets, namely: the Interagency Monitoring of Protected Visual Environments (IMPROVE for the United States, the European Monitoring and Evaluation Programme (EMEP as well as Aerosol Mass Spectrometry (AMS data measured in both Northern Hemisphere and tropical forest regions. All model simulations realistically predict the organic carbon mass observed in the Northern Hemisphere, although they tend to overestimate the concentrations in tropical forest regions. This overestimate may result from an unrealistically high uptake rate of glyoxal and methylglyoxal on aqueous aerosols and in cloud drops. The modeled OC in the free troposphere is in agreement with measurements in the ITCT-2K4 aircraft campaign over the North America and in pollution layers in Asia during the INTEX-B campaign, although the model underestimates OC in the free troposphere during the ACE-Asia campaign off the

  18. Differences in BVOC oxidation and SOA formation above and below the forest canopy

    Science.gov (United States)

    Schulze, Benjamin C.; Wallace, Henry W.; Flynn, James H.; Lefer, Barry L.; Erickson, Matt H.; Jobson, B. Tom; Dusanter, Sebastien; Griffith, Stephen M.; Hansen, Robert F.; Stevens, Philip S.; VanReken, Timothy; Griffin, Robert J.

    2017-02-01

    Gas-phase biogenic volatile organic compounds (BVOCs) are oxidized in the troposphere to produce secondary pollutants such as ozone (O3), organic nitrates (RONO2), and secondary organic aerosol (SOA). Two coupled zero-dimensional models have been used to investigate differences in oxidation and SOA production from isoprene and α-pinene, especially with respect to the nitrate radical (NO3), above and below a forest canopy in rural Michigan. In both modeled environments (above and below the canopy), NO3 mixing ratios are relatively small (urban forest environment increases the average contribution of NO3 to daytime below-canopy α-pinene oxidation to 32 %. Gas-phase RONO2 produced through NO3 oxidation undergoes net transport upward from the below-canopy environment during the day, and this transport contributes up to 30 % of total NO3-derived RONO2 production above the canopy in the morning (˜ 07:00). Modeled SOA mass loadings above and below the canopy ultimately differ by less than 0.5 µg m-3, and extremely low-volatility organic compounds dominate SOA composition. Lower temperatures below the canopy cause increased partitioning of semi-volatile gas-phase products to the particle phase and up to 35 % larger SOA mass loadings of these products relative to above the canopy in the model. Including transport between above- and below-canopy environments increases above-canopy NO3-derived α-pinene RONO2 SOA mass by as much as 45 %, suggesting that below-canopy chemical processes substantially influence above-canopy SOA mass loadings, especially with regard to monoterpene-derived RONO2.

  19. Virtual Acoustics

    Science.gov (United States)

    Lokki, Tapio; Savioja, Lauri

    The term virtual acoustics is often applied when sound signal is processed to contain features of a simulated acoustical space and sound is spatially reproduced either with binaural or with multichannel techniques. Therefore, virtual acoustics consists of spatial sound reproduction and room acoustics modeling.

  20. Virtual materiality

    DEFF Research Database (Denmark)

    Søndergaard, Dorte Marie

    an interesting platform for further development including virtual materiality and agency. If we choose to proceed along this line – some of our steps would include attention to the following points: 1. Working with virtual realities first of all undermines a pure realist conceptualization of materiality. We need......There are two questions that feed the curiosity of this paper: a theoretical question connected to the conceptualization of materiality across the real/virtual divide and an empirical question connected to the understanding of virtual experiences in children’s lives when studied in relation...... as their recounts of them and 3. the consumption of other media products like movies, reality shows, YouTube videos etc. How do we theorize ‘matter’ in such dimensions? Is it possible to theorize virtual matter as ‘materiality’ in line with any real life materiality? What conceptualization will help us understand...

  1. Virtual projects

    DEFF Research Database (Denmark)

    Svejvig, Per; Commisso, Trine Hald

    2012-01-01

    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...... for performing these projects. This paper compares best practices with practiced practices for virtual projects and discusses ways to bridge the gap between them. We have studied eleven virtual projects in five Danish organizations and compared them with a predefined list of best practices compiled from...... 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...

  2. Virtual Exploratories

    DEFF Research Database (Denmark)

    Jensen, Sisse Siggaard

    2006-01-01

    This paper proposes the notion of activity-systems to denote a virtual frame of activity that requires mutually coordinated action. The underlying assumption is that such framings may support the informal learning and reflective practices of actors, and especially so, when they are provoking...... and challenging. It is suggested that the prevailing ‘traditions’ of collaborative learning and knowledge sharing need to be challenged and complemented, if we are to be able to support the variety and the diversity in the repertoires of virtual learning activities. In order to conceptualize such activity......-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...

  3. Fully characterization of an active optical filter based on an equivalent-phase-shifted DFB-SOA

    Science.gov (United States)

    Deng, Ye; Li, Ming; Shi, Nuannuan; Tang, Jian; Sun, Shuqian; Zhang, Lihong; Li, Wei; Zhu, Ninghua

    2016-10-01

    A fully characterization of an active optical filter based on an equivalent-phase-shifted DFB-SOA has been theoretically analyzed and experimentally demonstrated in this paper. By employing an optical vector network analyzer (OVNA), transmission characteristics of the equivalent-phase-shifted DFB-SOA are obtained. The influences of driven current on transmission characteristics of the equivalent-phase-shifted DFB-SOA are also investigated. In addition to the advantage of integration, the proposed equivalent-phase-shifted DFB-SOA also shows significant application in design of photonic devices for all-optical signal processing and computing.

  4. Virtual Reality in Psychology

    Directory of Open Access Journals (Sweden)

    Nigel Foreman

    2009-01-01

    Full Text Available 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 interface flexibility, the reproducibility of virtual experience, and the opportunity for on-line monitoring of performance. Applications of VEs are many and varied, but are especially beneficial where experience can be tailored via augmentation, and where dangerous training situations can be avoided. The use of programmable agents has great future potential in relation to training and interpersonal skill development, also perhaps in clinical diagnosis and therapy. Progress in VE usage in psychological education is limited by cost and availability, though VEs are being used increasingly in classroom and laboratory teaching exercises. Virtual Reality was said to be “an answer waiting for a question”, but questions are being recognized, so that applications of VEs within the behavioural sciences are likely to multiply.

  5. Simulation of semi-explicit mechanisms of SOA formation from glyoxal in a 3D model

    Science.gov (United States)

    Knote, C. J.; Hodzic, A.; Jimenez, J. L.; Volkamer, R.; Orlando, J. J.; Baidar, S.; Brioude, J. F.; Fast, J. D.; Gentner, D. R.; Goldstein, A. H.; Hayes, P. L.; Knighton, W. B.; Oetjen, H.; Setyan, A.; Stark, H.; Thalman, R. M.; Tyndall, G. S.; Washenfelder, R. A.; Waxman, E.; Zhang, Q.

    2013-12-01

    Formation of secondary organic aerosols (SOA) through multi-phase processing of glyoxal has been proposed recently as a relevant contributor to SOA mass. Glyoxal has both anthropogenic and biogenic sources, and readily partitions into the aqueous-phase of cloud droplets and aerosols. Both reversible and irreversible chemistry in the liquid-phase has been observed. A recent laboratory study indicates that the presence of salts in the liquid-phase strongly enhances the Henry';s law constant of glyoxal, allowing for much more effective multi-phase processing. In our work we investigate the contribution of glyoxal to SOA formation on the regional scale. We employ the regional chemistry transport model WRF-chem with MOZART gas-phase chemistry and MOSAIC aerosols, which we both extended to improve the description of glyoxal formation in the gas-phase, and its interactions with aerosols. The detailed description of aerosols in our setup allows us to compare very simple (uptake coefficient) parameterizations of SOA formation from glyoxal, as has been used in previous modeling studies, with much more detailed descriptions of the various pathways postulated based on laboratory studies. Measurements taken during the CARES and CalNex campaigns in California in summer 2010 allowed us to constrain the model, including the major direct precursors of glyoxal. Simulations at convection-permitting resolution over a 2 week period in June 2010 have been conducted to assess the effect of the different ways to parameterize SOA formation from glyoxal and investigate its regional variability. We find that depending on the parameterization used the contribution of glyoxal to SOA is between 1 and 15% in the LA basin during this period, and that simple parameterizations based on uptake coefficients derived from box model studies lead to higher contributions (15%) than parameterizations based on lab experiments (1%). A kinetic limitation found in experiments hinders substantial contribution

  6. SOA在LIMS设计中的应用%Application of SOA in design of LIMS

    Institute of Scientific and Technical Information of China (English)

    刘国庆; 钱俊

    2012-01-01

    基于模块紧密耦合设计的LIMS(laboratory information management system)存在升级维护困难、成本大等缺点,利用松散耦合的SOA(service-oriented architecture)系统架构则较好地解决了这一问题.在分析SOA优点、实现方式等基础上,探讨了基于SOA架构的LIMS开发设计,采用Web服务与XML文档交互的实现方法,给出了一种新型的实验室信息管理系统架构.南方医科大学电子创新实验室LIMS的设计开发与应用表明基于SOA的LIMS开发是很有应用前景的.%The tightly coupling LIMS(laboratory information management system) is expensive and difficult to upgrade and maintain as opposed to SOA model based on relax coupling. Following the analysis of the merits and realization way of SOA, the design of LIMS based on SOA has been discussed. Adopting the realization way of alternating the Web Service and XML document, a novel LIMS has been presented. Finally the design and application of LIMS in the Electronic Innovation Laboratory in Southern Medical University have been introduced, illustrating the wide and promising application of LIMS based on SOA.

  7. 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)

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

    Science.gov (United States)

    Holt, Sylvester; Kankipati, Harish; De Graeve, Stijn; Van Zeebroeck, Griet; Foulquié-Moreno, Maria R.; Lindgreen, Stinus; Thevelein, Johan M.

    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 sul1Δ sul2Δ soa1Δ 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 sulfate as sulfur sources in the natural environment of S. cerevisiae and other fungi by identifying fungal transporters for these compounds. PMID:28165463

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

    Science.gov (United States)

    Marais, E. A.; Jacob, D. J.; Jimenez, J. L.; Campuzano-Jost, P.; Day, D. A.; Hu, W.; Krechmer, J.; Zhu, L.; Kim, P. S.; Miller, C. C.; Fisher, J. A.; Travis, K.; Yu, K.; Hanisco, T. F.; Wolfe, G. M.; Arkinson, H. L.; Pye, H. O. T.; Froyd, K. D.; Liao, J.; McNeill, V. F.

    2015-11-01

    % increase in isoprene SOA) and 48 % for SO2 (35 % decrease in isoprene SOA). The combined projected decreases in NOx and SO2 emissions reduce isoprene SOA yields from 3.3 to 2.3 %. 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.

  10. 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

    2015-11-01

    (leading to 7 % increase in isoprene SOA and 48 % for SO2 (35 % decrease in isoprene SOA. The combined projected decreases in NOx and SO2 emissions reduce isoprene SOA yields from 3.3 to 2.3 %. 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.

  11. Volumetric Virtual Environments

    Institute of Scientific and Technical Information of China (English)

    HE Taosong

    2000-01-01

    Driven by fast development of both virtual reality and volume visualization, we discuss some critical techniques towards building a volumetric VR system, specifically the modeling, rendering, and manipulations of a volumetric scene.Techniques such as voxel-based object simplification, accelerated volume rendering,fast stereo volume rendering, and volumetric "collision detection" are introduced and improved, with the idea of demonstrating the possibilities and potential benefits of incorporating volumetric models into VR systems.

  12. Virtual Machines and Networks - Installation, Performance Study, Advantages and Virtualization Options

    CERN Document Server

    Ali, Ishtiaq; 10.5121/ijnsa.2011.3101

    2011-01-01

    The interest in virtualization has been growing rapidly in the IT industry because of inherent benefits like better resource utilization and ease of system manageability. The experimentation and use of virtualization as well as the simultaneous deployment of virtual software are increasingly getting popular and in use by educational institutions for research and teaching. This paper stresses on the potential advantages associated with virtualization and the use of virtual machines for scenarios, which cannot be easily implemented and/or studied in a traditional academic network environment, but need to be explored and experimented by students to meet the raising needs and knowledge-base demanded by the IT industry. In this context, we discuss various aspects of virtualization - starting from the working principle of virtual machines, installation procedure for a virtual guest operating system on a physical host operating system, virtualization options and a performance study measuring the throughput obtained ...

  13. Key parameters controlling OH-initiated formation of secondary organic aerosol in the aqueous phase (aqSOA)

    Science.gov (United States)

    Ervens, Barbara; Sorooshian, Armin; Lim, Yong B.; Turpin, Barbara J.

    2014-04-01

    Secondary organic aerosol formation in the aqueous phase of cloud droplets and aerosol particles (aqSOA) might contribute substantially to the total SOA burden and help to explain discrepancies between observed and predicted SOA properties. In order to implement aqSOA formation in models, key processes controlling formation within the multiphase system have to be identified. We explore parameters affecting phase transfer and OH(aq)-initiated aqSOA formation as a function of OH(aq) availability. Box model results suggest OH(aq)-limited photochemical aqSOA formation in cloud water even if aqueous OH(aq) sources are present. This limitation manifests itself as an apparent surface dependence of aqSOA formation. We estimate chemical OH(aq) production fluxes, necessary to establish thermodynamic equilibrium between the phases (based on Henry's law constants) for both cloud and aqueous particles. Estimates show that no (currently known) OH(aq) source in cloud water can remove this limitation, whereas in aerosol water, it might be feasible. Ambient organic mass (oxalate) measurements in stratocumulus clouds as a function of cloud drop surface area and liquid water content exhibit trends similar to model results. These findings support the use of parameterizations of cloud-aqSOA using effective droplet radius rather than liquid water volume or drop surface area. Sensitivity studies suggest that future laboratory studies should explore aqSOA yields in multiphase systems as a function of these parameters and at atmospherically relevant OH(aq) levels. Since aerosol-aqSOA formation significantly depends on OH(aq) availability, parameterizations might be less straightforward, and oxidant (OH) sources within aerosol water emerge as one of the major uncertainties in aerosol-aqSOA formation.

  14. Silicon Photonics WDM Transceiver with SOA and Semiconductor Mode-Locked Laser

    CERN Document Server

    Moscoso-Mártir, Alvaro; Hauck, Johannes; Chimot, Nicolas; Setter, Rony; Badihi, Avner; Rasmussen, Daniel E; Garreau, Alexandre; Nielsen, Mads; Islamova, Elmira; Romero-García, Sebastián; Shen, Bin; Sandomirsky, Anna; Rockman, Sylvie; Li, Chao; Azadeh, Saeed Sharif; Lo, Guo-Qiang; Mentovich, Elad; Merget, Florian; Lelarge, François; Witzens, Jeremy

    2016-01-01

    We demonstrate a complete Silicon Photonics WDM link relying on a single section semiconductor mode-locked laser and a single SOA to support up to 12 multiplexed channels with a bit error rate of 1e-12 at serial data rates of 14 Gbps without channel pre-emphasis, equalization or forward error correction. Individual channels reach error free operation at 25 Gbps and multi-channel operation at 25 Gbps is shown to be compatible with standard 7% overhead hard decision forward error correction. Silicon Photonics transmitter and receiver chips are hybridly integrated with driver and receiver electronics. A detailed link model is derived and verified. Particular emphasis is placed on accurate system level modeling of laser RIN, SOA amplified spontaneous emission noise and receiver noise. The impact of the electrical receiver bandwidth and non-Gaussian statistics on level dependent amplified spontaneous emission noise are investigated in detail. The channel count scalability as limited by SOA saturation is further an...

  15. Dependency Modeling of a SOA Based System Through Colored Petri Nets

    Directory of Open Access Journals (Sweden)

    Pawan Kumar

    2016-09-01

    Full Text Available Dependency relationships play an important role in testing, maintenance and configuration management of software systems. The informal dependency representations fail to observe behavioral connections among subsystems and cause ambiguity in representing different types of dependency relationships. Therefore, dependency in a software system requires a formal and unambiguous representation so that its correct effects can be visualized. In this paper, we present a Colored Petri Net based dependency analysis of a Service Oriented Architecture (SOA based system that represents specification of dependency relationships and models the dependencies in a SOA based system at conceptual level. Different types of dependency relations are represented in a formal manner by using Service Algebra. A module SOA based system ‘Online Bookshop’ has been developed and used for the purpose of modeling and example demonstration. Such modeling can help in identification of inconsistency among services, and web services can be verified for safety and reliability.

  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...... optical networks. The factors governing the modulation bandwidth of SOAs are determined, and schemes for reducing detrimental patterning effects are discussed. Three types of SOA-based switches are investigated numerically: so-called standardmode and differential-mode switches, and the filtering assisted...... switch. Differential -mode switches are shown to eliminate one contribution to the patterning effects, referred to as the linear patterning. This enables operation at bitrates far beyond the limit set by the carrier lifetime, but ultimately a saturation-induced patterning effect, nonlinear patterning...

  17. Measurement of linewidth enhancement factor of SOA using fiber Sagnac Ring

    Institute of Scientific and Technical Information of China (English)

    GAO Hua-li; WU Chong-qing; LI Ya-jie; NI Dong

    2006-01-01

    Semiconductor optical amplifiers (SOA) are optical amplifying devices and key parts in optical switches and optical buffers.They are largely used in communication system.Linewidth enhancement factor is an important parameter for SOA.A method is proposed to measure the linewidth enhancement factor with Sagnac interferometer.Cross phase modulation (XPM) and cross gain modulation (XGM) coexist in SOA.The quantitative relation of linewidth enhancement factor to XGM and the interference extinction ratio is given.The experimental results indicate that the value of linewidth enhancement factor changes from 5.13 to 6.24 when the electric current varies from 130 mA to 240 mA.

  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. Virtual Poetry.

    Science.gov (United States)

    Gyori, Ladislao Pablo

    1996-01-01

    Presents a manifesto proposing the creation of a new kind of poetry--virtual poetry--that exists only in electronic space and computer networks. States that this new poetry is interactive, animated, hyper-linked, and navigational. (PA)

  20. Virtual Exploratories

    DEFF Research Database (Denmark)

    Jensen, Sisse Siggaard

    2006-01-01

    This paper proposes the notion of activity-systems to denote a virtual frame of activity that requires mutually coordinated action. The underlying assumption is that such framings may support the informal learning and reflective practices of actors, and especially so, when they are provoking...... and challenging. It is suggested that the prevailing ‘traditions’ of collaborative learning and knowledge sharing need to be challenged and complemented, if we are to be able to support the variety and the diversity in the repertoires of virtual learning activities. In order to conceptualize such activity...... 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. 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...... participated from different institutions in the workshop. The result of the workshop was experiences with different communication tools and media. Facing the difficulties and possibilities in collaborateting virtually concerned around group work and development of a shared presentation. All based on getting...... experiences for the learning design of MVU courses. The workshop intented to give the participants the possibility to draw their own experiences with issues on computer supported collaboration, group work in a virtual environment, synchronous and asynchronous communication media, and different perspectives...

  2. Virtual Teams.

    Science.gov (United States)

    Geber, Beverly

    1995-01-01

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

  3. Recent progress on intensity and chirp compensation of EADFB laser realized by SOA integration

    Science.gov (United States)

    Kobayashi, W.; Fujiwara, N.; Hasebe, K.; Kanazawa, S.; Sanjoh, H.; Itoh, M.

    2016-04-01

    A novel approach is demonstrated for overcoming the trade-off relationship between the power consumption and transmission distance of an electro-absorption modulator integrated with a DFB laser (EADFB laser). We demonstrate that the monolithic integration of a short semiconductor optical amplifier (SOA) with an EADFB laser is effective in overcoming the limitation imposed by the Kramers-Kronig (K-K) relation of the EA modulator, which cannot be overcome with the conventional method of optimizing the MQW structure of the EA modulator. Our approach provides an EADFB laser with two advantages. One is that we can realize a higher optical output power with smaller power consumption than with a conventional EADFB laser by reducing the DFB laser injection current and allocating it to the SOA section. We design the SOA length based on this concept. The other advantage is the chirp compensation of the EA modulator with the SOA. To confirm the validity of this approach, we investigate the SOA length dependence on the basic characteristics. By using an EADFB laser integrated with a 50-μm-long SOA, we achieve a 2 dB increase in the modulated output power compared with a stand-alone EADFB laser with the same power consumption. We realize an extended transmission distance of 5 km at 40 Gbit/s, and a 1.55-μm-wavelength window, which is conventionally achieved for a 2-km SMF transmission with an EADFB laser. These results indicate that this approach is a promising way to realize a high-speed light source with low power consumption for future large capacity optical network systems.

  4. Virtual reality and virtual bodies

    Science.gov (United States)

    Richards, Catherine; Korba, Larry W.; Shaw, Christopher D.; Green, Mark

    1994-04-01

    There are many ways to produce the sense of `presence' or telepresence in the user of virtual reality. For example attempting to increase the realism of the visual environment is a commonly accepted strategy. In contrast, this paper explores a way for the user to feel present in an unrealistic virtual body. It investigates an unusual approach, proprioceptive illusions. Proprioceptive or body illusions are used to generate and explore the experience of virtuality and presence outside of the normal body limits. These projects are realized in art installations.

  5. Experimental demonstration of a tunable laser using an SOA and an Opto-VLSI Processor.

    Science.gov (United States)

    Aljada, Muhsen; Zheng, Rong; Alameh, Kamal; Lee, Yong-Tak

    2007-07-23

    In this paper we propose and experimentally demonstrate a tunable laser structure cascading a semiconductor optical amplifier (SOA) that generates broadband amplified spontaneous emission and a reflective Opto-VLSI processor that dynamically reflects arbitrarily wavelengths and injects them back into the SOA, thus synthesizing an output signal of variable wavelength. The wavelength tunablility is performed using digital phase holograms uploaded on the Opto-VLSI processor. Experimental results demonstrate a tuning range from 1524nm to 1534nm, and show that the proposed tunable laser structure has a stable performance.

  6. VOC emissions, evolutions and contributions to SOA formation at a receptor site in Eastern China

    Directory of Open Access Journals (Sweden)

    B. Yuan

    2013-03-01

    Full Text Available Volatile organic compounds (VOCs were measured by two online instruments (GC-FID/MS and PTR-MS at a receptor site on Changdao Island (37.99° N, 120.70° E in eastern China. Reaction with OH radical dominated the chemical loss of most VOC species during the Changdao campaign. A photochemical age based parameterization method is used to calculate VOC emission ratios and to quantify the evolution of ambient VOCs. The calculated emission ratios of most hydrocarbons agree well with those obtained from emission inventory, but the emission ratios of oxygenated VOCs (OVOCs are significantly lower than those from emission inventory. The photochemical age based parameterization method is also used to investigate primary emissions and secondary formation of organic aerosol. The primary emission ratio of OA to CO are determined to be 14.9 μg m−3 ppm−1 and SOA are produced at an enhancement ratio of 18.8 μg m−3 ppm−1 to CO after 50 h of photochemical processing in the atmosphere. SOA formation is significantly higher than the level determined from VOC oxidation under both high-NOx (2.0 μg m−3 ppm−1 CO and low-NOx condition (6.5 μg m−3 ppm−1 CO. Polycyclic aromatic hydrocarbons (PAHs and higher alkanes (>C10 account for as high as 17.4% of SOA formation, which suggests semi-volatile organic compounds (SVOCs may be a large contributor to SOA formation during the Changdao campaign. SOA formation potential of primary VOC emissions determined from both field campaigns and emission inventory in China are lower than the measured SOA levels reported in Beijing and Pearl River Delta (PRD, indicating SOA formation cannot be explained by VOC oxidation in this regions. SOA budget in China is estimated to be 5.0–13.7 Tg yr−1, with a fraction of at least 2.7 Tg yr−1 from anthropogenic emissions, which are much higher than the previous estimates from regional models.

  7. Simulation of semi-explicit mechanisms of SOA formation from glyoxal in a 3-D model

    Science.gov (United States)

    Knote, C.; Hodzic, A.; Jimenez, J. L.; Volkamer, R.; Orlando, J. J.; Baidar, S.; Brioude, J.; Fast, J.; Gentner, D. R.; Goldstein, A. H.; Hayes, P. L.; Knighton, W. B.; Oetjen, H.; Setyan, A.; Stark, H.; Thalman, R.; Tyndall, G.; Washenfelder, R.; Waxman, E.; Zhang, Q.

    2013-10-01

    New pathways to form secondary organic aerosols (SOA) have been postulated recently. Glyoxal, the smallest dicarbonyl, is one of the proposed precursors. It has both anthropogenic and biogenic sources, and readily partitions into the aqueous-phase of cloud droplets and deliquesced aerosols where it undergoes both reversible and irreversible chemistry. In this work we extend the regional scale chemistry transport model WRF-Chem to include a detailed gas-phase chemistry of glyoxal formation as well as a state-of-the-science module describing its partitioning and reactions in the aqueous-phase of aerosols. A comparison of several proposed mechanisms is performed to quantify the relative importance of different formation pathways and their regional variability. The CARES/CalNex campaigns over California in summer 2010 are used as case studies to evaluate the model against observations. In all simulations the LA basin was found to be the hotspot for SOA formation from glyoxal, which contributes between 1% and 15% of the model SOA depending on the mechanism used. Our results indicate that a mechanism based only on a simple uptake coefficient, as frequently employed in global modeling studies, leads to higher SOA contributions from glyoxal compared to a more detailed description that considers aerosol phase state and chemical composition. In the more detailed simulations, surface uptake is found to be the main contributor to SOA mass compared to a volume process and reversible formation. We find that contribution of the latter is limited by the availability of glyoxal in aerosol water, which is in turn controlled by an increase in the Henry's law constant depending on salt concentrations ("salting-in"). A kinetic limitation in this increase prevents substantial partitioning of glyoxal into aerosol water at high salt concentrations. If this limitation is removed, volume pathways contribute >20% of glyoxal SOA mass, and the total mass formed (5.8% of total SOA in the LA

  8. Simulation of semi-explicit mechanisms of SOA formation from glyoxal in a 3-D model

    Directory of Open Access Journals (Sweden)

    C. Knote

    2013-10-01

    Full Text Available New pathways to form secondary organic aerosols (SOA have been postulated recently. Glyoxal, the smallest dicarbonyl, is one of the proposed precursors. It has both anthropogenic and biogenic sources, and readily partitions into the aqueous-phase of cloud droplets and deliquesced aerosols where it undergoes both reversible and irreversible chemistry. In this work we extend the regional scale chemistry transport model WRF-Chem to include a detailed gas-phase chemistry of glyoxal formation as well as a state-of-the-science module describing its partitioning and reactions in the aqueous-phase of aerosols. A comparison of several proposed mechanisms is performed to quantify the relative importance of different formation pathways and their regional variability. The CARES/CalNex campaigns over California in summer 2010 are used as case studies to evaluate the model against observations. In all simulations the LA basin was found to be the hotspot for SOA formation from glyoxal, which contributes between 1% and 15% of the model SOA depending on the mechanism used. Our results indicate that a mechanism based only on a simple uptake coefficient, as frequently employed in global modeling studies, leads to higher SOA contributions from glyoxal compared to a more detailed description that considers aerosol phase state and chemical composition. In the more detailed simulations, surface uptake is found to be the main contributor to SOA mass compared to a volume process and reversible formation. We find that contribution of the latter is limited by the availability of glyoxal in aerosol water, which is in turn controlled by an increase in the Henry's law constant depending on salt concentrations ("salting-in". A kinetic limitation in this increase prevents substantial partitioning of glyoxal into aerosol water at high salt concentrations. If this limitation is removed, volume pathways contribute >20% of glyoxal SOA mass, and the total mass formed (5.8% of total

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

    DEFF Research Database (Denmark)

    Xu, Jing; Zhang, Xinliang; Mørk, Jesper

    2010-01-01

    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...... 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....

  10. 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....

  11. LARGE-SCALE PHOTONIC INTEGRATED CIRCUIT FOR QPSK REGENERATION AND WAVELENGTH CONVERSION USING SOA-MZI

    Directory of Open Access Journals (Sweden)

    V.BHARATHI

    2013-06-01

    Full Text Available We investigate through numerical studies and experiments the performance of QPSK regeneration and wavelength-conversion of a large scale, silica-on-silicon photonic integrated circuit using cross phase modulation in a semiconductor optical amplifier(SOA. The phase changing is obtained because of the XPM in SOA. The QPSK signal is generated from 10 Gb/s two NRZ- OOK signals and RZ clock pulse signal. Simulation studies reveal the wavelength conversion potential of the circuit with enhanced regenerative capability of QPSK modulation. The tolerance power, BER, and Q factor value is analytically evaluated. Also calculate the power penalty.

  12. SOA-based OTDM-DPSK Demultiplexing Assisted by Offset-Filtering

    DEFF Research Database (Denmark)

    Xu, Jing; Ding, Yunhong; Peucheret, Christophe;

    2011-01-01

    We demonstrated for the first time 80 to 40 Gb/s OTDM-DPSK demultiplexing using a single SOA assisted by offset-filtering. Error free performance is achieved with an average power penalty of 5.5 dB.......We demonstrated for the first time 80 to 40 Gb/s OTDM-DPSK demultiplexing using a single SOA assisted by offset-filtering. Error free performance is achieved with an average power penalty of 5.5 dB....

  13. RFID在SOA-BPM集成平台仓储管理系统的应用

    Institute of Scientific and Technical Information of China (English)

    米志强; 王东

    2010-01-01

    RFD技术与SOA-BPM平台相集成,将RFID技术用于智能敏捷的SOA-BPM集成平台的仓储管理系统中,对仓储管理进行全程可视化管理,并对货物进行精确跟踪,可以提高仓储管理系统在操作、管理、决策等层面的敏捷性.

  14. A Framework for Developing Applications Based on SOA in Mobile Environment with Security Services

    Science.gov (United States)

    de Sene Fonseca, Johnneth; Abdelouahab, Zair

    Constant evolution of technologies used in mobile devices allows an increase of capabilities related to storage, processing and transmission of data, including more than one type of technology of transmission in a same device. These factors enable a greater number of applications but also it gives rise to a necessity to find a model of service development. One of the best options which currently exist is SOA (Service Oriented Architecture). This article aims to present a framework that allows the development of SOA in mobile environment. The objective of the framework is to give developers with all necessary tools for provision of services in this environment.

  15. Improving the All-Optical Response of SOAs Using a Modulated Holding Signal

    DEFF Research Database (Denmark)

    Bischoff, Svend; Nielsen, Mads Lønstrup; Mørk, Jesper

    2004-01-01

    A method for increasing the all-optical modulation bandwidth of semiconductor optical amplifiers (SOAs) by use of a cross-gain-modulated (XGM) holding signal is suggested and analyzed. The bandwidth improvement is numerically demonstrated by studying wavelength conversion in an SOA-based Mach......-Zehnder interferometer (MZI) at 160 and 40 Gb/s. The new scheme is predicted to improve the extinction ratio and the minimum mark output power, as well as to reduce the amplitude jitter of the wavelength converted signal....

  16. Molecular characterization of nitrogen and sulfur containing compounds in night-time SOA

    Science.gov (United States)

    Iinuma, Yoshiteru; Mutzel, Anke; Rodigast, Maria; Böge, Olaf; Herrmann, Hartmut

    2014-05-01

    The oxidation of volatile organic compounds (VOCs) leads to the formation of low volatile organic compounds that can form secondary organic aerosol (SOA). Studies in the past showed that laboratory generated and ambient SOA are made of polar molecules with O/C ratios generally greater than 0.5. More recent studies have shown that SOA compounds can contain heteroatoms mainly sulfur and nitrogen atoms. Offline chemical analysis with high-resolution mass spectrometers and fragmentation experiments has shown that sulphur containing compounds are mainly organosulfates and nitrogen containing species are aromatic heterocyclic compounds such as imidazole and nitrated aromatic compounds such as nitrophenols. In addition to these, SOA compounds containing both sulfur and nitrogen have been reported from the analysis of ambient organic aerosol, rainwater, fog and cloud samples. Based on the mass spectrometric evidence these compounds are attributed to nitrooxy-organosulfates originating from isoprene and monoterpenes. Although these compounds are ubiquitously detected in the ambient samples, reports about their detection in laboratory generated SOA are scares and their formation mechanisms are not well understood. In the present study, we investigated the formation of sulfur and nitrogen containing SOA species in the oxidation of biogenic VOCs. Photooxidation and night-time oxidation experiments were performed in a smog chamber to produce SOA samples. The laboratory generated SOA samples were analysed with UPLC-IMS-TOFMS (Ultra Performance Liquid Chromatography coupled to Ion Mobility Spectrometry and Time of Flight Mass Spectrometry). The presence of highly acidic sulphate seed particles (pH0) did not promote the formation of compounds with chemical formula of C10H17NO7S- and m/z value of 294.0653, indicating that the formation mechanisms of these compounds unlikely involve the ring opening reactions of epoxides and subsequent sulfation reactions. On the other hand, their

  17. Enhancing primary care clerkships with virtual patients.

    Science.gov (United States)

    Sobocan, Monika; Klemenc-Ketis, Zalika

    2016-11-01

    Virtual patients, computer-assisted patient scenarios, have been used in different medical disciplines over several years. Researchers have already gained knowledge on how it helps foster clinical thinking, fills knowledge gaps and enables patient management. Nonetheless, despite these advances in knowledge, the use of virtual patients in Family Medicine education remains limited. We point out the current knowledge, benefits and potential ways of using virtual patients in the Family Medicine setting. Virtual patients can be used as a preparation tool for clinical clerkships as well as learning about patient treatment not usually encountered in every day practice. Regardless of the means of implementation, students benefit from acquiring skills through multifaceted virtual patients. We firmly believe that, when intelligently applied, virtual patients can enhance and improve future Family Medicine education.

  18. Design and Application of SOA-SSH Layered Architecture%SOA-SSH分层架构的设计与应用

    Institute of Scientific and Technical Information of China (English)

    付更丽; 曹宝香

    2010-01-01

    文中对SOA、ESB、webservice、SSH分层架构等进行研究,针对当前业务系统异构难于集成的问题,利用SSH架构开发简便和分层解耦的优点,设计了基于SSH架构和SOA的 SOA-SSH分层架构.该架构将SOA系统进行分层管理,同时采用ESB做为服务注册中心来管理服务,解决了异构系统的整合问题.该架构通过分层解耦简化了SOA系统开发过程,使系统具有很强的扩展性和快速的业务重构能力.在技术上实现了基于SOA-SSH的PLM系统开发,并成功实现了PLM分层架构设计,从而证明了SOA-SSH架构的可行性.

  19. 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.

  20. Virtual instrumentation: Introduction of virtual

    OpenAIRE

    Ödlund, Erika

    2007-01-01

    The Large Hadron Collider (LHC) is the next large particle accelerator developed at CERN, constructed to enable studies of particles. The acceleration of the particles is carried out using magnets operating at about 1.9 K, a temperature achieved by regulating flow of superfluid helium. For economical reasons, control of the helium flow is based on feedback of virtual flow meter (VFT) estimates instead of real instrumentation. The main purpose of this work is to develop a virtual flow meter wi...

  1. Combining control electronics with SOA to equalize packet-to-packet power variations for optical 3R regeneration in optical networks at 10 Gbit/s

    DEFF Research Database (Denmark)

    Wessing, Henrik; Lavigne, B.; Sørensen, Brian Michael;

    2004-01-01

    We report on the combined effects of control electronics and a SOA as to suppress packet to packet power fluctuations. Associated to a SOA-MZI based 3R regenerator, we demonstrate a power dynamic range of 9 dB.......We report on the combined effects of control electronics and a SOA as to suppress packet to packet power fluctuations. Associated to a SOA-MZI based 3R regenerator, we demonstrate a power dynamic range of 9 dB....

  2. 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

  3. Virtualization: A double-edged sword

    CERN Document Server

    Wlodarz, Joachim J

    2007-01-01

    Virtualization became recently a hot topic once again, after being dormant for more than twenty years. In the meantime, it has been almost forgotten, that virtual machines are not so perfect isolating environments as it seems, when looking at the principles. These lessons were already learnt earlier when the first virtualized systems have been exposed to real life usage. Contemporary virtualization software enables instant creation and destruction of virtual machines on a host, live migration from one host to another, execution history manipulation, etc. These features are very useful in practice, but also causing headaches among security specialists, especially in current hostile network environments. In the present contribution we discuss the principles, potential benefits and risks of virtualization in a deja vu perspective, related to previous experiences with virtualization in the mainframe era.

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

    OpenAIRE

    K. O. Prosyukova

    2014-01-01

    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 educa...

  5. 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: t

  6. 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....

  7. Agile Information System Supporting Virtual Enterprise Operation

    Institute of Scientific and Technical Information of China (English)

    许青松; 陶丹; 范玉顺

    2001-01-01

    Dynamic collaboration is a relationship of companies working together for mutual benefit to bring acomplementary set of competencies to gain a market opportunity. A mechanism to manage and controlinformation flow among collaborating partners is described in this paper. Analysis of the virtual informationsystem requirements was used to develop an agile manufacturing information system (AMIS) to create, sustainand dissolve a virtual enterprise.``

  8. 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

  9. Pulse Extinction Ratio Improvement Using SPM in an SOA for OTDM Systems Applications

    DEFF Research Database (Denmark)

    Nielsen, Mads Lønstrup; Olsson, B.-E.; Blumenthal, D. J.

    2002-01-01

    Improvement of pulse extinction ratio from 15-20 dB to approximately 40 dB of a 10-GHz pulse train is demonstrated using the self-phase modulation-induced spectral shift caused by a semiconductor optical amplifier (SOA). The improvement permits penalty-free optical time-division multiplexing to 40...

  10. 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.

  11. Experimental demonstration of enhanced slow and fast light by forced coherent population oscillations in a SOA

    CERN Document Server

    Berger, Perrine; Alouini, Mehdi; de Valicourt, Guilhem; Brenot, \\linebreak Romain; Bretenaker, Fabien; Dolfi, Daniel

    2010-01-01

    We experimentally demonstrate enhanced slow and fast light by forced coherent population oscillations (CPOs) in a SOA. This approach is shown to rely on the interference between two different contributions. This opens the possibility to conceive a controllable RF phase shifter based on this set-up.

  12. ASSERT4SOA: Toward Security Certification of Service-Oriented Applications

    OpenAIRE

    2010-01-01

    ASSERT4SOA project proposes machine readable certificates to be used to allow Web service requesters to automatically assess the security properties of Web services (and their providers) as certified by a trusted third party. This vision promises to open up an entire new market for certification services.

  13. 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...

  14. Virtual care

    DEFF Research Database (Denmark)

    Kamp, Annette; Aaløkke Ballegaard, Stinne

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

  15. Virtual Tower

    Energy Technology Data Exchange (ETDEWEB)

    Wayne, R.A. [Sandia National Labs., Albuquerque, NM (United States). Security Engineering Dept.

    1997-08-01

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

  16. Virtual Violence.

    Science.gov (United States)

    2016-08-01

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

  17. Consideration of HOMs in α- and β-pinene SOA model

    Science.gov (United States)

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

    2016-04-01

    Secondary organic aerosol (SOA) is the major burden of the atmospheric organic particulate matter with 140 - 910 TgC yr-1 (Hallquist et al., 2009). SOA particles are formed via the oxidation of volatile organic carbons (VOCs), where the volatility of the VOCs is lowered due to the increase in their functionalization as well as their binding ability. Therefore, gaseous compounds can either nucleate to form new particles or condense on existing particles. The framework of SOA formation under natural conditions is very complex, because there are a multitude of gas-phase precursors, atmospheric degradation processes and products after oxidation. A lacking understanding about chemical and physical processes associated with SOA formation makes modeling of SOA processes difficult, leading to discrepancy between measured and modeled global SOA burdens. The present study utilizes a parcel model SPACCIM (SPectral Aerosol Cloud Chemistry Interaction Model, Wolke et al., 2005) that couples a multiphase chemical model with a microphysical model. For SOA modeling a further development of SPACCIM was necessary. Therefore, two components are added (i) a gas-phase chemistry mechanism for the VOC oxidation and (ii) a partitioning approach for the gas-to-particle phase transfer. An aggregated gas-phase chemistry mechanism for α- and β-pinene was adapted from Chen and Griffin (2005). For the phase transfer an absorptive partitioning approach (Pankow, 1994) and a kinetic approach (Zaveri et al., 2014) are implemented. Whereby the kinetic approach serves some advantages. The organic aerosol can be resolved in different size sections, whereby the particle radius is involved in the partitioning equations. The phase state of the organic material and the reactivity of the organic compounds in the particle-phase directly influence the modeled SOA yields. Recently, highly oxidized multifunctional organic compounds (HOMs) were found in the gas phase from lab and field studies. They are also

  18. 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…

  19. Severe open ankle sprain (SOAS): a lesion presenting as a penetrating soft tissue injury.

    Science.gov (United States)

    Soubeyrand, Marc; Vincent-Mansour, César; Guidon, Julie; Asselineau, Alain; Ducharnes, Gildas; Molina, Véronique

    2010-01-01

    The objective of this retrospective case study was to describe the incidence and clinical features of severe open ankle sprain (SOAS), defined as a tear of the lateral or medial collateral ligaments with an associated transverse tear of the skin over the corresponding malleolus. To this end, we reviewed the medical records of patients with SOAS managed between January 2005 and January 2009, using the databases of 3 different orthopedic trauma centers. Our review revealed 9 patients with SOAS, 7 (77.77%) of which involved the lateral ligaments and 2 (22.22%) of which involved the medial ligaments. The median age was 32 (range 21 to 45) years, and the injury occurred as a result of a motor vehicle accident in 6 (66.67%) patients, and as a result of a fall from a height in 3 (33.33%) patients. Two tendons were damaged in 2 (22.22%) patients, the deep fibular nerve (deep peroneal nerve) in 2 (22.22%) patients, and the anterior tibial artery in 1 (11.11%) patient. The only abnormality on plain radiographs was pneumarthrosis, which was present in 5 (55.56%) patients. The incidence of SOAS is rare, accounting for 0.002% (9/438,000) of all trauma cases and 0.22% (9/4142) of all cases of ankle trauma. The diagnosis was confirmed by intraoperative stress-maneuvers in all 9 patients. In conclusion, SOAS should be suspected in patients who present with a traumatic skin wound over the malleolus.

  20. 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

  1. Insights into Particle Growth from the Incorporation of Organic Nitrates into SOA from the Ozonolysis of α-Pinene

    Science.gov (United States)

    Perraud, V. M.; Vander Wall, A. C.; Finlayson-Pitts, B. J.

    2014-12-01

    Secondary organic aerosol (SOA) particles are formed in the atmosphere by oxidation of volatile organic compounds (VOC). However, the mechanism by which these particles form and grow, and how other compounds are taken up into the particle, is currently not well characterized. It appears that in many cases, the SOA is a highly viscous material such that uptake of semi-volatile oxidation products is irreversible. The goal of the present experiments was to study the incorporation of organic nitrates into SOA formed in the ozolonylsis of α-pinene using a large volume, slow-flow, stainless steel aerosol flow reactor. Gas phase 2-ethylhexyl nitrate (2EHN) was monitored by GC/MS using a simultaneous scan/single ion monitoring (SIM) mode following the signal at m/z 46 (NO2+) specific to organic nitrate. In addition, particle size distributions were monitored using a scanning mobility particle sizer (SMPS) and polydisperse particles were collected onto a Ge-ATR crystal using a custom impactor located at the end of the flow reactor (30 min reaction time). Particulate 2EHN was quantified by GC/MS after extraction of the SOA impacted on the Ge crystal. In parallel, evaporation of the SOA and its components was monitored by attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR). Insights into phase of the SOA and the uptake coefficient of 2EHN in the O3/α-pinene SOA are presented.

  2. 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…

  3. Virtual Savannah

    DEFF Research Database (Denmark)

    Rodil, Kasper; Eskildsen, Søren; Rehm, Matthias

    2012-01-01

    Virtual Savannah is constructed to visualize parts of a curriculum, which the educational service at Aalborg Zoo has difficulties in teaching children visiting the zoo. It contains rich media like audio, text, video and picture galleries about African ecology, but some of this episodic information...

  4. Virtual landmarks

    Science.gov (United States)

    Tong, Yubing; Udupa, Jayaram K.; Odhner, Dewey; Bai, Peirui; Torigian, Drew A.

    2017-03-01

    Much has been published on finding landmarks on object surfaces in the context of shape modeling. While this is still an open problem, many of the challenges of past approaches can be overcome by removing the restriction that landmarks must be on the object surface. The virtual landmarks we propose may reside inside, on the boundary of, or outside the object and are tethered to the object. Our solution is straightforward, simple, and recursive in nature, proceeding from global features initially to local features in later levels to detect landmarks. Principal component analysis (PCA) is used as an engine to recursively subdivide the object region. The object itself may be represented in binary or fuzzy form or with gray values. The method is illustrated in 3D space (although it generalizes readily to spaces of any dimensionality) on four objects (liver, trachea and bronchi, and outer boundaries of left and right lungs along pleura) derived from 5 patient computed tomography (CT) image data sets of the thorax and abdomen. The virtual landmark identification approach seems to work well on different structures in different subjects and seems to detect landmarks that are homologously located in different samples of the same object. The approach guarantees that virtual landmarks are invariant to translation, scaling, and rotation of the object/image. Landmarking techniques are fundamental for many computer vision and image processing applications, and we are currently exploring the use virtual landmarks in automatic anatomy recognition and object analytics.

  5. Virtual Expo

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The online version of the 2010 Shanghai Expo shows the future glory The 2010 Shanghai Expo is now open and letting visitors explore almost all its pavilions and exhib-its-virtually. The website for the World Expo launched on November 12,

  6. Virtual Savannah

    DEFF Research Database (Denmark)

    Rodil, Kasper; Eskildsen, Søren; Rehm, Matthias

    2012-01-01

    Virtual Savannah is constructed to visualize parts of a curriculum, which the educational service at Aalborg Zoo has difficulties in teaching children visiting the zoo. It contains rich media like audio, text, video and picture galleries about African ecology, but some of this episodic information...

  7. Virtual patrolling

    NARCIS (Netherlands)

    Vlist, van der M.; Wismans, L.J.J.; Beek, van P.; Suijs, L.C.W.

    2016-01-01

    Approximately 25 per cent of all congestion on motorways is caused by incidents. By virtual patrolling, incidents e.g. queues, accidents and car breakdowns on a road network, can be predicted or detected in an early stage. This early detection and prediction of an incident likely to happen, offers t

  8. Virtual Reality.

    Science.gov (United States)

    Newby, Gregory B.

    1993-01-01

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

  9. Virtually There.

    Science.gov (United States)

    Lanier, Jaron

    2001-01-01

    Describes tele-immersion, a new medium for human interaction enabled by digital technologies. It combines the display and interaction techniques of virtual reality with new vision technologies that transcend the traditional limitations of a camera. Tele-immersion stations observe people as moving sculptures without favoring a single point of view.…

  10. Virtual Savannah

    DEFF Research Database (Denmark)

    Eskildsen, Søren; Rodil, Kasper; Rehm, Matthias

    2012-01-01

    and the navigation. The test depicted how they managed to search the virtual world for answers in patterns related to restrictions in the system and using graphical points of interest as reference points. Collecting information about the complete interaction provides teachers with a tool to assess the individual...

  11. 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...

  12. Simulation of semi-explicit mechanisms of SOA formation from glyoxal in aerosol in a 3-D model

    Science.gov (United States)

    Knote, C.; Hodzic, A.; Jimenez, J. L.; Volkamer, R.; Orlando, J. J.; Baidar, S.; Brioude, J.; Fast, J.; Gentner, D. R.; Goldstein, A. H.; Hayes, P. L.; Knighton, W. B.; Oetjen, H.; Setyan, A.; Stark, H.; Thalman, R.; Tyndall, G.; Washenfelder, R.; Waxman, E.; Zhang, Q.

    2014-06-01

    New pathways to form secondary organic aerosol (SOA) have been postulated recently. Glyoxal, the smallest dicarbonyl, is one of the proposed precursors. It has both anthropogenic and biogenic sources, and readily partitions into the aqueous phase of cloud droplets and deliquesced particles where it undergoes both reversible and irreversible chemistry. In this work we extend the regional scale chemistry transport model WRF-Chem to include detailed gas-phase chemistry of glyoxal formation as well as a state-of-the-science module describing its partitioning and reactions in the aerosol aqueous-phase. A comparison of several proposed mechanisms is performed to quantify the relative importance of different formation pathways and their regional variability. The CARES/CalNex campaigns over California in summer 2010 are used as case studies to evaluate the model against observations. A month-long simulation over the continental United States (US) enables us to extend our results to the continental scale. In all simulations over California, the Los Angeles (LA) basin was found to be the hot spot for SOA formation from glyoxal, which contributes between 1% and 15% of the model SOA depending on the mechanism used. Our results indicate that a mechanism based only on a reactive (surface limited) uptake coefficient leads to higher SOA yields from glyoxal compared to a more detailed description that considers aerosol phase state and chemical composition. In the more detailed simulations, surface uptake is found to give the highest SOA mass yields compared to a volume process and reversible formation. We find that the yields of the latter are limited by the availability of glyoxal in aerosol water, which is in turn controlled by an increase in the Henry's law constant depending on salt concentrations ("salting-in"). A time dependence in this increase prevents substantial partitioning of glyoxal into aerosol water at high salt concentrations. If this limitation is removed, volume

  13. Simulation of semi-explicit mechanisms of SOA formation from glyoxal in aerosol in a 3-D model

    Directory of Open Access Journals (Sweden)

    C. Knote

    2014-06-01

    Full Text Available New pathways to form secondary organic aerosol (SOA have been postulated recently. Glyoxal, the smallest dicarbonyl, is one of the proposed precursors. It has both anthropogenic and biogenic sources, and readily partitions into the aqueous phase of cloud droplets and deliquesced particles where it undergoes both reversible and irreversible chemistry. In this work we extend the regional scale chemistry transport model WRF-Chem to include detailed gas-phase chemistry of glyoxal formation as well as a state-of-the-science module describing its partitioning and reactions in the aerosol aqueous-phase. A comparison of several proposed mechanisms is performed to quantify the relative importance of different formation pathways and their regional variability. The CARES/CalNex campaigns over California in summer 2010 are used as case studies to evaluate the model against observations. A month-long simulation over the continental United States (US enables us to extend our results to the continental scale. In all simulations over California, the Los Angeles (LA basin was found to be the hot spot for SOA formation from glyoxal, which contributes between 1% and 15% of the model SOA depending on the mechanism used. Our results indicate that a mechanism based only on a reactive (surface limited uptake coefficient leads to higher SOA yields from glyoxal compared to a more detailed description that considers aerosol phase state and chemical composition. In the more detailed simulations, surface uptake is found to give the highest SOA mass yields compared to a volume process and reversible formation. We find that the yields of the latter are limited by the availability of glyoxal in aerosol water, which is in turn controlled by an increase in the Henry's law constant depending on salt concentrations ("salting-in". A time dependence in this increase prevents substantial partitioning of glyoxal into aerosol water at high salt concentrations. If this limitation is

  14. VOC characteristics, emissions and contributions to SOA formation during hazy episodes

    Science.gov (United States)

    Sun, Jie; Wu, Fangkun; Hu, Bo; Tang, Guiqian; Zhang, Junke; Wang, Yuesi

    2016-09-01

    Volatile organic compounds (VOC) are important precursors of secondary organic aerosols (SOA). The pollution processes in Beijing were investigated from 18th October to 6th November 2013 to study the characteristics, SOA formation potential and contributing factors of VOC during hazy episodes. The mean concentrations of VOC were 67.4 ± 33.3 μg m-3 on clear days and have 5-7-fold increase in polluted periods. VOC concentrations rapidly increased at a visibility range of 4-5 km with the rate of 25%/km in alkanes, alkenes and halocarbons and the rate of 45%/km in aromatics. Analysis of the mixing layer height (MLH); wind speed and ratios of benzene/toluene (B/T), ethylbenzene/m,p-xylene (E/X), and isopentane/n-pentane (i/n) under different visibility conditions revealed that the MLH and wind speed were the 2 major factors affecting the variability of VOC during clear days and that local emissions and photochemical reactions were main causes of VOC variation on polluted days. Combined with the fractional aerosol coefficient (FAC) method, the SOA formation potentials of alkanes, alkenes and aromatics were 0.3 ± 0.2 μg m-3, 1.1 ± 1.0 μg m-3 and 6.5 ± 6.4 μg m-3, respectively. As the visibility deteriorated, the SOA formation potential increased from 2.1 μg m-3 to 13.2 μg m-3, and the fraction of SOA-forming aromatics rapidly increased from 56.3% to 90.1%. Initial sources were resolved by a positive matrix factorization (PMF) model. Vehicle-related emissions were an important source of VOC at all visibility ranges, accounting for 23%-32%. As visibility declined, emissions from solvents and the chemical industry increased from 13.2% and 6.3% to 34.2% and 23.0%, respectively. Solvents had the greatest SOA formation ability, accounting for 52.5% on average on hazy days, followed by vehicle-related emissions (20.7%).

  15. Virtual reality

    Energy Technology Data Exchange (ETDEWEB)

    Pokras, V. [Liebherr Mining Equipment Co. (US)

    2005-03-01

    The paper weighs up the pros and cons between virtual prototyping and physical prototyping. Liebherr Mining Equipment Co. (LME) started evaluating the multi-body dynamic simulation of a full truck six years ago. LME has developed a series of dynamic models to optimise design of its T282B diesel-electric truck. Also, LME has developed a GPS-based technique called Virtual Mine Site that allows easy obtaining of a haul cycle 3D road profile for a specific mine site. The system can obtain not only a travel path and elevation profile but also body pitch, roll and acceleration components, allowing design optimisation and validation for structural and mechanical components. 2 figs., 2 photos.

  16. Sensorial Virtualization: Coupling Gaming and Virtual Environment

    NARCIS (Netherlands)

    Garbaya, S.; Miraoui, C.; Wendrich, R.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

  17. Virtual teams

    OpenAIRE

    Sanders, David

    2010-01-01

    This paper describes some early results from observing and interviewing groups working to achieve intellectually complex tasks that required the use of computers, WWW and other research resources. Three groups were virtual (they were working at a distance and rarely meeting face to face) and two groups were simple control groups They were real groups (working in relatively close proximity so that face to face contact was possible most of the time). All five teams completed their tasks but a s...

  18. Virtual anthropology.

    Science.gov (United States)

    Weber, Gerhard W

    2015-02-01

    Comparative morphology, dealing with the diversity of form and shape, and functional morphology, the study of the relationship between the structure and the function of an organism's parts, are both important subdisciplines in biological research. Virtual anthropology (VA) contributes to comparative morphology by taking advantage of technological innovations, and it also offers new opportunities for functional analyses. It exploits digital technologies and pools experts from different domains such as anthropology, primatology, medicine, paleontology, mathematics, statistics, computer science, and engineering. VA as a technical term was coined in the late 1990s from the perspective of anthropologists with the intent of being mostly applied to biological questions concerning recent and fossil hominoids. More generally, however, there are advanced methods to study shape and size or to manipulate data digitally suitable for application to all kinds of primates, mammals, other vertebrates, and invertebrates or to issues regarding plants, tools, or other objects. In this sense, we could also call the field "virtual morphology." The approach yields permanently available virtual copies of specimens and data that comprehensively quantify geometry, including previously neglected anatomical regions. It applies advanced statistical methods, supports the reconstruction of specimens based on reproducible manipulations, and promotes the acquisition of larger samples by data sharing via electronic archives. Finally, it can help identify new, hidden traits, which is particularly important in paleoanthropology, where the scarcity of material demands extracting information from fragmentary remains. This contribution presents a current view of the six main work steps of VA: digitize, expose, compare, reconstruct, materialize, and share. The VA machinery has also been successfully used in biomechanical studies which simulate the stress and strains appearing in structures. Although

  19. 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.

  20. Core benefits

    National Research Council Canada - National Science Library

    Keith, Brian W

    2010-01-01

    This SPEC Kit explores the core employment benefits of retirement, and life, health, and other insurance -benefits that are typically decided by the parent institution and often have significant governmental regulation...

  1. A COMBINATIONAL APPROACH OF GIS AND SOA FOR PERFORMANCE IMPROVEMENT OF ORGANIZATION

    Directory of Open Access Journals (Sweden)

    Mortaza Saleh

    2012-02-01

    Full Text Available A GIS (Geographic Information System, is a system designed to capture, store, manipulate, analyze,manage, and present all types of geographically referenced data. In other words, GIS is the merging ofstatistical analysis, database technology and cartography that can be integrated into any enterpriseinformation system framework. But despite all these advantages, geographic information systems that usedin organizational structures, is faced with some problems such as lack of interoperability, businessalignment, and agility.This paper first analyzes the connotation, model structure and main features of GIS and Service OrientedArchitecture (SOA. Then we propose a service oriented GIS platform which uses SOA concepts as thebasic architectural concept and employs OGC (Open Geospatial Consortium standards to support GISconcerns in the organization. Our combinational approach, using features such as loose coupling,integrity, independence and etc., can overcome the most of GIS problems such as lack of interoperability,business alignment, and agility.

  2. Optical Bistability with Two Serially Integrated InP-SOAs on a Chip

    Science.gov (United States)

    Plascak, Michael Edward

    Optical Bistability with Two Serially Integrated InP-SOAs on a Chip Thesis Advisor: Dr. Azad Siahmakoun A photonic switch using two series-connected, reverse-biased semiconductor optical amplifiers integrated onto a single device has been proposed and switching operation has been verified experimentally. The switching operates on two principles; an electrical bistability arising from the connection of two p-i-n structures in series, and the quantum confined Stark effect in reverse-biased multiple quantum well structures. The result is an electroabsorption modulation of the light through the SOAs due to the alternating voltage states. The system simultaneously produces outputs with both inverted and non-inverted hysteresis behavior, with experimental switching speeds demonstrated up to 400 kHz for a reverse-bias voltage of VRB=2.000V.

  3. Fundamental Heterogeneous Reaction Chemistry Related to Secondary Organic Aerosols (SOA) in the Atmosphere

    Science.gov (United States)

    Akimoto, H.

    2016-11-01

    Typical reaction pathways of formation of dicarboxylic acids, larger multifunctional compounds, oligomers, and organosulfur and organonitrogen compounds in secondary organic aerosols (SOA), revealed by laboratory experimental studies are reviewed with a short introduction to field observations. In most of the reactions forming these compounds, glyoxal, methyl glyoxal and related difunctional carbonyl compounds play an important role as precursors, and so their formation pathways in the gas phase are discussed first. A substantial discussion is then presented for the OH-initiated aqueous phase radical oxidation reactions of glyoxal and other carbonyls which form dicarboxylic acids, larger multifunctional compounds and oligomers, and aqueous-phase non-radical reactions which form oligomers, organosulfates and organonitrogen compounds. Finally, the heterogeneous oxidation reaction of gaseous O3, OH and NO3 with liquid and solid organic aerosols at the air-particle interface is discussed relating to the aging of SOA in the atmosphere.

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

    Science.gov (United States)

    Sanmartin, Paul; Jimeno, Miguel

    2017-01-01

    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. PMID:28757557

  5. Optical Wavelength Converters Based on Four Wave Mixing in SOA-MZI Configuration

    Directory of Open Access Journals (Sweden)

    Rajni

    2016-01-01

    Full Text Available Wavelength converter plays an important role for increasing the capacity and flexibility of future broadcast network. This paper investigates the performance of a 10Gb/s the SOA based FWM wavelength converter. All performances are analyzed in terms of its shifted wavelength conversion efficiency, Q-factors and converted signal powers. The converters are modeled and simulated using Optisystem7 Software, by varying the probe signal wavelength and power. It was found that conversion efficiency and OSNR of the converted signal both decreased at large detuning wavelengths. Similarly, higher total SOA input powers worsened the conversion efficiency, but steadily improved the OSNR. FWM wavelength converter had the lowest conversion efficiency for CW sources.

  6. 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.

  7. Improvement in RUP Project Management via Service Monitoring: Best Practice of SOA

    CERN Document Server

    Saqib, Sheikh Muhammad; Hussain, Shahid; Ahmad, Bashir; Bano, Arjamand

    2010-01-01

    Management of project planning, monitoring, scheduling, estimation and risk management are critical issues faced by a project manager during development life cycle of software. In RUP, project management is considered as core discipline whose activities are carried in all phases during development of software products. On other side service monitoring is considered as best practice of SOA which leads to availability, auditing, debugging and tracing process. In this paper, authors define a strategy to incorporate the service monitoring of SOA into RUP to improve the artifacts of project management activities. Moreover, the authors define the rules to implement the features of service monitoring, which help the project manager to carry on activities in well define manner. Proposed frame work is implemented on RB (Resuming Bank) application and obtained improved results on PM (Project Management) work.

  8. Monolithically integrated 4x4 SOA switch fabricated using quantum well intermixing

    Science.gov (United States)

    Millett, Ronald; Hinzer, Karin; Hall, Trevor; Poirier, Maxime; Schriemer, Henry

    2009-02-01

    Monolithically-integrated semiconductor optical amplifiers (SOAs) have the potential for enabling high-speed and low-crosstalk optical switches in reconfigurable optical add-drop multiplexers (ROADMs). Using integrated 4x4 switches as the building blocks for large-scale ROADMs, instead of 2x2 switches, will reduce alignment issues and assembly steps during manufacturing. The switch is based on SOAs, quantum well intermixed (QWI) passive 1x4 MMI splitters/combiners, and total internal reflection mirrors. We present the results of the 4x4 switch design, for a switch of 5.3 mm x 3.5 mm in size, with estimated total excess on-chip losses of 23 dB.

  9. 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

  10. SOA Formation form the NO3 radicals Chemistry of Isoprene, Monoterpenes, Sesquiterpenes, Biogenic Oxygenated Compounds, and Aromatics

    Science.gov (United States)

    Kleindienst, T. E.; Jaoui, M.; Docherty, K.; Corse, E.; Offenberg, J. H.; Lewandowski, M.

    2011-12-01

    Volatile organic compounds (VOCs) are oxidized in the atmosphere primarily by hydroxyl radicals (OH) during daylight hours but also by nitrate radicals (NO3) during overnight, photochemically inactive periods. While reactions with OH have received considerable attention with regard to gas-phase reaction products and secondary organic aerosol (SOA) formation, less is known about the mechanisms and products resulting from nighttime NO3 reactions despite their potential for SOA formation. To date, there have been limited studies on the chemical characteristics of aerosol reaction products formed from VOCs oxidation with NO3, and few SOA reaction products have been identified. Nighttime reactions have nevertheless been incorporated into some air quality models despite the limited information available and substantial uncertainties which still exist. The National Exposure Research Laboratory of the U.S. Environmental Protection Agency recently undertook an integrated laboratory research effort to better understand the contribution of NO3 reactions to nighttime SOA formation. Isoprene, methacrolein, a-pinene, b-pinene, d-limonene, b-caryophyllene, farnesene, a-humulene, 2-methyl-3-buten-2-ol, toluene, m-xylene, and naphthalene were reacted with NO3 under a wide range of conditions in a series of separate photochemical reaction chamber experiments. These hydrocarbons are thought to contribute to ambient SOA formation. NO3 was formed through thermal decomposition of N2O5. The yield, physical characteristics, and composition of SOA formed in each experiment was analyzed by a suite of instruments including a scanning mobility particle sizer, a Sunset Labs semi continuous EC-OC monitor, a volatility differential mobility analyzer, a direct insertion probe-mass spectrometer, a high resolution time-of-flight aerosol mass spectrometer, and a gas-chromatography-mass spectrometer. To understand the relative contributions of nighttime versus daytime VOCs reactions, a similar

  11. PLANNING AND MANAGING VIRTUALIZED NEXT GENERATION NETWORKS

    Directory of Open Access Journals (Sweden)

    Sukant K. Mohapatra

    2015-11-01

    Full Text Available Service convergence, content digitization, rapid and flexible service delivery, reduction of capital and operating costs, economies of scale, changes in telecom policy and regulation, and ever increasing competition have been key factors in the evolution of virtualized Next Generation Networks (vNGN. IPcentric converged networks aim to provide a multitude of services over a single network infrastructure. Tremendous success and benefit of server virtualization in data centers is driving the adaption of network virtualization. Network virtualization is applicable to enterprise data center, and enterprise as well as wide area networks. The focus of this paper is network virtualization aspects of service providers’ next generation network. The key factors for moving to virtualized network is optimal use and sharing of network infrastructure even among competitive service providers, programmability of network and rapid introduction of new service and standard based on open platform rather than proprietary implementation. Evolving Software Defined Network (SDN and Network Function Virtualization (NFV shall enable common network infrastructure sharing, control, and management at a higher layer thus making network devices more generic and less intelligent, thus enabling cost competitiveness and quick service delivery. Network virtualization shall enable key benefits such as lower cost, flexibility, efficiency, and security, However, the deployment of virtualized next generation networks has brought its unique challenges for network managers and planners, as the network has to be planned in a comprehensive way with effective management of virtual network elements, its correlation with physical infrastructure and monitoring of control functions and server platforms. This paper discusses generic next generation network, its virtualization, and addresses the challenges related to the planning and managing of virtualized next generation networks. This

  12. Research on SOA Architecture Based on Historical Service and Data%基于历史的服务与数据SOA架构研究

    Institute of Scientific and Technical Information of China (English)

    罗冬梅

    2012-01-01

    从企业信息系统发展的现状出发,结合面向服务架构的基本思想,提出一种使用历史信息统一管理企业服务和企业数据的架构.并对该架构的基本组成以及它能够带来的益处进行一定的阐述。%Starting from the status quo of enterprise information systems development, combined with the basic idea of service-oriented architecture, brings out a SOA architecture which uses historical information to the unified management of corporate services and enterprise data architecture, and elaborates the basic components of the architecture and the benefits it can bring certain.

  13. 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...

  14. Sub-picosecond pulse generation employing an SOA-based nonlinear polarization switch in a ring cavity.

    Science.gov (United States)

    Yang, X; Li, Z; Tangdiongga, E; Lenstra, D; Khoe, G; Dorren, H

    2004-05-31

    We demonstrate the generation of sub-picosecond optical pulses using a semiconductor optical amplifier (SOA) and a linear polarizer placed in a ring-laser configuration. Nonlinear polarization rotation in the SOA serves as the passive mode-locking mechanism. The ring cavity generates pulses with duration below 800 fs (FWHM) at a repetition rate of 14 MHz. The time -bandwidth product is 0.48. Simulation results in good agreement with the experimental results are presented.

  15. Conversion of phase-modulated signals to amplitude-modulated signals in SOAs due to mirror reflections

    DEFF Research Database (Denmark)

    Blaaberg, Søren; Mørk, Jesper

    2009-01-01

    We present theoretical results that show conversion of phase modulated signals to amplitude modulated signals in an SOA. Large-signal and small-signal calculations show significant conversion responses caused by even minute reflections at the end mirrors.......We present theoretical results that show conversion of phase modulated signals to amplitude modulated signals in an SOA. Large-signal and small-signal calculations show significant conversion responses caused by even minute reflections at the end mirrors....

  16. Shifting Evaluation Windows: Predictable Forward Primes with Long SOAs Eliminate the Impact of Backward Primes

    OpenAIRE

    Fockenberg, Daniel A.; Koole, Sander L; Daniël Lakens; Semin, Gün R.

    2013-01-01

    Shifting Evaluation Windows: Predictable Forward Primes with Long SOAs Eliminate the Impact of Backward Primes Daniel A. Fockenberg1*, Sander L. Koole2, Danie¨ l Lakens3, Gu¨ n R. Semin4,5 1 Institut fu¨ r Psychologie, Albert-Ludwigs-Universita¨t Freiburg, Freiburg, Germany, 2 Department of Clinical Psychology, VU University Amsterdam, Amsterdam, The Netherlands, 3 Eindhoven University of Technology, Eindhoven, The Netherlands, 4 Royal Netherlands Academy for Arts and Sciences,...

  17. 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.

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

    Directory of Open Access Journals (Sweden)

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

    2012-04-01

    Full Text Available 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 important to extend the SOA so that non-functional characteristics of a web service can be determined at run-time and consumers are bound to a service that best meet their functional as well as non-functional requirements. Major research challenges in discovering Web services include, differentiating between services that share similar functionalities, improving Quality of Service (QoS, and enabling clients to customize the discovery process. To enable QoS enabled web services discovery, it is needed that a third party (other than service provider and service broker monitors quality of web service. In this paper, an extended web services framework based on SOA for enabling Web Service discovery based on QoS parameters such as availability and response time is proposed thereby maintaining the appropriate dynamic values of these QoS parameters.

  19. Compared propagation characteristics of superluminal and slow light in SOA and EDFA based on rectangle signals

    Science.gov (United States)

    Wang, Fu; Wang, Zhi; Wu, Chongqing; Sun, Zhenchao; Mao, Yaya; Liu, Lanlan; Li, Qiang

    2015-10-01

    Based on the general mechanism of the coherent population oscillations (CPO) in the Semiconductor optical amplifiers (SOA) and Erbium doped fiber amplifiers (EDFA), the group time delay of rectangle signal propagating in the active media is deduced. Compared with the sinusoidal signal, the time delay difference between the fundamental harmonics (FHFD: fundamental harmonic fractional delay) is first investigated in detail for the rectangle signal which is more popularly used in the digital signal systems. The plenty of simulations based on the propagation equations and some experiments for the sinusoidal and rectangle signals are used to analyze the differences and evaluate the slow and superluminal light effects. Furthermore, the time delay/advance always takes place accompanying with the signal distortion, which is evaluated by the total harmonic distortion (THD). The distortion caused by the SOA is smaller than that by the EDFA. A factor Q which is defined to evaluate the trade-off between the FHFD and the THD, shows that higher input power or higher optical gain is better for optical signal processing and optical telecommunications, and the SOA is more suitable for the higher modulation frequency (>10 GHz).

  20. SEMANTIC WEB-BASED SOFTWARE ENGINEERING BY AUTOMATED REQUIREMENTS ONTOLOGY GENERATION IN SOA

    Directory of Open Access Journals (Sweden)

    Vahid Rastgoo

    2014-04-01

    Full Text Available This paper presents an approach for automated generation of requirements ontology using UML diagrams in service-oriented architecture (SOA. The goal of this paper is to convenience progress of software engineering processes like software design, software reuse, service discovering and etc. The proposed method is based on a four conceptual layers. The first layer includes requirements achieved by stakeholders, the second one designs service-oriented diagrams from the data in first layer and extracts XMI codes of them. The third layer includes requirement ontology and protocol ontology to describe behavior of services and relationships between them semantically. Finally the forth layer makes standard the concepts exists in ontologies of previous layer. The generated ontology exceeds absolute domain ontology because it considers the behavior of services moreover the hierarchical relationship of them. Experimental results conducted on a set of UML4Soa diagrams in different scopes demonstrate the improvement of the proposed approach from different points of view such as: completeness of requirements ontology, automatic generation and considering SOA.

  1. On phaser-based processing of impulse radio UWB over fiber systems employing SOA

    Science.gov (United States)

    Taki, H.; Azou, S.; Hamie, A.; Al Housseini, A.; Alaeddine, A.; Sharaiha, A.

    2017-07-01

    In this study, we adopt a phaser-based processing to enhance the performance of impulse radio over fiber system utilizing SOA. The amplifier has been placed at a distance in the optical link, so as to extend the coverage area of proposed transceiver. Operating in the linear or saturation region for SOA, adds ASE noise or strong nonlinearities acting on the propagated pulses, respectively. Both lead to a degradation in the power efficiency and bit error rate performance. By applying up and down analog chirping technique, we have reduced the ASE power and nonlinearity simultaneously. Based on the 5th Gaussian pulse and Abraha's combination of doublets, a significant improvement has been achieved at extremely low and high input powers entering the amplifier (<-15 dBm and 0 dBm), recording a very good bit error rate performance and power efficiency. Better signal quality was observed after photo-detector, due to the fact that waveforms with lower frequency components are less affected by SOA nonlinearity. Our scheme has proved to be effective for 1 Gbps OOK and 0.5 Gbps PPM transmissions, while reaching a distance of 160 km in the optical fiber.

  2. High molecular weight SOA formation during limonene ozonolysis: insights from ultrahigh-resolution FT-ICR mass spectrometry characterization

    Science.gov (United States)

    Kundu, S.; Fisseha, R.; Putman, A. L.; Rahn, T. A.; Mazzoleni, L. R.

    2012-06-01

    The detailed molecular composition of laboratory generated limonene ozonolysis secondary organic aerosol (SOA) was studied using ultrahigh-resolution Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry. Approximately 1200 molecular formulas were identified in the SOA over the mass range of 140 to 850 Da. Four characteristic groups of high relative abundance species were observed; they indicate an array of accretion products that retain a large fraction of the limonene skeleton. The identified molecular formulas of each of the groups are related to one another by CH2, O and CH2O homologous series. The CH2 and O homologous series of the low molecular weight (MW) SOA (m/z z > 300) were found to constitute a significant number fraction of the identified SOA components. The formation of high MW compounds was evaluated by molecular formula trends, fragmentation analysis of select high MW compounds and a comprehensive reaction matrix including the identified low MW SOA, hydroperoxides and Criegee radicals as building blocks. Although the formation of high MW SOA may occur via a variety of radical and non-radical reaction channels, the combined approach indicates a greater importance of the non-condensation reactions over aldol and ester condensation reaction channels. Among these hemi-acetal reactions appear to be most dominant followed by hydroperoxide and Criegee reaction channels.

  3. [Numerical modeling analysis of secondary organic aerosol (SOA) combined with the ground-based measurements in the Pearl River Delta region].

    Science.gov (United States)

    Guo, Xiao-Shuang; Situ, Shu-Ping; Wang, Xue-Mei; Ding, Xiang; Wang, Xin-Ming; Yan, Cai-Qing; Li, Xiao-Ying; Zheng, Mei

    2014-05-01

    Two simulations were conducted with different secondary organic aerosol (SOA) methods-VBS (volatile basis set) approach and SORGAM (secondary organic aerosol model) , which have been coupled in the WRF/Chem (weather research and forecasting model with chemistry) model. Ground-based observation data from 18th to 25th November 2008 were used to examine the model performance of SOA in the Pearl River Delta(PRD)region. The results showed that VBS approach could better reproduce the temporal variation and magnitude of SOA compared with SORGAM, and the mean absolute deviation and correlation coefficient between the observed and the simulated data using VBS approach were -4.88 microg m-3 and 0.91, respectively, while they were -5.32 microg.m-3 and 0. 18 with SORGAM. This is mainly because the VBS approach considers SOA precursors with a wider volatility range and the process of chemical aging in SOA formation. Spatiotemporal distribution of SOA in the PRD from the VBS simulation was also analyzed. The results indicated that the SOA has a significant diurnal variation, and the maximal SOA concentration occurred at noon and in the early afternoon. Because of the transport and the considerable spatial distribution of O3 , the SOA concentrations were different in different PRD cities, and the highest concentration of SOA was observed in the downwind area, including Zhongshan, Zhuhai and Jiangmen.

  4. Virtual Reality

    Directory of Open Access Journals (Sweden)

    Bhavana Gupta

    2012-10-01

    Full Text Available An artificial environment created with co mputer hardware and software and presented to the user in such a way that it appears and feels like a real environment. To "enter" a virtual reality, a user does special gloves, earphones, and goggles, all of which receive their input from the computer system. In this way, at least three of the five senses are controlled by the computer. In addition to feeding sensory input to the user, the devices also monitor the user's actions

  5. 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.

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

    Directory of Open Access Journals (Sweden)

    N. K. Meyer

    2008-05-01

    Full Text Available 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 ((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

  7. 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....

  8. SECURING VIRTUAL IMAGES USING BLIND AUTHENTICATION PROTOCOL

    Directory of Open Access Journals (Sweden)

    RAVIKIRAN PEELUKHANA,

    2011-04-01

    Full Text Available The cloud virtualization technology improves the economy of scale for data centers through server consolidation, application consolidation and resources consolidation. Virtualization allows the provider to move Virtual Images from more congested host to less-congested hosts, as required. Enterprises also get improved server reliability, which in turn increases application performance. Despite these benefits, it includes major security challenges with the portability of Virtual Images between different cloud providers.The security and integrity of Virtual images is the foundation for the overall security of the cloud. Many of the Virtual images are intended to be shared by diverse and unrelated users. Unfortunately, existing approaches to cloud security built by cloud practitioners fall short when dealing with Virtual images. Secure transmission of virtual Images can bepossible by providing authentication using Blind Authentication protocol (BAP. The proposed approach authenticates the allocation of virtual images using Blind authentication protocol. It provides provable protection against replay and client side attacks even if the keys of the user are compromised. The encryption also provides template protection, revocability and alleviates the concerns on privacy in widespread use of biometrics. Carrying out the authentication in the encrypted domain is a secure process, while the encryption key acts as an additional layer of security.

  9. 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...

  10. Virtual Touch

    DEFF Research Database (Denmark)

    Stenslie, Ståle

    The central focus of this thesis is the use and experience of touch in artistic, multimodal and computer-based environments. The haptic experience of touch is an area that has only received limited research-based interest. Touch is too often seen as the effect, and not the cause of our everyday...... Erotogod. The third chapter investigates the foundations of touch through a physiological and psychological approach. Chapter four presents an alternative haptic history of Virtual Realities through the presentation and discussion of several technological and artistic works that are computer......-based. In chapter five touch is approached from a theoretical point of view. It develops a theory of touch based on phenomenology and shows how this approach advances an embodied thinking. Chapter six presents practice-based experiments of touch through the Erotogod installation. The last and seventh part...

  11. Virtual materiality

    DEFF Research Database (Denmark)

    Søndergaard, Dorte Marie

    to bullying practices in school. The theoretical question concerns the conceptual challenges that arise from empirical data which contain 1. children’s narratives about matter and meaning as they intertwine in their nightly dreams, 2. the observations of children’s’ computer gaming practices as well...... the character and effects of the skeleton army, which came across the sea to drown the boys in Phillip’s school class: a central scene in one of the dreams he recounted? Are the boat and the water in that dream materialities? Discourse? Part of some kind of enacted subjectivity? How will our decision of which......, experiences etc. Among these many interacting forces technologies play a crucial part – as do bodies, whether they are fighting, playing, dreaming, loving or hating bodies. And as do weapons - whether in the shape of virtual weapons of the computer games (as in e.g. Battlefield, Counter Strike, Grand Theft...

  12. Virtual Laboratories

    CERN Document Server

    Hut, P

    2006-01-01

    At the frontier of most areas in science, computer simulations play a central role. The traditional division of natural science into experimental and theoretical investigations is now completely outdated. Instead, theory, simulation, and experimentation form three equally essential aspects, each with its own unique flavor and challenges. Yet, education in computational science is still lagging far behind, and the number of text books in this area is minuscule compared to the many text books on theoretical and experimental science. As a result, many researchers still carry out simulations in a haphazard way, without properly setting up the computational equivalent of a well equipped laboratory. The art of creating such a virtual laboratory, while providing proper extensibility and documentation, is still in its infancy. A new approach is described here, Open Knowledge, as an extension of the notion of Open Source software. Besides open source code, manuals, and primers, an open knowledge project provides simul...

  13. 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

  14. 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.

  15. IMPLICATIONS OF STORAGE VIRTUALIZATION FOR SMB

    Directory of Open Access Journals (Sweden)

    Adriana BARNOSCHI

    2009-12-01

    Full Text Available In today’s datacenters, the unexpected increase of virtual and physical servers has led to exponential increases in data transfer volumes, bandwidth bottlenecks, and connectivity costs. This growth causes major problems for IT managers as they struggle to see more cost effective, scalable ways to manage the increasing complexity of servers and their associated LAN and SAN environments. Virtualization is a general term that could be applied to:  storage systems, databases and networks. In this article, I present an overview of server virtualization architecture. I also specify the goals and benefits of virtualization for a SMB. The article points out some issues about server virtualization: definition, implementing problems and security features. In case of major calamity, you need a disaster recovery plan. The article lists a series of differences and similar parts of DR planning and business continuity plan.

  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. Health Education capabilities Based on Virtual Reality

    OpenAIRE

    Paiva, Paulo Vinícius de Farias; Machado,Liliane dos Santos; Santos,Sérgio Ribeiro dos; Romero, Renata Olívia Gadelha

    2013-01-01

    The main goal of virtual reality is to create three-dimensional environments that users can explore and manipulate with the feeling of being immersed in realistic simulations. VR systems are mainly characterized by a high degree of realism in their simulation of real world experiences or even fictitious situations. Medicine and healthcare are benefiting from VR, especially the collaborative virtual environments for teaching various procedures that enable distance education as well as collabor...

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

    Science.gov (United States)

    Sareen, Neha; Carlton, Annmarie G.; Surratt, Jason D.; Gold, Avram; Lee, Ben; Lopez-Hilfiker, Felipe D.; Mohr, Claudia; Thornton, Joel A.; Zhang, Zhenfa; Lim, Yong B.; Turpin, Barbara J.

    2016-11-01

    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 complexes). Thus

  19. Aqueous SOA formation from radical oligomerization of methyl vinyl ketone (MVK) and methacrolein (MACR)

    Science.gov (United States)

    Renard, P.; Siekmann, F.; Ravier, S.; Temime-Roussel, B.; Clément, J.; Ervens, B.; Monod, A.

    2013-12-01

    It is now accepted that one of the important pathways of secondary organic aerosol (SOA) formation occurs through aqueous phase chemistry in the atmosphere. However, the chemical mechanisms leading to macromolecules are still not well understood. It was recently shown that oligomer production by OH radical oxidation in the aerosol aqueous phase from α-dicarbonyl precursors, such as methylglyoxal and glyoxal, is irreversible and fast. We have investigated the aqueous phase photooxidation of MACR and MVK, which are biogenic organic compounds derived from isoprene. Aqueous phase photooxidation of MVK and MACR was investigated in a photoreactor using photolysis of H2O2 as OH radical source. Electrospray high resolution mass spectrometry analysis of the solutions brought clear evidence for the formation of oligomer systems having a mass range of up to 1800 Da within less than 15 minutes of reaction. Highest oligomer formation rates were obtained under conditions of low dissolved oxygen, highest temperature (T = 298 K) and highest precursor initial concentrations ([MVK]0 = 20 mM). A radical mechanism of oligomerization is proposed to explain the formation of the high molecular weight products. Furthermore, we quantified the total amount of carbon present in oligomers. Kinetic parameters of the proposed oligomerization mechanism are constrained by means of a box model that is able to reproduce the temporal evolution of intermediates and products as observed in the laboratory experiments. Additional model simulations for atmospherically-relevant conditions will be presented that show the extent to which these radical processes contribute to SOA formation in the atmospheric multiphase system as compared to other aqueous phase as well as traditional SOA sources. MVK time profile (as measured by UV Spectroscopy) and mass spectra (obtained using UPLC-ESI-MS for the retention time range 0-5 min in the positive mode) at 5, 10 and 50 min of reaction (MVK 20 mM, 25° C, under

  20. Virtual anthropology meets biomechanics.

    Science.gov (United States)

    Weber, Gerhard W; Bookstein, Fred L; Strait, David S

    2011-05-17

    A meeting in Vienna in October 2010 brought together researchers using Virtual Anthropology (VA) and Finite Element Analysis (FEA) in order to explore the benefits and problems facing a collaboration between the two fields. FEA is used to test mechanical hypotheses in functional anatomy and VA complements and augments this process by virtue of its tools for acquiring data, for segmenting and preparing virtual specimens, and for generating reconstructions and artificial forms. This represents a critical methodological advance because geometry is one of the crucial inputs of FEA and is often the variable of interest in functional anatomy. However, we currently lack tools that quantitatively relate differences in geometry to differences in stress and strain, or that evaluate the impact on FEA of variation within and between biological samples. Thus, when comparing models of different geometry, we do not currently obtain sufficiently informative answers to questions such as "How different are these models, and in what manner are they different? Are they different in some anatomical regions but not others?" New methodologies must be developed in order to maximize the potential of FEA to address questions in comparative and evolutionary biology. In this paper we review these and other important issues that were raised during our Vienna meeting.

  1. Dependence of SOA oxidation on organic aerosol mass concentration and OH exposure: experimental PAM chamber studies

    Directory of Open Access Journals (Sweden)

    E. Kang

    2011-02-01

    Full Text Available The oxidation of secondary organic aerosol (SOA is studied with mass spectra analysis of SOA formed in a Potential Aerosol Mass (PAM chamber, a small flow-through photo-oxidation chamber with extremely high OH and ozone levels. The OH exposure from a few minutes in the PAM chamber is similar to that from days to weeks in the atmosphere. The mass spectra were measured with a Quadrupole Aerosol Mass Spectrometer (Q-AMS for SOA formed from oxidation of α-pinene, m-xylene, p-xylene, and a mixture of the three. The organic mass fractions of m/z 44 (CO2+ and m/z 43 (mainly C2H3O+, named f44 and f43 respectively, are used as indicators of the degree of organic aerosol (OA oxidation that occurs as the OA mass concentration or the OH exposure are varied. The degree of oxidation is sensitive to both. For a fixed OH exposure, the degree of oxidation initially decreases rapidly and then more slowly as the OA mass concentration increases. For fixed initial precursor VOC amounts, the degree of oxidation increases linearly with OH exposure, with f44 increasing and f43 decreasing. In this study, the degree of SOA oxidation spans much of the range observed in the atmosphere. These results, while sensitive to the determination of f44 and f43, provide evidence that some characteristics of atmospheric OA oxidation can be generated in a PAM chamber. For all measurements in this study, the sum of f44 and f43 is 0.25 ± 0.03, so that the slope of a linear regression is approximately −1 on an f44 vs. f43 plot. This constancy of the sum suggests that these ions are complete proxies for organic mass in the OA studied.

  2. Secondary Organic Aerosol (SOA) Formation from Hydroxyl Radical Oxidation and Ozonolysis of Monoterpenes

    Science.gov (United States)

    Zhao, Defeng; Kaminski, Martin; Schlag, Patrick; Fuchs, Hendrik; Acir, Ismail-Hakki; Bohn, Birger; Haeseler, Rolf; Kiendler-Scharr, Astrid; Rohrer, Franz; Tillmann, Ralf; Wang, Mingjin; Wegner, Robert; Wahner, Andreas; Mentel, Thomas

    2014-05-01

    Hydroxyl radical (OH) oxidation and ozonolysis are the two major pathways of daytime biogenic volatile organic compounds (VOCs) oxidation and secondary organic aerosol (SOA) formation. The pure OH oxidation of monoterpenes, an important biogenic VOC class, has seldom been investigated. In order to elucidate the importance of the reaction pathyways of the OH oxidation and ozonolysis and their roles in particle formation and growth, we investigated the particle formation of several common monoterpenes (alpha-pinene, beta-pinene, and limonene) in the large atmosphere simulation chamber SAPHIR in Juelich, Germany. The experiments were conducted for both OH dominant and pure ozonolysis case (in the presence of CO as OH scavenger) at ambient relevant conditions (low OA, low VOC and low NOx concentration). OH and ozone (O3) concentrations were measured so that the oxidation rates of OH and O3 with precursors were quantified. The particle formation and growth, aerosol yield, multi-generation reaction process and aerosol composition were analyzed. Pure ozonolysis generated a large amount of particles indicating ozonolysis plays an important role in particle formation as well as OH oxidation. In individual experiments, particle growth rates did not necessarily correlate with OH or O3 oxidation rates. However, comparing the growth rates at similar OH or O3 oxidation rates shows that generally, OH oxidation and ozonolysis have similar efficiency in particle growth. Multi-generation products are shown to be important in the OH oxidation experiment based on aerosol yield "growth curve" (Ng et al., 2006). The reaction process of OH oxidation experiments was analyzed as a function of OH dose to elucidate the role of functionalization and fragmentation. A novel analysis was developed to link the particle formation with the reaction with OH, which was also used to examine the role of functionalization and fragmentation in the particle formation by OH oxidation. These analyses show

  3. Socioeconomic benefits

    African Journals Online (AJOL)

    User

    perception on the benefits of shade trees in coffee production systems in southwestern part of Ethiopia. ... with growing coffee without shade tree plants that included stunted growth which ultimately ...... coffee producers' price risk. J. Inter.

  4. Medicaid Benefits

    Science.gov (United States)

    ... Benefits Close About Us Messages from CMCS Program History Leadership Organization Visit CMS Contact Us Close Home > Medicaid > ... for Coverage LTSS Prescription Drugs About Us Program History Leadership Organization Visit CMS Contact Us State Medicaid & CHIP ...

  5. 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 South Afri...

  6. Secondary organic aerosol formation in cloud droplets and aqueous particles (aqSOA: a review of laboratory, field and model studies

    Directory of Open Access Journals (Sweden)

    B. Ervens

    2011-11-01

    Full Text Available Progress has been made over the past decade in predicting secondary organic aerosol (SOA mass in the atmosphere using vapor pressure-driven partitioning, which implies that SOA compounds are formed in the gas phase and then partition to an organic phase (gasSOA. However, discrepancies in predicting organic aerosol oxidation state, size and product (molecular mass distribution, relative humidity (RH dependence, color, and vertical profile suggest that additional SOA sources and aging processes may be important. The formation of SOA in cloud and aerosol water (aqSOA is not considered in these models even though water is an abundant medium for atmospheric chemistry and such chemistry can form dicarboxylic acids and "humic-like substances" (oligomers, high-molecular-weight compounds, i.e. compounds that do not have any gas phase sources but comprise a significant fraction of the total SOA mass. There is direct evidence from field observations and laboratory studies that organic aerosol is formed in cloud and aerosol water, contributing substantial mass to the droplet mode.

    This review summarizes the current knowledge on aqueous phase organic reactions and combines evidence that points to a significant role of aqSOA formation in the atmosphere. Model studies are discussed that explore the importance of aqSOA formation and suggestions for model improvements are made based on the comprehensive set of laboratory data presented here. A first comparison is made between aqSOA and gasSOA yields and mass predictions for selected conditions. These simulations suggest that aqSOA might contribute almost as much mass as gasSOA to the SOA budget, with highest contributions from biogenic emissions of volatile organic compounds (VOC in the presence of anthropogenic pollutants (i.e. NOx at high relative humidity and cloudiness. Gaps in the current understanding of aqSOA processes are discussed and further studies (laboratory, field, model

  7. Virtual Laboratories

    Science.gov (United States)

    Hut, P.

    At the frontier of most areas in science, computer simulations playa central role. The traditional division of natural science into experimental and theoretical investigations is now completely outdated. Instead, theory, simulation, and experimentation form three equally essential aspects, each with its own unique flavor and challenges. Yet, education in computational science is still lagging far behind, and the number of text books in this area is minuscule compared to the many text books on theoretical and experimental science. As a result, many researchers still carry out simulations in a haphazard way, without properly setting up the computational equivalent of a well equipped laboratory. The art of creating such a virtual laboratory, while providing proper extensibility and documentation, is still in its infancy. A new approach is described here, Open Knowledge, as an extension of the notion of Open Source software. Besides open source code, manuals, and primers, an open knowledge project provides simulated dialogues between code developers, thus sharing not only the code, but also the motivations behind the code.

  8. Theoretical study of the spurious-free dynamic range of a tunable delay line based on slow light in SOA.

    Science.gov (United States)

    Berger, Perrine; Bourderionnet, Jérôme; Alouini, Mehdi; Bretenaker, Fabien; Dolfi, Daniel

    2009-10-26

    We developed a predictive model describing harmonic generation and intermodulation distortions in semiconductor optical amplifiers (SOAs). This model takes into account the variations of the saturation parameters along the propagation axis inside the SOA, and uses a rigorous expression of the gain oscillations harmonics. We derived the spurious-free dynamic range (SFDR) of a slow light delay line based on coherent population oscillation (CPO) effects, in a frequency range covering radar applications (from 40 kHz up to 30 GHz), and for a large range of injected currents. The influence of the high order distortions in the input microwave spectrum is discussed, and in particular, an interpretation of the SFDR improvement of a Mach-Zehnder modulator by CPOs effects in a SOA is given.

  9. Simple pre-distortion schemes for improving the power efficiency of SOA-based IR-UWB over fiber systems

    Science.gov (United States)

    Taki, H.; Azou, S.; Hamie, A.; Al Housseini, A.; Alaeddine, A.; Sharaiha, A.

    2017-01-01

    In this paper, we investigate the usage of SOA for reach extension of an impulse radio over fiber system. Operating in the saturated regime translates into strong nonlinearities and spectral distortions, which drops the power efficiency of the propagated pulses. After studying the SOA response versus operating conditions, we have enhanced the system performance by applying simple analog pre-distortion schemes for various derivatives of the Gaussian pulse and their combination. A novel pulse shape has also been designed by linearly combining three basic Gaussian pulses, offering a very good spectral efficiency (> 55 %) for a high power (0 dBm) at the amplifier input. Furthermore, the potential of our technique has been examined considering a 1.5 Gbps-OOK and 0.75 Gbps-PPM modulation schemes. Pre-distortion proved an advantage for a large extension of optical link (150 km), with an inline amplification via SOA at 40 km.

  10. 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.

  11. 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.

  12. 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

  13. Virtual button interface

    Science.gov (United States)

    Jones, Jake S.

    1999-01-01

    An apparatus and method of issuing commands to a computer by a user interfacing with a virtual reality environment. 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.

  14. 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.

  15. Virtual Goods Recommendations in Virtual Worlds

    Directory of Open Access Journals (Sweden)

    Kuan-Yu Chen

    2015-01-01

    Full Text Available 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.

  16. Modelling Competences for Partner Selection in Service-Oriented Virtual Organization Breeding Environments

    CERN Document Server

    Paszkiewicz, Zbigniew

    2011-01-01

    In the context of globalization and dynamic markets, collaboration among organizations is a condition sine qua non for organizations, especially small and medium enterprises, to remain competitive. Virtual organizations have been proposed as an organizational structure adapted to collaboration among organizations. The concept of Virtual Organization Breeding Environment (VOBE) has been proposed as a means to support the creation and operation of virtual organizations. With the rise of the service-oriented architecture (SOA), the concept of service-oriented VOBE (SOVOBE) has been proposed as a VOBE systematically organized around the concept of services. In the context of SOVOBEs, novel competence models supporting both service orientation and collaboration among organizations have to be developed to support efficiently partner selection, a key aspect of VO creation. In this paper, such a competence model is presented. Our competence model consists of a competence description model, a competence verification m...

  17. 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.

  18. ESA e l’utilizzo di tecnologia Grid e SOA per l’Osservazione della Terra

    Directory of Open Access Journals (Sweden)

    Roberto Cossu

    2009-03-01

    Full Text Available ESA grid and SOA Technologies for Earth ObservationDue to its intensive data processing and highly distributedorganization, the multidisciplinary Earth Science (ES applications community is uniquely positioned for the uptake and exploitation of Grid technologies. This article describes a number of initiatives that the European Space Agency is carrying focusing on a ES e-collaboration platform that makes use of Grid and SOA technologies. Starting from the experience gained so far with ESA Grid Processing on Demand, we will discuss the vision of a dedicated ES platform. The aim is to enable scientists to locate, access, combine and integrate historical and fresh Earth-related data from space, airborne and in-situ sensors archived in large distributed repositories. The big challenge is to allow Earth Science communities to easil and quickly derive objective information and share knowledge based on all environmentally sensitive domains. The GENESIDR project is already taking important steps in developing this platform.

  19. 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.

  20. Efficient Checkpointing of Virtual Machines using Virtual Machine Introspection

    Energy Technology Data Exchange (ETDEWEB)

    Aderholdt, Ferrol [Tennessee Technological University; Han, Fang [Tennessee Technological University; Scott, Stephen L [ORNL; Naughton, III, Thomas J [ORNL

    2014-01-01

    Cloud Computing environments rely heavily on system-level virtualization. This is due to the inherent benefits of virtualization including fault tolerance through checkpoint/restart (C/R) mechanisms. Because clouds are the abstraction of large data centers and large data centers have a higher potential for failure, it is imperative that a C/R mechanism for such an environment provide minimal latency as well as a small checkpoint file size. Recently, there has been much research into C/R with respect to virtual machines (VM) providing excellent solutions to reduce either checkpoint latency or checkpoint file size. However, these approaches do not provide both. This paper presents a method of checkpointing VMs by utilizing virtual machine introspection (VMI). Through the usage of VMI, we are able to determine which pages of memory within the guest are used or free and are better able to reduce the amount of pages written to disk during a checkpoint. We have validated this work by using various benchmarks to measure the latency along with the checkpoint size. With respect to checkpoint file size, our approach results in file sizes within 24% or less of the actual used memory within the guest. Additionally, the checkpoint latency of our approach is up to 52% faster than KVM s default method.

  1. Clock recovery for 320 Gb/s OTDM Data using filtering-assisted XPM in an SOA

    DEFF Research Database (Denmark)

    Oxenløwe, Leif Katsuo; Zibar, Darko; Galili, Michael

    2005-01-01

    In this paper, we report on a novel technique, which enables clock recovery at 320 Gb/s and relies on a filtering-assisted cross-phase modulation (f-a XPM) in a semiconductor optical amplifier (SOA). This technique is more spectrally efficient than four wave mixing (FWM) and can improve the effic......In this paper, we report on a novel technique, which enables clock recovery at 320 Gb/s and relies on a filtering-assisted cross-phase modulation (f-a XPM) in a semiconductor optical amplifier (SOA). This technique is more spectrally efficient than four wave mixing (FWM) and can improve...

  2. Simultaneous optical carrier and radio frequency re-modulation in radio-over-fiber systems employing reflective SOA modulators

    DEFF Research Database (Denmark)

    Kassar, Carvalho; Calabretta, Nicola; Tafur Monroy, Idelfonso

    2007-01-01

    We demonstrate an innovative full-duplex radio-over-fibre transmission system employing a reflective SOA to perform simultaneous reusing of the optical carrier and data re-modulation, thus avoiding the use of local radiofrequency oscillator at the station sites.......We demonstrate an innovative full-duplex radio-over-fibre transmission system employing a reflective SOA to perform simultaneous reusing of the optical carrier and data re-modulation, thus avoiding the use of local radiofrequency oscillator at the station sites....

  3. Experimental validation of efficient methods for the prediction of patterning effects in SOA-based optical switches

    DEFF Research Database (Denmark)

    Xu, Jing; Ding, Yunhong; Xue, Weiqi

    2010-01-01

    We experimentally investigate and verify simple and efficient methods for characterizing the patterning effects (PE) of SOA-based optical switches. The onset of PE saturation is well predicted by the theory. an experimental method to capture the maximum PE is developed.......We experimentally investigate and verify simple and efficient methods for characterizing the patterning effects (PE) of SOA-based optical switches. The onset of PE saturation is well predicted by the theory. an experimental method to capture the maximum PE is developed....

  4. Demonstration of quantum dot SOA-based colorless ONU transmitter for symmetric 40 Gb/s TWDM PON

    Science.gov (United States)

    Sun, Xiao; Chang, Qingjiang; Gao, Zhensen; Ye, Chenhui; Xiao, Simiao; Huang, Xiaoan; Hu, Xiaofeng; Zhang, Kaibin

    2016-02-01

    Detailed numerical investigation of self-seeded colorless ONU transmitter using quantum dot (QD) SOA as the intensity modulator for symmetric 40 Gb/s TWDM-PON has been developed. It is shown that the QD SOA-based intensity modulator is able to support 10 Gb/s OOK upstream signal transmission with an optical extinction ratio of over 10 dB. Chromatic dispersion compensation free of 20 km passive transmission has been achieved for error free reception. Moreover, the system performance and power budget have been analyzed and discussed for different transmission distance and split ratio.

  5. Possible Application of Virtual Reality in Geography Teaching

    OpenAIRE

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

    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...

  6. Virtual Trackballs Revisited

    DEFF Research Database (Denmark)

    Henriksen, Knud; Sporring, Jon; Hornbæk, Kasper

    2004-01-01

    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 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...

  7. 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

    OpenAIRE

    2016-01-01

    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 stu...

  8. A Proposed Virtualization Technique to Enhance IT Services

    Directory of Open Access Journals (Sweden)

    Hossam Abdel Rahman Mohamed

    2012-11-01

    Full Text Available System virtualization is an antique art that will continue as long as applications need isolation and performance independence. Virtualization provides many benefits and greater efficiency in CPU utilization, greener IT with less power consumption, better management through central environmental control, more availability, reduced project timelines by eliminating hardware procurement, improved disaster recovery capability, more central control of the desktop, and improved outsourcing services. In this paper we will deliver new and enhanced IT services in less time and with greater agility. The goal of providing rapid near real-time response to customer requirements is in part being achieved by taking advantage of virtualization. Virtualization provides many benefits, including improved physical resource utilization, improved hardware efficiency, and reduced power and cooling expenses. However, it introduces another set of systems (virtual machines that have to be controlled, provisioned, managed, updated, patched, and retired. This paper is organized into the following areas- An introduction to virtualization and its benefits, the Challenges of Virtualization techniques, an overview of the hardware virtualization technique, an overview of the software virtualization technique. The paper also proposes an effective and flexible distributed scheme with three phases, opposing to its predecessors. Our scheme achieves reducing the workload of a data center and continual service improvement.

  9. Study on Third Party Logistics Information System Based on SOA-BPM Combination Architecture%基于SOA-BPM组合架构的第三方物流信息系统研究

    Institute of Scientific and Technical Information of China (English)

    张彤

    2012-01-01

    In this paper we adopted the SO A-BPM comhination architecture to realize the loose ooupling of the heterogeneous information systems of logistics enterprises, presented its overall architecture and the major technologies for its realization, and then in the case of Liuzhou State-operated Transportation Company Limited, introduced the actual application of the SOA-BPM-based logistics information system.%为了解决物流企业之间信息系统的异构问题,采用SOA-BPM组合架构实现系统松散耦合,可以尽量少地改造现有系统.提出基于SOA-BPM组合架构的物流信息系统的总体构架,分析实现该架构的主要技术,并且以柳州市国联运输有限责任公司为例,介绍了基于SOA-BPM组合架构的物流信息系统的实际应用.

  10. 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…

  11. The Potential for Scientific Collaboration in Virtual Ecosystems

    Science.gov (United States)

    Magerko, Brian

    2010-01-01

    This article explores the potential benefits of creating "virtual ecosystems" from real-world data. These ecosystems are intended to be realistic virtual representations of environments that may be costly or difficult to access in person. They can be constructed as 3D worlds rendered from stereo video data, augmented with scientific data, and then…

  12. Avatars Talking: The Use of Virtual Worlds within Communication Courses

    Science.gov (United States)

    Sarachan, Jeremy; Burk, Nanci; Day, Kenneth; Trevett-Smith, Matthew

    2013-01-01

    Virtual worlds have become an invaluable space for online learning and the exploration of digital cultures. Communication departments can benefit from using these spaces to educate their students in the logistics of virtual worlds and as a way to better understand how the process of interpersonal and global communication functions in both online…

  13. The Potential for Scientific Collaboration in Virtual Ecosystems

    Science.gov (United States)

    Magerko, Brian

    2010-01-01

    This article explores the potential benefits of creating "virtual ecosystems" from real-world data. These ecosystems are intended to be realistic virtual representations of environments that may be costly or difficult to access in person. They can be constructed as 3D worlds rendered from stereo video data, augmented with scientific data, and then…

  14. Virtualization for the LHCb Online system

    Science.gov (United States)

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

    2011-12-01

    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&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.

  15. Virtual Commissioning of an Assembly Cell with Cooperating Robots

    National Research Council Canada - National Science Library

    S. Makris; G. Michalos; G. Chryssolouris

    2012-01-01

      The Virtual Commissioning (VC) technology is the latest trend in automotive assembly which, among other benefits, promises a more efficient handling of the complexity in assembly systems, a great reduction in the system's ramp-up...

  16. 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.

  17. Virtual XML:a New Approach to an XML-based Virtualization of Data Resources

    Institute of Scientific and Technical Information of China (English)

    吴吉义

    2007-01-01

    Virtual XML is a new approach to virtualise data resources and thus enable applications to access both XML and non-XML sources,which can benefit a variety of general-purpose software products and tools and applica- tions dealing with stationary data and data streams.After the architectural components that enable virtual XML—a toolbox that includes a cursor model,Data Format Description Language(DFDL),and XML processing languages were illustrated,the architecture of virtual XML Documents was put forward.

  18. 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.

  19. Factors affecting assessment of severity of aggressive incidents: using the Staff Observation Aggression Scale - Revised (SOAS-R) in Japan

    NARCIS (Netherlands)

    Noda, T.; Nijman, H.L.I.; Sugiyama, N.; Tsujiwaki, K.; Putkonen, H.; Sailas, E.; Kontio, R.; Ito, H.; Joffe, G.

    2012-01-01

    Accessible summary Consumer gender and age, and nurse gender influenced the perception of overall severity of aggressive incidents, in addition to the aggression data provided by the Staff Observation Aggression Scale Revised (SOAS-R) scores. The factors influencing assessments of aggression inciden

  20. 基于SOA架构的信息安全研究%Research on Information Security of SOA

    Institute of Scientific and Technical Information of China (English)

    刘铭; 刘长文; 佟晖

    2013-01-01

      SOA架构的开放特征具有灵活性、易于集成的优势,但是也造成SOA安全性和易管理性的威胁。阐述了SOA应用现状,分析了SOA安全性面临的内外部问题和安全管理需求,从安全技术、安全服务和安全机制三个维度研究设计SOA的信息安全空间体系模型,为设计安全方案提供参考。%Open characteristics of SOA architecture is fexible, easy to integrate, but it causes the SOA security and manageability threat. This paper expounds the present situation of SOA application, analyzes the internal and external problems and security management requirement facing SOA information security. Information security space system model is researched and designed from the three dimensions of security technology, security service and security mechanism, providing reference for the design of security scheme.

  1. 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....

  2. All-optical reconfigurable multi-logic gates based on nonlinear polarization rotation effect in a single SOA

    Institute of Scientific and Technical Information of China (English)

    Lilin Yi; Weisheng Hu; Hao He; Yi Dong; Yaohui Jin; Weiqiang Sun

    2011-01-01

    We demonstrate an all-optical reconfigurable logic gate based on dominant nonlinear polarization rotation accompanied with cross-gain modulation effect in a singlc semiconductor optical amplifier (SOA). Five logic functions, including NOT, OR, NOR, AND, and NAND, are realized using 10-Gb/s on-off keying signals with flexible wavelength tunability. The operation principle is explained in detail. By adjusting polarization controllers, multiple logic functions corresponding to different input polarization states are separately achieved using a single SOA with high flexibility.%@@ We demonstrate an all-optical reconfigurable logic gate based on dominant nonlinear polarization rotation accompanied with cross-gain modulation effect in a single semiconductor optical amplifier (SOA).Five logic functions, including NOT, OR, NOR, AND, and NAND, are realized using 10-Gb/s on-off keying signals with flexible wavelength tunability.The operation principle is explained in detail.By adjusting polarization controllers, multiple logic functions corresponding to different input polarization states are separately achieved using a single SOA with high flexibility.

  3. 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.…

  4. 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...

  5. All-Optical Flip-Flop Based on an SOA/DFB-Laser Diode Optical Feedback Scheme

    DEFF Research Database (Denmark)

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

    2007-01-01

    We report on the dynamic all-optical flip-flop (AOFF) operation of an optical feedback scheme consisting of a semiconductor optical amplifier (SOA) and a distributed feedback laser diode (DFB-LD), bidirectionally coupled to each other. The operation of the AOFF relies on the interplay between...

  6. 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

    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...

  7. Understanding Empathy Training with Virtual Patients.

    Science.gov (United States)

    Kleinsmith, Andrea; Rivera-Gutierrez, Diego; Finney, Glen; Cendan, Juan; Lok, Benjamin

    2015-11-01

    While the use of virtual characters in medical education is becoming more and more commonplace, an understanding of the role they can play in empathetic communication skills training is still lacking. This paper presents a study aimed at building this understanding by determining if students can respond to a virtual patient's statement of concern with an empathetic response. A user study was conducted at the [blinded] College of Medicine in which early stage medical students interacted with virtual patients in one session and real humans trained to portray real patients (i.e., standardized patients) in a separate session about a week apart. During the interactions, the virtual and 'real' patients presented the students with empathetic opportunities which were later rated by outside observers. The results of pairwise comparisons indicate that empathetic responses made to virtual patients were rated as significantly more empathetic than responses made to standardized patients. Even though virtual patients may be perceived as artificial, the educational benefit of employing them for training medical students' empathetic communications skills is that virtual patients offer a low pressure interaction which allows students to reflect on their responses.

  8. Virtual reference services

    OpenAIRE

    Márdero Arellano, Miguel Ángel

    2001-01-01

    Analysis of virtual reference services, their standandars and new technologies that have changed the tradicional practice at the library’s reference desk. Major American virtual reference services initiatives and their characteristics are described.

  9. High molecular weight SOA formation during limonene ozonolysis: insights from ultrahigh-resolution FT-ICR mass spectrometry characterization

    Directory of Open Access Journals (Sweden)

    S. Kundu

    2012-06-01

    Full Text Available The detailed molecular composition of laboratory generated limonene ozonolysis secondary organic aerosol (SOA was studied using ultrahigh-resolution Fourier transform ion cyclotron resonance (FT-ICR mass spectrometry. Approximately 1200 molecular formulas were identified in the SOA over the mass range of 140 to 850 Da. Four characteristic groups of high relative abundance species were observed; they indicate an array of accretion products that retain a large fraction of the limonene skeleton. The identified molecular formulas of each of the groups are related to one another by CH2, O and CH2O homologous series. The CH2 and O homologous series of the low molecular weight (MW SOA (m/z < 300 are explained with a combination of functionalization and fragmentation of radical intermediates and reactive uptake of gas-phase carbonyls. They include isomerization and elimination reactions of Criegee radicals, reactions between alkyl peroxy radicals, and scission of alkoxy radicals resulting from the Criegee radicals. The presence of compounds with 10–15 carbon atoms in the first group (e.g. C11H18O6 provides evidence for SOA formation by the reactive uptake of gas-phase carbonyls during limonene ozonolysis. The high MW compounds (m/z > 300 were found to constitute a significant number fraction of the identified SOA components. The formation of high MW compounds was evaluated by molecular formula trends, fragmentation analysis of select high MW compounds and a comprehensive reaction matrix including the identified low MW SOA, hydroperoxides and Criegee radicals as building blocks. Although the formation of high MW SOA may occur via a variety of radical and non-radical reaction channels, the combined approach indicates a greater importance of the non-condensation reactions over aldol and ester condensation reaction channels. Among these hemi-acetal reactions appear to be most

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

    Science.gov (United States)

    Murphy, Benjamin N.; Woody, Matthew C.; Jimenez, Jose L.; Carlton, Ann Marie G.; Hayes, Patrick L.; Liu, Shang; Ng, Nga L.; Russell, Lynn M.; Setyan, Ari; Xu, Lu; Young, Jeff; Zaveri, Rahul A.; Zhang, Qi; Pye, Havala O. T.

    2017-09-01

    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 improves predictions of

  11. Virtual reality exposure therapy

    OpenAIRE

    Rothbaum, BO; Hodges, L; Kooper, R

    1997-01-01

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

  12. The Virtual Lab System

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A virtual lab system is the simulation of real devices and experiments using computer and network tech-nology. It can make users do experiments easily, observe experiment phenomena and results through the remote termi-nal. Consequently, users can get final results to verify relative theory. The article analyses the features of virtual labsystems. A real virtual lab system named "Multimedia Virtual Lab for Digital Circuit Logic Design (MVLDCLD) "which has been developed by the authors and their group is also presented.

  13. Virtual currencies- Real opportunities?

    OpenAIRE

    Selldahl, Sara

    2013-01-01

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

  14. A SOA-Based Platform-Specific Framework for Context-Aware Mobile Applications

    Science.gov (United States)

    Daniele, Laura M.; Silva, Eduardo; Pires, Luís Ferreira; van Sinderen, Marten

    Context-aware mobile applications are intelligent applications that can monitor the user’s context and, in case of changes in this context, consequently adapt their behaviour in order to satisfy the user’s current needs or anticipate the user’s intentions. The design of such applications relies on dynamic middleware platforms that consist of a variety of components. These components are distributed in the environment and interoperate by making use of each other’s services. In the A-MUSE project, we defined a design methodology based on MDA principles that relies on a SOA reference architecture for context-aware mobile applications. This paper shows how abstract concepts in the design of such applications can be applied to realize concrete components that guarantee architectural interoperability. We also present a platform-specific framework that uses BPEL, UDDI registry and web services as target technologies to implement our reference architecture.

  15. Reactive nitrogen fate in the southeastern U.S.: Preliminary results from the SOAS campaign

    Science.gov (United States)

    Ayres, B. R.; Draper, D. C.; Allen, H.; Fry, J.; Wild, R.; Brown, S. S.; Koss, A.; De Gouw, J. A.; Olson, K. F.; Goldstein, A. H.; Baumann, K.; Edgerton, E.

    2013-12-01

    High biogenic volatile organic compound (BVOC) emissions and regional NOx pollution influence make the southeastern U.S. ideal for studying the fate of reactive nitrogen. At the 2013 Southern Oxidant and Aerosol Study (SOAS) campaign, we measured a variety of reactive nitrogen species using a Monitor of AeRosols and Gasses in Ambient air (MARGA) and two cavity ringdown spectrometers (NO, NO2, O3, NOy and NO3, N2O5 CRDS). Initial analysis suggests fast reaction of anthropogenic NO3 with BVOC produces gas- and aerosol-phase organonitrates from the ambient mix of predominantly isoprene, alpha-pinene, beta-pinene and limonene. The inorganic aerosol composition is observed to be acidic, with excess of both SO42- and NO3- under the high-RH conditions of the southeastern U.S. summer. Episodic changes in inorganic composition will be compared to organonitrate production to assess regional reactive nitrogen fate.

  16. 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.

  17. The improvement of the semantic classification tool to a SOA to ensure a better tutoring

    Directory of Open Access Journals (Sweden)

    Saadia Lgarch

    2011-07-01

    Full Text Available For a best collaboration between tutor and learner and relatively to discussion forum, we have proposed to tutor a semantic classification tool of messages, which helps him to manage the mass of messages accumulating during the time. The tool provides a semantic classification mechanism based on a chosen theme. For a classification more intelligent semantically, and focusing more the chosen theme, our tool incorporates essentially a formal OWL ontology. The reuse and interoperability offered by ontology remain restrictive in the tool's knowledge base. To overcome this limitation, the improvement of the SOA architecture already proposed will be presented in this paper. An implementation of our classifier using the composite application concept will also be explained. The respect of standards: XML, SOAP, WSDL and BPEL in our implementation, will guarantee the tool's interoperability with platforms which solicit its classification service, while allowing its reuse with a high degree of granularity.

  18. Improving the power efficiency of SOA-based UWB over fiber systems via pulse shape randomization

    Science.gov (United States)

    Taki, H.; Azou, S.; Hamie, A.; Al Housseini, A.; Alaeddine, A.; Sharaiha, A.

    2016-09-01

    A simple pulse shape randomization scheme is considered in this paper for improving the performance of ultra wide band (UWB) communication systems using On Off Keying (OOK) or pulse position modulation (PPM) formats. The advantage of the proposed scheme, which can be either employed for impulse radio (IR) or for carrier-based systems, is first theoretically studied based on closed-form derivations of power spectral densities. Then, we investigate an application to an IR-UWB over optical fiber system, by utilizing the 4th and 5th orders of Gaussian derivatives. Our approach proves to be effective for 1 Gbps-PPM and 2 Gbps-OOK transmissions, with an advantage in terms of power efficiency for short distances. We also examine the performance for a system employing an in-line Semiconductor Optical Amplifier (SOA) with the view to achieve a reach extension, while limiting the cost and system complexity.

  19. Struts Framework Application Based on SOA%基于SOA的Struts框架应用

    Institute of Scientific and Technical Information of China (English)

    蒋宏潮; 尹怡欣; 班晓娟

    2009-01-01

    为简化、规范Web应用系统的开发和部署,提高系统的可移植性、安全性,该文利用Struts框架结构的Web应用系统开发原理及特性,采用面向服务架构的开发模式SOA,将SOA思想引入Struts框架中,形成一种新的开发框架模式.通过信息管理系统的开发实例介绍基于SOA架构的Struts框架的实现过程.基于SOA架构的Struts框架新模式能实现平台间的直接互操作,有效提升Web应用系统的可移植性和安全性.

  20. Complex networks and SOA: Mathematical modelling of granularity based web service compositions

    Indian Academy of Sciences (India)

    S Chatla; S Kadam; D Kolluru; S Sinha; A Viswandhuni; A Vaidya

    2011-08-01

    Service Oriented Architecture (SOA) can be defined as a way of defining and implementing enterprise applications that deals with the intercommunication of loosely coupled, coarse grained (business level), reusable artifacts (services). In this paper, we attempt to mathematically model the preliminary steps in the larger problem of providing an optimal architecture. The problem is treated as a complex network, particularly a process-task-network. We employ statistical and graph-theoretic methods namely, Jaccard’s distance analysis, Multiple Correspondence method and the Minimum Spanning Tree method, to find appropriate clusters. These methods are used to cluster tasks across business processes to propose services. Additional properties and features of these clusters are discussed. We propose a leverage factor which demonstrates the importance of a task within the service and its impact on service composition.

  1. Case study of virtual private network

    Science.gov (United States)

    Hernandez, Harold; Chung, Ping-Tsai

    2001-07-01

    In this study, business benefits for this Virtual Private Network (VPN) and protocols, techniques, equipments used in this VPN are reported. In addition, our design experience for fault tolerance, security and network management and administration on this VPN are showed. Finally, the issues for future planning of this VPN is addressed.

  2. 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…

  3. 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.

  4. Modeling Gas-Particle Partitioning of SOA: Effects of Aerosol Physical State and RH

    Science.gov (United States)

    Zuend, A.; Seinfeld, J.

    2011-12-01

    Aged tropospheric aerosol particles contain mixtures of inorganic salts, acids, water, and a large variety of organic compounds. In liquid aerosol particles non-ideal mixing of all species determines whether the condensed phase undergoes liquid-liquid phase separation or whether it is stable in a single mixed phase, and whether it contains solid salts in equilibrium with their saturated solution. The extended thermodynamic model AIOMFAC is able to predict such phase states by representing the variety of organic components using functional groups within a group-contribution concept. The number and composition of different condensed phases impacts the diversity of reaction media for multiphase chemistry and the gas-particle partitioning of semivolatile species. Recent studies show that under certain conditions biogenic and other organic-rich particles can be present in a highly viscous, semisolid or amorphous solid physical state, with consequences regarding reaction kinetics and mass transfer limitations. We present results of new gas-particle partitioning computations for aerosol chamber data using a model based on AIOMFAC activity coefficients and state-of-the-art vapor pressure estimation methods. Different environmental conditions in terms of temperature, relative humidity (RH), salt content, amount of precursor VOCs, and physical state of the particles are considered. We show how modifications of absorptive and adsorptive gas-particle mass transfer affects the total aerosol mass in the calculations and how the results of these modeling approaches compare to data of aerosol chamber experiments, such as alpha-pinene oxidation SOA. For a condensed phase in a mixed liquid state containing ammonium sulfate, the model predicts liquid-liquid phase separation up to high RH in case of, on average, moderately hydrophilic organic compounds, such as first generation oxidation products of alpha-pinene. The computations also reveal that treating liquid phases as ideal

  5. 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.

  6. 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.

  7. Proximity-based access control for context-sensitive information provision in SOA-based systems

    Science.gov (United States)

    Rajappan, Gowri; Wang, Xiaofei; Grant, Robert; Paulini, Matthew

    2014-06-01

    Service Oriented Architecture (SOA) has enabled open-architecture integration of applications within an enterprise. For net-centric Command and Control (C2), this elucidates information sharing between applications and users, a critical requirement for mission success. The Information Technology (IT) access control schemes, which arbitrate who gets access to what information, do not yet have the contextual knowledge to dynamically allow this information sharing to happen dynamically. The access control might prevent legitimate users from accessing information relevant to the current mission context, since this context may be very different from the context for which the access privileges were configured. We evaluate a pair of data relevance measures - proximity and risk - and use these as the basis of dynamic access control. Proximity is a measure of the strength of connection between the user and the resource. However, proximity is not sufficient, since some data might have a negative impact, if leaked, which far outweighs importance to the subject's mission. For this, we use a risk measure to quantify the downside of data compromise. Given these contextual measures of proximity and risk, we investigate extending Attribute-Based Access Control (ABAC), which is used by the Department of Defense, and Role-Based Access Control (RBAC), which is widely used in the civilian market, so that these standards-based access control models are given contextual knowledge to enable dynamic information sharing. Furthermore, we consider the use of such a contextual access control scheme in a SOA-based environment, in particular for net-centric C2.

  8. 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…

  9. A Virtual Class Calculus

    DEFF Research Database (Denmark)

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

    2006-01-01

    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...

  10. Virtual Reality: An Overview.

    Science.gov (United States)

    Franchi, Jorge

    1994-01-01

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

  11. Virtual Team Meetings: Reflections on a Class Exercise Exploring Technology Choice

    Science.gov (United States)

    Bull Schaefer, Rebecca A.; Erskine, Laura

    2012-01-01

    Students find that choosing the appropriate technology for a virtual team meeting is not as simple as it first appears. The authors describe a class exercise used to demonstrate the benefits and drawbacks of using virtual team meetings by requiring students to replace a face-to-face meeting with a virtual meeting. The exercise challenged students'…

  12. Virtual computers offer to the modern educational solutions

    Directory of Open Access Journals (Sweden)

    Tadeusz Wilusz

    2010-12-01

    Full Text Available During first decade of the 21 st century more and more production ICT environments have already switched towards virtualized solution. Th is is still ongoing process which offers a lot of benefits but at the same time makes understanding relations between physical environment and virtualized systems harder. The article starts with a short survey of some problems related to effectiveness usa ge of IT capabilities in modern educational environments with conclusion how they can be solved using computer virtualization technique in the way which may result wi th better understanding invisible physical processes in virtualized e-business systems

  13. 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....

  14. 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.

  15. 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.

  16. Virtual World Security Inspection

    Directory of Open Access Journals (Sweden)

    Nicholas Charles Patterson

    2012-06-01

    Full Text Available Virtual property theft is a serious problem that exists in virtual worlds. Legitimate users of these worlds invest considerable amounts of time, effort and real-world money into obtaining virtual property, but unfortunately, are becoming victims of theft in high numbers. It is reported that there are over 1 billion registered users of virtual worlds containing virtual property items worth an estimated US$50 billion dollars. The problem of virtual property theft is complex, involving many legal, social and technological issues. The software used to access virtual worlds is of great importance as they form the primary interface to these worlds and as such the primary interface to conduct virtual property theft. The security vulnerabilities of virtual world applications have not, to date, been examined. This study aims to use the process of software inspection to discover security vulnerabilities that may exist within virtual world software – vulnerabilities that enable virtual property theft to occur. Analyzing three well know virtual world applications World of Warcraft, Guild Wars and Entropia Universe, this research utilized security analysis tools and scenario testing with focus on authentication, trading, intruder detection and virtual property recovery. It was discovered that all three examples were susceptible to keylogging, mail and direct trade methods were the most likely method for transferring stolen items, intrusion detection is of critical concern to all VWEs tested, stolen items were unable to be recovered in all cases and lastly occurrences of theft were undetectable in all cases. The results gained in this study present the key problem areas which need to be addressed to improve security and reduce the occurrence of virtual property theft.

  17. Who benefits?

    DEFF Research Database (Denmark)

    Hjorth, Frederik Georg

    2016-01-01

    Cross-border welfare rights for citizens of European Union member states are intensely contested, yet there is limited research into voter opposition to such rights, sometimes denoted ‘welfare chauvinism’. We highlight an overlooked aspect in scholarly work: the role of stereotypes about...... beneficiaries of cross-border welfare. We present results from an original large-scale survey experiment (N=2525) among Swedish voters, randomizing exposure to cues about recipients' country of origin and family size. Consistent with a model emphasizing the role of stereotypes, respondents react to cues about...... recipient identity. These effects are strongest among respondents high in ethnic prejudice and economic conservatism. The findings imply that stereotypes about who benefits from cross-border welfare rights condition public support for those rights....

  18. 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.

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

    OpenAIRE

    Elby Roy; Mahmoud M. Bakr; Roy George

    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. 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.

  1. 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.

  2. Molecular transformations of phenolic SOA during photochemical aging in the aqueous phase: competition among oligomerization, functionalization, and fragmentation

    Science.gov (United States)

    Yu, Lu; Smith, Jeremy; Laskin, Alexander; George, Katheryn M.; Anastasio, Cort; Laskin, Julia; Dillner, Ann M.; Zhang, Qi

    2016-04-01

    Organic aerosol is formed and transformed in atmospheric aqueous phases (e.g., cloud and fog droplets and deliquesced airborne particles containing small amounts of water) through a multitude of chemical reactions. Understanding these reactions is important for a predictive understanding of atmospheric aging of aerosols and their impacts on climate, air quality, and human health. In this study, we investigate the chemical evolution of aqueous secondary organic aerosol (aqSOA) formed during reactions of phenolic compounds with two oxidants - the triplet excited state of an aromatic carbonyl (3C∗) and hydroxyl radical (•OH). Changes in the molecular composition of aqSOA as a function of aging time are characterized using an offline nanospray desorption electrospray ionization mass spectrometer (nano-DESI MS) whereas the real-time evolution of SOA mass, elemental ratios, and average carbon oxidation state (OSC) are monitored using an online aerosol mass spectrometer (AMS). Our results indicate that oligomerization is an important aqueous reaction pathway for phenols, especially during the initial stage of photooxidation equivalent to ˜ 2 h irradiation under midday winter solstice sunlight in Northern California. At later reaction times functionalization (i.e., adding polar oxygenated functional groups to the molecule) and fragmentation (i.e., breaking of covalent bonds) become more important processes, forming a large variety of functionalized aromatic and open-ring products with higher OSC values. Fragmentation reactions eventually dominate the photochemical evolution of phenolic aqSOA, forming a large number of highly oxygenated ring-opening molecules with carbon numbers (nC) below 6. The average nC of phenolic aqSOA decreases while average OSC increases over the course of photochemical aging. In addition, the saturation vapor pressures (C∗) of dozens of the most abundant phenolic aqSOA molecules are estimated. A wide range of C∗ values is observed, varying

  3. Virtual Campus in the Context of an Educational Virtual City

    Science.gov (United States)

    Fominykh, Mikhail; Prasolova-Forland, Ekaterina; Morozov, Mikhail; Gerasimov, Alexey

    2011-01-01

    This paper is focused on virtual campuses, i.e. virtual worlds representing real educational institutions that are based on the metaphor of a university and provide users with different learning tools. More specifically, the idea of integrating a virtual campus into the context of a virtual city is suggested. Such a virtual city, where students…

  4. Application of SOA (Service Oriented Architecture) in Early Warning Systems for Tsunamis and other Natural Hazards

    Science.gov (United States)

    Lendholt, Matthias; Hammitzsch, Martin; Wächter, Joachim

    2010-05-01

    The DEWS (Distant Early Warning System) [1] project, funded under the 6th Framework Programme of the European Union, has the target to create a new generation of interoperable early warning systems. Two major objectives have steered the development process: usage of free and open source software (FOSS) and compliance to the principles of a Service Oriented Architecture (SOA). The second objective was mainly driven by the superior ambition of the development of a generic early warning framework not only for tsunamis but also for other natural hazards. The development of a reference architecture enforced the clear separation between hazard-specific and generic functionality. Integration of sensor networks was realized with Open Geospatial Consortium (OGC) [2] Sensor Web Enablement (SWE) [3] services. Sensor types are relatively specific for different hazard types: while inundation sensors can be used both for tsunami and floodwater hazards, contamination meters requires a complete different semantic integration into the client application. Based on sensor measurements a simulation system supports the operator with forecasts to enable the dissemination of precise warning messages. The simulation integration was realized with the Web Processing Service (WPS) [4] but here again semantic integration is simulation specific and has to be realized inside the client application. In contrast the integration of Spatial Data Infrastructure (SDI) via Web Mapping Service (WMS) [5] and Web Feature Service (WFS) [6] to complete the situation report is independent from any hazard type and depends on the data availability and requirements of each warning centre. The downstream component - the message dissemination from the operator via information logistics to the dissemination channel endpoints - has been realized independently from any specific hazard type. Using the Common Alerting Protocol (CAP) [7] and Emergency Data Exchange Language (EDXL) [8] enables the re-usage for all kind

  5. Organic Aerosol Formation in the Humid, Photochemically-Active Southeastern US: SOAS Experiments and Simulations

    Science.gov (United States)

    Sareen, N.; Lim, Y. B.; Carlton, A. G.; Turpin, B. J.

    2013-12-01

    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, health, and the environment. 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 other precursors that are atmospherically important. In this study, ambient mixtures of water-soluble gases were scrubbed from the atmosphere at Brent, Alabama during the Southern Oxidant and Aerosol Study (SOAS). Four mist chambers in parallel collected ambient gases in a DI water medium at 20-25 LPM with a 4 hr collection time. Total organic carbon (TOC) values in daily composited samples were 64-180 μM. Aqueous OH radical oxidation experiments were conducted with these mixtures in a newly designed cuvette chamber to understand the formation of SOA through gas followed by aqueous chemistry. OH radicals (3.5E-2 μM [OH] s-1) were formed in-situ in the chamber, continuously by H2O2 photolysis. Precursors and products of these aqueous OH experiments were characterized using ion chromatography (IC), electrospray ionization mass spectrometry (ESI-MS), and IC-ESI-MS. ESI-MS results from a June 12th, 2013 sample showed precursors to be primarily odd, positive mode ions, indicative of the presence of non-nitrogen containing alcohols, aldehydes, organic peroxides, or epoxides. Products were seen in the negative mode and included organic acid ions like pyruvate

  6. Virtual reality exposure therapy.

    Science.gov (United States)

    Rothbaum, B O; Hodges, L; Kooper, R

    1997-01-01

    It has been proposed that virtual reality (VR) exposure may be an alternative to standard in vivo exposure. Virtual reality integrates real-time computer graphics, body tracking devices, visual displays, and other sensory input devices to immerse a participant in a computer-generated virtual environment. Virtual reality exposure is potentially an efficient and cost-effective treatment of anxiety disorders. VR exposure therapy reduced the fear of heights in the first controlled study of virtual reality in treatment of a psychiatric disorder. A case study supported the efficacy of VR exposure therapy for the fear of flying. The potential for virtual reality exposure treatment for these and other disorders is explored, and therapeutic issues surrounding the delivery of VR exposure are discussed.

  7. 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...

  8. 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

  9. 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.

  10. 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

    2008-08-01

    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 aerosol, mild acidification with sulphuric acid (SA, 3SOA formation is found enhanced by several orders of magnitude in the photochemical system. The SOA yields (YSOA ranged from 1% to 20% and did not correlate with the organic mass portion of the seed, but increased linearly with liquid water content (LWC of the seed. For fixed LWC, YSOA varied by more than a factor of five. Water soluble organic carbon (WSOC photochemistry in the liquid water associated with internally mixed inorganic/WSOC seed aerosols is found responsible for this seed effect. WSOC photochemistry enhances the SOA 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.

  11. Trust and virtual worlds

    DEFF Research Database (Denmark)

    Ess, Charles; Thorseth, May

    2011-01-01

    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....... of embodiment in establishing trust in (primarily) disembodied venues; how far artificial agents and other forms of machine intelligence can be trusted in any strong sense; and how diverse ethical frameworks, as developed in embodied contexts and histories, may (not) be applied to ethical issues evoked...

  12. Framing Virtual Law

    OpenAIRE

    Edelmann, Peter

    2005-01-01

    This paper proposes a framework for understanding the real-virtual dichotomy in terms of a series of five frames or layers which interact simultaneously to create the phenomena associated with virtual worlds. The framework presented in this paper is intended to be used as an analytical tool in studying phenomena related specifically to virtual worlds, but is undoubtedly applicable to a broad subset of computer games and interactive fiction. The model provides a useful tool fpr studying a numb...

  13. Virtual Campus Hub technology

    DEFF Research Database (Denmark)

    Vercoulen, Frank; Badger, Merete; Monaco, Lucio;

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

  14. Managing global virtual teams

    OpenAIRE

    Saarinen, Johanna

    2016-01-01

    Advances in technology-enabled communication and a constant search for economic advantage have led global organizations to rely on virtual collaboration. Together with rapid changes in working life, virtuality has also altered the context for leadership and has had a significant impact on the work of managers. This study addresses managerial work in global virtual teams. In my study, I give voice to the managers themselves with the aim of enhancing our understanding of what the work of virtua...

  15. Wireless Virtual Joystick

    OpenAIRE

    Hu, Yuning

    2013-01-01

    Wireless Virtual Joystick is an Android application which enables users to use their Android mobile device act like a real joystick. It provides a solution to establish a wireless connection between Android mobile device and server computer. Whenever the server receives correct message, the server will simulate a virtual joystick input signal. Wireless Virtual Joystick does not worry about the small space, wires jam or USB port limitation. The objective of this thesis project is to develop a ...

  16. Virtual currencies : Real opportunities?

    OpenAIRE

    Selldahl, Sara

    2013-01-01

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

  17. Virtual articulators in prosthodontics

    National Research Council Canada - National Science Library

    R.S., Gugwad; M., Basavakumar; K., Abhijeet; M., Arvind; M., Sudhindra; C., Ramesh

    2011-01-01

    Virtual technologies in dentistry provide better education and training by simulating complex contexts and enhancing procedures that are traditionally limited, such as work with mechanical articulator...

  18. Debugging the virtual machine

    Energy Technology Data Exchange (ETDEWEB)

    Miller, P.; Pizzi, R.

    1994-09-02

    A computer program is really nothing more than a virtual machine built to perform a task. The program`s source code expresses abstract constructs using low level language features. When a virtual machine breaks, it can be very difficult to debug because typical debuggers provide only low level machine implementation in formation to the software engineer. We believe that the debugging task can be simplified by introducing aspects of the abstract design into the source code. We introduce OODIE, an object-oriented language extension that allows programmers to specify a virtual debugging environment which includes the design and abstract data types of the virtual machine.

  19. Spacebody actual virtual

    DEFF Research Database (Denmark)

    Kjøbek, Jytte; Sørensen, Gert

    2005-01-01

    DVD som indeholder filmen 'spacebody actual virtual' . Videoen er værkdelen af forskningsprojektet Arkitektur og skikkelse, spacebody actual virtual. Foruden DVD'en indeholder projektet et reflekterende materiale på hjemmesiden www.spacebody.dk Fysisk medie: DVD......DVD som indeholder filmen 'spacebody actual virtual' . Videoen er værkdelen af forskningsprojektet Arkitektur og skikkelse, spacebody actual virtual. Foruden DVD'en indeholder projektet et reflekterende materiale på hjemmesiden www.spacebody.dk Fysisk medie: DVD...

  20. Learning by doing virtually.

    Science.gov (United States)

    von Sternberg, N; Bartsch, M S; Petersik, A; Wiltfang, J; Sibbersen, W; Grindel, T; Tiede, U; Warnke, P H; Heiland, M; Russo, P A J; Terheyden, H; Pohlenz, P; Springer, I N

    2007-05-01

    Selective reduction of bone without collateral damage (nerves, teeth) is essential in apicectomy. To test whether skills acquired on a virtual apicectomy simulator (VOXEL-MAN system with integrated force-feedback) are transferable from virtual to physical reality, two groups of trainees were compared. Group 1 received computer-based virtual surgical training before performing an apicectomy in a pig cadaver model. The probability of preserving vital neighboring structures was improved significantly, i.e. six-fold, after virtual surgical training (Papicectomy simulator appears to be effective, and the skills acquired are transferable to physical reality.

  1. Virtual Machine Introspection

    Directory of Open Access Journals (Sweden)

    S C Rachana

    2014-06-01

    Full Text Available Cloud computing is an Internet-based computing solution which provides the resources in an effective manner. A very serious issue in cloud computing is security which is a major obstacle for the adoption of cloud. The most important threats of cloud computing are Multitenancy, Availability, Loss of control, Loss of Data, outside attacks, DOS attacks, malicious insiders, etc. Among many security issues in cloud, the Virtual Machine Security is one of the very serious issues. Thus, monitoring of virtual machine is essential. The paper proposes a Virtual Network Introspection [VMI] System to secure the Virtual machines from Distributed Denial of Service [DDOS] and Zombie attacks.

  2. Virtual Machine Introspection

    Directory of Open Access Journals (Sweden)

    S C Rachana

    2015-11-01

    Full Text Available Cloud computing is an Internet-based computing solution which provides the resources in an effective manner. A very serious issue in cloud computing is security which is a major obstacle for the adoption of cloud. The most important threats of cloud computing are Multitenancy, Availability, Loss of control, Loss of Data, outside attacks, DOS attacks, malicious insiders, etc. Among many security issues in cloud, the Virtual Machine Security is one of the very serious issues. Thus, monitoring of virtual machine is essential. The paper proposes a Virtual Network Introspection [VMI] System to secure the Virtual machines from Distributed Denial of Service [DDOS] and Zombie attacks.

  3. Virtual Reality Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Performs basic and applied research in interactive 3D computer graphics, including visual analytics, virtual environments, and augmented reality (AR). The...

  4. Virtual Training Devices Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Virtual Training Devices (VTD) Laboratory at the Life Cycle Software Engineering Center, Picatinny Arsenal, provides a software testing and support environment...

  5. VIRTUAL FUEL-PUMP DESIGN

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Some concepts of virtual product are discussed. The key technologies of virtual fuel-pump development are in detail analysed, which include virtual fuel-pump product modeling, intelligent simulation, distributed design environment, and virtual assembly. The virtual fuel-pump development prototype system considers requirement analysis, concept design, injection preferment analysis, detailed design, and assembly analysis.

  6. The Effect of Bark Borer Herbivory on BVOC Emissions in Boreal Forests and Implications for SOA Formation

    Science.gov (United States)

    Faiola, Celia; Joutsensaari, Jorma; Holopainen, Jarmo; Yli-Juuti, Taina; Kokkola, Harri; Blande, James; Guenther, Alex; Virtanen, Annele

    2015-04-01

    Herbivore outbreaks are expected to increase as a result of climate change. These outbreaks can have significant effects on the emissions of biogenic volatile organic compound (BVOC) from vegetation, which contribute to the formation of secondary organic aerosol (SOA). We have synthesized the published results investigating changes to BVOC emissions from herbivory by the pine weevil, Hylobius abietis--a bark borer herbivore. Previous lab experiments have shown that bark borer herbivory on Scots pine trees increases monoterpene emissions 4-fold and sesquiterpene emissions 7-fold. Norway spruce exhibits a similar response. The BVOCs most impacted were linalool, beta-phellandrene, limonene, alpha-pinene, beta-pinene, myrcene, and sesquiterpenes like beta-farnesene, beta-bourbonene, and longifolene. The quantitative results from these studies were used to estimate potential impacts of bark borer herbivory on BVOC emissions at a regional scale using the Model of Emissions of Gases and Aerosols from Nature (MEGAN). MEGAN was run under baseline and herbivore outbreak conditions for a typical boreal forest environment in spring. Emissions output from MEGAN was used to run a microphysical box model to estimate the SOA formation potential under baseline and outbreak conditions. This estimate could provide us with an upper limit to the potential impact of bark borer outbreaks on SOA formation in a boreal forest.

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

    Directory of Open Access Journals (Sweden)

    Y. Tan

    2011-06-01

    Full Text Available Previous experiments have demonstrated that the aqueous OH radical oxidation of methylglyoxal produces low volatility products including 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 is an important intermediate in aqueous methylglyoxal oxidation and a ubiquitous product of gas phase photochemistry, making it a potential "aqueous" SOA precursor in its own right. Altieri et al. (2008 proposed that acetic acid was the precursor of oligoesters observed in methylglyoxal oxidation. However, the fate of acetic acid upon aqueous-phase oxidation is not well understood. In this research, acetic acid at concentrations relevant to atmospheric waters (20 μM–10 mM was oxidized by OH radical. Products were analyzed by ion chromatography (IC, electrospray ionization mass spectrometry (ESI-MS, and IC-ESI-MS. The formation of glyoxylic, glycolic, and oxalic acids were observed. In contrast to methylglyoxal oxidation, succinic acid and oligomers were not detected. Using results from these and methylglyoxal + OH radical 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.

  8. Performing broadband optical transmission links by appropriate spectral combination of broadband SOA gain, Raman amplification and transmission fiber losses

    Science.gov (United States)

    Motaweh, T.; Sharaiha, A.; Ghisa, L.; Morel, P.; Guégan, M.; Brenot, R.; Verdier, A.

    2017-02-01

    We present the principle of a broadband optical transmission link based on the appropriate combination of the spectral profiles of broadband SOA gain, Raman amplification and transmission fiber losses. We show that, thanks to this principle, a bandwidth as wide as 89 nm (defined at -1 dB) over 75.5 km can be obtained. This bandwidth remains better than 80 nm over a wide range of optical input powers and broadband SOA bias currents, by optimizing the Raman pump. We also show theoretically that the bandwidth of our link is nearly constant for a fiber length from 25 to 100 km optimizing the SOA current. Our broadband transmission link, extended by 24.5 km of fiber, is then validated by achieving the transmission of five CWDM channels modulated at 10 Gbit/s. All five channels were transmitted over 100 km with a minimum received power sensibility of about -15.5 dBm for a reference BER of 10-3.

  9. 基于SOA的SLE API系统设计%Design of an SOA-based SLE API Svstem

    Institute of Scientific and Technical Information of China (English)

    王喆; 鲍忠贵; 高三红; 苑刚

    2011-01-01

    介绍了CCSDS(空间数据系统咨询委员会)标准下的SLE(空间链路扩展)系统中API(应用程序接口)系统的概念和模型,并基于SOA(面向服务的体系结构)思想深入分析了SLE API系统的设计模式.SOA模型具有松耦合、重用性高、扩展性强等特点,这与我国提出的建立系统间“互联、互通、互操作”的新一代测控网的目标相吻合.本文在SOA模型框架下,针对我国测控网的现状,提出新型测控网可能的发展方向.%This paper introduces the concept and model of SLE API (Space Link Extension Application Program Interface) systems in CCSDS recommendations and analyzes SLE API system design based on SOA (Service Oriented Architecture). SOA model has the characteristics of loose coupling, great reusability and scalability. These are consistent with the interconnectivity and interoperability objectives of China's next generation TT&-C networks. Furthermore, the paper puts forward a probable approach for a new TT&.C management system.

  10. 一种基于SOA的企业集成平台%SOA-based Enterprise Integration Platform

    Institute of Scientific and Technical Information of China (English)

    张朝晖; 徐立臻; 董逸生; 徐宏炳

    2011-01-01

    An SOA-based enterprise integration platform called JSSOA is presented.Cored on Enterprise Service Integration(ESI) middleware,JSSOA supports transparent integration of heterogeneous systems and services, MDA-based and business user oriented process modeling and service composition, semantic and QoS based service finding and service oriented UI creating.JSSOA simplifies the creation, running and maintenance of SOA-based applications by encapsulating the complicate details of SOA technology.%提出一种基于SOA的企业集成平台--JSSOA,以企业服务集成中间件为核心,实现异构系统和多种类型服务的透明集成,支持基于MDA方法面向最终用户的流程建模和服务组合、基于语义及QoS的服务查找、基于服务的个性化应用系统用户界面创制.该平台封装了复杂的SOA技术细节,使基于SOA的应用系统的构建、运行和维护更简单、高效.

  11. 基于IIFA算法的SOA安全模型%SOA Security Model Design Based on IIFA Algorithm

    Institute of Scientific and Technical Information of China (English)

    蔡亮; 王兵; 李辉

    2011-01-01

    针对SOAP消息传输过程中可能引发安全威胁,运用关联规则对SOAP消息进行挖掘,建立IIFA-SOA安全模型.基于系统实时性要求,采用索引生成频繁集算法(IIFA)进行关联规则的挖掘.实例表明,所建立的IIFA-SOA安全模型,可以进行安全威胁的预测与销毁,提高了系统的安全性.%For the SOAP message transmission process may lead to security threats. In this paper we address to mine SOAP messages using association rules, and establish IIFA-SOA security model. Based on the requirements of system real-time, we introduce Index Induce Frequent algorithm for frequent itemsets mining association rules. Experimental results show that the IIFA-SOA security model can make the prediction and elimination of security threats, accordingly improve system security.

  12. Probing the Morphology and Diffusivity of Mixed SOA/Squalane Particles Using Size-resolved Composition and Single-particle Measurements.

    Science.gov (United States)

    Robinson, E. S.; Saleh, R.; Donahue, N. M.

    2014-12-01

    We present an analysis of the formation and evaporation of mixed-particles comprised of squalane and SOA. First, we use a two-population smog chamber experiment to test the phase-behavior between isotopically-labeled squalane (D62-squalane) and SOA (from α-pinene + O3). Next, we present mixed-particle experiments where one particle type (squalane or SOA) was prepared first to serve as surface area for condensation of the other material, forming the mixed particles. The mixed particles were then subjected to a heating ramp from 22 to 44 ◦C in the chamber. From these experiments, we were able to determine that: 1) squalane and SOA phase separate; 2) the vast majority of squalane is able to evaporate from the mixed particles on the same timescale regardless of the order of preparation; 3) almost all of the SOA mass is comprised of material less volatile than squalane; 4) AMS collection efficiency in these mixed-particle systems varies widely but systematically the course of these experiments where particle phase is dynamic, and can be parameterized as a function of the mass fraction of squalane; and 5) the evaporation profile of squalane can be used to estimate the diffusion coefficient (Dorg) of squalane through SOA.

  13. Design of SOA interface model in service robot cloud computing platform%服务机器人云计算平台 SOA 接口层模型设计

    Institute of Scientific and Technical Information of China (English)

    陈宏兴; 周风余; 田天; 姜志飞; 陈竹敏

    2015-01-01

    An interface model of cloud computing platform based on SOA(service-oriented architecture)architecture was presented for the cloud service robot in the family usage scenarios.The basic functions of cloud computing platform were defined as meta services,the service of SOA layer was decomposed into a list of meta services according to the da-ta type and platform level,service decomposition and reconstruction were accomplished through the meta service list and related resources,reorganization and reuse of the meta service was achieved.Stubs of service quality were used to save the real-time information against the problem of service quality monitoring,mapping and management of services were accomplished through the meta service list and stubs of service quality,service dynamic scheduling was realized by the service management and service scheduling layer.The effectiveness and feasibility of the SOA interface model were tested by experiments.%面向云服务机器人在家庭场景下的使用需求,设计了一种基于 SOA(service-oriented architecture)架构的云计算平台接口层模型。模型将云计算平台的基本功能定义为元服务,根据数据类型和平台层次将 SOA 层服务分解为元服务的有序组合,并与服务相关资源组合构成元服务列表,完成服务的分解和重构流程,达到了元服务重组和复用的目的。针对服务执行过程中的服务质量监测问题,采用基于服务描述的服务质量存根保存服务的实时信息,设计服务管理层和服务调度层,通过元服务列表和服务质量存根完成服务的映射和管理工作,实现了服务的动态调度。实验验证了机器人云计算平台 SOA 接口层模型在服务映射和服务管理方面的可行性和有效性。

  14. Distributed virtual environment for emergency medical training

    Science.gov (United States)

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

    1997-07-01

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

  15. 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.

  16. An Optimized Business Service Directory for the ESB Platform in SOA

    Directory of Open Access Journals (Sweden)

    RajniMohana

    2012-10-01

    Full Text Available Service Oriented Architecture (SOA helps toprovide value added services to the user with agility byfollowing a publish-find-compose technique. Business Service Directory is one of the key components ofEnterprise Service Bus and its implementation involves many challenges. One of the essential challengesis how to provide a suitable set of service candidates faster. This paper proposes a business servicedirectory which employs ranking based, quality driven publishing and searching. The proposed businessservice directory is a fuzzy expert system which requires no human intervention. The implementation ofoptimized business service directory is composed of two steps, first the rule base is designed whichcontains auto generated rules to rank the web service. Fuzzy clustering and PSO is used to not onlygenerate rules automatically using training dataset but also removing redundant and less effective rules.The next step is to design inference engine which triggers the rules in the rule base. The proposedBusiness service directory minimizes administrative overhead and increases usability by locating the bestweb service among the large number of functionally equivalent web services and it’s also adaptive innature.

  17. SOA - An Architecture Which Creates a Flexible Link between Business Processes and IT

    Directory of Open Access Journals (Sweden)

    Radu Stefan MOLEAVIN

    2012-05-01

    Full Text Available To be viable, a company must be adapted continously to the market’s requirements. The adaption of a company to the market’s requirements means also changes in the business processes of the firm. Till several years ago, in any enterprise there was a strong link between business processes and IT applications. Any changes in the business processes lead to a change in the IT applications. This means that any change in the business side involves time, human resources and material resources consumption.This fact can be translated in a slow adapting to the market changes and a cost increasing for changing IT applications side necessary for their adaptation to new business market. Today the market changes quickly and it has a great development; this means that the enterprise adaptation to the market’s requirements must be done quickly and with low consumption of either human or material resources. Also, the market changes which cause changes in the business processes should not cause major changes in the IT area. This goal can be achieved using an architecture services-based (SOA for the enterprise. This architecture allows us, like in a puzzle game, to use the same pieces of material ("services" to build different models ("business processes".

  18. 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.

  19. Integration of Agile Ontology Mapping towards NLP Search in I-SOAS

    CERN Document Server

    Ahmed, Zeeshan

    2010-01-01

    In this research paper we address the importance of Product Data Management (PDM) with respect to its contributions in industry. Moreover we also present some currently available major challenges to PDM communities and targeting some of these challenges we present an approach i.e. I-SOAS, and briefly discuss how this approach can be helpful in solving the PDM community's faced problems. Furthermore, limiting the scope of this research to one challenge, we focus on the implementation of a semantic based search mechanism in PDM Systems. Going into the details, at first we describe the respective field i.e. Language Technology (LT), contributing towards natural language processing, to take advantage in implementing a search engine capable of understanding the semantic out of natural language based search queries. Then we discuss how can we practically take advantage of LT by implementing its concepts in the form of software application with the use of semantic web technology i.e. Ontology. Later, in the end of t...

  20. 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

  1. Cloud Condensation Nuclei Activity, Droplet Growth Kinetics and Hygroscopicity of Biogenic and Anthropogenic Secondary Organic Aerosol (SOA)

    Science.gov (United States)

    Zhao, Defeng; Buchholz, Angela; Kortner, Birthe; Schlag, Patrick; Rubach, Florian; Hendrik, Fucks; Kiendler-Scharr, Astrid; Tillmann, Ralf; Wahner, Andreas; Hallquist, Mattias; Flores, Michel; Rudich, Yinon; Glasius, Marianne; Kourtchev, Ivan; Kalberer, Markus; Mentel, Thomas

    2015-04-01

    Recent field data and model analysis show that secondary organic aerosol (SOA) formation is enhanced under anthropogenic influences (de Gouw et al. 2005, Spracklen et al. 2011). The interaction of biogenic VOCs (BVOCs) with anthropogenic emissions such as anthropogenic VOCs (AVOCs) could change the particle formation yields and the aerosol properties, as was recently demonstrated (Emanuelsson et al., 2013; Flores et al., 2014). However, the effect of the interaction of BVOCs with AVOCs on cloud condensation nuclei (CCN) activity and hygroscopicity of SOA remains elusive. Characterizing such changes is necessary in order to assess the indirect radiative forcing of biogenic aerosols that form under anthropogenic influence. In this study, we investigated the influence of AVOCs on CCN activation and hygroscopic growth of BSOA. SOA was formed from photooxidation of monoterpenes and aromatics as representatives of BVOCs and AVOCs, respectively. The hygroscopicity and CCN activation of BSOA were studied and compared with that of anthropogenic SOA (ASOA) and the mixture of ASOA and BSOA (ABSOA). We found that ASOA had a significantly higher hygroscopicity than BSOA at similar OH dose, which is attributed to a higher oxidation level of ASOA. While the ASOA fraction had an enhancing effect on the hygroscopicity of ABSOA compared to BSOA, the hygroscopicity of ABSOA cannot be explained by a linear combination of the pure ASOA and BSOA systems, indicating potentially additional non-linear effects such as oligomerization. However, in contrast to hygroscopicity, ASOA showed similar CCN activity as BSOA, in spite of its higher oxidation level. The ASOA fraction did not enhance the CCN activity of ABSOA. The discrepancy between hygroscopicity and CCN activity is discussed. In addition, BSOA, ABSOA and ASOA formed similar droplet size with ammonium sulfate in CCN at a given supersaturation, indicating none of these aerosols had a delay in the water uptake in the supersaturated

  2. Taxation of virtual currency

    NARCIS (Netherlands)

    Bal, Aleksandra Marta

    2014-01-01

    The Information Age has created a new concept of money – virtual currencies existing solely in the cyberspace in the form of intangible computer code. The most prominent virtual currency scheme, Bitcoin, grabbed the public attention as its value skyrocketed at the beginning of 2012. Whereas Bitcoin

  3. OVERLAPPING VIRTUAL CADASTRAL DOCUMENTATION

    Directory of Open Access Journals (Sweden)

    Madalina - Cristina Marian

    2013-12-01

    Full Text Available Two cadastrale plans of buildings, can overlap virtual. Overlap is highlighted when digital reception. According to Law no. 7/1996 as amended and supplemented, to solve these problems is by updating the database graphs, the repositioning. This paper addresses the issue of overlapping virtual cadastre in the history of the period 1999-2012.

  4. VEM: Virtual Enterprise Methodology

    DEFF Research Database (Denmark)

    Tølle, Martin; Vesterager, Johan

    2003-01-01

    This chapter presents a virtual enterprise methodology (VEM) that outlines activities to consider when setting up and managing virtual enterprises (VEs). As a methodology the VEM helps companies to ask the right questions when preparing for and setting up an enterprise network, which works...

  5. Taxation of virtual currency

    NARCIS (Netherlands)

    Bal, Aleksandra Marta

    2014-01-01

    The Information Age has created a new concept of money – virtual currencies existing solely in the cyberspace in the form of intangible computer code. The most prominent virtual currency scheme, Bitcoin, grabbed the public attention as its value skyrocketed at the beginning of 2012. Whereas Bitcoin

  6. Virtual Seminar Room

    DEFF Research Database (Denmark)

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

    1999-01-01

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

  7. Virtual Company and Modelbank

    DEFF Research Database (Denmark)

    Thorsteinsson, Uffe

    1996-01-01

    Ansøgning til Socrates programmet vedr. Tematisk netværk inden for området Virtual Company and Modelbank......Ansøgning til Socrates programmet vedr. Tematisk netværk inden for området Virtual Company and Modelbank...

  8. Designing Virtual Learning Environments

    DEFF Research Database (Denmark)

    Veirum, Niels Einar

    2003-01-01

    The main objective of this working paper is to present a conceptual model for media integrated communication in virtual learning environments. The model for media integrated communication is very simple and identifies the necessary building blocks for virtual place making in a synthesis of methods...

  9. Virtual Reality Disruption

    National Research Council Canada - National Science Library

    Michael B Horn

    2016-01-01

    ... speculation about virtual reality's readiness to break through to the educational mainstream. The question is whether we should believe the hype. More Broadband, More Investment First, schools are upgrading their Internet connectivity, which is setting the stage for broadband-dependent virtual-reality learning. The federal ConnectED i...

  10. Virtual Trackballs Revisited

    DEFF Research Database (Denmark)

    Henriksen, Knud; Sporring, Jon; Hornbæk, Kasper

    2004-01-01

    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...

  11. Virtual School Counseling

    Science.gov (United States)

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

    2015-01-01

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

  12. Virtual School Counseling

    Science.gov (United States)

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

    2015-01-01

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

  13. Virtual Auditory Displays

    Science.gov (United States)

    2000-01-01

    timbre , intensity, distance, room modeling, radio communication Virtual Environments Handbook Chapter 4 Virtual Auditory Displays Russell D... musical note “A” as a pure sinusoid, there will be 440 condensations and rarefactions per second. The distance between two adjacent condensations or...and complexity are pitch, loudness, and timbre respectively. This distinction between physical and perceptual measures of sound properties is an

  14. Virtual Trauma Team

    NARCIS (Netherlands)

    Jones, Valerie M.; Bults, Richard G.A.

    2001-01-01

    The clinical motivation for Virtual Trauma Team is to improve quality of care in trauma care in the vital first "golden hour" where correct intervention can greatly improve likely health outcome. The motivation for Virtual Homecare Team is to improve quality of life and independence for patients by

  15. VEM: Virtual Enterprise Methodology

    DEFF Research Database (Denmark)

    Tølle, Martin; Vesterager, Johan

    2003-01-01

    This chapter presents a virtual enterprise methodology (VEM) that outlines activities to consider when setting up and managing virtual enterprises (VEs). As a methodology the VEM helps companies to ask the right questions when preparing for and setting up an enterprise network, which works as a b...

  16. Digging the Virtual Past

    Science.gov (United States)

    Polymeropoulou, Panagiota

    2014-01-01

    In this paper we will investigate the way that the technological progress and the Informatics contributed greatly to the field of Archaeology. There will be analyzed the terms of virtual archaeology and virtual reality in archaeology and there will be an extended reference to the applications and the computer graphics that archaeologists could use…

  17. Virtual reality musical instruments

    DEFF Research Database (Denmark)

    Serafin, Stefania; Erkut, Cumhur; Kojs, Juraj

    2016-01-01

    The rapid development and availability of low cost technologies has created a wide interest in virtual reality (VR), but how to design and evaluate multisensory interactions in VR remains as a challenge. In this paper, we focus on virtual reality musical instruments, present an overview of our...

  18. Virtual Schools. Literature Review

    Science.gov (United States)

    Blazer, Christie

    2009-01-01

    The majority of school districts in the U.S. are providing some form of online learning for their students. In the past, virtual schools primarily targeted advanced students who didn't have access to certain courses in their regular schools. Recently, however, many virtual schools have shifted their focus to credit recovery as a way to provide…

  19. Designing Virtual Learning Environments

    DEFF Research Database (Denmark)

    Veirum, Niels Einar

    2003-01-01

    The main objective of this working paper is to present a conceptual model for media integrated communication in virtual learning environments. The model for media integrated communication is very simple and identifies the necessary building blocks for virtual place making in a synthesis of methods...... from Cultural Media Science, Architecture and Digital Design...

  20. The issue of virtual teams

    OpenAIRE

    Fleiberková, Šárka

    2012-01-01

    The aim of this diploma thesis is the introduction of teamwork and virtual teams. The theoretical part of this work describes the birth of teamwork, its definition, properties, advantages and disadvantages. Next part of diploma thesis is dedicated to the virtual team. It describes the difference among virtual and traditional team, definition and characteristics of virtual team as well as tools that are used in virtual team. The second, practical, unit is focused on virtual teams at universiti...

  1. 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...... 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...... the audio-visual characteristics of designing in multi-user virtual environments generate experiential, interpersonal and textual meaning potentials....

  2. Intelligent virtual teacher

    Science.gov (United States)

    Takács, Ondřej; Kostolányová, Kateřina

    2016-06-01

    This paper describes the Virtual Teacher that uses a set of rules to automatically adapt the way of teaching. These rules compose of two parts: conditions on various students' properties or learning situation; conclusions that specify different adaptation parameters. The rules can be used for general adaptation of each subject or they can be specific to some subject. The rule based system of Virtual Teacher is dedicated to be used in pedagogical experiments in adaptive e-learning and is therefore designed for users without education in computer science. The Virtual Teacher was used in dissertation theses of two students, who executed two pedagogical experiments. This paper also describes the phase of simulating and modeling of the theoretically prepared adaptive process in the modeling tool, which has all the required parameters and has been created especially for the occasion. The experiments are being conducted on groups of virtual students and by using a virtual study material.

  3. Organization Virtual or Networked?

    Directory of Open Access Journals (Sweden)

    Rūta Tamošiūnaitė

    2013-08-01

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

  4. Organization Virtual or Networked?

    Directory of Open Access Journals (Sweden)

    Rūta Tamošiūnaitė

    2011-08-01

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

  5. Mercury: Combining Performance with Dependability Using Self-Virtualization

    Institute of Scientific and Technical Information of China (English)

    Hai-Bo Chen; Feng-Zhe Zhang; Rong Chen; Bin-Yu Zang; Pen-Chung Yew

    2012-01-01

    Virtualization has recently gained popularity largely due to its promise in increasing utilization,improving availability and enhancing security.Very often,the role of computer systems needs to change as the business environment changes.Initially,the system may only need to host one operating system and seek full execution speed.Later,it may be required to add other functionalities such as allowing easy software/hardware maintenance,surviving system failures and hosting multiple operating systems.Virtualization allows these functionalities to be supported easily and effectively.However,virtualization techniques generally incur non-negligible performance penalty.Fortunately,many virtualization-enabled features such as online software/hardware maintenance and fault tolerance do not require virtualization standby all the time. Based on this observation,this paper proposes a technique,called Self-virtualization,which provides the operating system with the capability to turn on and off virtualization on demand,without disturbing running applications.This technique enables computer systems to reap most benefits from virtualization without sacrificing performance.This paper presents the design and implementation of Mercury,a working prototype based on Linux and Xen virtual machine monitor.The performance measurement shows that Mercury incurs very little overhead:about 0.2 ms on 3 GHz Xeon CPU to complete a mode switch,and negligible performance degradation compared to Linux.

  6. Realization of Reconfigurable Virtual Environments for Virtual Testing

    Institute of Scientific and Technical Information of China (English)

    Wen-Yan Wu; Zheng-Xu Zhao

    2005-01-01

    This paper presents the design and implementation of reconfigurable virtual environments (VEs) for virtual testing. It proposes a hybrid design approach that is derived from a so-called integration and composition of the reconfiguration strategy. The designing process has thus evolved from binding virtual objects using reconfiguration rules within the context of virtual testing scenarios. Therefore reconfigurable virtual environments are established with improved flexibility and scalability, tailored to a wide range of virtual testing applications. Those virtual environments integrate virtual testing scenarios, data acquisition, databases, rule mapping and application interfaces, which yield modular testing functions and an open-ended system architecture with a set of extensible interface tools to realize data exchange within reconfigurable VEs.This enables virtual testing scenarios to be reconfigured interactively based on real time data and communication between virtual environments and real environments. A virtual testing application has been implemented using reconfigurable VEs.

  7. Virtualizing observation computing infrastructure at Subaru Telescope

    Science.gov (United States)

    Jeschke, Eric; Inagaki, Takeshi; Kackley, Russell; Schubert, Kiaina; Tait, Philip

    2016-08-01

    Subaru Telescope, an 8-meter class optical telescope located in Hawaii, has been using a high-availability commodity cluster as a platform for our Observation Control System (OCS). Until recently, we have followed a tried-and-tested practice of running the system under a native (Linux) OS installation with dedicated attached RAID systems and following a strict cluster deployment model to facilitate failover handling of hardware problems,1.2 Following the apparent benefits of virtualizing (i.e. running in Virtual Machines (VMs)) many of the non- observation critical systems at the base facility, we recently began to explore the idea of migrating other parts of the observatory's computing infrastructure to virtualized systems, including the summit OCS, data analysis systems and even the front ends of various Instrument Control Systems. In this paper we describe our experience with the initial migration of the Observation Control System to virtual machines running on the cluster and using a new generation tool - ansible - to automate installation and deployment. This change has significant impacts for ease of cluster maintenance, upgrades, snapshots/backups, risk-management, availability, performance, cost-savings and energy use. In this paper we discuss some of the trade-offs involved in this virtualization and some of the impacts for the above-mentioned areas, as well as the specific techniques we are using to accomplish the changeover, simplify installation and reduce management complexity.

  8. 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.

  9. Audiovisual navigation in virtual mazes : The benefits of audiovisual landmarks

    NARCIS (Netherlands)

    Werkhoven, Peter; Philippi, Tom; van Erp, J.B.F.

    2014-01-01

    It has been shown that multisensory presentation can improve perception, attention, and object memory compared with unisensory presentation. Consequently, we expect that multisensory presentation of landmarks can improve spatial memory and navigation. In this study we tested the effect of visual,

  10. Navigating virtual mazes : The benefits of audiovisual landmarks

    NARCIS (Netherlands)

    Werkhoven, P.; Erp, J.B.F. van; Philippi, T.G.

    2014-01-01

    It has been shown that multisensory presentation can improve perception, attention, and object memory compared with unisensory presentation. Consequently, we expect that multisensory presentation of landmarks can improve spatial memory and navigation. In this study we tested the effect of visual,

  11. Exercise: Benefits of Exercise

    Medline Plus

    Full Text Available ... A-Z > Exercise: Benefits of Exercise: Health Benefits In This Topic Health Benefits Benefits for Everyday Life ... Try Exercise: How to Stay Active The information in this topic was provided by the National Institute ...

  12. Virtual power plants with electric vehicles

    OpenAIRE

    Grau, Iñaki; Papadopoulos, Panagiotis; Skarvelis-Kazakos, Spyros; Cipcigan, Liana M.; Jenkins, Nick

    2010-01-01

    The benefits of integrating aggregated Electric Vehicles (EV) within the Virtual Power Plant (VPP) concept, are addressed. Two types of EV aggregators are identified: i) Electric Vehicle Residential Aggregator (EVRA), which is responsible for the management of dispersed and clustered EVs in a residential area and ii) Electric Vehicle Commercial Aggregator (EVCA), which is responsible for the management of EVs clustered in a single car park. A case study of a workplace EVCA is presented, provi...

  13. 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.

  14. Role of virtual reality simulation in endoscopy training

    Institute of Scientific and Technical Information of China (English)

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

    2015-01-01

    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 simula-tors and the long-term benefits of their use are also discussed.

  15. 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.

  16. Combined effects of surface conditions, boundary layer dynamics and chemistry on diurnal SOA evolution

    Directory of Open Access Journals (Sweden)

    R. H. H. Janssen

    2012-08-01

    Full Text Available We study the combined effects of land surface conditions, atmospheric boundary layer dynamics and chemistry on the diurnal evolution of biogenic secondary organic aerosol in the atmospheric boundary layer, using a model that contains the essentials of all these components. First, we evaluate the model for a case study in Hyytiälä, Finland, and find that it is able to satisfactorily reproduce the observed dynamics and gas-phase chemistry. We show that the exchange of organic aerosol between the free troposphere and the boundary layer (entrainment must be taken into account in order to explain the observed diurnal cycle in organic aerosol (OA concentration. An examination of the budgets of organic aerosol and terpene concentrations show that the former is dominated by entrainment, while the latter is mainly driven by emission and chemical transformation. We systematically investigate the role of the land surface, which governs both the surface energy balance partitioning and terpene emissions, and the large-scale atmospheric process of vertical subsidence. Entrainment is especially important for the dilution of organic aerosol concentrations under conditions of dry soils and low terpene emissions. Subsidence suppresses boundary layer growth while enhancing entrainment. Therefore, it influences the relationship between organic aerosol and terpene concentrations. Our findings indicate that the diurnal evolution of secondary organic aerosols (SOA in the boundary layer is the result of coupled effects of the land surface, dynamics of the atmospheric boundary layer, chemistry, and free troposphere conditions. This has potentially some consequences for the design of both field campaigns and large-scale modeling studies.

  17. Penerapan SOA menggunakan Enterprise Service Bus pada Proses Pengecekan Status Perizinan Pemerintah Kabupaten Sleman

    Directory of Open Access Journals (Sweden)

    Kabul Kurniawan

    2016-07-01

    Full Text Available The Implementation of web services using point-to-point method considered to be irrelevant weather the number of services are growing up rapidly and more complex. In the other hand, the differences of web service implementation standard is also being a serious problem when the integration and communication among web services are needed.One way that can be applied to provide management information system integration among others is the implementation of Enterprise Service Bus (ESB. ESB is an infrastructure that can be the solution of n-to-n integration complexity problem. ESB concept strongly supports the implementation of Service Oriented Architecture (SOA. This research will discuss about the implementation of ESB in government area, especially in Sleman, sub-district of Daerah Istimewa Yogyakarta local government, Indonesia. Some of ESB functionality such as Routing and Transformation  are applied to solve the  integration problem between Government to Public (G2P in case of checking lisence process at Badan Penanaman Modal dan Izin Terpadu (BMPT Sleman Sub-Distric. The results show that the ESB can be used as the mediator of information integration in case of checking lisence process. Beside that, the results of performance testing shows that the average execution time (AET for service operations reach up  to 0,085 seconds. Furthermore, the system has an average amount of execution  about 11.99 times and produces  data about 15746.86 bytes or equivalent to 15.38 KB per second. These results indicate that the execution time is considered to be small enaugh so that the services will not interfere the process of the transactions.

  18. 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.

  19. Simulation of aromatic SOA formation using the lumping model integrated with explicit gas-phase kinetic mechanisms and aerosol-phase reactions

    Science.gov (United States)

    Im, Y.; Jang, M.; Beardsley, R. L.

    2014-04-01

    The Unified Partitioning-Aerosol phase Reaction (UNIPAR) model has been developed to predict the secondary organic aerosol (SOA) formation through multiphase reactions. The model was evaluated with aromatic SOA data produced from the photooxidation of toluene and 1,3,5-trimethylbenzene (135-TMB) under various concentrations of NOx and SO2 using an outdoor reactor (University of Florida Atmospheric PHotochemical Outdoor Reactor (UF-APHOR) chamber). When inorganic species (sulfate, ammonium and water) are present in aerosol, the prediction of both toluene SOA and 135-TMB SOA, in which the oxygen-to-carbon (O : C) ratio is lower than 0.62, are approached under the assumption of a complete organic/electrolyte-phase separation below a certain relative humidity. An explicit gas-kinetic model was employed to express gas-phase oxidation of aromatic hydrocarbons. Gas-phase products are grouped based on their volatility (6 levels) and reactivity (5 levels) and exploited to construct the stoichiometric coefficient (αi,j) matrix, the set of parameters used to describe the concentrations of organic compounds in multiphase. Weighting of the αi,j matrix as a function of NOx improved the evaluation of NOx effects on aromatic SOA. The total amount of organic matter (OMT) is predicted by two modules in the UNIPAR model: OMP by a partitioning process and OMAR by aerosol-phase reactions. The OMAR module predicts multiphase reactions of organic compounds, such as oligomerization, acid-catalyzed reactions, and organosulfate (OS) formation. The model reasonably simulates SOA formation under various aerosol acidities, NOx concentrations, humidities and temperatures. Furthermore, the OS fractions in the SOA predicted by the model were in good agreement with the experimentally measured OS fractions.

  20. Biogenic SOA formation through gas-phase oxidation and gas-to-particle partitioning – comparison between process models of varying complexity

    Directory of Open Access Journals (Sweden)

    E. Hermansson

    2014-05-01

    Full Text Available Biogenic volatile organic compounds (BVOCs emitted by the vegetation play an important role for the aerosol mass loadings since the oxidation products of these compounds can take part in the formation and growth of secondary organic aerosols (SOA. The concentrations and properties of BVOCs and their oxidation products in the atmosphere are poorly characterized, which leads to high uncertainties in modeled SOA mass and properties. In this study the formation of SOA has been modeled along an air mass trajectory over the northern European boreal forest using two aerosol dynamics box models where the prediction of the condensable organics from the gas-phase oxidation of BVOC is handled with schemes of varying complexity. The use of box model simulations along an air mass trajectory allows us to, under atmospheric relevant conditions, compare different model parameterizations and their effect on SOA formation. The result of the study shows that the modeled mass concentration of SOA is highly dependent on the organic oxidation scheme used to predict the oxidation products. A near-explicit treatment of organic gas-phase oxidation (Master Chemical Mechanism version 3.2 was compared to oxidation schemes that use the volatility basis set (VBS approach. The resulting SOA mass modeled with different VBS-schemes varies by a factor of about 7 depending on how the first generation oxidation products are parameterized and how they subsequently age (e.g. how fast the gas-phase oxidation products react with the OH-radical, how they respond to temperature changes and if they are allowed to fragment during the aging process. Since the VBS approach is frequently used in regional and global climate models due to its relatively simple treatment of the oxidation products compared to near-explicit oxidation schemes; better understanding of the abovementioned processes are needed. Compared to the most commonly used VBS-schemes, the near-explicit method produces less

  1. Analisis Risk Assessment Menggunakan Process Hazard Analysis (PHA dan Safety Objective Analysis (SOA pada Central Gathering Station (CGS di Onshore Facilities

    Directory of Open Access Journals (Sweden)

    Dimas Jouhari

    2014-03-01

    Full Text Available Keselamatan proses merupakan faktor utama yang sering dibahas oleh industri-industri kimia beberapa tahun terakhir ini. Salah satu metode semi-kuantitatif yang dapat digunakan untuk mengidentifikasi, menganalisis, dan menetapkan tingkat risiko bahaya yaitu dengan Process Hazard Analysis (PHA dan Safety Objective Analysis (SOA. Hazard and Operability Studies (HAZOP dan What-If Analysis merupakan metode identifikasi bahaya kualitatif yang sering diterapkan secara simultan untuk PHA-SOA. Process Hazard Analysis (PHA ialah rangkaian aktivitas mengidentifikasi hazard, mengestimasi konsekuensi, mengestimasi likelihood suatu skenario proses disertai dengan safeguard, dan mendapatkan risk ranking yang dapat dilihat pada matrik PHA 6x6. Sedangkan Safety Objective Analysis (SOA merupakan rangkaian aktivitas yang bergantung pada penyebab skenario, dan konsekuensi dari PHA, menghasilkan kebutuhan IPL (Independent Protective Layer menggunakan matrik SOA 6x6. Risk ranking 6 pada penilaian PHA diketegorikan aman jika safeguard yang ada selalu siap mengurangi risiko yang timbul dari skenario tersebut. Namun tidak semua safeguard dapat selalu siap mengurangi risiko tersebut. Oleh karena itu, perlu adanya analisis tambahan untuk memastikan risiko dari skenario dapat diperkecil. Analisis safety suatu skenario dengan SOA menghasilkan kebutuhan IPL yang dapat ditutup dengan mengkonfirmasi safeguard yang sesuai menjadi IPL. Hasil penilaian PHA-SOA CGS 1, CGS 3, CGS 4, dan CGS 5 menunjukkan bahwa ada penilaian severity dan PHA-SOA likelihood yang berbeda di tiap CGS padahal proses pada CGS tersebut identik, maka perlu adanya analisis konsistensi. Hasil analisis konsistensi ini dapat dijadikan pedoman untuk melakukan safety review pada risk assessment workshop kedepannya, yang biasanya diadakan setiap tiga hingga lima tahun sekali oleh industri.

  2. Manufatura Virtual: conceituação e desafios Virtual Manufacturing: concepts and challenges

    Directory of Open Access Journals (Sweden)

    Arthur José Vieira Porto

    2002-12-01

    Full Text Available A Manufatura Virtual é uma nova proposta que está sendo utilizada por algumas empresas para revolucionar seus processos, visando introduzir no mercado produtos superiores, mais rapidamente e a um menor custo. A estratégia é criar um ambiente integrado, composto de diversos sistemas e ferramentas de software, com a finalidade de gerar um novo método de desenvolvimento de produto. Este artigo tem por objetivo apresentar o conceito de Manufatura Virtual, bem como os paradigmas envolvidos em sua definição, as aplicações potenciais e os benefícios esperados. Apresenta também os sistemas de suporte às atividades de Manufatura Virtual e uma análise dos desafios técnicos e socioculturais para sua implementação.Virtual Manufacturing has been used by some companies to improve their processes, introducing more quickly new products in the market. The strategy is to create an integrated environment, composed by several software tools and systems, aiming at generating a new method to develop products. The purpose of this paper is to present the Virtual Manufacturing concept and the paradigms involved in its definition. Then the paper describes the potential application areas and the resulting benefits. In addition, the technical and social challenges in development of a Virtual Manufacturing system are discussed at the end of the text.

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

    OpenAIRE

    Jan-Maarten Luursema; Marc Vorstenbosch; Jan Kooloos

    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 ...

  4. High availability using virtualization

    CERN Document Server

    Calzolari, Federico

    2009-01-01

    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 to share the running virtual machines over the servers up and running, by exploiting the features of the virtualization layer: start, stop and move virtual machines between physical hosts. The system (3RC) is based on a finite state machine with hysteresis, 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 virtu...

  5. Research of ODS elimination ability management information systems based on SOA and WCF%SOA 和 WCF 在 ODS 淘汰能力管理信息系统中的应用与研究

    Institute of Scientific and Technical Information of China (English)

    崔艳春

    2014-01-01

    This paper is based on the research background of ozone-depleting substances ( ODS) elimination a-bility management information systems for Jiangsu Province , discusses how to use SOA and WCF technology to realize ODS management information system .Partial function of the system is realized with WCF service applica-tion, and self-hosting adopted .Examples of typical operation are proposed with SOA concepts and WCF tech-niques .The result shows that ,SOA concepts and WCF techniques are introduced to the design and implementa-tion of ODS management information systems , software developers can distribute the task and cooperate better , development efficiency is improved , and difficulty of post-maintenance is decreased .%文中以江苏省消耗臭氧层物质( ozone depleting substances ,ODS)淘汰能力管理信息系统为研究背景,旨在论述如何使用SOA( service-oriented architecture )和WCF( windows communication foundation )技术实现ODS管理信息系统。系统部分功能以WCF服务应用程序实现,并采用自托管形式将服务宿主,融入SOA理念和WCF技术,给出了典型的运行实例。系统开发结果表明:SOA理念和WCF技术应用到ODS管理信息系统的设计与实现中,软件开发人员能够更好地分工协作,提高开发效率,降低后期维护难度。

  6. Modeling the formation of secondary organic aerosol (SOA). 2. The predicted effects of relative humidity on aerosol formation in the alpha-pinene-, beta-pinene-, sabinene-, delta 3-carene-, and cyclohexene-ozone systems.

    Science.gov (United States)

    Seinfeld, J H; Erdakos, G B; Asher, W E; Pankow, J F

    2001-05-01

    Atmospheric oxidation of volatile organic compounds can lead to the formation of secondary organic aerosol (SOA) through the gas/particle (G/P) partitioning of the oxidation products. Since water is ubiquitous in the atmosphere, the extent of the partitioning for any individual organic product depends not only on the amounts and properties of the partitioning organic compounds, but also on the amount of water present. Predicting the effects of water on the atmospheric G/P distributions of organic compounds is, therefore, central to understanding SOA formation. The goals of the current work are to gain understanding of how increases in RH affect (1) overall SOA yields, (2) water uptake by SOA, (3) the behaviors of individual oxidation products, and (4) the fundamental physical properties of the SOA phase that govern the G/P distribution of each of the oxidation products. Part 1 of this series considered SOA formation from five parent hydrocarbons in the absence of water. This paper predicts how adding RH to those systems uniformly increases both the amount of condensed organic mass and the amount of liquid water in the SOA phase. The presence of inorganic components is not considered. The effect of increasing RH is predicted to be stronger for SOA produced from cyclohexene as compared to SOA produced from four monoterpenes. This is likely a result of the greater general degree of oxidation (and hydrophilicity) of the cyclohexene products. Good agreement was obtained between predicted SOA yields and laboratory SOA yield data actually obtained in the presence of water. As RH increases, the compounds that play the largest roles in changing both the organic and water masses in the SOA phase are those with vapor pressures that are intermediate between those of essentially nonvolatile and highly volatile species. RH-driven changes in the compound-dependent G/P partitioning coefficient Kp result from changes in both the average molecular weight MWom of the absorbing

  7. The Virtual Dressing Room

    DEFF Research Database (Denmark)

    Holte, Michael Boelstoft; Gao, Yi; Petersson, Eva

    2015-01-01

    This paper presents the design and evaluation of a usability and user experience test of a virtual dressing room. First, we motivate and introduce our recent developed prototype of a virtual dressing room. Next, we present the research and test design grounded in related usability and user experi...... experience studies. We give a description of the experimental setup and the execution of the designed usability and user experience test. To this end, we report interesting results and discuss the results with respect to user-centered design and development of a virtual dressing room....

  8. Virtually Abelian quantum walks

    Science.gov (United States)

    Mauro D'Ariano, Giacomo; Erba, Marco; Perinotti, Paolo; Tosini, Alessandro

    2017-01-01

    We study discrete-time quantum walks on Cayley graphs of non-Abelian groups, focusing on the easiest case of virtually Abelian groups. We present a technique to reduce the quantum walk to an equivalent one on an Abelian group with coin system having larger dimension. This method allows one to extend the notion of wave-vector to the virtually Abelian case and study analytically the walk dynamics. We apply the technique in the case of two quantum walks on virtually Abelian groups with planar Cayley graphs, finding the exact solution in terms of dispersion relation.

  9. The virtual Haken conjecture

    CERN Document Server

    Agol, Ian; Manning, Jason

    2012-01-01

    We prove that cubulated hyperbolic groups are virtually special. The proof relies on results of Haglund and Wise which also imply that they are linear groups, and quasi-convex subgroups are separable. A consequence is that closed hyperbolic 3-manifolds have finite-sheeted Haken covers, which resolves the virtual Haken question of Waldhausen and Thurston's virtual fibering question. An appendix to this paper by Agol, Groves, and Manning proves a generalization of the main result of "Residual finiteness, QCERF and fillings of hyperbolic groups".

  10. Virtual Reality Musical Instruments

    DEFF Research Database (Denmark)

    Serafin, Stefania; Erkut, Cumhur; Kojs, Juraj

    2016-01-01

    The rapid development and availability of low-cost technologies have created a wide interest in virtual reality. In the field of computer music, the term “virtual musical instruments” has been used for a long time to describe software simulations, extensions of existing musical instruments......, and ways to control them with new interfaces for musical expression. Virtual reality musical instruments (VRMIs) that include a simulated visual component delivered via a head-mounted display or other forms of immersive visualization have not yet received much attention. In this article, we present a field...

  11. Virtual Reality Musical Instruments

    DEFF Research Database (Denmark)

    Serafin, Stefania; Erkut, Cumhur; Kojs, Juraj

    2016-01-01

    The rapid development and availability of low-cost technologies have created a wide interest in virtual reality. In the field of computer music, the term “virtual musical instruments” has been used for a long time to describe software simulations, extensions of existing musical instruments......, and ways to control them with new interfaces for musical expression. Virtual reality musical instruments (VRMIs) that include a simulated visual component delivered via a head-mounted display or other forms of immersive visualization have not yet received much attention. In this article, we present a field...

  12. [Clinical pathology on the verge of virtual microscopy].

    Science.gov (United States)

    Tolonen, Teemu; Näpänkangas, Juha; Isola, Jorma

    2015-01-01

    For more than 100 years, examinations of pathology specimens have relied on the use of the light microscope. The technological progress of the last few years is enabling the digitizing of histologic specimen slides and application of the virtual microscope in diagnostics. Virtual microscopy will facilitate consultation possibilities, and digital image analysis serves to enhance the level of diagnostics. Organizing and monitoring clinicopathological meetings will become easier. Digital archive of histologic specimens and the virtual microscopy network are expected to benefit training and research as well, particularly what applies to the Finnish biobank network which is currently being established.

  13. 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

  14. Development of Networked Virtual Experiment System Based on Virtual Campus

    OpenAIRE

    Tian-tai Guo; Guo, Lin; Li, Dong-Sheng

    2009-01-01

    China’s higher education has been going through a period of rapid expansion in undergraduate population,and this means a much heavier demand on teaching resources such as laboratories, experiments, teaching staff,etc., which cannot possibly be made available all of a sudden.To deal with this situation, we found virtual reality (VR) technology very helpful. Virtual reality (VR) has found many applications in education; and the resources of virtual education such as virtual campus, virtual labo...

  15. Virtual Museums as Educational Tool

    DEFF Research Database (Denmark)

    2007-01-01

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

  16. Virtual Museums as Educational Tool

    DEFF Research Database (Denmark)

    2007-01-01

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

  17. The surface properties of SOA generated from limonene and toluene using specific molecular probes: exploration of a new experimental technique

    Directory of Open Access Journals (Sweden)

    B. Demirdjian

    2005-02-01

    Full Text Available A new experimental technique of characterizing the aerosol-atmosphere surface has been explored using three examples: the secondary organic aerosols (SOA resulting from the reaction of limonene with O3 and from the photooxidation of toluene in comparison with the combustion aerosol (soot from a toluene diffusion flame. Rather than investigating the bulk composition of the aerosol by complete chemical analysis and identification of the many dozens if not more of constituent compounds we have interrogated the type and number of functional groups located at the aerosol surface by interacting them with specific molecular probes such as O3, NO2, N(CH33, and NH2OH to probe for the presence of oxidizable sites, acidic sites and carbonyl functionalities, respectively, that are present on the surface of the aerosol particle. In practice, typical amounts of one to a few mg of laboratory-generated SOA of limonene, toluene and soot have been deposited on a PTFE membrane filter that subsequently has been transferred to a molecular flow reactor used for the titration reaction of the surface functional groups by the molecular probes. Absolute amounts Ni with i=O3, NO2, N(CH33, NH2OH of probe molecules taken up by the filter sample measured using molecular beam sampling mass spectrometry have been converted into the number of surface group functionalities per unit surface area S using the aerosol particle distribution function (PDF of limonene and toluene SOA and the BET total surface area of toluene flame soot to result in Ni/S. Arguments are presented that support the transfer of the PDF of the suspended to the aerosol collected on the Teflon filter.

  18. Cuenca, realidad virtual

    National Research Council Canada - National Science Library

    Concepción Rodríguez Ruza; Adela Mª Muñoz Marquina; Aurelio Lorente González; Virginia Cañas Córdoba

    2012-01-01

    This project, Cuenca, realidad virtual, was created so that the key periods of the historical evolution of Cuenca could be explained, where the Islamic Cuenca, Christian Cuenca and Cuenca in the 18th...

  19. Virtual neutron scattering experiments

    DEFF Research Database (Denmark)

    Overgaard, Julie Hougaard; Bruun, Jesper; May, Michael

    2017-01-01

    We describe how virtual experiments can be utilized in a learning design that prepares students for hands-on experiments at large-scale facilities. We illustrate the design by showing how virtual experiments are used at the Niels Bohr Institute in a master level course on neutron scattering....... In the last week of the course, students travel to a large-scale neutron scattering facility to perform real neutron scattering experiments. Through student interviews and survey answers, we argue, that the virtual training prepares the students to engage more fruitfully with experiments by letting them focus...... on physics and data rather than the overwhelming instrumentation. We argue that this is because they can transfer their virtual experimental experience to the real-life situation. However, we also find that learning is still situated in the sense that only knowledge of particular experiments is transferred...

  20. Virtual neutron scattering experiments

    DEFF Research Database (Denmark)

    Overgaard, Julie Hougaard; Bruun, Jesper; May, Michael

    2016-01-01

    We describe how virtual experiments can be utilized in a learning design that prepares students for hands-on experiments at large-scale facilities. We illustrate the design by showing how virtual experiments are used at the Niels Bohr Institute in a master level course on neutron scattering....... In the last week of the course, students travel to a large-scale neutron scattering facility to perform real neutron scattering experiments. Through student interviews and survey answers, we argue, that the virtual training prepares the students to engage more fruitfully with experiments by letting them focus...... on physics and data rather than the overwhelming instrumentation. We argue that this is because they can transfer their virtual experimental experience to the real-life situation. However, we also find that learning is still situated in the sense that only knowledge of particular experiments is transferred...

  1. Virtual Factory Testbed

    Data.gov (United States)

    Federal Laboratory Consortium — The Virtual Factory Testbed (VFT) is comprised of three physical facilities linked by a standalone network (VFNet). The three facilities are the Smart and Wireless...

  2. Development of Networked Virtual Experiment System Based on Virtual Campus

    Directory of Open Access Journals (Sweden)

    Tian-tai Guo

    2009-10-01

    Full Text Available China’s higher education has been going through a period of rapid expansion in undergraduate population,and this means a much heavier demand on teaching resources such as laboratories, experiments, teaching staff,etc., which cannot possibly be made available all of a sudden.To deal with this situation, we found virtual reality (VR technology very helpful. Virtual reality (VR has found many applications in education; and the resources of virtual education such as virtual campus, virtual laboratory etc. are used more and more widely, especially in the field of higher education. But so far virtual campus was mainly regarded as a means of image exhibition, and virtual laboratories were no more than 2D display of experimental processes and equipments. To make better use of these resources, this paper puts forward the concept of networked virtual experiment systems based on virtual campus by combining the virtual laboratory and virtual campus with the technique of LAN (Local area network, and establishes its theoretical model. Finally, a networked virtual experiment system based on virtual campus is developed using VRML and 3DSMAX. Networked virtual experiment system based on virtual campus has a promising future for various applications in higher education.

  3. Virtual Fitting Rooms

    OpenAIRE

    Becerra Rodríguez, Carlos Alfredo

    2016-01-01

    In the last decade a considerable number of efforts have been devoted into developing Virtual Fitting Rooms (VFR) due to the great popularity of Virtual Reality (VR) and Augmented Reality (AR) in the fashion design industry. The existence of new technologies such as Kinect, powerful web cameras and smartphones permit us to examine new ways to try on clothes without doing it physically in a store center. This research is primarily dedicated to review some important aspects about...

  4. Virtual screening against obesity.

    Science.gov (United States)

    Markt, P; Herdlinger, S; Schuster, D

    2011-01-01

    The development of novel drugs against obesity is one of the top priorities of worldwide drug research. In recent years, it has been facilitated by the application of virtual screening methods. In this review, we give a short introduction into obesity-related protein targets and computer-aided drug design techniques. Furthermore, we highlight the most successful virtual screening studies, outline their results, and provide suggestions for future anti-obesity drug development.

  5. Quantum Virtual Machine (QVM)

    Energy Technology Data Exchange (ETDEWEB)

    2016-11-18

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

  6. Taxation of virtual currency

    OpenAIRE

    Bal, Aleksandra Marta

    2014-01-01

    The Information Age has created a new concept of money – virtual currencies existing solely in the cyberspace in the form of intangible computer code. The most prominent virtual currency scheme, Bitcoin, grabbed the public attention as its value skyrocketed at the beginning of 2012. Whereas Bitcoin has many proper ties that could make it an ideal currency for mainstream consumers and merchants, its main drawback is lack of clarity regarding its legal status and tax treatment. The European Cen...

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

    OpenAIRE

    Yuntao Zhao; Hengchi Liu; Yongxin Feng

    2016-01-01

    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 destinati...

  8. Half baudrate electrical clock based demultiplexing scheme for OTDM-DQPSK signal using SOA and optical filter

    Institute of Scientific and Technical Information of China (English)

    Hui Wang; Deming Kong; Yan Li; Junyi Zhang; Jian Wu; Jintong Lin

    2012-01-01

    A demultiplexing scheme based on semiconductor optical amplifier (SOA) and optical filter for optical time division multiplexing differential quadrature phase shift keying (OTDM-DQPSK) system is proposed and investigated experimentally.With only a common half baudrate electrical clock modulated 33% duty cycle return-to-zero (RZ-33) optical clock signal as pump,this scheme is cost-effective,energy-efficient,and integration-potential.A proof-of-concept experiment is carried out for the demultiplexing of a 2×40GBd OTDM-DQPSK signal.Error-free performance is demonstrated,and the average power penalty for both channels is about 3 dB.

  9. 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

    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......We present an all-optical adaptive-antenna radio over fiber transport system that uses proven, commercially-available components to effectively deliver standard-compliant optical signaling to adaptive multiantenna arrays for current and emerging radio technology implementations. The system is based...

  10. IMPROVING VIRTUAL MACHINE SECURITY THROUGH INTELLIGENT INTRUSION DETECTION SYSTEM

    Directory of Open Access Journals (Sweden)

    Ambikavathi C

    2015-04-01

    Full Text Available Virtualization is the key feature of cloud computing which facilitates sharing of common resources among cloud users. As cloud computing is a shared facility and accessed remotely, it is vulnerable to various attacks. The shared resources may be exploited by the attackers through vulnerabilities. Virtualization technology is implemented by instantiating a virtual machine to each cloud user based on their requirements. Many virtual machines are instantiated on a single physical infrastructure. Although this virtualization technology is more beneficent for the users by means of low cost and for service providers by means of better utilization, it has several risks, in which security is the major one. Benefits of virtualization go beyond the cost savings. By better planning and management virtualization risk can be mitigated. The proposed work secures virtual machines by creating VM profiles, packet monitoring and by conducting periodic centralized vulnerability scans. It is consistent because both signature based and anomaly based IDS are combined. It is efficient because only the VMs affected by infected packets are scanned for vulnerability.

  11. Virtual integral holography

    Science.gov (United States)

    Venolia, Dan S.; Williams, Lance

    1990-08-01

    A range of stereoscopic display technologies exist which are no more intrusive, to the user, than a pair of spectacles. Combining such a display system with sensors for the position and orientation of the user's point-of-view results in a greatly enhanced depiction of three-dimensional data. As the point of view changes, the stereo display channels are updated in real time. The face of a monitor or display screen becomes a window on a three-dimensional scene. Motion parallax naturally conveys the placement and relative depth of objects in the field of view. Most of the advantages of "head-mounted display" technology are achieved with a less cumbersome system. To derive the full benefits of stereo combined with motion parallax, both stereo channels must be updated in real time. This may limit the size and complexity of data bases which can be viewed on processors of modest resources, and restrict the use of additional three-dimensional cues, such as texture mapping, depth cueing, and hidden surface elimination. Effective use of "full 3D" may still be undertaken in a non-interactive mode. Integral composite holograms have often been advanced as a powerful 3D visualization tool. Such a hologram is typically produced from a film recording of an object on a turntable, or a computer animation of an object rotating about one axis. The individual frames of film are multiplexed, in a composite hologram, in such a way as to be indexed by viewing angle. The composite may be produced as a cylinder transparency, which provides a stereo view of the object as if enclosed within the cylinder, which can be viewed from any angle. No vertical parallax is usually provided (this would require increasing the dimensionality of the multiplexing scheme), but the three dimensional image is highly resolved and easy to view and interpret. Even a modest processor can duplicate the effect of such a precomputed display, provided sufficient memory and bus bandwidth. This paper describes the

  12. 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.

  13. 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.

  14. Single-mode SOA-based 1kHz-linewidth dual-wavelength random fiber laser.

    Science.gov (United States)

    Xu, Yanping; Zhang, Liang; Chen, Liang; Bao, Xiaoyi

    2017-07-10

    Narrow-linewidth multi-wavelength fiber lasers are of significant interests for fiber-optic sensors, spectroscopy, optical communications, and microwave generation. A novel narrow-linewidth dual-wavelength random fiber laser with single-mode operation, based on the semiconductor optical amplifier (SOA) gain, is achieved in this work for the first time, to the best of our knowledge. A simplified theoretical model is established to characterize such kind of random fiber laser. The inhomogeneous gain in SOA mitigates the mode competition significantly and alleviates the laser instability, which are frequently encountered in multi-wavelength fiber lasers with Erbium-doped fiber gain. The enhanced random distributed feedback from a 5km non-uniform fiber provides coherent feedback, acting as mode selection element to ensure single-mode operation with narrow linewidth of ~1kHz. The laser noises are also comprehensively investigated and studied, showing the improvements of the proposed random fiber laser with suppressed intensity and frequency noises.

  15. 基于SOA架构的BPO业务流研究%BPO Business Flow Study Based on SOA Architecture

    Institute of Scientific and Technical Information of China (English)

    杨倩; 秦凤梅

    2013-01-01

    低成本不再是中国软件外包产业中的优势,在人力成本方面会失去优势.在这种情况下,BPO(业务流程外包)将成为更加主流的外包形式,BPO带来的不只是技术上的先进,更多的是服务和管理上的进步.该文从介绍SOA体系架构的思想和分析BPO业务流程入手,分析了当前BPO业务的需求,进而提出了一种基于SOA体系架构的BPO业务流的构建方式,并描述了这过程中涉及到几个关键步骤.%Low cost is no longer a Chinese software outsourcing industry 's advantage,It will lose its edge in terms of cost of hu?man. In this case, the BPO ( business process outsourcing ) will become more mainstream form of outsourcing, BPO not only bring advanced technology, more is the service and management of progress. This paper introduces the architecture of SOA thought and analysis of BPO business process proceed with, analysed current BPO business needs, then proposed one kind based on the SOA system architecture of the BPO business flow construction, and describes the process involved in several key steps.

  16. Exercise: Benefits of Exercise

    Medline Plus

    Full Text Available ... please turn Javascript on. Exercise: Benefits of Exercise Health Benefits One of the Healthiest Things You Can ... yourself. Studies have shown that exercise provides many health benefits and that older adults can gain a ...

  17. Benefits of Physical Activity

    Science.gov (United States)

    ... page from the NHLBI on Twitter. Benefits of Physical Activity Physical activity has many health benefits. These benefits ... of physical activity for your heart and lungs. Physical Activity Strengthens Your Heart and Improves Lung Function When ...

  18. 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.

  19. Soul Anatomy: A virtual cadaver

    Directory of Open Access Journals (Sweden)

    Moaz Bambi

    2014-01-01

    Full Text Available In the traditional science of medicine and medical education, teaching human anatomy in the class has always been done using human cadavers. Not only does this violate human sanctity, but according to our research, it is not adequate to provide students with the alleged educational value that it is supposed to deliver. It is very cumbersome to organise all the aspects of cadaver care. Cadavers are also very limited when it comes to controlling their structures and any benefit is almost completely altered the first time the cadaver is used (dissected, and ironically, it is very weak at delivering actual real-life scenarios of a human body to students. Virtual anatomy has been a promising solution that many are counting on. But even today, we have not found a complete solution that combines all the benefits of using human cadavers and those introduced by its technical counterparts. "Soul Anatomy" aims to do just that. It brings the best of all worlds, from a natural intuitive control system, life-like feel of organs, precise accuracy in moving and controlling bodily structures, to the smallest details of being able to show medical information overlays from various medical databases connected to the internet; thus making use of technology in teaching human anatomy by providing a modern learning experience.

  20. 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.