National Culture in Practice: Its Impact on Knowledge Sharing in Global Virtual Collaboration

ERIC Educational Resources Information Center

Wei, Kangning

2009-01-01

Issues concerning global virtual collaboration have received considerable attention in both the academic and practical world; however, little research has been conducted on knowledge-sharing activities in global virtual collaboration, which is a key process to achieve collaboration effectiveness. Due to national culture having been seen as one of…

Stochastic Prediction and Feedback Control of Router Queue Size in a Virtual Network Environment

DTIC Science & Technology

2014-09-18

predictor equations, while the update equations for measurement can be thought of as corrector equations. 11 2.3.1.1 Predict Equations In the... Adaptive Filters and Self -Learning Systems. Springer London, 2005. [11] Zarchan, P., and Musoff, H. Fundamentals of Kalman filtering: A Practical...iv AFIT-ENG-T-14-S-10 Abstract Modern congestion and routing management algorithms work well for networks with static topologies and moderate

A Proposed Framework for Collaborative Design in a Virtual Environment

NASA Astrophysics Data System (ADS)

Breland, Jason S.; Shiratuddin, Mohd Fairuz

This paper describes a proposed framework for a collaborative design in a virtual environment. The framework consists of components that support a true collaborative design in a real-time 3D virtual environment. In support of the proposed framework, a prototype application is being developed. The authors envision the framework will have, but not limited to the following features: (1) real-time manipulation of 3D objects across the network, (2) support for multi-designer activities and information access, (3) co-existence within same virtual space, etc. This paper also discusses a proposed testing to determine the possible benefits of a collaborative design in a virtual environment over other forms of collaboration, and results from a pilot test.

Virtual Teaming and Collaboration Technology: A Study of Influences on Virtual Project Outcomes

ERIC Educational Resources Information Center

Broils, Gary C.

2014-01-01

The purpose of this quantitative correlational study was to explore the relationships between the independent variables, contextual factors for virtual teams and collaboration technology, and the dependent variable, virtual project outcomes. The problem leading to the need for the study is a lower success rate for virtual projects compared to…

Incorporating Brokers within Collaboration Environments

NASA Astrophysics Data System (ADS)

Rajasekar, A.; Moore, R.; de Torcy, A.

2013-12-01

A collaboration environment, such as the integrated Rule Oriented Data System (iRODS - http://irods.diceresearch.org), provides interoperability mechanisms for accessing storage systems, authentication systems, messaging systems, information catalogs, networks, and policy engines from a wide variety of clients. The interoperability mechanisms function as brokers, translating actions requested by clients to the protocol required by a specific technology. The iRODS data grid is used to enable collaborative research within hydrology, seismology, earth science, climate, oceanography, plant biology, astronomy, physics, and genomics disciplines. Although each domain has unique resources, data formats, semantics, and protocols, the iRODS system provides a generic framework that is capable of managing collaborative research initiatives that span multiple disciplines. Each interoperability mechanism (broker) is linked to a name space that enables unified access across the heterogeneous systems. The collaboration environment provides not only support for brokers, but also support for virtualization of name spaces for users, files, collections, storage systems, metadata, and policies. The broker enables access to data or information in a remote system using the appropriate protocol, while the collaboration environment provides a uniform naming convention for accessing and manipulating each object. Within the NSF DataNet Federation Consortium project (http://www.datafed.org), three basic types of interoperability mechanisms have been identified and applied: 1) drivers for managing manipulation at the remote resource (such as data subsetting), 2) micro-services that execute the protocol required by the remote resource, and 3) policies for controlling the execution. For example, drivers have been written for manipulating NetCDF and HDF formatted files within THREDDS servers. Micro-services have been written that manage interactions with the CUAHSI data repository, the DataONE information catalog, and the GeoBrain broker. Policies have been written that manage transfer of messages between an iRODS message queue and the Advanced Message Queuing Protocol. Examples of these brokering mechanisms will be presented. The DFC collaboration environment serves as the intermediary between community resources and compute grids, enabling reproducible data-driven research. It is possible to create an analysis workflow that retrieves data subsets from a remote server, assemble the required input files, automate the execution of the workflow, automatically track the provenance of the workflow, and share the input files, workflow, and output files. A collaborator can re-execute a shared workflow, compare results, change input files, and re-execute an analysis.

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

ERIC Educational Resources Information Center

Nunez Esquer, Gustavo; Sheremetov, Leonid

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

Collaborative Virtual Gaming Worlds in Higher Education

ERIC Educational Resources Information Center

Whitton, Nicola; Hollins, Paul

2008-01-01

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 multi-player 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…

A study on haptic collaborative game in shared virtual environment

NASA Astrophysics Data System (ADS)

Lu, Keke; Liu, Guanyang; Liu, Lingzhi

2013-03-01

A study on collaborative game in shared virtual environment with haptic feedback over computer networks is introduced in this paper. A collaborative task was used where the players located at remote sites and played the game together. The player can feel visual and haptic feedback in virtual environment compared to traditional networked multiplayer games. The experiment was desired in two conditions: visual feedback only and visual-haptic feedback. The goal of the experiment is to assess the impact of force feedback on collaborative task performance. Results indicate that haptic feedback is beneficial for performance enhancement for collaborative game in shared virtual environment. The outcomes of this research can have a powerful impact on the networked computer games.

A collaborative molecular modeling environment using a virtual tunneling service.

PubMed

Lee, Jun; Kim, Jee-In; Kang, Lin-Woo

2012-01-01

Collaborative researches of three-dimensional molecular modeling can be limited by different time zones and locations. A networked virtual environment can be utilized to overcome the problem caused by the temporal and spatial differences. However, traditional approaches did not sufficiently consider integration of different computing environments, which were characterized by types of applications, roles of users, and so on. We propose a collaborative molecular modeling environment to integrate different molecule modeling systems using a virtual tunneling service. We integrated Co-Coot, which is a collaborative crystallographic object-oriented toolkit, with VRMMS, which is a virtual reality molecular modeling system, through a collaborative tunneling system. The proposed system showed reliable quantitative and qualitative results through pilot experiments.

Share (And Not) Share Alike: Improving Virtual Team Climate and Decision Performance

ERIC Educational Resources Information Center

Cordes, Sean

2017-01-01

Virtual teams face unique communication and collaboration challenges that impact climate development and performance. First, virtual teams rely on technology mediated communication which can constrain communication. Second, team members lack skill for adapting process to the virtual setting. A collaboration process structure was designed to…

A Collaborative Molecular Modeling Environment Using a Virtual Tunneling Service

PubMed Central

Lee, Jun; Kim, Jee-In; Kang, Lin-Woo

2012-01-01

Collaborative researches of three-dimensional molecular modeling can be limited by different time zones and locations. A networked virtual environment can be utilized to overcome the problem caused by the temporal and spatial differences. However, traditional approaches did not sufficiently consider integration of different computing environments, which were characterized by types of applications, roles of users, and so on. We propose a collaborative molecular modeling environment to integrate different molecule modeling systems using a virtual tunneling service. We integrated Co-Coot, which is a collaborative crystallographic object-oriented toolkit, with VRMMS, which is a virtual reality molecular modeling system, through a collaborative tunneling system. The proposed system showed reliable quantitative and qualitative results through pilot experiments. PMID:22927721

A workout for virtual bodybuilders (design issues for embodiment in multi-actor virtual environments)

NASA Technical Reports Server (NTRS)

Benford, Steve; Bowers, John; Fahlen, Lennart E.; Greenhalgh, Chris; Snowdon, Dave

1994-01-01

This paper explores the issue of user embodiment within collaborative virtual environments. By user embodiment we mean the provision of users with appropriate body images so as to represent them to others and also to themselves. By collaborative virtual environments we mean multi-user virtual reality systems which support cooperative work (although we argue that the results of our exploration may also be applied to other kinds of collaborative systems). The main part of the paper identifies a list of embodiment design issues including: presence, location, identity, activity, availability, history of activity, viewpoint, action point, gesture, facial expression, voluntary versus involuntary expression, degree of presence, reflecting capabilities, manipulating the user's view of others, representation across multiple media, autonomous and distributed body parts, truthfulness and efficiency. Following this, we show how these issues are reflected in our own DIVE and MASSIVE prototype collaborative virtual environments.

Concurrent array-based queue

DOEpatents

Heidelberger, Philip; Steinmacher-Burow, Burkhard

2015-01-06

According to one embodiment, a method for implementing an array-based queue in memory of a memory system that includes a controller includes configuring, in the memory, metadata of the array-based queue. The configuring comprises defining, in metadata, an array start location in the memory for the array-based queue, defining, in the metadata, an array size for the array-based queue, defining, in the metadata, a queue top for the array-based queue and defining, in the metadata, a queue bottom for the array-based queue. The method also includes the controller serving a request for an operation on the queue, the request providing the location in the memory of the metadata of the queue.

An investigation of the efficacy of collaborative virtual reality systems for moderated remote usability testing.

PubMed

Chalil Madathil, Kapil; Greenstein, Joel S

2017-11-01

Collaborative virtual reality-based systems have integrated high fidelity voice-based communication, immersive audio and screen-sharing tools into virtual environments. Such three-dimensional collaborative virtual environments can mirror the collaboration among usability test participants and facilitators when they are physically collocated, potentially enabling moderated usability tests to be conducted effectively when the facilitator and participant are located in different places. We developed a virtual collaborative three-dimensional remote moderated usability testing laboratory and employed it in a controlled study to evaluate the effectiveness of moderated usability testing in a collaborative virtual reality-based environment with two other moderated usability testing methods: the traditional lab approach and Cisco WebEx, a web-based conferencing and screen sharing approach. Using a mixed methods experimental design, 36 test participants and 12 test facilitators were asked to complete representative tasks on a simulated online shopping website. The dependent variables included the time taken to complete the tasks; the usability defects identified and their severity; and the subjective ratings on the workload index, presence and satisfaction questionnaires. Remote moderated usability testing methodology using a collaborative virtual reality system performed similarly in terms of the total number of defects identified, the number of high severity defects identified and the time taken to complete the tasks with the other two methodologies. The overall workload experienced by the test participants and facilitators was the least with the traditional lab condition. No significant differences were identified for the workload experienced with the virtual reality and the WebEx conditions. However, test participants experienced greater involvement and a more immersive experience in the virtual environment than in the WebEx condition. The ratings for the virtual environment condition were not significantly different from those for the traditional lab condition. The results of this study suggest that participants were productive and enjoyed the virtual lab condition, indicating the potential of a virtual world based approach as an alternative to conventional approaches for synchronous usability testing. Copyright © 2017 Elsevier Ltd. All rights reserved.

Designing and Deploying 3D Collaborative Games in Education

ERIC Educational Resources Information Center

Mavridis, Apostolos; Tsiatsos, Thrasyvoulos; Terzidou, Theodouli

2016-01-01

This paper focuses on methodologies of serious games deployment and evaluation. Particularly, this study will present a specific category of serious games that are based on Collaborative Virtual Environments and they aim to support Collaborative Learning. We call these serious games Collaborative Virtual Educational Games (CVEG). The paper aims to…

Cyberinfrastructure and Scientific Collaboration: Application of a Virtual Team Performance Framework with Potential Relevance to Education. WCER Working Paper No. 2010-12

ERIC Educational Resources Information Center

Kraemer, Sara; Thorn, Christopher A.

2010-01-01

The purpose of this exploratory study was to identify and describe some of the dimensions of scientific collaborations using high throughput computing (HTC) through the lens of a virtual team performance framework. A secondary purpose was to assess the viability of using a virtual team performance framework to study scientific collaborations using…

Distributed collaborative environments for virtual capability-based planning

NASA Astrophysics Data System (ADS)

McQuay, William K.

2003-09-01

Distributed collaboration is an emerging technology that will significantly change how decisions are made in the 21st century. Collaboration involves two or more geographically dispersed individuals working together to share and exchange data, information, knowledge, and actions. The marriage of information, collaboration, and simulation technologies provides the decision maker with a collaborative virtual environment for planning and decision support. This paper reviews research that is focusing on the applying open standards agent-based framework with integrated modeling and simulation to a new Air Force initiative in capability-based planning and the ability to implement it in a distributed virtual environment. Virtual Capability Planning effort will provide decision-quality knowledge for Air Force resource allocation and investment planning including examining proposed capabilities and cost of alternative approaches, the impact of technologies, identification of primary risk drivers, and creation of executable acquisition strategies. The transformed Air Force business processes are enabled by iterative use of constructive and virtual modeling, simulation, and analysis together with information technology. These tools are applied collaboratively via a technical framework by all the affected stakeholders - warfighter, laboratory, product center, logistics center, test center, and primary contractor.

Communication, Collaboration, and Enhancing the Learning Experience: Developing a Collaborative Virtual Enquiry Service in University Libraries in the North of England

ERIC Educational Resources Information Center

Jolly, Liz; White, Sue

2016-01-01

This article uses the case study of developing a collaborative "out-of-hours" virtual enquiry service by members of the Northern Collaboration Group of academic libraries in the north of England to explore the importance of communication and collaboration between academic library services in enhancing student learning. Set within the…

Knowledge Sharing in Virtual Teams: The Impact on Trust, Collaboration, and Team Effectiveness

ERIC Educational Resources Information Center

Alsharo, Mohammad K.

2013-01-01

Virtual teams are utilized by organizations to gather experts to collaborate online in order to accomplish organizational tasks. However, the characteristics of these teams create challenges to effective collaboration and effective team outcome. Collaboration is an essential component of teamwork, the notion of forming teams in organizations is…

Virtual Collaboration Readiness Measurement a Case Study in the Automobile Industry

NASA Astrophysics Data System (ADS)

Ziarati, Koorush; Khayami, Raouf; Parvinnia, Elham; Afroozi Milani, Ghazal

In end of the last century information and communication technology caused a veritable evolution in the world of business and commerce. Globalization has changed all the commerce equations and business plans. Old companies have to change their strategies if they want to survive after this technological revolution. A new form of collaboration between the distributed and networked organizations has emerged as the "Virtual Organization" paradigm. A company can not join a virtual organization before obtaining a virtual maturity. This maturity shows the readiness of the company to begin a virtual collaboration. In this paper, based on the coherent and formal definition of virtual organizations, the criteria for measuring the readiness of companies are proposed. Our criteria are confirmed, modified or combined by using the factor analysis method on a sufficient number of virtual companies in the automobile manufacturing industry.

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

USDA-ARS?s Scientific Manuscript database

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

Virtual Teams and E-Collaboration Technology: A Case Study Investigating the Dynamics of Virtual Team Communication

ERIC Educational Resources Information Center

Mattison, Theresa

2011-01-01

The purpose of this study was to determine to what extent the use of e-collaboration tools when used as a primary channel of communication affected virtual team members' trust and motivation, in a spatially dispersed environment. Structured interviews were conducted with 18 project managers, who were responsible for leading virtual projects…

Implementing Advanced Characteristics of X3D Collaborative Virtual Environments for Supporting e-Learning: The Case of EVE Platform

ERIC Educational Resources Information Center

Bouras, Christos; Triglianos, Vasileios; Tsiatsos, Thrasyvoulos

2014-01-01

Three dimensional Collaborative Virtual Environments are a powerful form of collaborative telecommunication applications, enabling the users to share a common three-dimensional space and interact with each other as well as with the environment surrounding them, in order to collaboratively solve problems or aid learning processes. Such an…

Handbook of Research on Collaborative Teaching Practice in Virtual Learning Environments

ERIC Educational Resources Information Center

Panconesi, Gianni, Ed.; Guida, Maria, Ed.

2017-01-01

Modern technology has enhanced many aspects of life, including classroom education. By offering virtual learning experiences, educational systems can become more efficient and effective at teaching the student population. The "Handbook of Research on Collaborative Teaching Practice in Virtual Learning Environments" highlights program…

Elearn: A Collaborative Educational Virtual Environment.

ERIC Educational Resources Information Center

Michailidou, Anna; Economides, Anastasios A.

Virtual Learning Environments (VLEs) that support collaboration are one of the new technologies that have attracted great interest. VLEs are learning management software systems composed of computer-mediated communication software and online methods of delivering course material. This paper presents ELearn, a collaborative VLE for teaching…

Efficient accesses of data structures using processing near memory

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

Jayasena, Nuwan S.; Zhang, Dong Ping; Diez, Paula Aguilera

Systems, apparatuses, and methods for implementing efficient queues and other data structures. A queue may be shared among multiple processors and/or threads without using explicit software atomic instructions to coordinate access to the queue. System software may allocate an atomic queue and corresponding queue metadata in system memory and return, to the requesting thread, a handle referencing the queue metadata. Any number of threads may utilize the handle for accessing the atomic queue. The logic for ensuring the atomicity of accesses to the atomic queue may reside in a management unit in the memory controller coupled to the memory wheremore » the atomic queue is allocated.« less

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

ERIC Educational Resources Information Center

Wright, Sharon L.

2013-01-01

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

Preventing messaging queue deadlocks in a DMA environment

DOEpatents

Blocksome, Michael A; Chen, Dong; Gooding, Thomas; Heidelberger, Philip; Parker, Jeff

2014-01-14

Embodiments of the invention may be used to manage message queues in a parallel computing environment to prevent message queue deadlock. A direct memory access controller of a compute node may determine when a messaging queue is full. In response, the DMA may generate and interrupt. An interrupt handler may stop the DMA and swap all descriptors from the full messaging queue into a larger queue (or enlarge the original queue). The interrupt handler then restarts the DMA. Alternatively, the interrupt handler stops the DMA, allocates a memory block to hold queue data, and then moves descriptors from the full messaging queue into the allocated memory block. The interrupt handler then restarts the DMA. During a normal messaging advance cycle, a messaging manager attempts to inject the descriptors in the memory block into other messaging queues until the descriptors have all been processed.

Virtual Teaming: Faculty Collaboration in Online Spaces

ERIC Educational Resources Information Center

Almjeld, Jen; Rybas, Natalia; Rybas, Sergey

2013-01-01

This collaborative article chronicles the experiences of three faculty at three universities utilizing wiki technology to transform themselves and their students into a virtual team. Rooted in workplace approaches to distributed teaming, the project expands notions of classroom collaboration to include planning, administration, and assessment of a…

Message passing with queues and channels

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

Dozsa, Gabor J; Heidelberger, Philip; Kumar, Sameer

In an embodiment, a reception thread receives a source node identifier, a type, and a data pointer from an application and, in response, creates a receive request. If the source node identifier specifies a source node, the reception thread adds the receive request to a fast-post queue. If a message received from a network does not match a receive request on a posted queue, a polling thread adds a receive request that represents the message to an unexpected queue. If the fast-post queue contains the receive request, the polling thread removes the receive request from the fast-post queue. If themore » receive request that was removed from the fast-post queue does not match the receive request on the unexpected queue, the polling thread adds the receive request that was removed from the fast-post queue to the posted queue. The reception thread and the polling thread execute asynchronously from each other.« less

Increasing available FIFO space to prevent messaging queue deadlocks in a DMA environment

DOEpatents

Blocksome, Michael A [Rochester, MN; Chen, Dong [Croton On Hudson, NY; Gooding, Thomas [Rochester, MN; Heidelberger, Philip [Cortlandt Manor, NY; Parker, Jeff [Rochester, MN

2012-02-07

Embodiments of the invention may be used to manage message queues in a parallel computing environment to prevent message queue deadlock. A direct memory access controller of a compute node may determine when a messaging queue is full. In response, the DMA may generate an interrupt. An interrupt handler may stop the DMA and swap all descriptors from the full messaging queue into a larger queue (or enlarge the original queue). The interrupt handler then restarts the DMA. Alternatively, the interrupt handler stops the DMA, allocates a memory block to hold queue data, and then moves descriptors from the full messaging queue into the allocated memory block. The interrupt handler then restarts the DMA. During a normal messaging advance cycle, a messaging manager attempts to inject the descriptors in the memory block into other messaging queues until the descriptors have all been processed.

Collaborative Learning in Online Courses: Exploring Students' Perceptions

ERIC Educational Resources Information Center

Faja, Silvana

2013-01-01

Virtual collaborative activities have the potential to keep students engaged, create a sense of community in online courses and allow them to experience and practice virtual teamwork skills. This study presents an attempt to explore students' perceptions of online collaborative learning involving both process and product oriented activities. The…

The Impact of Using Synchronous Collaborative Virtual Tangram in Children's Geometric

ERIC Educational Resources Information Center

Lin, Chiu-Pin; Shao, Yin-juan; Wong, Lung-Hsiang; Li, Yin-Jen; Niramitranon, Jitti

2011-01-01

This study aimed to develop a collaborative and manipulative virtual Tangram puzzle to facilitate children to learn geometry in the computer-supported collaborative learning environment with Tablet PCs. In promoting peer interactions and stimulating students' higher-order thinking and creativity toward geometric problem-solving, we designed a…

Does Gender Matter? Collaborative Learning in a Virtual Corporate Community of Practice

ERIC Educational Resources Information Center

Tomcsik, Rachel E.

2010-01-01

The purpose of this study was to investigate how gender identity construction in virtuality and actuality affect collaborative learning in a corporate community of practice. As part of a virtual ethnographic design, participants were employees from a major American corporation who were interested specifically in social networking applications. The…

Virtual Collaboration: Advantages and Disadvantages in the Planning and Execution of Operations in the Information Age

DTIC Science & Technology

2004-02-09

FINAL 3. DATES COVERED (From - To) 4. TITLE AND SUBTITLE VIRTUAL COLLABORATION: 5a. CONTRACT NUMBER ADVANTAGES AND DISADVANTAGES IN THE PLANNING AND...warfare is not one system; it is a system of systems from sensors to information flow. In analyzing the specific advantages and disadvantages of one of...Standard Form 298 (Rev. 8-98) NAVAL WAR COLLEGE Newport, R.I. VIRTUAL COLLABORATION: ADVANTAGES AND DISADVANTAGES IN THE PLANNING AND EXECUTION OF OPERATIONS

BESIII physical offline data analysis on virtualization platform

NASA Astrophysics Data System (ADS)

Huang, Q.; Li, H.; Kan, B.; Shi, J.; Lei, X.

2015-12-01

In this contribution, we present an ongoing work, which aims at benefiting BESIII computing system for higher resource utilization and more efficient job operations brought by cloud and virtualization technology with Openstack and KVM. We begin with the architecture of BESIII offline software to understand how it works. We mainly report the KVM performance evaluation and optimization from various factors in hardware and kernel. Experimental results show the CPU performance penalty of KVM can be approximately decreased to 3%. In addition, the performance comparison between KVM and physical machines in aspect of CPU, disk IO and network IO is also presented. Finally, we present our development work, an adaptive cloud scheduler, which allocates and reclaims VMs dynamically according to the status of TORQUE queue and the size of resource pool to improve resource utilization and job processing efficiency.

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

ERIC Educational Resources Information Center

Salinas Vacca, Yakelin

2014-01-01

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

Online Teacher Development: Collaborating in a Virtual Learning Environment

ERIC Educational Resources Information Center

Ernest, Pauline; Guitert Catasús, Montse; Hampel, Regine; Heiser, Sarah; Hopkins, Joseph; Murphy, Linda; Stickler, Ursula

2013-01-01

Over recent years, educational institutions have been making increasing use of virtual environments to set up collaborative activities for learners. While it is recognized that teachers play an important role in facilitating learner collaboration online, they may not have the necessary skills to do so successfully. Thus, a small-scale professional…

The Proposed Model of Collaborative Virtual Learning Environment for Introductory Programming Course

ERIC Educational Resources Information Center

Othman, Mahfudzah; Othman, Muhaini

2012-01-01

This paper discusses the proposed model of the collaborative virtual learning system for the introductory computer programming course which uses one of the collaborative learning techniques known as the "Think-Pair-Share". The main objective of this study is to design a model for an online learning system that facilitates the…

Exploring the use of Virtual Field Trips with elementary school teachers: A collaborative action research approach

NASA Astrophysics Data System (ADS)

Scott, Jeffrey Lance

This research examines how elementary school teachers, when supported, use Virtual Field Trips (VFTs) to address the curricula in meaningful ways. I conducted a qualitative study with six teachers, in a collaborative action research context over a six month period. The teachers, five males and one female, all taught either grade five or six and utilized Virtual Field Trips within a variety of curricula areas including science, social studies, music and language arts. In addition, the thesis examines resulting integration of technology into the regular classroom program as a product of the utilization of Virtual Field Trips. The process of collaborative action research was applied as a means of personal and professional growth both for the participants and the researcher/facilitator. By the end of the research study, all participants had learned to integrate Virtual Field Trips into their classroom program, albeit with different levels of success and in different curricula areas. The development of attitudes, skills and knowledge for students and teachers alike was fostered through the participation in Virtual Field Trips. A common concern regarding the utilization of Virtual Field Trips was the time spent locating an appropriate site that met curricula expectations. Participation in the collaborative action research process allowed each teacher to grow professionally, personally and socially. Each participant strongly encouraged the utilization of a long term project with a common area of exploration as a means for positive professional development. Implications and recommendations for future research on the utilization of Virtual Field Trips, as well as the viability of collaborative action research to facilitate teacher development are presented.

Competing for jobs: labor queues and gender sorting in the hiring process.

PubMed

Fernandez, Roberto M; Mors, Marie Louise

2008-12-01

While much research has documented the pattern and extent of sex segregation of workers once they are employed, few studies have addressed the pre-hire mechanisms that are posited to produce sex segregation in employment. While the notion of a labor queue-the rank order of the set of people that employers choose among-plays a prominent role in pre-hire accounts of job sex sorting mechanisms, few studies have examined the ways in which job candidates are sorted into labor queues. In this paper, we explore the mechanisms by which labor queues contribute to the gendering of jobs by studying the hiring process for all jobs at a call center. Being placed in a queue has a clear gendering effect on the hiring process: the sex distribution of applicants who are matched to queues and those who are rejected at this phase diverge, and among those assigned to queues, women are prevalent in queues for low pay, low status jobs. The screening process also contributes to the gendering of the population of hires at this firm. Females are more prevalent among hires than they are among candidates at initial queue assignment. Among high status jobs, however, males are more prevalent than females. Moreover, there are important wage implications associated with matching to queues. While there are large between-queue sex differences in the paid wages associated with allocation to queues, once allocated to queues the wage differences between male and female candidates are nil. Consequently, the roots of gender wage inequality in this setting lie in the initial sorting of candidates to labor queues.

Lightweight scheduling of elastic analysis containers in a competitive cloud environment: a Docked Analysis Facility for ALICE

NASA Astrophysics Data System (ADS)

Berzano, D.; Blomer, J.; Buncic, P.; Charalampidis, I.; Ganis, G.; Meusel, R.

2015-12-01

During the last years, several Grid computing centres chose virtualization as a better way to manage diverse use cases with self-consistent environments on the same bare infrastructure. The maturity of control interfaces (such as OpenNebula and OpenStack) opened the possibility to easily change the amount of resources assigned to each use case by simply turning on and off virtual machines. Some of those private clouds use, in production, copies of the Virtual Analysis Facility, a fully virtualized and self-contained batch analysis cluster capable of expanding and shrinking automatically upon need: however, resources starvation occurs frequently as expansion has to compete with other virtual machines running long-living batch jobs. Such batch nodes cannot relinquish their resources in a timely fashion: the more jobs they run, the longer it takes to drain them and shut off, and making one-job virtual machines introduces a non-negligible virtualization overhead. By improving several components of the Virtual Analysis Facility we have realized an experimental “Docked” Analysis Facility for ALICE, which leverages containers instead of virtual machines for providing performance and security isolation. We will present the techniques we have used to address practical problems, such as software provisioning through CVMFS, as well as our considerations on the maturity of containers for High Performance Computing. As the abstraction layer is thinner, our Docked Analysis Facilities may feature a more fine-grained sizing, down to single-job node containers: we will show how this approach will positively impact automatic cluster resizing by deploying lightweight pilot containers instead of replacing central queue polls.

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

ERIC Educational Resources Information Center

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

2013-01-01

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

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

ERIC Educational Resources Information Center

Kim, Mi Hwa

2013-01-01

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

Learning in 3D Virtual Environments: Collaboration and Knowledge Spirals

ERIC Educational Resources Information Center

Burton, Brian G.; Martin, Barbara N.

2010-01-01

The purpose of this case study was to determine if learning occurred within a 3D virtual learning environment by determining if elements of collaboration and Nonaka and Takeuchi's (1995) knowledge spiral were present. A key portion of this research was the creation of a Virtual Learning Environment. This 3D VLE utilized the Torque Game Engine…

Automated X-ray and Optical Analysis of the Virtual Observatory and Grid Computing

NASA Technical Reports Server (NTRS)

Ptak, A.; Krughoff, S.; Connolly, A.

2011-01-01

We are developing a system to combine the Web Enabled Source Identification with X-Matching (WESIX) web service, which emphasizes source detection on optical images,with the XAssist program that automates the analysis of X-ray data. XAssist is continuously processing archival X-ray data in several pipelines. We have established a workflow in which FITS images and/or (in the case of X ray data) an X-ray field can be input to WESIX. Intelligent services return available data (if requested fields have been processed) or submit job requests to a queue to be performed asynchronously. These services will be available via web services (for non-interactive use by Virtual Observatory portals and applications) and through web applications (written in the Django web application framework). We are adding web services for specific XAssist functionality such as determining .the exposure and limiting flux for a given position on the sky and extracting spectra and images for a given region. We are improving the queuing system in XAssist to allow for "watch lists" to be specified by users, and when X-ray fields in a user's watch list become publicly available they will be automatically added to the queue. XAssist is being expanded to be used as a survey planning 1001 when coupled with simulation software, including functionality for NuStar, eRosita, IXO, and the Wide Field Xray Telescope (WFXT), as part of an end to end simulation/analysis system. We are also investigating the possibility of a dedicated iPhone/iPad app for querying pipeline data, requesting processing, and administrative job control.

Comparative study on collaborative interaction in non-immersive and immersive systems

NASA Astrophysics Data System (ADS)

Shahab, Qonita M.; Kwon, Yong-Moo; Ko, Heedong; Mayangsari, Maria N.; Yamasaki, Shoko; Nishino, Hiroaki

2007-09-01

This research studies the Virtual Reality simulation for collaborative interaction so that different people from different places can interact with one object concurrently. Our focus is the real-time handling of inputs from multiple users, where object's behavior is determined by the combination of the multiple inputs. Issues addressed in this research are: 1) The effects of using haptics on a collaborative interaction, 2) The possibilities of collaboration between users from different environments. We conducted user tests on our system in several cases: 1) Comparison between non-haptics and haptics collaborative interaction over LAN, 2) Comparison between non-haptics and haptics collaborative interaction over Internet, and 3) Analysis of collaborative interaction between non-immersive and immersive display environments. The case studies are the interaction of users in two cases: collaborative authoring of a 3D model by two users, and collaborative haptic interaction by multiple users. In Virtual Dollhouse, users can observe physics law while constructing a dollhouse using existing building blocks, under gravity effects. In Virtual Stretcher, multiple users can collaborate on moving a stretcher together while feeling each other's haptic motions.

The Completion of Non-Steady-State Queue Model on The Queue System in Dr. Yap Eye Hospital Yogyakarta

NASA Astrophysics Data System (ADS)

Helmi Manggala Putri, Arum; Subekti, Retno; Binatari, Nikenasih

2017-06-01

Dr Yap Eye Hospital Yogyakarta is one of the most popular reference eye hospitals in Yogyakarta. There are so many patients coming from other cities and many of them are BPJS (Badan Penyelenggara Jaminan Sosial, Social Security Administrative Bodies) patients. Therefore, it causes numerous BPJS patients were in long queue at counter C of the registration section so that it needs to be analysed using queue system. Queue system analysis aims to give queue model overview and determine its effectiveness measure. The data collecting technique used in this research are by interview and observation. After getting the arrival data and the service data of BPJS patients per 5 minutes, the next steps are investigating steady-state condition, examining the Poisson distribution, determining queue models, and counting the effectiveness measure. Based on the result of data observation on Tuesday, February 16th, 2016, it shows that the queue system at counter C has (M/M/1):(GD/∞/∞) queue model. The analysis result in counter C shows that the queue system is a non-steady-state condition. Three ways to cope a non-steady-state problem on queue system are proposed in this research such as bounding the capacity of queue system, adding the servers, and doing Monte Carlo simulation. The queue system in counter C will reach steady-state if the capacity of patients is not more than 52 BPJS patients or adding one more server. By using Monte Carlo simulation, it shows that the effectiveness measure of the average waiting time for BPJS patients in counter C is 36 minutes 65 seconds. In addition, the average queue length of BPJS patients is 11 patients.

Development of collaborative-creative learning model using virtual laboratory media for instrumental analytical chemistry lectures

NASA Astrophysics Data System (ADS)

Zurweni, Wibawa, Basuki; Erwin, Tuti Nurian

2017-08-01

The framework for teaching and learning in the 21st century was prepared with 4Cs criteria. Learning providing opportunity for the development of students' optimal creative skills is by implementing collaborative learning. Learners are challenged to be able to compete, work independently to bring either individual or group excellence and master the learning material. Virtual laboratory is used for the media of Instrumental Analytical Chemistry (Vis, UV-Vis-AAS etc) lectures through simulations computer application and used as a substitution for the laboratory if the equipment and instruments are not available. This research aims to design and develop collaborative-creative learning model using virtual laboratory media for Instrumental Analytical Chemistry lectures, to know the effectiveness of this design model adapting the Dick & Carey's model and Hannafin & Peck's model. The development steps of this model are: needs analyze, design collaborative-creative learning, virtual laboratory media using macromedia flash, formative evaluation and test of learning model effectiveness. While, the development stages of collaborative-creative learning model are: apperception, exploration, collaboration, creation, evaluation, feedback. Development of collaborative-creative learning model using virtual laboratory media can be used to improve the quality learning in the classroom, overcome the limitation of lab instruments for the real instrumental analysis. Formative test results show that the Collaborative-Creative Learning Model developed meets the requirements. The effectiveness test of students' pretest and posttest proves significant at 95% confidence level, t-test higher than t-table. It can be concluded that this learning model is effective to use for Instrumental Analytical Chemistry lectures.

User-Centered Iterative Design of a Collaborative Virtual Environment

DTIC Science & Technology

2001-03-01

cognitive task analysis methods to study land navigators. This study was intended to validate the use of user-centered design methodologies for the design of...have explored the cognitive aspects of collaborative human way finding and design for collaborative virtual environments. Further investigation of design paradigms should include cognitive task analysis and behavioral task analysis.

Improving Virtual Team Collaboration Outcomes through Collaboration Process Structuring

ERIC Educational Resources Information Center

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

2010-01-01

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

Enhancing Intercultural Competence of Engineering Students via GVT (Global Virtual Teams)-Based Virtual Exchanges: An International Collaborative Course in Intralogistics Education

ERIC Educational Resources Information Center

Wang, Rui; Rechl, Friederike; Bigontina, Sonja; Fang, Dianjun; Günthner, Willibald A.; Fottner, Johannes

2017-01-01

In order to enhance the intercultural competence of engineering students, an international collaborative course in intralogistics education was initiated and realized between the Technical University of Munich in Germany and the Tongji University in China. In this course, students worked in global virtual teams (GVTs) and solved a concrete case…

Do case-generic measures of queue performance for bypass surgery accurately reflect the waiting-list experiences of those most urgent?

PubMed

Burstein, Jason; Lee, Douglas S; Alter, David A

2006-02-01

Queue performance is typically assessed using generic measures, which capture the queue in aggregate. The objective of this study was to examine whether case-generic measures of queue performance appropriately reflected the waiting-list experiences of those patients with greatest disease severity. We examined the queue for isolated coronary artery bypass grafting (CABG) in Ontario between April 1993 and March 2000 using data obtained from the Cardiac Care Network. Our primary measure of queue performance was the proportion of patients who received their bypass surgery within their recommended maximum waiting times (%RMWTs) in any given month. We compared case-generic measures of queue performance to case-specific measures of queue performance stratified by urgency level. The queue was largely comprised of elective cases ranging from 73% (1993) to 57%(1999). Urgent patients comprised the minority of the queue ranging from 14% (1993) to 20% (1999). Case-generic month-to-month variations in the percentage of cases completed within RMWTs (an aggregated waiting list measure encompassing the characteristics of all patients in the queue) closely resembled the experiences of elective patients (R2 = 0.81), but conversely, bore little relationship to the waiting-list experiences of those most urgent (R2 = 0.15). Case-generic measures of queue performance for bypass surgery in Ontario were not reflective of the waiting-list experiences of those most urgent. Our results reinforce the concept that urgency-specific waiting list monitoring systems are required to best evaluate and appropriately respond to fluctuations in queue performance.

The WorkQueue project - a task queue for the CMS workload management system

NASA Astrophysics Data System (ADS)

Ryu, S.; Wakefield, S.

2012-12-01

We present the development and first experience of a new component (termed WorkQueue) in the CMS workload management system. This component provides a link between a global request system (Request Manager) and agents (WMAgents) which process requests at compute and storage resources (known as sites). These requests typically consist of creation or processing of a data sample (possibly terabytes in size). Unlike the standard concept of a task queue, the WorkQueue does not contain fully resolved work units (known typically as jobs in HEP). This would require the WorkQueue to run computationally heavy algorithms that are better suited to run in the WMAgents. Instead the request specifies an algorithm that the WorkQueue uses to split the request into reasonable size chunks (known as elements). An advantage of performing lazy evaluation of an element is that expanding datasets can be accommodated by having job details resolved as late as possible. The WorkQueue architecture consists of a global WorkQueue which obtains requests from the request system, expands them and forms an element ordering based on the request priority. Each WMAgent contains a local WorkQueue which buffers work close to the agent, this overcomes temporary unavailability of the global WorkQueue and reduces latency for an agent to begin processing. Elements are pulled from the global WorkQueue to the local WorkQueue and into the WMAgent based on the estimate of the amount of work within the element and the resources available to the agent. WorkQueue is based on CouchDB, a document oriented NoSQL database. The WorkQueue uses the features of CouchDB (map/reduce views and bi-directional replication between distributed instances) to provide a scalable distributed system for managing large queues of work. The project described here represents an improvement over the old approach to workload management in CMS which involved individual operators feeding requests into agents. This new approach allows for a system where individual WMAgents are transient and can be added or removed from the system as needed.

Embodied collaboration support system for 3D shape evaluation in virtual space

NASA Astrophysics Data System (ADS)

Okubo, Masashi; Watanabe, Tomio

2005-12-01

Collaboration mainly consists of two tasks; one is each partner's task that is performed by the individual, the other is communication with each other. Both of them are very important objectives for all the collaboration support system. In this paper, a collaboration support system for 3D shape evaluation in virtual space is proposed on the basis of both studies in 3D shape evaluation and communication support in virtual space. The proposed system provides the two viewpoints for each task. One is the viewpoint of back side of user's own avatar for the smooth communication. The other is that of avatar's eye for 3D shape evaluation. Switching the viewpoints satisfies the task conditions for 3D shape evaluation and communication. The system basically consists of PC, HMD and magnetic sensors, and users can share the embodied interaction by observing interaction between their avatars in virtual space. However, the HMD and magnetic sensors, which are put on the users, would restrict the nonverbal communication. Then, we have tried to compensate the loss of nodding of partner's avatar by introducing the speech-driven embodied interactive actor InterActor. Sensory evaluation by paired comparison of 3D shapes in the collaborative situation in virtual space and in real space and the questionnaire are performed. The result demonstrates the effectiveness of InterActor's nodding in the collaborative situation.

Why Are Drugs So Hard to Quit?

MedlinePlus

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A Low-Power Instruction Issue Queue for Microprocessors

NASA Astrophysics Data System (ADS)

Watanabe, Shingo; Chiyonobu, Akihiro; Sato, Toshinori

Instruction issue queue is a key component which extracts instruction level parallelism (ILP) in modern out-of-order microprocessors. In order to exploit ILP for improving processor performance, instruction queue size should be increased. However, it is difficult to increase the size, since instruction queue is implemented by a content addressable memory (CAM) whose power and delay are much large. This paper introduces a low power and scalable instruction queue that replaces the CAM with a RAM. In this queue, instructions are explicitly woken up. Evaluation results show that the proposed instruction queue decreases processor performance by only 1.9% on average. Furthermore, the total energy consumption is reduced by 54% on average.

Towards Gesture-Based Multi-User Interactions in Collaborative Virtual Environments

NASA Astrophysics Data System (ADS)

Pretto, N.; Poiesi, F.

2017-11-01

We present a virtual reality (VR) setup that enables multiple users to participate in collaborative virtual environments and interact via gestures. A collaborative VR session is established through a network of users that is composed of a server and a set of clients. The server manages the communication amongst clients and is created by one of the users. Each user's VR setup consists of a Head Mounted Display (HMD) for immersive visualisation, a hand tracking system to interact with virtual objects and a single-hand joypad to move in the virtual environment. We use Google Cardboard as a HMD for the VR experience and a Leap Motion for hand tracking, thus making our solution low cost. We evaluate our VR setup though a forensics use case, where real-world objects pertaining to a simulated crime scene are included in a VR environment, acquired using a smartphone-based 3D reconstruction pipeline. Users can interact using virtual gesture-based tools such as pointers and rulers.

Collaboration and Synergy among Government, Industry and Academia in M&S Domain: Turkey’s Approach

DTIC Science & Technology

2009-10-01

Analysis, Decision Support System Design and Implementation, Simulation Output Analysis, Statistical Data Analysis, Virtual Reality , Artificial... virtual and constructive visual simulation systems as well as integrated advanced analytical models. Collaboration and Synergy among Government...simulation systems that are ready to use, credible, integrated with C4ISR systems.  Creating synthetic environments and/or virtual prototypes of concepts

Online matching with queueing dynamics.

DOT National Transportation Integrated Search

2016-12-01

We consider a variant of the multiarmed bandit problem where jobs queue for service, and service rates of different servers may be unknown. We study algorithms that minimize queue-regret: the (expected) difference between the queue-lengths obtained b...

Field test implementation of queue control : final report.

DOT National Transportation Integrated Search

2011-12-01

A major challenge for implementing queue control has been to accurately estimate on-ramp queue lengths, particularly during saturated onramp : conditions, when the vehicle queue extends around or beyond the ramp entrance. The main outcome of the rese...

Queues with Choice via Delay Differential Equations

NASA Astrophysics Data System (ADS)

Pender, Jamol; Rand, Richard H.; Wesson, Elizabeth

Delay or queue length information has the potential to influence the decision of a customer to join a queue. Thus, it is imperative for managers of queueing systems to understand how the information that they provide will affect the performance of the system. To this end, we construct and analyze two two-dimensional deterministic fluid models that incorporate customer choice behavior based on delayed queue length information. In the first fluid model, customers join each queue according to a Multinomial Logit Model, however, the queue length information the customer receives is delayed by a constant Δ. We show that the delay can cause oscillations or asynchronous behavior in the model based on the value of Δ. In the second model, customers receive information about the queue length through a moving average of the queue length. Although it has been shown empirically that giving patients moving average information causes oscillations and asynchronous behavior to occur in U.S. hospitals, we analytically and mathematically show for the first time that the moving average fluid model can exhibit oscillations and determine their dependence on the moving average window. Thus, our analysis provides new insight on how operators of service systems should report queue length information to customers and how delayed information can produce unwanted system dynamics.

Generalized priority-queue network dynamics: Impact of team and hierarchy

NASA Astrophysics Data System (ADS)

Cho, Won-Kuk; Min, Byungjoon; Goh, K.-I.; Kim, I.-M.

2010-06-01

We study the effect of team and hierarchy on the waiting-time dynamics of priority-queue networks. To this end, we introduce generalized priority-queue network models incorporating interaction rules based on team-execution and hierarchy in decision making, respectively. It is numerically found that the waiting-time distribution exhibits a power law for long waiting times in both cases, yet with different exponents depending on the team size and the position of queue nodes in the hierarchy, respectively. The observed power-law behaviors have in many cases a corresponding single or pairwise-interacting queue dynamics, suggesting that the pairwise interaction may constitute a major dynamic consequence in the priority-queue networks. It is also found that the reciprocity of influence is a relevant factor for the priority-queue network dynamics.

Automated X-ray and Optical Analysis of the Virtual Observatory and Grid Computing

NASA Astrophysics Data System (ADS)

Ptak, A.; Krughoff, S.; Connolly, A.

2011-07-01

We are developing a system to combine the Web Enabled Source Identification with X-Matching (WESIX) web service, which emphasizes source detection on optical images,with the XAssist program that automates the analysis of X-ray data. XAssist is continuously processing archival X-ray data in several pipelines. We have established a workflow in which FITS images and/or (in the case of X-ray data) an X-ray field can be input to WESIX. Intelligent services return available data (if requested fields have been processed) or submit job requests to a queue to be performed asynchronously. These services will be available via web services (for non-interactive use by Virtual Observatory portals and applications) and through web applications (written in the Django web application framework). We are adding web services for specific XAssist functionality such as determining the exposure and limiting flux for a given position on the sky and extracting spectra and images for a given region. We are improving the queuing system in XAssist to allow for "watch lists" to be specified by users, and when X-ray fields in a user's watch list become publicly available they will be automatically added to the queue. XAssist is being expanded to be used as a survey planning tool when coupled with simulation software, including functionality for NuStar, eRosita, IXO, and the Wide-Field Xray Telescope (WFXT), as part of an end-to-end simulation/analysis system. We are also investigating the possibility of a dedicated iPhone/iPad app for querying pipeline data, requesting processing, and administrative job control. This work was funded by AISRP grant NNG06GE59G.

Multi-Agent Framework for Virtual Learning Spaces.

ERIC Educational Resources Information Center

Sheremetov, Leonid; Nunez, Gustavo

1999-01-01

Discussion of computer-supported collaborative learning, distributed artificial intelligence, and intelligent tutoring systems focuses on the concept of agents, and describes a virtual learning environment that has a multi-agent system. Describes a model of interactions in collaborative learning and discusses agents for Web-based virtual…

Control of Entry to a Queueing System

DTIC Science & Technology

1979-11-01

being devoted to the use of queueing theory to control ard optimize the o~peration i f a system. Here, queueing analyses are used to design a system...operpting costs below somae upper bound while maximizing throughput of the queue. This more recent approach of designing or controlling a queueing system...ports designated as high density traffic airports, the Federal Aviation Administration (FAA) limits the number of instrument flight r’ule (IFR

Peregrine Queue Changes | High-Performance Computing | NREL

Science.gov Websites

that the best path is to disable the large queue and move the nodes from the "large" queue to jobs that request a large number of nodes. The large queue was disabled during the October System time

The network queueing system

NASA Technical Reports Server (NTRS)

Kingsbury, Brent K.

1986-01-01

Described is the implementation of a networked, UNIX based queueing system developed on contract for NASA. The system discussed supports both batch and device requests, and provides the facilities of remote queueing, request routing, remote status, queue access controls, batch request resource quota limits, and remote output return.

An analytical study of various telecomminication networks using markov models

NASA Astrophysics Data System (ADS)

Ramakrishnan, M.; Jayamani, E.; Ezhumalai, P.

2015-04-01

The main aim of this paper is to examine issues relating to the performance of various Telecommunication networks, and applied queuing theory for better design and improved efficiency. Firstly, giving an analytical study of queues deals with quantifying the phenomenon of waiting lines using representative measures of performances, such as average queue length (on average number of customers in the queue), average waiting time in queue (on average time to wait) and average facility utilization (proportion of time the service facility is in use). In the second, using Matlab simulator, summarizes the finding of the investigations, from which and where we obtain results and describing methodology for a) compare the waiting time and average number of messages in the queue in M/M/1 and M/M/2 queues b) Compare the performance of M/M/1 and M/D/1 queues and study the effect of increasing the number of servers on the blocking probability M/M/k/k queue model.

Fast concurrent array-based stacks, queues and deques using fetch-and-increment-bounded, fetch-and-decrement-bounded and store-on-twin synchronization primitives

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

Chen, Dong; Gara, Alana; Heidelberger, Philip

Implementation primitives for concurrent array-based stacks, queues, double-ended queues (deques) and wrapped deques are provided. In one aspect, each element of the stack, queue, deque or wrapped deque data structure has its own ticket lock, allowing multiple threads to concurrently use multiple elements of the data structure and thus achieving high performance. In another aspect, new synchronization primitives FetchAndIncrementBounded (Counter, Bound) and FetchAndDecrementBounded (Counter, Bound) are implemented. These primitives can be implemented in hardware and thus promise a very fast throughput for queues, stacks and double-ended queues.

Reaching across Continents: Engaging Students through Virtual Collaborations

ERIC Educational Resources Information Center

Wilmot, Natalie Victoria; Rushton, Diane; Zandona Hofmann, Anelise Seleme

2016-01-01

Business schools have the responsibility of preparing students for work in multicultural organisations and global markets. This paper examines a situated learning experience for undergraduates through a virtual collaboration between a UK university and a Brazilian university. This facilitated remote communication using social media and smart…

Telemetry Standards, RCC Standard 106-17. Chapter 24. Message Formats

DTIC Science & Technology

2017-07-01

strength indicator TCP Transmission Control Protocol TE Traffic Engineering TAI International Atomic Time TLV Type-Length-Value TmNS Telemetry...to a specific radio link. TE Queue Status Report 10 This TLV is used by a radio to report Traffic Engineering (TE) queue levels for each of the 8...24.3.2.6 Traffic Engineering Queue Status Report TLV The TE Queue Status Report TLV shall be used to report the queue levels of the eight

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

PubMed

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

2018-02-01

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

Virtual Communities of Collaborative Learning for Higher Education

ERIC Educational Resources Information Center

Sotomayor, Gilda E.

2014-01-01

This article aims to outline and project three new learning scenarios for Higher Education that, after the emergence of ICT and communication through the Network-lnternet, have appeared under the generic name of virtual communities. To that end, we start from a previous conceptual analysis on collaborative learning, cooperative learning and…

Real-Time Collaboration of Virtual Laboratories through the Internet

ERIC Educational Resources Information Center

Jara, Carlos A.; Candelas, Francisco A.; Torres, Fernando; Dormido, Sebastian; Esquembre, Francisco; Reinoso, Oscar

2009-01-01

Web-based learning environments are becoming increasingly popular in higher education. One of the most important web-learning resources is the virtual laboratory (VL), which gives students an easy way for training and learning through the Internet. Moreover, on-line collaborative communication represents a practical method to transmit the…

Collaborative Virtual Environment Technology for People with Autism

ERIC Educational Resources Information Center

Moore, David; Cheng, Yufang; McGrath, Paul; Powell, Norman J.

2005-01-01

Collaborative virtual environments (CVEs) hold great potential for people with autism. An exploratory empirical study was conducted to determine if children and youth with autism could understand basic emotions as represented by a humanoid avatar. Thirty-four participants (ages 7.8-16 years) reported to have autism interacted with a software…

Tools for Teaching Virtual Teams: A Comparative Resource Review

ERIC Educational Resources Information Center

Larson, Barbara; Leung, Opal; Mullane, Kenneth

2017-01-01

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

Current limitations into the application of virtual reality to mental health research.

PubMed

Huang, M P; Alessi, N E

1998-01-01

Virtual Reality (VR) environments have significant potential as a tool in mental health research, but are limited by technical factors and by mental health research factors. Technical difficulties include cost and complexity of virtual environment creation. Mental health research difficulties include current inadequacy of standards to specify needed details for virtual environment design. Technical difficulties are disappearing with technological advances, but the mental health research difficulties will take a concerted effort to overcome. Some of this effort will need to be directed at the formation of collaborative projects and standards for how such collaborations should proceed.

Message passing with queues and channels

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

Dozsa, Gabor J; Heidelberger, Philip; Kumar, Sameer

In an embodiment, a send thread receives an identifier that identifies a destination node and a pointer to data. The send thread creates a first send request in response to the receipt of the identifier and the data pointer. The send thread selects a selected channel from among a plurality of channels. The selected channel comprises a selected hand-off queue and an identification of a selected message unit. Each of the channels identifies a different message unit. The selected hand-off queue is randomly accessible. If the selected hand-off queue contains an available entry, the send thread adds the first sendmore » request to the selected hand-off queue. If the selected hand-off queue does not contain an available entry, the send thread removes a second send request from the selected hand-off queue and sends the second send request to the selected message unit.« less

Analysis of bulk arrival queueing system with batch size dependent service and working vacation

NASA Astrophysics Data System (ADS)

Niranjan, S. P.; Indhira, K.; Chandrasekaran, V. M.

2018-04-01

This paper concentrates on single server bulk arrival queue system with batch size dependent service and working vacation. The server provides service in two service modes depending upon the queue length. The server provides single service if the queue length is at least `a'. On the other hand the server provides fixed batch service if the queue length is at least `k' (k > a). Batch service is provided with some fixed batch size `k'. After completion of service if the queue length is less than `a' then the server leaves for working vacation. During working vacation customers are served with lower service rate than the regular service rate. Service during working vacation also contains two service modes. For the proposed model probability generating function of the queue length at an arbitrary time will be obtained by using supplementary variable technique. Some performance measures will also be presented with suitable numerical illustrations.

Transient queue-size distribution in a finite-capacity queueing system with server breakdowns and Bernoulli feedback

NASA Astrophysics Data System (ADS)

Kempa, Wojciech M.

2017-12-01

A finite-capacity queueing system with server breakdowns is investigated, in which successive exponentially distributed failure-free times are followed by repair periods. After the processing a customer may either rejoin the queue (feedback) with probability q, or definitely leave the system with probability 1 - q. The system of integral equations for transient queue-size distribution, conditioned by the initial level of buffer saturation, is build. The solution of the corresponding system written for Laplace transforms is found using the linear algebraic approach. The considered queueing system can be successfully used in modelling production lines with machine failures, in which the parameter q may be considered as a typical fraction of items demanding corrections. Morever, this queueing model can be applied in the analysis of real TCP/IP performance, where q stands for the fraction of packets requiring retransmission.

Optimal routing and buffer allocation for a class of finite capacity queueing systems

NASA Technical Reports Server (NTRS)

Towsley, Don; Sparaggis, Panayotis D.; Cassandras, Christos G.

1992-01-01

The problem of routing jobs to K parallel queues with identical exponential servers and unequal finite buffer capacities is considered. Routing decisions are taken by a controller which has buffering space available to it and may delay routing of a customer to a queue. Using ideas from weak majorization, it is shown that the shorter nonfull queue delayed (SNQD) policy minimizes both the total number of customers in the system at any time and the number of customers that are rejected by that time. The SNQD policy always delays routing decisions as long as all servers are busy. Only when all the buffers at the controller are occupied is a customer routed to the queue with the shortest queue length that is not at capacity. Moreover, it is shown that, if a fixed number of buffers is to be distributed among the K queues, then the optimal allocation scheme is the one in which the difference between the maximum and minimum queue capacities is minimized, i.e., becomes either 0 or 1.

Queueing system analysis of multi server model at XYZ insurance company in Tasikmalaya city

NASA Astrophysics Data System (ADS)

Muhajir, Ahmad; Binatari, Nikenasih

2017-08-01

Queueing theory or waiting line theory is a theory that deals with the queue process from the customer comes, queue to be served, served and left on service facilities. Queue occurs because of a mismatch between the numbers of customers that will be served with the available number of services, as an example at XYZ insurance company in Tasikmalaya. This research aims to determine the characteristics of the queue system which then to optimize the number of server in term of total cost. The result shows that the queue model can be represented by (M/M/4):(GD/∞/∞), where the arrivals are Poisson distributed while the service time is following exponential distribution. The probability of idle customer service is 2,39% of the working time, the average number of customer in the queue is 3 customers, the average number of customer in a system is 6 customers, the average time of a customer spent in the queue is 15,9979 minutes, the average time a customer spends in the system is 34,4141 minutes, and the average number of busy customer servicer is 3 server. The optimized number of customer service is 5 servers, and the operational cost has minimum cost at Rp 4.323.

Waiting to see the doctor. The impact of organizational structure on medical practice.

PubMed

Wolinsky, F D; Marder, W D

1983-05-01

In this article it is assessed whether or not the scheduling and office visit queues a patient faces depend upon the organizational structure of the physician's practice (i.e., does the physician practice in the fee-for-service system or in a health maintenance organization [HMO], and if in an HMO, in what type of an HMO). Data pooled from two national studies (N = 2448) reveal two major findings. First, although scheduling queues may be predicted from the organizational structure of physicians' practices and other factors, office queues appear to be more of a random phenomenon. Second, a distinct pattern emerges among the effects of the organizational structure of physicians' practices on patient queues, including 1) physicians in solo practice offer their patients the shortest queues, 2) physicians in group model HMOs maximize scheduling queues but minimize waiting room queues, 3) patient queues for physicians practicing in IPAs are no different from those of their counterparts in group-practice fee-for-service settings, and 4) patient queues for salaried physicians practicing in a predominantly salaried environment are among the longest. The implications of these findings are discussed with special reference to extent and future studies of the effects of organizational structure on medical practice.

Network resiliency through memory health monitoring and proactive management

DOEpatents

Andrade Costa, Carlos H.; Cher, Chen-Yong; Park, Yoonho; Rosenburg, Bryan S.; Ryu, Kyung D.

2017-11-21

A method for managing a network queue memory includes receiving sensor information about the network queue memory, predicting a memory failure in the network queue memory based on the sensor information, and outputting a notification through a plurality of nodes forming a network and using the network queue memory, the notification configuring communications between the nodes.

Medical ethics and new public management in Sweden.

PubMed

Hansson, Sven Ove

2014-07-01

In order to shorten queues to healthcare, the Swedish government has introduced a yearly "queue billion" that is paid out to the county councils in proportion to how successful they are in reducing queues. However, only the queues for first visits are covered. Evidence has accumulated that queues for return visits have become longer. This affects the chronically and severely ill. Swedish physicians, and the Swedish Medical Association, have strongly criticized the queue billion and have claimed that it conflicts with medical ethics. Instead they demand that their professional judgments on priority setting and medical urgency be respected. This discussion provides an interesting illustration of some of the limitations of new public management and also more generally of the complicated relationships between medical ethics and public policy.

Priority Queues for Computer Simulations

NASA Technical Reports Server (NTRS)

Steinman, Jeffrey S. (Inventor)

1998-01-01

The present invention is embodied in new priority queue data structures for event list management of computer simulations, and includes a new priority queue data structure and an improved event horizon applied to priority queue data structures. ne new priority queue data structure is a Qheap and is made out of linked lists for robust, fast, reliable, and stable event list management and uses a temporary unsorted list to store all items until one of the items is needed. Then the list is sorted, next, the highest priority item is removed, and then the rest of the list is inserted in the Qheap. Also, an event horizon is applied to binary tree and splay tree priority queue data structures to form the improved event horizon for event management.

Skill Transfer and Virtual Training for IND Response Decision-Making: Models for Government-Industry Collaboration for the Development of Game-Based Training Tools

DTIC Science & Technology

2016-05-05

Training for IND Response Decision-Making: Models for Government–Industry Collaboration for the Development of Game -Based Training Tools R.M. Seater...Skill Transfer and Virtual Training for IND Response Decision-Making: Models for Government–Industry Collaboration for the Development of Game -Based...unlimited. This page intentionally left blank. iii EXECUTIVE SUMMARY Game -based training tools, sometimes called “serious games ,” are becoming

An experimental study on CHVE's performance evaluation.

PubMed

Paiva, Paulo V F; Machado, Liliane S; Oliveira, Jauvane C

2012-01-01

Virtual reality-based training simulators, with collaborative capabilities, are known to improve the way users interact with one another while learning or improving skills on a given medical procedure. Performance evaluation of Collaborative Haptic Virtual Environments (CHVE) allows us to understand how such systems can work in the Internet, as well as the requirements for multisensorial and real-time data. This work discloses new performance evaluation results for the collaborative module of the CyberMed VR framework.

Fostering Learning Through Interprofessional Virtual Reality Simulation Development.

PubMed

Nicely, Stephanie; Farra, Sharon

2015-01-01

This article presents a unique strategy for improving didactic learning and clinical skill while simultaneously fostering interprofessional collaboration and communication. Senior-level nursing students collaborated with students enrolled in the Department of Interactive Media Studies to design a virtual reality simulation based upon disaster management and triage techniques. Collaborative creation of the simulation proved to be a strategy for enhancing students' knowledge of and skill in disaster management and triage while impacting attitudes about interprofessional communication and teamwork.

Collaboration Modality, Cognitive Load, and Science Inquiry Learning in Virtual Inquiry Environments

ERIC Educational Resources Information Center

Erlandson, Benjamin E.; Nelson, Brian C.; Savenye, Wilhelmina C.

2010-01-01

Educational multi-user virtual environments (MUVEs) have been shown to be effective platforms for situated science inquiry curricula. While researchers find MUVEs to be supportive of collaborative scientific inquiry processes, the complex mix of multi-modal messages present in MUVEs can lead to cognitive overload, with learners unable to…

The Essence of Using Collaborative Technology for Virtual Team Members: A Study Using Interpretative Phenomenology

ERIC Educational Resources Information Center

Houck, Christiana L.

2013-01-01

This interpretative phenomenological study used semi-structured interviews of 10 participants to gain a deeper understanding of the experience for virtual team members using collaborative technology. The participants were knowledge workers from global software companies working on cross-functional project teams at a distance. There were no…

TeamXchange: A Team Project Experience Involving Virtual Teams and Fluid Team Membership

ERIC Educational Resources Information Center

Dineen, Brian R.

2005-01-01

TeamXchange, an online team-based exercise, is described. TeamXchange is consistent with the collaborative model of learning and provides a means of fostering enhanced student learning and engagement through collaboration in virtual teams experiencing periodic membership changes. It was administered in an undergraduate Organizational Behavior…

Prospects for Digital Campus with Extensive Applications of Virtual Collaborative Space

ERIC Educational Resources Information Center

Nishide, Ryo

2011-01-01

This paper proposes extensive applications of virtual collaborative space in order to enhance the efficiency and capability of Digital Campus. The usability of Digital Campus has been experimented in different learning environments and evaluated by questionnaire as that the presence technology and a sense of solidarity influence the participants'…

Collaboration and Knowledge Sharing Using 3D Virtual World on "Second Life"

ERIC Educational Resources Information Center

Rahim, Noor Faridah A.

2013-01-01

A collaborative and knowledge sharing virtual activity on "Second Life" using a learner-centred teaching methodology was initiated between Temasek Polytechnic and The Hong Kong Polytechnic University (HK PolyU) in the October 2011 semester. This paper highlights the author's experience in designing and implementing this e-learning…

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

ERIC Educational Resources Information Center

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

2017-01-01

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

EdMOO: One Approach to a Multimedia Collaborative Environment.

ERIC Educational Resources Information Center

Holkner, Bernard

The nature of the multiuser object oriented (MOO) environment lends itself to flexible and rich interactive collaboration space providing interactive discussion, mail, mailing list, and news features to its virtual denizens. EdMOO (HREF1) was created in mid-1995 as an environment for teachers to experience the text based virtual reality…

The Development of Virtual Educational Environments to Support Inter-School Collaboration

ERIC Educational Resources Information Center

Stevens, Ken

2007-01-01

The introduction of inter-school electronic networks has added a new dimension to education in Canada that has many implications for students who attend schools in rural communities. Collaborative internet-based teaching and learning and the creation of virtual classes within regional intranets now complement traditional on-site instruction in…

Effects of Collaborative Activities on Group Identity in Virtual World

ERIC Educational Resources Information Center

Park, Hyungsung; Seo, Sumin

2013-01-01

The purpose of this study was to analyze the effects of collaborative activities on group identity in a virtual world such as "Second Life." To achieve this purpose, this study adopted events that promoted participants' interactions using tools inherent in "Second Life." The interactive tools given to the control group in this…

Virtual Collaborative Simulation Environment for Integrated Product and Process Development

NASA Technical Reports Server (NTRS)

Gulli, Michael A.

1997-01-01

Deneb Robotics is a leader in the development of commercially available, leading edge three- dimensional simulation software tools for virtual prototyping,, simulation-based design, manufacturing process simulation, and factory floor simulation and training applications. Deneb has developed and commercially released a preliminary Virtual Collaborative Engineering (VCE) capability for Integrated Product and Process Development (IPPD). This capability allows distributed, real-time visualization and evaluation of design concepts, manufacturing processes, and total factory and enterprises in one seamless simulation environment.

Rocinante, a virtual collaborative visualizer

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

McDonald, M.J.; Ice, L.G.

1996-12-31

With the goal of improving the ability of people around the world to share the development and use of intelligent systems, Sandia National Laboratories` Intelligent Systems and Robotics Center is developing new Virtual Collaborative Engineering (VCE) and Virtual Collaborative Control (VCC) technologies. A key area of VCE and VCC research is in shared visualization of virtual environments. This paper describes a Virtual Collaborative Visualizer (VCV), named Rocinante, that Sandia developed for VCE and VCC applications. Rocinante allows multiple participants to simultaneously view dynamic geometrically-defined environments. Each viewer can exclude extraneous detail or include additional information in the scene as desired.more » Shared information can be saved and later replayed in a stand-alone mode. Rocinante automatically scales visualization requirements with computer system capabilities. Models with 30,000 polygons and 4 Megabytes of texture display at 12 to 15 frames per second (fps) on an SGI Onyx and at 3 to 8 fps (without texture) on Indigo 2 Extreme computers. In its networked mode, Rocinante synchronizes its local geometric model with remote simulators and sensory systems by monitoring data transmitted through UDP packets. Rocinante`s scalability and performance make it an ideal VCC tool. Users throughout the country can monitor robot motions and the thinking behind their motion planners and simulators.« less

Investigating the Use of Cloudbursts for High-Throughput Medical Image Registration

PubMed Central

Kim, Hyunjoo; Parashar, Manish; Foran, David J.; Yang, Lin

2010-01-01

This paper investigates the use of clouds and autonomic cloudbursting to support a medical image registration. The goal is to enable a virtual computational cloud that integrates local computational environments and public cloud services on-the-fly, and support image registration requests from different distributed researcher groups with varied computational requirements and QoS constraints. The virtual cloud essentially implements shared and coordinated task-spaces, which coordinates the scheduling of jobs submitted by a dynamic set of research groups to their local job queues. A policy-driven scheduling agent uses the QoS constraints along with performance history and the state of the resources to determine the appropriate size and mix of the public and private cloud resource that should be allocated to a specific request. The virtual computational cloud and the medical image registration service have been developed using the CometCloud engine and have been deployed on a combination of private clouds at Rutgers University and the Cancer Institute of New Jersey and Amazon EC2. An experimental evaluation is presented and demonstrates the effectiveness of autonomic cloudbursts and policy-based autonomic scheduling for this application. PMID:20640235

Telearch - Integrated visual simulation environment for collaborative virtual archaeology.

NASA Astrophysics Data System (ADS)

Kurillo, Gregorij; Forte, Maurizio

Archaeologists collect vast amounts of digital data around the world; however, they lack tools for integration and collaborative interaction to support reconstruction and interpretation process. TeleArch software is aimed to integrate different data sources and provide real-time interaction tools for remote collaboration of geographically distributed scholars inside a shared virtual environment. The framework also includes audio, 2D and 3D video streaming technology to facilitate remote presence of users. In this paper, we present several experimental case studies to demonstrate the integration and interaction with 3D models and geographical information system (GIS) data in this collaborative environment.

Internet-based distributed collaborative environment for engineering education and design

NASA Astrophysics Data System (ADS)

Sun, Qiuli

2001-07-01

This research investigates the use of the Internet for engineering education, design, and analysis through the presentation of a Virtual City environment. The main focus of this research was to provide an infrastructure for engineering education, test the concept of distributed collaborative design and analysis, develop and implement the Virtual City environment, and assess the environment's effectiveness in the real world. A three-tier architecture was adopted in the development of the prototype, which contains an online database server, a Web server as well as multi-user servers, and client browsers. The environment is composed of five components, a 3D virtual world, multiple Internet-based multimedia modules, an online database, a collaborative geometric modeling module, and a collaborative analysis module. The environment was designed using multiple Intenet-based technologies, such as Shockwave, Java, Java 3D, VRML, Perl, ASP, SQL, and a database. These various technologies together formed the basis of the environment and were programmed to communicate smoothly with each other. Three assessments were conducted over a period of three semesters. The Virtual City is open to the public at www.vcity.ou.edu. The online database was designed to manage the changeable data related to the environment. The virtual world was used to implement 3D visualization and tie the multimedia modules together. Students are allowed to build segments of the 3D virtual world upon completion of appropriate undergraduate courses in civil engineering. The end result is a complete virtual world that contains designs from all of their coursework and is viewable on the Internet. The environment is a content-rich educational system, which can be used to teach multiple engineering topics with the help of 3D visualization, animations, and simulations. The concept of collaborative design and analysis using the Internet was investigated and implemented. Geographically dispersed users can build the same geometric model simultaneously over the Internet and communicate with each other through a chat room. They can also conduct finite element analysis collaboratively on the same object over the Internet. They can mesh the same object, apply and edit the same boundary conditions and forces, obtain the same analysis results, and then discuss the results through the Internet.

A framework using cluster-based hybrid network architecture for collaborative virtual surgery.

PubMed

Qin, Jing; Choi, Kup-Sze; Poon, Wai-Sang; Heng, Pheng-Ann

2009-12-01

Research on collaborative virtual environments (CVEs) opens the opportunity for simulating the cooperative work in surgical operations. It is however a challenging task to implement a high performance collaborative surgical simulation system because of the difficulty in maintaining state consistency with minimum network latencies, especially when sophisticated deformable models and haptics are involved. In this paper, an integrated framework using cluster-based hybrid network architecture is proposed to support collaborative virtual surgery. Multicast transmission is employed to transmit updated information among participants in order to reduce network latencies, while system consistency is maintained by an administrative server. Reliable multicast is implemented using distributed message acknowledgment based on cluster cooperation and sliding window technique. The robustness of the framework is guaranteed by the failure detection chain which enables smooth transition when participants join and leave the collaboration, including normal and involuntary leaving. Communication overhead is further reduced by implementing a number of management approaches such as computational policies and collaborative mechanisms. The feasibility of the proposed framework is demonstrated by successfully extending an existing standalone orthopedic surgery trainer into a collaborative simulation system. A series of experiments have been conducted to evaluate the system performance. The results demonstrate that the proposed framework is capable of supporting collaborative surgical simulation.

General bulk service queueing system with N-policy, multiplevacations, setup time and server breakdown without interruption

NASA Astrophysics Data System (ADS)

Sasikala, S.; Indhira, K.; Chandrasekaran, V. M.

2017-11-01

In this paper, we have considered an MX / (a,b) / 1 queueing system with server breakdown without interruption, multiple vacations, setup times and N-policy. After a batch of service, if the size of the queue is ξ (< a), then the server immediately takes a vacation. Upon returns from a vacation, if the queue is less than N, then the server takes another vacation. This process continues until the server finds atleast N customers in the queue. After a vacation, if the server finds at least N customers waiting for service, then the server needs a setup time to start the service. After a batch of service, if the amount of waiting customers in the queue is ξ (≥ a) then the server serves a batch of min(ξ,b) customers, where b ≥ a. We derived the probability generating function of queue length at arbitrary time epoch. Further, we obtained some important performance measures.

Realistic terrain visualization based on 3D virtual world technology

NASA Astrophysics Data System (ADS)

Huang, Fengru; Lin, Hui; Chen, Bin; Xiao, Cai

2009-09-01

The rapid advances in information technologies, e.g., network, graphics processing, and virtual world, have provided challenges and opportunities for new capabilities in information systems, Internet applications, and virtual geographic environments, especially geographic visualization and collaboration. In order to achieve meaningful geographic capabilities, we need to explore and understand how these technologies can be used to construct virtual geographic environments to help to engage geographic research. The generation of three-dimensional (3D) terrain plays an important part in geographical visualization, computer simulation, and virtual geographic environment applications. The paper introduces concepts and technologies of virtual worlds and virtual geographic environments, explores integration of realistic terrain and other geographic objects and phenomena of natural geographic environment based on SL/OpenSim virtual world technologies. Realistic 3D terrain visualization is a foundation of construction of a mirror world or a sand box model of the earth landscape and geographic environment. The capabilities of interaction and collaboration on geographic information are discussed as well. Further virtual geographic applications can be developed based on the foundation work of realistic terrain visualization in virtual environments.

Realistic terrain visualization based on 3D virtual world technology

NASA Astrophysics Data System (ADS)

Huang, Fengru; Lin, Hui; Chen, Bin; Xiao, Cai

2010-11-01

The rapid advances in information technologies, e.g., network, graphics processing, and virtual world, have provided challenges and opportunities for new capabilities in information systems, Internet applications, and virtual geographic environments, especially geographic visualization and collaboration. In order to achieve meaningful geographic capabilities, we need to explore and understand how these technologies can be used to construct virtual geographic environments to help to engage geographic research. The generation of three-dimensional (3D) terrain plays an important part in geographical visualization, computer simulation, and virtual geographic environment applications. The paper introduces concepts and technologies of virtual worlds and virtual geographic environments, explores integration of realistic terrain and other geographic objects and phenomena of natural geographic environment based on SL/OpenSim virtual world technologies. Realistic 3D terrain visualization is a foundation of construction of a mirror world or a sand box model of the earth landscape and geographic environment. The capabilities of interaction and collaboration on geographic information are discussed as well. Further virtual geographic applications can be developed based on the foundation work of realistic terrain visualization in virtual environments.

Scaffolding Interprofessional Education: Unfolding Case Studies, Virtual World Simulations, and Patient-Centered Care.

PubMed

Zook, Sharon Strang; Hulton, Linda J; Dudding, Carol C; Stewart, Anne L; Graham, Amy C

Fragmentation of health care negatively impacts quality; one of the contributing factors may be ineffective collaboration among health care professionals. This article describes the implementation of an interprofessional education curriculum for graduate students enrolled in nursing, psychology, and speech-language pathology programs. Over 3 semesters, students engaged in interprofessional collaboration modules, unfolding case studies, virtual simulation, and shared case planning experiences. The curriculum's impact on students' attitudes and values toward interprofessional collaborative practice was measured.

Time Is Not on Our Side: How Radiology Practices Should Manage Customer Queues.

PubMed

Loving, Vilert A; Ellis, Richard L; Rippee, Robert; Steele, Joseph R; Schomer, Donald F; Shoemaker, Stowe

2017-11-01

As health care shifts toward patient-centered care, wait times have received increasing scrutiny as an important metric for patient satisfaction. Long queues form when radiology practices inefficiently service their customers, leading to customer dissatisfaction and a lower perception of value. This article describes a four-step framework for radiology practices to resolve problematic queues: (1) analyze factors contributing to queue formation; (2) improve processes to reduce service times; (3) reduce variability; (4) address the psychology of queues. Copyright © 2017 American College of Radiology. Published by Elsevier Inc. All rights reserved.

End-to-end QoS bounds for RTP-based service subnetworks

NASA Astrophysics Data System (ADS)

Pitts, Jonathan M.; Schormans, John A.

1999-11-01

With the increasing focus on traffic prioritization to support voice-data integration in corporate intranets, practical methods are needed to dimension and manage cost efficient service partitions. This is particularly important for the provisioning of real time, delay sensitive services such as telephony and voice/video conferencing applications. Typically these can be provided over RTP/UDP/IP or ATM DBR/SBR bearers but, irrespective of the specific networking technology, the switches or routers need to implement some form of virtual buffer management with queue scheduling mechanisms to provide partitioning. The key requirement is for operators of such networks to be able to dimension the partitions and virtual buffer sizes for efficient resource utilization, instead of simply over-dimensioning. This paper draws on recent work at Queen Mary, University of London, supported by the UK Engineering and Physical Sciences Research Council, to investigate approximate analytical methods for assessing end to end delay variation bounds in cell based and packet based networks.

Experiences of Fast Queue health care users in primary health care facilities in eThekwini district, South Africa.

PubMed

Sokhela, Dudu G; Makhanya, Nonhlanhla J; Sibiya, Nokuthula M; Nokes, Kathleen M

2013-07-05

Comprehensive Primary Health Care (PHC), based on the principles of accessibility, availability, affordability, equity and acceptability, was introduced in South Africa to address inequalities in health service provision. Whilst the Fast Queue was instrumental in the promotion of access to health care, a major goal of the PHC approach, facilities were not prepared for the sudden influx of clients. Increased access resulted in long waiting times and queues contributing to dissatisfaction with the service which could lead to missed appointments and non-compliance with established treatment plans. Firstly to describe the experiences of clients using the Fast Queue strategy to access routine healthcare services and secondly, to determine how the clients' experiences led to satisfaction or dissatisfaction with the Fast Queue service. A descriptive qualitative survey using content analysis explored the experiences of the Fast Queue users in a PHC setting. Setting was first identified based on greatest number using the Fast Queue and geographic diversity and then a convenience sample of health care users of the Fast Queue were sampled individually along with one focus group of users who accessed the Queue monthly for medication refills. The same interview guide questions were used for both individual interviews and the one focus group discussion. Five clinics with the highest number of attendees during a three month period and a total of 83 health care users of the Fast Queue were interviewed. The average participant was female, 31 years old, single and unemployed. Two themes with sub-themes emerged: health care user flow and communication, which highlights both satisfaction and dissatisfaction with the fast queue and queue marshals, could assist in directing users to the respective queues, reduce waiting time and keep users satisfied with the use of sign posts where there is a lack of human resources. Effective health communication strategies contribute to positive experiences by health care users and these can be effected by: (1) involvement of health care providers in planning the construction of health facilities to give input about patient flow, infection prevention and control and provision of privacy, (2) effective complaints mechanisms for users to ensure that complaints are followed up and (3)encouraging users to arrive at the facility throughout the day, rather than the present practice where all users arrive at the clinic early in the morning.

Marine Vessel Traffic System

DTIC Science & Technology

2001-06-19

Queue Get Put The MutexQ module provides primitive queue operations which synchronize access to the queues and ensure queue structure integrity...interface provides for synchronous data rates ranging from 64 Kbps to 1.536 Mbps, while an RS-232 interface accommodates asynchronous data up to...interface VME Communications processor 57 and 8-channel serial I/O board. This board set provides a 68040 processor and 8-channels of synchronous

The Benefits and Barriers of Virtual Collaboration among Online Adjuncts

ERIC Educational Resources Information Center

Schieffer, Lori

2016-01-01

Online education is a current trend in higher education. This has left colleges needing to hire more part-time remote adjuncts to fill the fluctuating number of available courses. Because remote online adjuncts are susceptible to isolation, the need has arisen to study the benefits and barriers of virtual collaboration. The purpose of this…

Tracing Success: Graphical Methods for Analysing Successful Collaborative Problem Solving

ERIC Educational Resources Information Center

Joiner, Richard; Issroff, Kim

2003-01-01

The aim of this paper is to evaluate the use of trace diagrams for analysing collaborative problem solving. The paper describes a study where trace diagrams were used to analyse joint navigation in a virtual environment. Ten pairs of undergraduates worked together on a distributed virtual task to collect five flowers using two bees with each…

Training Teachers for Virtual Collaboration: A Case Study

ERIC Educational Resources Information Center

Vinagre, Margarita

2016-01-01

This study aims to explore the development of teachers' competences when trained in virtual collaboration. In order to do so, we analyse the data gathered from a group of nine in-service teachers who were trained in a forum and a wiki to become future telecollaborative teachers (TTs). During the course, participants worked in small groups and they…

Fostering Collaboration in CALL: Benefits and Challenges of Using Virtual Language Resource Centres

ERIC Educational Resources Information Center

Medina, Liliana Cuesta; Alvarez, Claudia Patricia

2014-01-01

This paper presents the findings from a qualitative study on collaborative CALL design and implementation carried out with two groups of postgraduate language-teacher trainees who designed and piloted nine virtual language resource centres (VLRC) at 16 educational institutions of different levels and contents for an academic year. The project was…

Collaborative Science Learning in Three-Dimensional Immersive Virtual Worlds: Pre-Service Teachers' Experiences in Second Life

ERIC Educational Resources Information Center

Nussli, Natalie; Oh, Kevin; McCandless, Kevin

2014-01-01

The purpose of this mixed methods study was to help pre-service teachers experience and evaluate the potential of Second Life, a three-dimensional immersive virtual environment, for potential integration into their future teaching. By completing collaborative assignments in Second Life, nineteen pre-service general education teachers explored an…

Cognitive Presence in Virtual Collaborative Learning: Assessing and Improving Critical Thinking in Online Discussion Forums

ERIC Educational Resources Information Center

Beckmann, Jennifer; Weber, Peter

2016-01-01

Purpose: The purpose of this study is to introduce a virtual collaborative learning setting called "Net Economy", which we established as part of an international learning network of currently six universities, and present our approach to continuously improve the course in each cycle. Design/ Methodology/Approach: Using the community of…

Wiki or Word? Evaluating Tools for Collaborative Writing and Editing

ERIC Educational Resources Information Center

Dishaw, Mark; Eierman, Michael A.; Iversen, Jakob H.; Philip, George C.

2011-01-01

Businesses and other organizations are relying increasingly on virtual teams to perform a range of business activities. A key challenge in utilizing virtual teams is to support collaboration among team members who are separated by distance and/or time. In this paper we use a research model based on a combination of the Technology Acceptance Model…

Educational Visualizations in 3D Collaborative Virtual Environments: A Methodology

ERIC Educational Resources Information Center

Fominykh, Mikhail; Prasolova-Forland, Ekaterina

2012-01-01

Purpose: Collaborative virtual environments (CVEs) have become increasingly popular in educational settings and the role of 3D content is becoming more and more important. Still, there are many challenges in this area, such as lack of empirical studies that provide design for educational activities in 3D CVEs and lack of norms of how to support…

Cognitive Presence in Virtual Collaborative Learning: Assessing and Improving Critical Thinking in Online Discussion Forums

ERIC Educational Resources Information Center

Beckmann, Jennifer; Weber, Peter

2015-01-01

The paper introduces a virtual collaborative learning setting called "Net Economy," which we established as part of an international learning network of currently seven universities. Using the Community of Inquiry framework as guidance and Canonical Action Research (CAR) as the chosen research design, the discussion forum of the online…

Live theater on a virtual stage: incorporating soft skills and teamwork in computer graphics education.

PubMed

Schweppe, M; Geigel, J

2011-01-01

Industry has increasingly emphasized the need for "soft" or interpersonal skills development and team-building experience in the college curriculum. Here, we discuss our experiences with providing such opportunities via a collaborative project called the Virtual Theater. In this joint project between the Rochester Institute of Technology's School of Design and Department of Computer Science, the goal is to enable live performance in a virtual space with participants in different physical locales. Students work in teams, collaborating with other students in and out of their disciplines.

Apparatus and method for managing digital resources by passing digital resource tokens between queues

DOEpatents

Crawford, H.J.; Lindenstruth, V.

1999-06-29

A method of managing digital resources of a digital system includes the step of reserving token values for certain digital resources in the digital system. A selected token value in a free-buffer-queue is then matched to an incoming digital resource request. The selected token value is then moved to a valid-request-queue. The selected token is subsequently removed from the valid-request-queue to allow a digital agent in the digital system to process the incoming digital resource request associated with the selected token. Thereafter, the selected token is returned to the free-buffer-queue. 6 figs.

Two tandem queues with general renewal input. 2: Asymptotic expansions for the diffusion model

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

Knessl, C.; Tier, C.

1999-10-01

In Part 1 the authors formulated and solved a diffusion model for two tandem queues with exponential servers and general renewal arrivals. They thus obtained the easy traffic diffusion approximation to the steady state joint queue length distribution for this network. Here they study asymptotic and numerical properties of the diffusion approximation. In particular, analytical expressions are obtained for the tail probabilities. Both the joint distribution of the two queues and the marginal distribution of the second queue are considered. They also give numerical illustrations of how this marginal is affected by changes in the arrival and service processes.

Apparatus and method for managing digital resources by passing digital resource tokens between queues

DOEpatents

Crawford, Henry J.; Lindenstruth, Volker

1999-01-01

A method of managing digital resources of a digital system includes the step of reserving token values for certain digital resources in the digital system. A selected token value in a free-buffer-queue is then matched to an incoming digital resource request. The selected token value is then moved to a valid-request-queue. The selected token is subsequently removed from the valid-request-queue to allow a digital agent in the digital system to process the incoming digital resource request associated with the selected token. Thereafter, the selected token is returned to the free-buffer-queue.

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

NASA Astrophysics Data System (ADS)

Jabro, A.; Jabro, J.

2012-04-01

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

A novel fair active queue management algorithm based on traffic delay jitter

NASA Astrophysics Data System (ADS)

Wang, Xue-Shun; Yu, Shao-Hua; Dai, Jin-You; Luo, Ting

2009-11-01

In order to guarantee the quantity of data traffic delivered in the network, congestion control strategy is adopted. According to the study of many active queue management (AQM) algorithms, this paper proposes a novel active queue management algorithm named JFED. JFED can stabilize queue length at a desirable level by adjusting output traffic rate and adopting a reasonable calculation of packet drop probability based on buffer queue length and traffic jitter; and it support burst packet traffic through the packet delay jitter, so that it can traffic flow medium data. JFED impose effective punishment upon non-responsible flow with a full stateless method. To verify the performance of JFED, it is implemented in NS2 and is compared with RED and CHOKe with respect to different performance metrics. Simulation results show that the proposed JFED algorithm outperforms RED and CHOKe in stabilizing instantaneous queue length and in fairness. It is also shown that JFED enables the link capacity to be fully utilized by stabilizing the queue length at a desirable level, while not incurring excessive packet loss ratio.

NASA Team Collaboration Pilot: Enabling NASA's Virtual Teams

NASA Technical Reports Server (NTRS)

Prahst, Steve

2003-01-01

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

Virtual Reality Based Collaborative Design by Children with High-Functioning Autism: Design-Based Flexibility, Identity, and Norm Construction

ERIC Educational Resources Information Center

Ke, Fengfeng; Lee, Sungwoong

2016-01-01

This exploratory case study examined the process and potential impact of collaborative architectural design and construction in an OpenSimulator-based virtual reality (VR) on the social skills development of children with high-functioning autism (HFA). Two children with a formal medical diagnosis of HFA and one typically developing peer, aged…

A Social Network Analysis of Teaching and Research Collaboration in a Teachers' Virtual Learning Community

ERIC Educational Resources Information Center

Lin, Xiaofan; Hu, Xiaoyong; Hu, Qintai; Liu, Zhichun

2016-01-01

Analysing the structure of a social network can help us understand the key factors influencing interaction and collaboration in a virtual learning community (VLC). Here, we describe the mechanisms used in social network analysis (SNA) to analyse the social network structure of a VLC for teachers and discuss the relationship between face-to-face…

A Survey of Students' Experiences on Collaborative Virtual Learning Activities Based on Five-Stage Model

ERIC Educational Resources Information Center

Karaman, M. Kemal; Özen, Sevil Orhan

2016-01-01

In this study, we aimed to design collaborative virtual learning (CVL) activities by using a five-stage model (FSM) and survey of students' experiences. The study group consisted of 14 voluntary students in the Turkish Teaching Department. In this case study, data were collected through observations, recordings in Second Life (SL) and interviews.…

A Framework for Web-Based Interprofessional Education for Midwifery and Medical Students.

PubMed

Reis, Pamela J; Faser, Karl; Davis, Marquietta

2015-01-01

Scheduling interprofessional team-based activities for health sciences students who are geographically dispersed, with divergent and often competing schedules, can be challenging. The use of Web-based technologies such as 3-dimensional (3D) virtual learning environments in interprofessional education is a relatively new phenomenon, which offers promise in helping students come together in online teams when face-to-face encounters are not possible. The purpose of this article is to present the experience of a nurse-midwifery education program in a Southeastern US university in delivering Web-based interprofessional education for nurse-midwifery and third-year medical students utilizing the Virtual Community Clinic Learning Environment (VCCLE). The VCCLE is a 3D, Web-based, asynchronous, immersive clinic environment into which students enter to meet and interact with instructor-controlled virtual patient and virtual preceptor avatars and then move through a classic diagnostic sequence in arriving at a plan of care for women throughout the lifespan. By participating in the problem-based management of virtual patients within the VCCLE, students learn both clinical competencies and competencies for interprofessional collaborative practice, as described by the Interprofessional Education Collaborative Core Competencies for Interprofessional Collaborative Practice. This article is part of a special series of articles that address midwifery innovations in clinical practice, education, interprofessional collaboration, health policy, and global health. © 2015 by the American College of Nurse-Midwives.

Incorporating a collaborative web-based virtual laboratory in an undergraduate bioinformatics course.

PubMed

Weisman, David

2010-01-01

Face-to-face bioinformatics courses commonly include a weekly, in-person computer lab to facilitate active learning, reinforce conceptual material, and teach practical skills. Similarly, fully-online bioinformatics courses employ hands-on exercises to achieve these outcomes, although students typically perform this work offsite. Combining a face-to-face lecture course with a web-based virtual laboratory presents new opportunities for collaborative learning of the conceptual material, and for fostering peer support of technical bioinformatics questions. To explore this combination, an in-person lecture-only undergraduate bioinformatics course was augmented with a remote web-based laboratory, and tested with a large class. This study hypothesized that the collaborative virtual lab would foster active learning and peer support, and tested this hypothesis by conducting a student survey near the end of the semester. Respondents broadly reported strong benefits from the online laboratory, and strong benefits from peer-provided technical support. In comparison with traditional in-person teaching labs, students preferred the virtual lab by a factor of two. Key aspects of the course architecture and design are described to encourage further experimentation in teaching collaborative online bioinformatics laboratories. Copyright © 2010 International Union of Biochemistry and Molecular Biology, Inc.

Evaluation of roadway sites for queue management.

DOT National Transportation Integrated Search

1991-01-01

This study addresses the problem of queueing on highway facilities, wherein a large number of computerized methods for the analysis of different queueing situations are available. A three-tier classification system of the methodologies was used with ...

Throughput-optimal scheduling for broadcast channels

NASA Astrophysics Data System (ADS)

Eryilmaz, Atilla; Srikant, Rayadurgam; Perkins, James R.

2001-07-01

In this paper, we consider a degraded Gaussian broadcast channel, where the transmitter maintains separate queues for each receiver. We present throughput optimal policies that stabilize the queues without knowing the statistics of the arrival processes to these queues.

Queues with Dropping Functions and General Arrival Processes

PubMed Central

Chydzinski, Andrzej; Mrozowski, Pawel

2016-01-01

In a queueing system with the dropping function the arriving customer can be denied service (dropped) with the probability that is a function of the queue length at the time of arrival of this customer. The potential applicability of such mechanism is very wide due to the fact that by choosing the shape of this function one can easily manipulate several performance characteristics of the queueing system. In this paper we carry out analysis of the queueing system with the dropping function and a very general model of arrival process—the model which includes batch arrivals and the interarrival time autocorrelation, and allows for fitting the actual shape of the interarrival time distribution and its moments. For such a system we obtain formulas for the distribution of the queue length and the overall customer loss ratio. The analytical results are accompanied with numerical examples computed for several dropping functions. PMID:26943171

Nonfixed Retirement Age for University Professors: Modeling Its Effects on New Faculty Hires.

PubMed

Larson, Richard C; Diaz, Mauricio Gomez

2012-03-01

We model the set of tenure-track faculty members at a university as a queue, where "customers" in queue are faculty members in active careers. Arrivals to the queue are usually young, untenured assistant professors, and departures from the queue are primarily those who do not pass a promotion or tenure hurdle and those who retire. There are other less-often-used ways to enter and leave the queue. Our focus is on system effects of the elimination of mandatory retirement age. In particular, we are concerned with estimating the number of assistant professor slots that annually are no longer available because of the elimination of mandatory retirement. We start with steady-state assumptions that require use of Little's Law of Queueing, and we progress to a transient model using system dynamics. We apply these simple models using available data from our home university, the Massachusetts Institute of Technology.

Nonfixed Retirement Age for University Professors: Modeling Its Effects on New Faculty Hires

PubMed Central

Larson, Richard C.; Diaz, Mauricio Gomez

2013-01-01

We model the set of tenure-track faculty members at a university as a queue, where “customers” in queue are faculty members in active careers. Arrivals to the queue are usually young, untenured assistant professors, and departures from the queue are primarily those who do not pass a promotion or tenure hurdle and those who retire. There are other less-often-used ways to enter and leave the queue. Our focus is on system effects of the elimination of mandatory retirement age. In particular, we are concerned with estimating the number of assistant professor slots that annually are no longer available because of the elimination of mandatory retirement. We start with steady-state assumptions that require use of Little’s Law of Queueing, and we progress to a transient model using system dynamics. We apply these simple models using available data from our home university, the Massachusetts Institute of Technology. PMID:23936582

A virtual environment for medical radiation collaborative learning.

PubMed

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

2015-06-01

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

Evaluation of DOTD's Existing Queue Estimation Procedures : Research Project Capsule

DOT National Transportation Integrated Search

2017-10-01

The primary objective of this study is to evaluate the effectiveness of DOTDs queue estimation procedures by comparing results with those obtained directly from site observations through video camera footage or other means. Actual queue start time...

Computing moving and intermittent queue propagation in highway work zones.

DOT National Transportation Integrated Search

2012-07-01

Drivers may experience intermittent congestion and moving queue conditions in work zones due to several reasons such as presence of lane closure, roadway geometric changes, higher demand, lower speed, and reduced capacity. The congestion and queue ha...

A hardware and software architecture to deal with multimodal and collaborative interactions in multiuser virtual reality environments

NASA Astrophysics Data System (ADS)

Martin, P.; Tseu, A.; Férey, N.; Touraine, D.; Bourdot, P.

2014-02-01

Most advanced immersive devices provide collaborative environment within several users have their distinct head-tracked stereoscopic point of view. Combining with common used interactive features such as voice and gesture recognition, 3D mouse, haptic feedback, and spatialized audio rendering, these environments should faithfully reproduce a real context. However, even if many studies have been carried out on multimodal systems, we are far to definitively solve the issue of multimodal fusion, which consists in merging multimodal events coming from users and devices, into interpretable commands performed by the application. Multimodality and collaboration was often studied separately, despite of the fact that these two aspects share interesting similarities. We discuss how we address this problem, thought the design and implementation of a supervisor that is able to deal with both multimodal fusion and collaborative aspects. The aim of this supervisor is to ensure the merge of user's input from virtual reality devices in order to control immersive multi-user applications. We deal with this problem according to a practical point of view, because the main requirements of this supervisor was defined according to a industrial task proposed by our automotive partner, that as to be performed with multimodal and collaborative interactions in a co-located multi-user environment. In this task, two co-located workers of a virtual assembly chain has to cooperate to insert a seat into the bodywork of a car, using haptic devices to feel collision and to manipulate objects, combining speech recognition and two hands gesture recognition as multimodal instructions. Besides the architectural aspect of this supervisor, we described how we ensure the modularity of our solution that could apply on different virtual reality platforms, interactive contexts and virtual contents. A virtual context observer included in this supervisor in was especially designed to be independent to the content of the virtual scene of targeted application, and is use to report high-level interactive and collaborative events. This context observer allows the supervisor to merge these interactive and collaborative events, but is also used to deal with new issues coming from our observation of two co-located users in an immersive device performing this assembly task. We highlight the fact that when speech recognition features are provided to the two users, it is required to automatically detect according to the interactive context, whether the vocal instructions must be translated into commands that have to be performed by the machine, or whether they take a part of the natural communication necessary for collaboration. Information coming from this context observer that indicates a user is looking at its collaborator, is important to detect if the user is talking to its partner. Moreover, as the users are physically co-localised and head-tracking is used to provide high fidelity stereoscopic rendering, and natural walking navigation in the virtual scene, we have to deals with collision and screen occlusion between the co-located users in the physical work space. Working area and focus of each user, computed and reported by the context observer is necessary to prevent or avoid these situations.

An Adaptive Property-Aware HW/SW Framework for DDDAS

DTIC Science & Technology

2014-10-21

sleep queue stores sleeping tasks until their activation time. The task with the earliest activation time is at the front of the sleep queue. At the...queue) or activation time ( sleep queue). Chetan et al. / Procedia Computer Science 00 (2012) 1–9 4 Figure 2: A high level architecture diagram of the...conservative will be the WCET estimation. Vestal et al. suggested the use of Audesly’s prioirity assignment scheme [6] and period transformation technique

A dynamic routing strategy with limited buffer on scale-free network

NASA Astrophysics Data System (ADS)

Wang, Yufei; Liu, Feng

2016-04-01

In this paper, we propose an integrated routing strategy based on global static topology information and local dynamic data packet queue lengths to improve the transmission efficiency of scale-free networks. The proposed routing strategy is a combination of a global static routing strategy (based on the shortest path algorithm) and local dynamic queue length management, in which, instead of using an infinite buffer, the queue length of each node i in the proposed routing strategy is limited by a critical queue length Qic. When the network traffic is lower and the queue length of each node i is shorter than its critical queue length Qic, it forwards packets according to the global routing table. With increasing network traffic, when the buffers of the nodes with higher degree are full, they do not receive packets due to their limited buffers and the packets have to be delivered to the nodes with lower degree. The global static routing strategy can shorten the transmission time that it takes a packet to reach its destination, and the local limited queue length can balance the network traffic. The optimal critical queue lengths of nodes have been analysed. Simulation results show that the proposed routing strategy can get better performance than that of the global static strategy based on topology, and almost the same performance as that of the global dynamic routing strategy with less complexity.

Utilising a Collaborative Macro-Script to Enhance Student Engagement: A Mixed Method Study in a 3D Virtual Environment

ERIC Educational Resources Information Center

Bouta, Hara; Retalis, Symeon; Paraskeva, Fotini

2012-01-01

This study examines the effect of using an online 3D virtual environment in teaching Mathematics in Primary Education. In particular, it explores the extent to which student engagement--behavioral, affective and cognitive--is fostered by such tools in order to enhance collaborative learning. For the study we used a purpose-created 3D virtual…

The evaluation of a formalized queue management system for coronary angiography waiting lists.

PubMed

Alter, D A; Newman, Alice M; Cohen, Eric A; Sykora, Kathy; Tu, Jack V

2005-11-01

Lengthy waiting lists for coronary angiography have been described in many health care systems worldwide. The extent to which formal queue management systems may improve the prioritization and survival of patients in the angiography queue is unknown. To prospectively evaluate the performance of a formal queue management system for patients awaiting coronary angiography in Ontario. The coronary angiography urgency scale, a formal queue management system developed in 1993 using a modified Delphi panel, allocates recommended maximum waiting times (RMWTs) in accordance with clinical necessity. By using a provincial clinical registry, 35,617 consecutive patients referred into the coronary angiography queue between April 1, 2001, and March 31, 2002, were prospectively tracked. Cox proportional hazards models were used to examined mortality risk across urgency after adjusting for additional clinical and comorbid factors. Good agreement was determined in urgency ratings between scores from the coronary angiography urgency scale and implicit physician judgement, which was obtained independently at the time of the index referral (weighted kappa = 0.49). The overall mortality in the queue was 0.3% (0.47%, 0.26% and 0.13% for urgent, semiurgent and elective patients, respectively). Urgency, as specified by the coronary angiography urgency scale, was the strongest predictor of death in the queue (P<0.001). However, when patients were censored according to their RMWTs, mortality was similar across different levels of urgency. Consequently, up to 18.5 deaths per 10,000 patients could have potentially been averted had patients been triaged and undergone coronary angiography within the RMWT as specified by the coronary angiography urgency scale. The incorporation of the coronary angiography urgency scale as a formal queue management system may decrease mortality in the coronary angiography queue. The authors recommend its implementation in health care systems where patients experience excessive waiting time delays for coronary angiography.

Reducing a congestion with introduce the greedy algorithm on traffic light control

NASA Astrophysics Data System (ADS)

Catur Siswipraptini, Puji; Hendro Martono, Wisnu; Hartanti, Dian

2018-03-01

The density of vehicles causes congestion seen at every junction in the city of jakarta due to the static or manual traffic timing lamp system consequently the length of the queue at the junction is uncertain. The research has been aimed at designing a sensor based traffic system based on the queue length detection of the vehicle to optimize the duration of the green light. In detecting the length of the queue of vehicles using infrared sensor assistance placed in each intersection path, then apply Greedy algorithm to help accelerate the movement of green light duration for the path that requires, while to apply the traffic lights regulation program based on greedy algorithm which is then stored on microcontroller with Arduino Mega 2560 type. Where a developed system implements the greedy algorithm with the help of the infrared sensor it will extend the duration of the green light on the long vehicle queue and accelerate the duration of the green light at the intersection that has the queue not too dense. Furthermore, the design is made to form an artificial form of the actual situation of the scale model or simple simulator (next we just called as scale model of simulator) of the intersection then tested. Sensors used are infrared sensors, where the placement of sensors in each intersection on the scale model is placed within 10 cm of each sensor and serves as a queue detector. From the results of the test process on the scale model with a longer queue obtained longer green light time so it will fix the problem of long queue of vehicles. Using greedy algorithms can add long green lights for 2 seconds on tracks that have long queues at least three sensor levels and accelerate time at other intersections that have longer queue sensor levels less than level three.

Collaborative virtual environments art exhibition

NASA Astrophysics Data System (ADS)

Dolinsky, Margaret; Anstey, Josephine; Pape, Dave E.; Aguilera, Julieta C.; Kostis, Helen-Nicole; Tsoupikova, Daria

2005-03-01

This panel presentation will exhibit artwork developed in CAVEs and discuss how art methodologies enhance the science of VR through collaboration, interaction and aesthetics. Artists and scientists work alongside one another to expand scientific research and artistic expression and are motivated by exhibiting collaborative virtual environments. Looking towards the arts, such as painting and sculpture, computer graphics captures a visual tradition. Virtual reality expands this tradition to not only what we face, but to what surrounds us and even what responds to our body and its gestures. Art making that once was isolated to the static frame and an optimal point of view is now out and about, in fully immersive mode within CAVEs. Art knowledge is a guide to how the aesthetics of 2D and 3D worlds affect, transform, and influence the social, intellectual and physical condition of the human body through attention to psychology, spiritual thinking, education, and cognition. The psychological interacts with the physical in the virtual in such a way that each facilitates, enhances and extends the other, culminating in a "go together" world. Attention to sharing art experience across high-speed networks introduces a dimension of liveliness and aliveness when we "become virtual" in real time with others.

B-1B Avionics/Automatic Test Equipment: Maintenance Queueing Analysis.

DTIC Science & Technology

1983-12-01

analysis (which is logistics terminology for an avionics/ATE queueing analysis). To allow each vendor the opportunity to perform such an analysis...for system performance measures may be found for the queueing system in Figure 7. This is due to the preemptive blocking caused by ATE failures. The...D-R14l1i75 B-iB AVIONICS/AUTOMPTIC TEST EQUIPMENT: MRINTENRNCE 1/2 QUEUEING RNRLYSIS(U) RIP FORCE INST OF TECH HRIGHT-PRTTERSON RFB OH SCHOOL OF

On-Line Scheduling of Parallel Machines

DTIC Science & Technology

1990-11-01

machine without losing any work; this is referred to as the preemptive model. In contrast to the nonpreemptive model which we have considered in this paper...that there exists no schedule of length d. The 2-relaxed decision procedure is as follows. Put each job into the queue of the slowest machine Mk such...in their queues . If a machine’s queue is empty it takes jobs to process from the queue of the first machine that is slower than it and that has a

NASA's Solar System Exploration Research Virtual Institute: Building Collaboration Through International Partnerships

NASA Technical Reports Server (NTRS)

Gibbs, K. E.; Schmidt, G. K.

2017-01-01

The NASA Solar System Exploration Research Virtual Institute (SSERVI) is a virtual institute focused on re-search at the intersection of science and exploration, training the next generation of lunar scientists, and community development. As part of the SSERVI mission, we act as a hub for opportunities that engage the larger scientific and exploration communities in order to form new interdisciplinary, research-focused collaborations. This talk will describe the international partner re-search efforts and how we are engaging the international science and exploration communities through workshops, conferences, online seminars and classes, student exchange programs and internships.

Virtual pharmaceutical companies: collaborating flexibly in pharmaceutical development.

PubMed

Forster, Simon P; Stegmaier, Julia; Spycher, Rene; Seeger, Stefan

2014-03-01

Research and development (R&D) collaborations represent one approach chosen by the pharmaceutical industry to tackle current challenges posed by declining internal R&D success rates and fading of the blockbuster model. In recent years, a flexible concept to collaborate in R&D has emerged: virtual pharmaceutical companies (VPCs). These differ from other R&D companies, such as biotech start-ups, collaborating with big pharmaceutical companies, because they solely comprise experienced teams of managers. VPCs have only been described anecdotally in literature. Thus, we present here the characteristics of a VPC and suggest how big pharma can leverage the concept of VPCs by introducing five possible modes of collaboration. We find that one mode, investing, is particularly promising for big pharma. Copyright © 2013 Elsevier Ltd. All rights reserved.

Virtual Organizations: Trends and Models

NASA Astrophysics Data System (ADS)

Nami, Mohammad Reza; Malekpour, Abbaas

The Use of ICT in business has changed views about traditional business. With VO, organizations with out physical, geographical, or structural constraint can collaborate with together in order to fulfill customer requests in a networked environment. This idea improves resource utilization, reduces development process and costs, and saves time. Virtual Organization (VO) is always a form of partnership and managing partners and handling partnerships are crucial. Virtual organizations are defined as a temporary collection of enterprises that cooperate and share resources, knowledge, and competencies to better respond to business opportunities. This paper presents an overview of virtual organizations and main issues in collaboration such as security and management. It also presents a number of different model approaches according to their purpose and applications.

The Geography of Virtual Questioning

ERIC Educational Resources Information Center

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

2009-01-01

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

The Sojourn Time in a Three Node, Acyclic, Jackson Queueing Network.

DTIC Science & Technology

1982-01-27

Effect of Intermediate Storage on Production Lines with Dependent Machines, Robert D. Foley and Petcharat Chansaenwilai 8015 Some Conditions for the...Queues, Robert D. Foley 8105 Reversibility of Production Lines with Dependent Machines, Petcharat Chansaenwilai 1 8106 Queues with Delayed Feedback, Robert

Method and apparatus for efficiently tracking queue entries relative to a timestamp

DOEpatents

Blumrich, Matthias A.; Chen, Dong; Gara, Alan G.; Giampapa, Mark E.; Heidelberger, Philip; Ohmacht, Martin; Salapura, Velentina; Vranas, Pavlos

2014-06-17

An apparatus and method for tracking coherence event signals transmitted in a multiprocessor system. The apparatus comprises a coherence logic unit, each unit having a plurality of queue structures with each queue structure associated with a respective sender of event signals transmitted in the system. A timing circuit associated with a queue structure controls enqueuing and dequeuing of received coherence event signals, and, a counter tracks a number of coherence event signals remaining enqueued in the queue structure and dequeued since receipt of a timestamp signal. A counter mechanism generates an output signal indicating that all of the coherence event signals present in the queue structure at the time of receipt of the timestamp signal have been dequeued. In one embodiment, the timestamp signal is asserted at the start of a memory synchronization operation and, the output signal indicates that all coherence events present when the timestamp signal was asserted have completed. This signal can then be used as part of the completion condition for the memory synchronization operation.

Virtual Laboratory Enabling Collaborative Research in Applied Vehicle Technologies

NASA Technical Reports Server (NTRS)

Lamar, John E.; Cronin, Catherine K.; Scott, Laura E.

2005-01-01

The virtual laboratory is a new technology, based on the internet, that has had wide usage in a variety of technical fields because of its inherent ability to allow many users to participate simultaneously in instruction (education) or in the collaborative study of a common problem (real-world application). The leadership in the Applied Vehicle Technology panel has encouraged the utilization of this technology in its task groups for some time and its parent organization, the Research and Technology Agency, has done the same for its own administrative use. This paper outlines the application of the virtual laboratory to those fields important to applied vehicle technologies, gives the status of the effort, and identifies the benefit it can have on collaborative research. The latter is done, in part, through a specific example, i.e. the experience of one task group.

The Effects of Communicative Genres on Intra-Group Conflict in Virtual Student Teams

ERIC Educational Resources Information Center

Hsu, Jung-Lung; Chou, Huey-Wen

2009-01-01

With increasing convenience and prevalence, the distant communication application has become a promising way for individuals who are eager to cooperate and interact virtually. This study explored the question of whether the collaborative interaction of the virtual teams has any effect on the conflict and network structure of virtual groups. A…

Importance of Diversified Leadership Roles in Improving Team Effectiveness in a Virtual Collaboration Learning Environment

ERIC Educational Resources Information Center

Chen, Charlie C.; Wu, Jiinpo; Yang, Samuel C.; Tsou, Hsin-Yi

2008-01-01

Virtual teams enabled by information and communications technologies (ICT) are increasingly being adopted not only by for-profit organizations but also by education institutions as well. This study investigates what contributes to the success of virtual learning teams. Specifically, we examine the issue of leadership in virtual learning teams. The…

How to report and monitor the performance of waiting list management.

PubMed

Torkki, Markus; Linna, Miika; Seitsalo, Seppo; Paavolainen, Pekka

2002-01-01

Potential problems concerning waiting list management are often monitored using mean waiting times based on empirical samples. However, the appropriateness of mean waiting time as an indicator of access can be questioned if a waiting list is not managed well, e.g., if the queue discipline is violated. This study was performed to find out about the queue discipline in waiting lists for elective surgery to reveal potential discrepancies in waiting list management. There were 1,774 waiting list patients for hallux valgus or varicose vein surgery or sterilization. The waiting time distributions of patients receiving surgery and of patients still waiting for an operation are presented in column charts. The charts are compared with two model charts. One model chart presents a high queue discipline (first in-first out) and another a poor queue discipline (random) queue. There were significant differences in waiting list management across hospitals and patient categories. Examples of a poor queue discipline were found in queues for hallux valgus and varicose vein operations. A routine waiting list reporting should be used to guarantee the quality of waiting list management and to pinpoint potential problems in access. It is important to monitor not only the number of patients in the waiting list but also the queue discipline and the balance between demand and supply of surgical services. The purpose for this type of reporting is to ensure that the priority setting made at health policy level also works in practise.

Interference Drop Scheme: Enhancing QoS Provision in Multi-Hop Ad Hoc Networks

NASA Astrophysics Data System (ADS)

Luo, Chang-Yi; Komuro, Nobuyoshi; Takahashi, Kiyoshi; Kasai, Hiroyuki; Ueda, Hiromi; Tsuboi, Toshinori

Ad hoc networking uses wireless technologies to construct networks with no physical infrastructure and so are expected to provide instant networking in areas such as disaster recovery sites and inter-vehicle communication. Unlike conventional wired networks services, services in ad hoc networks are easily disrupted by the frequent changes in traffic and topology. Therefore, solutions to assure the Quality of Services (QoS) in ad hoc networks are different from the conventional ones used in wired networks. In this paper, we propose a new queue management scheme, Interference Drop Scheme (IDS) for ad hoc networks. In the conventional queue management approaches such as FIFO (First-in First-out) and RED (Random Early Detection), a queue is usually managed by a queue length limit. FIFO discards packets according to the queue limit, and RED discards packets in an early and random fashion. IDS, on the other hand, manages the queue according to wireless interference time, which increases as the number of contentions in the MAC layer increases. When there are many MAC contentions, IDS discards TCP data packets. By observing the interference time and discarding TCP data packets, our simulation results show that IDS improves TCP performance and reduces QoS violations in UDP in ad hoc networks with chain, grid, and random topologies. Our simulation results also demonstrate that wireless interference time is a better metric than queue length limit for queue management in multi-hop ad hoc networks.

Synthetic hardware performance analysis in virtualized cloud environment for healthcare organization.

PubMed

Tan, Chee-Heng; Teh, Ying-Wah

2013-08-01

The main obstacles in mass adoption of cloud computing for database operations in healthcare organization are the data security and privacy issues. In this paper, it is shown that IT services particularly in hardware performance evaluation in virtual machine can be accomplished effectively without IT personnel gaining access to actual data for diagnostic and remediation purposes. The proposed mechanisms utilized the hypothetical data from TPC-H benchmark, to achieve 2 objectives. First, the underlying hardware performance and consistency is monitored via a control system, which is constructed using TPC-H queries. Second, the mechanism to construct stress-testing scenario is envisaged in the host, using a single or combination of TPC-H queries, so that the resource threshold point can be verified, if the virtual machine is still capable of serving critical transactions at this constraining juncture. This threshold point uses server run queue size as input parameter, and it serves 2 purposes: It provides the boundary threshold to the control system, so that periodic learning of the synthetic data sets for performance evaluation does not reach the host's constraint level. Secondly, when the host undergoes hardware change, stress-testing scenarios are simulated in the host by loading up to this resource threshold level, for subsequent response time verification from real and critical transactions.

Queues and Reference Service: Some Implications for Staffing

ERIC Educational Resources Information Center

Regazzi, John J.; Hersberger, Rodney M.

1978-01-01

This study at an academic library used a simulation technique (1) to analyze the extent to which queues develop at a reference desk during peak periods, (2) to propose alternative staffing models to reduce queues, and (3) to examine the cost effectiveness of the alternatives. (Author/JAB)

Why Virtual, Why Environments? Implementing Virtual Reality Concepts in Computer-Assisted Language Learning.

ERIC Educational Resources Information Center

Schwienhorst, Klaus

2002-01-01

Discussion of computer-assisted language learning focuses on the benefits of virtual reality environments, particularly for foreign language contexts. Topics include three approaches to learner autonomy; supporting reflection, including self-awareness; supporting interaction, including collaboration; and supporting experimentation, including…

Towards a Framework for Virtual Internationalization

ERIC Educational Resources Information Center

Bruhn, Elisa

2017-01-01

Internationalization and digitalization--how do these two higher education trends go together? Projects dealing with virtual mobility, collaborative online international learning (COIL), or virtual transnational education (TNE) have shown that the link between the international and the digital is not only a theoretical possibility but already a…

Awareware: Narrowcasting Attributes for Selective Attention, Privacy, and Multipresence

NASA Astrophysics Data System (ADS)

Cohen, Michael; Newton Fernando, Owen Noel

The domain of cscw, computer-supported collaborative work, and DSC, distributed synchronous collaboration, spans real-time interactive multiuser systems, shared information spaces, and applications for teleexistence and artificial reality, including collaborative virtual environments ( cves) (Benford et al., 2001). As presence awareness systems emerge, it is important to develop appropriate interfaces and architectures for managing multimodal multiuser systems. Especially in consideration of the persistent connectivity enabled by affordable networked communication, shared distributed environments require generalized control of media streams, techniques to control source → sink transmissions in synchronous groupware, including teleconferences and chatspaces, online role-playing games, and virtual concerts.

Towards Monitoring-as-a-service for Scientific Computing Cloud applications using the ElasticSearch ecosystem

NASA Astrophysics Data System (ADS)

Bagnasco, S.; Berzano, D.; Guarise, A.; Lusso, S.; Masera, M.; Vallero, S.

2015-12-01

The INFN computing centre in Torino hosts a private Cloud, which is managed with the OpenNebula cloud controller. The infrastructure offers Infrastructure-as-a-Service (IaaS) and Platform-as-a-Service (PaaS) services to different scientific computing applications. The main stakeholders of the facility are a grid Tier-2 site for the ALICE collaboration at LHC, an interactive analysis facility for the same experiment and a grid Tier-2 site for the BESIII collaboration, plus an increasing number of other small tenants. The dynamic allocation of resources to tenants is partially automated. This feature requires detailed monitoring and accounting of the resource usage. We set up a monitoring framework to inspect the site activities both in terms of IaaS and applications running on the hosted virtual instances. For this purpose we used the ElasticSearch, Logstash and Kibana (ELK) stack. The infrastructure relies on a MySQL database back-end for data preservation and to ensure flexibility to choose a different monitoring solution if needed. The heterogeneous accounting information is transferred from the database to the ElasticSearch engine via a custom Logstash plugin. Each use-case is indexed separately in ElasticSearch and we setup a set of Kibana dashboards with pre-defined queries in order to monitor the relevant information in each case. For the IaaS metering, we developed sensors for the OpenNebula API. The IaaS level information gathered through the API is sent to the MySQL database through an ad-hoc developed RESTful web service. Moreover, we have developed a billing system for our private Cloud, which relies on the RabbitMQ message queue for asynchronous communication to the database and on the ELK stack for its graphical interface. The Italian Grid accounting framework is also migrating to a similar set-up. Concerning the application level, we used the Root plugin TProofMonSenderSQL to collect accounting data from the interactive analysis facility. The BESIII virtual instances used to be monitored with Zabbix, as a proof of concept we also retrieve the information contained in the Zabbix database. In this way we have achieved a uniform monitoring interface for both the IaaS and the scientific applications, mostly leveraging off-the-shelf tools. At present, we are working to define a model for monitoring-as-a-service, based on the tools described above, which the Cloud tenants can easily configure to suit their specific needs.

Playing in the Virtual Sandbox: Students' Collaborative Practices in Minecraft

ERIC Educational Resources Information Center

Davis, Katie; Boss, Julian A.; Meas, Perry

2018-01-01

Researchers, teachers, and the news media have touted Minecraft as an effective, engaging way to promote students' 21st century skills, including collaboration. However, little is known about what collaboration looks like in Minecraft, including what factors support and undermine high quality collaboration. The current exploratory study…

Ontology Enabled Annotation and Knowledge Management for Collaborative Learning in Virtual Learning Community

ERIC Educational Resources Information Center

Yang, Stephen J. H.; Chen, Irene Ya-Ling; Shao, Norman W. Y.

2004-01-01

The nature of collaborative learning involves intensive interactions among collaborators, such as articulating knowledge into written, verbal or symbolic forms, authoring articles or posting messages to this community's discussion forum, responding or adding comments to messages or articles posted by others, etc. Knowledge collaborators'…

Interaction Forms in Successful Collaborative Learning in Virtual Learning Environments

ERIC Educational Resources Information Center

Vuopala, Essi; Hyvönen, Pirkko; Järvelä, Sanna

2016-01-01

Despite the numerous studies on social interaction in collaborative learning, little is known about interaction forms in successful computer-supported collaborative learning situations. The purpose of this study was to explore and understand student interaction in successful collaborative learning during a university course which was mediated by…

41 CFR 105-60.402-2 - Response to initial requests.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Management Regulations System (Continued) GENERAL SERVICES ADMINISTRATION Regional Offices-General Services... denial. (e) GSA may, at its discretion, establish three processing queues based on whether any requests... each queue, responses will be prepared on a “first in, first out” basis. One queue will be made up of...

Performance characteristics of a batch service queueing system with functioning server failure and multiple vacations

NASA Astrophysics Data System (ADS)

Niranjan, S. P.; Chandrasekaran, V. M.; Indhira, K.

2018-04-01

This paper examines bulk arrival and batch service queueing system with functioning server failure and multiple vacations. Customers are arriving into the system in bulk according to Poisson process with rate λ. Arriving customers are served in batches with minimum of ‘a’ and maximum of ‘b’ number of customers according to general bulk service rule. In the service completion epoch if the queue length is less than ‘a’ then the server leaves for vacation (secondary job) of random length. After a vacation completion, if the queue length is still less than ‘a’ then the server leaves for another vacation. The server keeps on going vacation until the queue length reaches the value ‘a’. The server is not stable at all the times. Sometimes it may fails during functioning of customers. Though the server fails service process will not be interrupted.It will be continued for the current batch of customers with lower service rate than the regular service rate. The server will be repaired after the service completion with lower service rate. The probability generating function of the queue size at an arbitrary time epoch will be obtained for the modelled queueing system by using supplementary variable technique. Moreover various performance characteristics will also be derived with suitable numerical illustrations.

ICCE/ICCAI 2000 Full & Short Papers (Virtual Lab/Classroom/School).

ERIC Educational Resources Information Center

2000

This document contains the following full and short papers on virtual laboratories, classrooms, and schools from ICCE/ICCAI 2000 (International Conference on Computers in Education/International Conference on Computer-Assisted Instruction): (1) "A Collaborative Learning Support System Based on Virtual Environment Server for Multiple…

Virtual Mobility in Higher Education. The UNED Campus Net Program

ERIC Educational Resources Information Center

Aguado, Teresa; Monge, Fernando; Del Olmo, Alicia

2014-01-01

We present the UNED Virtual Mobility Campus Net Program, implemented since 2012 in collaboration with European and Latin American universities. Program's objectives, participating institutions, procedures, and evaluation are exposed. Virtual mobility is understood as a meaningful strategy for intercultural learning by studying an undergraduate or…

Information Seeking in a Virtual Learning Environment.

ERIC Educational Resources Information Center

Byron, Suzanne M.; Young, Jon I.

2000-01-01

Examines the applicability of Kuhlthau's Information Search Process Model in the context of a virtual learning environment at the University of North Texas that used virtual collaborative software. Highlights include cognitive and affective aspects of information seeking; computer experience and confidence; and implications for future research.…

Using Virtual Microscopy to Scaffold Learning of Pathology: A Naturalistic Experiment on the Role of Visual and Conceptual Cues

ERIC Educational Resources Information Center

Nivala, Markus; Saljo, Roger; Rystedt, Hans; Kronqvist, Pauliina; Lehtinen, Erno

2012-01-01

New representational technologies, such as virtual microscopy, create new affordances for medical education. In the article, a study on the following two issues is reported: (a) How does collaborative use of virtual microscopy shape students' engagement with and learning from virtual slides of tissue specimen? (b) How do visual and conceptual cues…

Fostering Verbal and Non-Verbal Social Interactions in a 3D Collaborative Virtual Learning Environment: A Case Study of Youth with Autism Spectrum Disorders Learning Social Competence in iSocial

ERIC Educational Resources Information Center

Wang, Xianhui; Laffey, James; Xing, Wanli; Galyen, Krista; Stichter, Janine

2017-01-01

This case study describes the verbal and nonverbal social interaction of 11 youth with Autism Spectrum Disorders in a 3D Collaborative Virtual Learning Environment-iSocial. The youth were developing social competence through participation in a social competence intervention curriculum implemented online so as to provide access to high quality…

Transient probabilities for queues with applications to hospital waiting list management.

PubMed

Joy, Mark; Jones, Simon

2005-08-01

In this paper we study queuing systems within the NHS. Recently imposed government performance targets lead NHS executives to investigate and instigate alternative management strategies, thereby imposing structural changes on the queues. Under such circumstances, it is most unlikely that such systems are in equilibrium. It is crucial, in our opinion, to recognise this state of affairs in order to make a balanced assessment of the role of queue management in the modern NHS. From a mathematical perspective it should be emphasised that measures of the state of a queue based upon the assumption of statistical equilibrium (a pervasive methodology in the study of queues) are simply wrong in the above scenario. To base strategic decisions around such ideas is therefore highly questionable and it is one of the purposes of this paper to offer alternatives: we present some (recent) research whose results generate performance measures and measures of risk, for example, of waiting-times growing unacceptably large; we emphasise that these results concern the transient behaviour of the queueing model-there is no asssumption of statistical equilibrium. We also demonstrate that our results are computationally tractable.

Single stage queueing/manufacturing system model that involves emission variable

NASA Astrophysics Data System (ADS)

Murdapa, P. S.; Pujawan, I. N.; Karningsih, P. D.; Nasution, A. H.

2018-04-01

Queueing is commonly occured at every industry. The basic model of queueing theory gives a foundation for modeling a manufacturing system. Nowadays, carbon emission is an important and inevitable issue due to its huge impact to our environment. However, existing model of queuing applied for analysis of single stage manufacturing system has not taken Carbon emissions into consideration. If it is applied to manufacturing context, it may lead to improper decisisions. By taking into account of emission variables into queuing models, not only the model become more comprehensive but also it creates awareness on the issue to many parties that involves in the system. This paper discusses the single stage M/M/1 queueing model that involves emission variable. Hopefully it could be a starting point for the next more complex models. It has a main objective for determining how carbon emissions could fit into the basic queueing theory. It turned out that the involvement of emission variables into the model has modified the traditional model of a single stage queue to a calculation model of production lot quantity allowed per period.

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

ERIC Educational Resources Information Center

Eakin, Lori; Pomerantz, Jeffrey

2009-01-01

Libraries nationwide are in yet another phase of belt tightening. Without an understanding of the economic factors that influence library operations, however, controlling costs and performing cost-benefit analyses on services is difficult. This paper describes a project to develop a cost model for collaborative virtual reference services. This…

Parameters for Successful Management of Cross Cultural Virtual Teams

ERIC Educational Resources Information Center

Gullett, Evelyn; Sixl-Daniell, Karin

2008-01-01

Virtual teams are a common phenomenon in organizations today. Universities are no exception to this trend and, in response, are offering class rooms without boundaries by introducing online programs which allow individuals from all walks of life and diverse geographical locations to come together. Cross-cultural virtual teams, collaborating with…

The World's the Limit in the Virtual High School.

ERIC Educational Resources Information Center

Berman, Sheldon; Tinker, Robert

1997-01-01

Assisted by a U.S. Department of Education Technology Innovation Challenge Grant, the Hudson (Massachusetts) Public Schools, the Concord Consortium Educational Technology Lab, and 30 collaborating high schools across the nation have developed a virtual high school over the Internet. Through Internet-based courses, Virtual High School significantly…

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

ERIC Educational Resources Information Center

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

2017-01-01

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

Building a Virtual Learning Network for Teachers in a Suburban School District

ERIC Educational Resources Information Center

Kurtzworth-Keen, Kristin A.

2011-01-01

Emerging research indicates that learning management systems such as Moodle can function as virtual, collaborative environments, where collegial interactions promote professional learning opportunities. This study deployed a mixed methods design in order to describe and analyze teacher participation in a virtual learning network (VLN) that was…

The Virtual Classroom: A Catalyst for Institutional Transformation

ERIC Educational Resources Information Center

Subramaniam, Nantha Kumar; Kandasamy, Maheswari

2011-01-01

This study explores the use of the virtual classroom which has been created in "myVLE", a learning management system used by the Open University Malaysia (OUM). The virtual classroom in "myVLE" is an asynchronous-based online learning environment that delivers course materials to learners and provides collaboration and…

Virtual Patient Simulations for Medical Education: Increasing Clinical Reasoning Skills through Deliberate Practice

ERIC Educational Resources Information Center

McCoy, Lise

2014-01-01

Virtual Patient Simulations (VPS) are web-based exercises involving simulated patients in virtual environments. This study investigates the utility of VPS for increasing medical student clinical reasoning skills, collaboration, and engagement. Many studies indicate that VPS provide medical students with essential practice in clinical decision…

An Ethnographic Study of a Developing Virtual Organization in Education

ERIC Educational Resources Information Center

Couch, Stephanie R.

2012-01-01

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

Learning through Place-Making: Virtual Environments and Future Literacies

ERIC Educational Resources Information Center

Berry, Maryanne Susan

2010-01-01

This study examines a project through which elementary school and high school students collaborated with university Architecture/New Media students in building models of virtual, immersive libraries. It presents the project in the context of multiple and cross-disciplinary fields currently investigating the use of virtual and immersive…

VO-KOREL: A Fourier Disentangling Service of the Virtual Observatory

NASA Astrophysics Data System (ADS)

Škoda, Petr; Hadrava, Petr; Fuchs, Jan

2012-04-01

VO-KOREL is a web service exploiting the technology of the Virtual Observatory for providing astronomers with the intuitive graphical front-end and distributed computing back-end running the most recent version of the Fourier disentangling code KOREL. The system integrates the ideas of the e-shop basket, conserving the privacy of every user by transfer encryption and access authentication, with features of laboratory notebook, allowing the easy housekeeping of both input parameters and final results, as well as it explores a newly emerging technology of cloud computing. While the web-based front-end allows the user to submit data and parameter files, edit parameters, manage a job list, resubmit or cancel running jobs and mainly watching the text and graphical results of a disentangling process, the main part of the back-end is a simple job queue submission system executing in parallel multiple instances of the FORTRAN code KOREL. This may be easily extended for GRID-based deployment on massively parallel computing clusters. The short introduction into underlying technologies is given, briefly mentioning advantages as well as bottlenecks of the design used.

Numbers or apologies? Customer reactions to telephone waiting time fillers.

PubMed

Munichor, Nira; Rafaeli, Anat

2007-03-01

The authors examined the effect of time perception and sense of progress in telephone queues on caller reactions to 3 telephone waiting time fillers: music, apologies, and information about location in the queue. In Study 1, conducted on 123 real calls, call abandonment was lowest, and call evaluations were most positive with information about location in the queue as the time filler. In Study 2, conducted with 83 participants who experienced a simulated telephone wait experience, sense of progress in the queue rather than perceived waiting time mediated the relationship between telephone waiting time filler and caller reactions. The findings provide insight for the management and design of telephone queues, as well as theoretical insight into critical cognitive processes that underlie telephone waiting, opening up an important new research agenda. (c) 2007 APA, all rights reserved.

Store operation with conditional push of a tag value to a queue

DOEpatents

Heidelberger, Philip; Steinmacher-Burow, Burkhard

2015-07-28

According to one embodiment, a method for a store operation with a conditional push of a tag value to a queue is provided. The method includes configuring a queue that is accessible by an application, setting a value at an address in a memory device including a memory and a controller, receiving a request for an operation using the value at the address and performing the operation. The method also includes the controller writing a result of the operation to the address, thus changing the value at the address, the controller determining if the result of the operation meets a condition and the controller pushing a tag value to the queue based on the condition being met, where the tag value in the queue indicates to the application that the condition is met.

Design and development of cell queuing, processing, and scheduling modules for the iPOINT input-buffered ATM testbed

NASA Astrophysics Data System (ADS)

Duan, Haoran

1997-12-01

This dissertation presents the concepts, principles, performance, and implementation of input queuing and cell-scheduling modules for the Illinois Pulsar-based Optical INTerconnect (iPOINT) input-buffered Asynchronous Transfer Mode (ATM) testbed. Input queuing (IQ) ATM switches are well suited to meet the requirements of current and future ultra-broadband ATM networks. The IQ structure imposes minimum memory bandwidth requirements for cell buffering, tolerates bursty traffic, and utilizes memory efficiently for multicast traffic. The lack of efficient cell queuing and scheduling solutions has been a major barrier to build high-performance, scalable IQ-based ATM switches. This dissertation proposes a new Three-Dimensional Queue (3DQ) and a novel Matrix Unit Cell Scheduler (MUCS) to remove this barrier. 3DQ uses a linked-list architecture based on Synchronous Random Access Memory (SRAM) to combine the individual advantages of per-virtual-circuit (per-VC) queuing, priority queuing, and N-destination queuing. It avoids Head of Line (HOL) blocking and provides per-VC Quality of Service (QoS) enforcement mechanisms. Computer simulation results verify the QoS capabilities of 3DQ. For multicast traffic, 3DQ provides efficient usage of cell buffering memory by storing multicast cells only once. Further, the multicast mechanism of 3DQ prevents a congested destination port from blocking other less- loaded ports. The 3DQ principle has been prototyped in the Illinois Input Queue (iiQueue) module. Using Field Programmable Gate Array (FPGA) devices, SRAM modules, and integrated on a Printed Circuit Board (PCB), iiQueue can process incoming traffic at 800 Mb/s. Using faster circuit technology, the same design is expected to operate at the OC-48 rate (2.5 Gb/s). MUCS resolves the output contention by evaluating the weight index of each candidate and selecting the heaviest. It achieves near-optimal scheduling and has a very short response time. The algorithm originates from a heuristic strategy that leads to 'socially optimal' solutions, yielding a maximum number of contention-free cells being scheduled. A novel mixed digital-analog circuit has been designed to implement the MUCS core functionality. The MUCS circuit maps the cell scheduling computation to the capacitor charging and discharging procedures that are conducted fully in parallel. The design has a uniform circuit structure, low interconnect counts, and low chip I/O counts. Using 2 μm CMOS technology, the design operates on a 100 MHz clock and finds a near-optimal solution within a linear processing time. The circuit has been verified at the transistor level by HSPICE simulation. During this research, a five-port IQ-based optoelectronic iPOINT ATM switch has been developed and demonstrated. It has been fully functional with an aggregate throughput of 800 Mb/s. The second-generation IQ-based switch is currently under development. Equipped with iiQueue modules and MUCS module, the new switch system will deliver a multi-gigabit aggregate throughput, eliminate HOL blocking, provide per-VC QoS, and achieve near-100% link bandwidth utilization. Complete documentation of input modules and trunk module for the existing testbed, and complete documentation of 3DQ, iiQueue, and MUCS for the second-generation testbed are given in this dissertation.

On Enhancing On-Line Collaboration Using Fuzzy Logic Modeling

ERIC Educational Resources Information Center

Hadjileontiadou, Sofia J.; Nikolaidou, Georgia N.; Hadjileontiadis, Leontios J.; Balafoutas, George N.

2004-01-01

Web-based collaboration calls for professional skills and competences to the benefit of the quality of the collaboration and its output. Within this framework, educational virtual environments may provide a means for training upon these skills and in particular the collaborative ones. On the basis of the existing technological means such training…

Collaboration, Multi-Tasking and Problem Solving Performance in Shared Virtual Spaces

ERIC Educational Resources Information Center

Lin, Lin; Mills, Leila A.; Ifenthaler, Dirk

2016-01-01

Collaborative problem-solving is often not a sequential process; instead, it can involve tasking switching or dual tasking (i.e., multitasking) activities in that the collaborators need to shift their attention between the targeted problems and the conversations they carry on with their collaborators. It is not known to what extent the…

Application of queueing models to multiprogrammed computer systems operating in a time-critical environment

NASA Technical Reports Server (NTRS)

Eckhardt, D. E., Jr.

1979-01-01

A model of a central processor (CPU) which services background applications in the presence of time critical activity is presented. The CPU is viewed as an M/M/1 queueing system subject to periodic interrupts by deterministic, time critical process. The Laplace transform of the distribution of service times for the background applications is developed. The use of state of the art queueing models for studying the background processing capability of time critical computer systems is discussed and the results of a model validation study which support this application of queueing models are presented.

Evaluation of concurrent priority queue algorithms. Technical report

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

Huang, Q.

1991-02-01

The priority queue is a fundamental data structure that is used in a large variety of parallel algorithms, such as multiprocessor scheduling and parallel best-first search of state-space graphs. This thesis addresses the design and experimental evaluation of two novel concurrent priority queues: a parallel Fibonacci heap and a concurrent priority pool, and compares them with the concurrent binary heap. The parallel Fibonacci heap is based on the sequential Fibonacci heap, which is theoretically the most efficient data structure for sequential priority queues. This scheme not only preserves the efficient operation time bounds of its sequential counterpart, but also hasmore » very low contention by distributing locks over the entire data structure. The experimental results show its linearly scalable throughput and speedup up to as many processors as tested (currently 18). A concurrent access scheme for a doubly linked list is described as part of the implementation of the parallel Fibonacci heap. The concurrent priority pool is based on the concurrent B-tree and the concurrent pool. The concurrent priority pool has the highest throughput among the priority queues studied. Like the parallel Fibonacci heap, the concurrent priority pool scales linearly up to as many processors as tested. The priority queues are evaluated in terms of throughput and speedup. Some applications of concurrent priority queues such as the vertex cover problem and the single source shortest path problem are tested.« less

77 FR 15095 - Combined Notice of Filings #1

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-14

.... 3250; Queue No. W2-091 to be effective 2/14/2012. Filed Date: 3/7/12. Accession Number: 20120307-5041.... Description: Original Service Agreement No. 3249; Queue No. W2-088 effective 2/14/2012 [initial submission description misidentified as No. 3250; Queue No. W2-091. Filed Date: 3/7/12. Accession Number: 20120307-5051...

A collaborative interaction and visualization multi-modal environment for surgical planning.

PubMed

Foo, Jung Leng; Martinez-Escobar, Marisol; Peloquin, Catherine; Lobe, Thom; Winer, Eliot

2009-01-01

The proliferation of virtual reality visualization and interaction technologies has changed the way medical image data is analyzed and processed. This paper presents a multi-modal environment that combines a virtual reality application with a desktop application for collaborative surgical planning. Both visualization applications can function independently but can also be synced over a network connection for collaborative work. Any changes to either application is immediately synced and updated to the other. This is an efficient collaboration tool that allows multiple teams of doctors with only an internet connection to visualize and interact with the same patient data simultaneously. With this multi-modal environment framework, one team working in the VR environment and another team from a remote location working on a desktop machine can both collaborate in the examination and discussion for procedures such as diagnosis, surgical planning, teaching and tele-mentoring.

A collaborative virtual reality environment for neurosurgical planning and training.

PubMed

Kockro, Ralf A; Stadie, Axel; Schwandt, Eike; Reisch, Robert; Charalampaki, Cleopatra; Ng, Ivan; Yeo, Tseng Tsai; Hwang, Peter; Serra, Luis; Perneczky, Axel

2007-11-01

We have developed a highly interactive virtual environment that enables collaborative examination of stereoscopic three-dimensional (3-D) medical imaging data for planning, discussing, or teaching neurosurgical approaches and strategies. The system consists of an interactive console with which the user manipulates 3-D data using hand-held and tracked devices within a 3-D virtual workspace and a stereoscopic projection system. The projection system displays the 3-D data on a large screen while the user is working with it. This setup allows users to interact intuitively with complex 3-D data while sharing this information with a larger audience. We have been using this system on a routine clinical basis and during neurosurgical training courses to collaboratively plan and discuss neurosurgical procedures with 3-D reconstructions of patient-specific magnetic resonance and computed tomographic imaging data or with a virtual model of the temporal bone. Working collaboratively with the 3-D information of a large, interactive, stereoscopic projection provides an unambiguous way to analyze and understand the anatomic spatial relationships of different surgical corridors. In our experience, the system creates a unique forum for open and precise discussion of neurosurgical approaches. We believe the system provides a highly effective way to work with 3-D data in a group, and it significantly enhances teaching of neurosurgical anatomy and operative strategies.

VBOT: Motivating computational and complex systems fluencies with constructionist virtual/physical robotics

NASA Astrophysics Data System (ADS)

Berland, Matthew W.

As scientists use the tools of computational and complex systems theory to broaden science perspectives (e.g., Bar-Yam, 1997; Holland, 1995; Wolfram, 2002), so can middle-school students broaden their perspectives using appropriate tools. The goals of this dissertation project are to build, study, evaluate, and compare activities designed to foster both computational and complex systems fluencies through collaborative constructionist virtual and physical robotics. In these activities, each student builds an agent (e.g., a robot-bird) that must interact with fellow students' agents to generate a complex aggregate (e.g., a flock of robot-birds) in a participatory simulation environment (Wilensky & Stroup, 1999a). In a participatory simulation, students collaborate by acting in a common space, teaching each other, and discussing content with one another. As a result, the students improve both their computational fluency and their complex systems fluency, where fluency is defined as the ability to both consume and produce relevant content (DiSessa, 2000). To date, several systems have been designed to foster computational and complex systems fluencies through computer programming and collaborative play (e.g., Hancock, 2003; Wilensky & Stroup, 1999b); this study suggests that, by supporting the relevant fluencies through collaborative play, they become mutually reinforcing. In this work, I will present both the design of the VBOT virtual/physical constructionist robotics learning environment and a comparative study of student interaction with the virtual and physical environments across four middle-school classrooms, focusing on the contrast in systems perspectives differently afforded by the two environments. In particular, I found that while performance gains were similar overall, the physical environment supported agent perspectives on aggregate behavior, and the virtual environment supported aggregate perspectives on agent behavior. The primary research questions are: (1) What are the relative affordances of virtual and physical constructionist robotics systems towards computational and complex systems fluencies? (2) What can middle school students learn using computational/complex systems learning environments in a collaborative setting? (3) In what ways are these environments and activities effective in teaching students computational and complex systems fluencies?

Queue observing at the Observatoire du Mont-Mégantic 1.6-m telescope

NASA Astrophysics Data System (ADS)

Artigau, Étienne; Lamontagne, Robert; Doyon, René; Malo, Lison

2010-07-01

Queue planning of observation and service observing are generally seen as specific to large, world-class, astronomical observatories that draw proposal from a large community. One of the common grievance, justified or not, against queue planning and service observing is the fear of training a generation of astronomers without hands-on observing experience. At the Observatoire du Mont-Mégantic (OMM) 1.6-m telescope, we are developing a student-run service observing program. Queue planning and service observing are used as training tools to expose students to a variety of scientific project and instruments beyond what they would normally use for their own research project. The queue mode at the OMM specifically targets relatively shallow observations that can be completed in less than a few hours and are too short to justify a multi-night classical observing run.

Study on queueing behavior in pedestrian evacuation by extended cellular automata model

NASA Astrophysics Data System (ADS)

Hu, Jun; You, Lei; Zhang, Hong; Wei, Juan; Guo, Yangyong

2018-01-01

This paper proposes a pedestrian evacuation model for effective simulation of evacuation efficiency based on extended cellular automata. In the model, pedestrians' momentary transition probability to a target position is defined in terms of the floor field and queueing time, and the critical time is defined as the waiting time threshold in a queue. Queueing time and critical time are derived using Fractal Brownian Motion through analysis of pedestrian arrival characteristics. Simulations using the platform and actual evacuations were conducted to study the relationships among system evacuation time, average system velocity, pedestrian density, flow rate, and critical time. The results demonstrate that at low pedestrian density, evacuation efficiency can be improved through adoption of the shortest route strategy, and critical time has an inverse relationship with average system velocity. Conversely, at higher pedestrian densities, it is better to adopt the shortest queueing time strategy, and critical time is inversely related to flow rate.

The Potential for Scientific Collaboration in Virtual Ecosystems

ERIC Educational Resources Information Center

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…

The Doubtful Guest? A Virtual Research Environment for Education

ERIC Educational Resources Information Center

Laterza, Vito; Carmichael, Patrick; Procter, Richard

2007-01-01

In this paper the authors describe a novel "Virtual Research Environment" (VRE) based on the Sakai Virtual Collaboration Environment and designed to support education research. This VRE has been used for the past two years by projects of the UK Economic and Social Research Council's Teaching and Learning Research Programme, 10 of which…

A Taxonomy of Virtual Worlds Usage in Education

ERIC Educational Resources Information Center

Duncan, Ishbel; Miller, Alan; Jiang, Shangyi

2012-01-01

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

Innovation Education Enabled through a Collaborative Virtual Reality Learning Environment

ERIC Educational Resources Information Center

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

2006-01-01

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

A Collaborative Virtual Environment for Situated Language Learning Using VEC3D

ERIC Educational Resources Information Center

Shih, Ya-Chun; Yang, Mau-Tsuen

2008-01-01

A 3D virtually synchronous communication architecture for situated language learning has been designed to foster communicative competence among undergraduate students who have studied English as a foreign language (EFL). We present an innovative approach that offers better e-learning than the previous virtual reality educational applications. The…

Requirements for plug and play information infrastructure frameworks and architectures to enable virtual enterprises

NASA Astrophysics Data System (ADS)

Bolton, Richard W.; Dewey, Allen; Horstmann, Paul W.; Laurentiev, John

1997-01-01

This paper examines the role virtual enterprises will have in supporting future business engagements and resulting technology requirements. Two representative end-user scenarios are proposed that define the requirements for 'plug-and-play' information infrastructure frameworks and architectures necessary to enable 'virtual enterprises' in US manufacturing industries. The scenarios provide a high- level 'needs analysis' for identifying key technologies, defining a reference architecture, and developing compliant reference implementations. Virtual enterprises are short- term consortia or alliances of companies formed to address fast-changing opportunities. Members of a virtual enterprise carry out their tasks as if they all worked for a single organization under 'one roof', using 'plug-and-play' information infrastructure frameworks and architectures to access and manage all information needed to support the product cycle. 'Plug-and-play' information infrastructure frameworks and architectures are required to enhance collaboration between companies corking together on different aspects of a manufacturing process. This new form of collaborative computing will decrease cycle-time and increase responsiveness to change.

A robust and high-performance queue management controller for large round trip time networks

NASA Astrophysics Data System (ADS)

Khoshnevisan, Ladan; Salmasi, Farzad R.

2016-05-01

Congestion management for transmission control protocol is of utmost importance to prevent packet loss within a network. This necessitates strategies for active queue management. The most applied active queue management strategies have their inherent disadvantages which lead to suboptimal performance and even instability in the case of large round trip time and/or external disturbance. This paper presents an internal model control robust queue management scheme with two degrees of freedom in order to restrict the undesired effects of large and small round trip time and parameter variations in the queue management. Conventional approaches such as proportional integral and random early detection procedures lead to unstable behaviour due to large delay. Moreover, internal model control-Smith scheme suffers from large oscillations due to the large round trip time. On the other hand, other schemes such as internal model control-proportional integral and derivative show excessive sluggish performance for small round trip time values. To overcome these shortcomings, we introduce a system entailing two individual controllers for queue management and disturbance rejection, simultaneously. Simulation results based on Matlab/Simulink and also Network Simulator 2 (NS2) demonstrate the effectiveness of the procedure and verify the analytical approach.

The congestion control algorithm based on queue management of each node in mobile ad hoc networks

NASA Astrophysics Data System (ADS)

Wei, Yifei; Chang, Lin; Wang, Yali; Wang, Gaoping

2016-12-01

This paper proposes an active queue management mechanism, considering the node's own ability and its importance in the network to set the queue threshold. As the network load increases, local congestion of mobile ad hoc network may lead to network performance degradation, hot node's energy consumption increase even failure. If small energy nodes congested because of forwarding data packets, then when it is used as the source node will cause a lot of packet loss. This paper proposes an active queue management mechanism, considering the node's own ability and its importance in the network to set the queue threshold. Controlling nodes buffer queue in different levels of congestion area probability by adjusting the upper limits and lower limits, thus nodes can adjust responsibility of forwarding data packets according to their own situation. The proposed algorithm will slow down the send rate hop by hop along the data package transmission direction from congestion node to source node so that to prevent further congestion from the source node. The simulation results show that, the algorithm can better play the data forwarding ability of strong nodes, protect the weak nodes, can effectively alleviate the network congestion situation.

Propagation speed of a starting wave in a queue of pedestrians.

PubMed

Tomoeda, Akiyasu; Yanagisawa, Daichi; Imamura, Takashi; Nishinari, Katsuhiro

2012-09-01

The propagation speed of a starting wave, which is a wave of people's successive reactions in the relaxation process of a queue, has an essential role for pedestrians and vehicles to achieve smooth movement. For example, a queue of vehicles with appropriate headway (or density) alleviates traffic jams since the delay of reaction to start is minimized. In this paper, we have investigated the fundamental relation between the propagation speed of a starting wave and the initial density by both our mathematical model built on the stochastic cellular automata and experimental measurements. Analysis of our mathematical model implies that the relation is characterized by the power law αρ-β (β≠1), and the experimental results verify this feature. Moreover, when the starting wave is characterized by the power law (β>1), we have revealed the existence of optimal density, where the required time, i.e., the sum of the waiting time until the starting wave reaches the last pedestrian in a queue and his/her travel time to pass the head position of the initial queue, is minimized. This optimal density inevitably plays a significant role in achieving a smooth movement of crowds and vehicles in a queue.

Virtual Partnerships in Research and Education.

ERIC Educational Resources Information Center

Payne, Deborah A.; Keating, Kelly A.; Myers, James D.

The William R. Wiley Environmental Molecular Sciences Laboratory (EMSL) at the Pacific Northwest National Laboratory (Washington) is a collaborative user facility with many unique scientific capabilities. The EMSL expects to support many of its remote users and collaborators by electronic means and is creating a collaborative environment for this…

Virtual Scavenger Hunt: An AI-Powered Virtual Environment Designed for Training Individuals in Effective Teamwork, and Analyzing Cross-Cultural Behavior

DTIC Science & Technology

2009-03-20

involved the development of an environment within the Multiverse virtual world, oriented toward allowing individuals to acquire and reinforce skills via...PetBrain software G2: Creation of a scavenger hunt scenario in the Multiverse virtual world, in which humans and AIs can collaboratively play scavenger...carried out by Novamente LLC for AOARD during June 2008 ? February 2009. It involved the development of an environment within the Multiverse virtual world

The Cloud Area Padovana: from pilot to production

NASA Astrophysics Data System (ADS)

Andreetto, P.; Costa, F.; Crescente, A.; Dorigo, A.; Fantinel, S.; Fanzago, F.; Sgaravatto, M.; Traldi, S.; Verlato, M.; Zangrando, L.

2017-10-01

The Cloud Area Padovana has been running for almost two years. This is an OpenStack-based scientific cloud, spread across two different sites: the INFN Padova Unit and the INFN Legnaro National Labs. The hardware resources have been scaled horizontally and vertically, by upgrading some hypervisors and by adding new ones: currently it provides about 1100 cores. Some in-house developments were also integrated in the OpenStack dashboard, such as a tool for user and project registrations with direct support for the INFN-AAI Identity Provider as a new option for the user authentication. In collaboration with the EU-funded Indigo DataCloud project, the integration with Docker-based containers has been experimented with and will be available in production soon. This computing facility now satisfies the computational and storage demands of more than 70 users affiliated with about 20 research projects. We present here the architecture of this Cloud infrastructure, the tools and procedures used to operate it. We also focus on the lessons learnt in these two years, describing the problems that were found and the corrective actions that had to be applied. We also discuss about the chosen strategy for upgrades, which combines the need to promptly integrate the OpenStack new developments, the demand to reduce the downtimes of the infrastructure, and the need to limit the effort requested for such updates. We also discuss how this Cloud infrastructure is being used. In particular we focus on two big physics experiments which are intensively exploiting this computing facility: CMS and SPES. CMS deployed on the cloud a complex computational infrastructure, composed of several user interfaces for job submission in the Grid environment/local batch queues or for interactive processes; this is fully integrated with the local Tier-2 facility. To avoid a static allocation of the resources, an elastic cluster, based on cernVM, has been configured: it allows to automatically create and delete virtual machines according to the user needs. SPES, using a client-server system called TraceWin, exploits INFN’s virtual resources performing a very large number of simulations on about a thousand nodes elastically managed.

Control of Networked Traffic Flow Distribution - A Stochastic Distribution System Perspective

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

Wang, Hong; Aziz, H M Abdul; Young, Stan

Networked traffic flow is a common scenario for urban transportation, where the distribution of vehicle queues either at controlled intersections or highway segments reflect the smoothness of the traffic flow in the network. At signalized intersections, the traffic queues are controlled by traffic signal control settings and effective traffic lights control would realize both smooth traffic flow and minimize fuel consumption. Funded by the Energy Efficient Mobility Systems (EEMS) program of the Vehicle Technologies Office of the US Department of Energy, we performed a preliminary investigation on the modelling and control framework in context of urban network of signalized intersections.more » In specific, we developed a recursive input-output traffic queueing models. The queue formation can be modeled as a stochastic process where the number of vehicles entering each intersection is a random number. Further, we proposed a preliminary B-Spline stochastic model for a one-way single-lane corridor traffic system based on theory of stochastic distribution control.. It has been shown that the developed stochastic model would provide the optimal probability density function (PDF) of the traffic queueing length as a dynamic function of the traffic signal setting parameters. Based upon such a stochastic distribution model, we have proposed a preliminary closed loop framework on stochastic distribution control for the traffic queueing system to make the traffic queueing length PDF follow a target PDF that potentially realizes the smooth traffic flow distribution in a concerned corridor.« less

Virtual Globes and Glacier Research: Integrating research, collaboration, logistics, data archival, and outreach into a single tool

NASA Astrophysics Data System (ADS)

Nolan, M.

2006-12-01

Virtual Globes are a paradigm shift in the way earth sciences are conducted. With these tools, nearly all aspects of earth science can be integrated from field science, to remote sensing, to remote collaborations, to logistical planning, to data archival/retrieval, to PDF paper retriebal, to education and outreach. Here we present an example of how VGs can be fully exploited for field sciences, using research at McCall Glacier, in Arctic Alaska.

A Queueing Model for Supervisory Control of Unmanned Autonomous Vehicles

DTIC Science & Technology

2013-09-01

Autonomous Vehicles Joseph DiVita, PhD Robert L. Morris Maria Olinda Rodas SSC Pacific Approved...298 (Rev. 8/98) Prescribed by ANSI Std. Z39.18 09–2013 Final A Queueing Model for Supervisory Control of Unmanned Autonomous Vehicles Joseph...Mission Area: Command and Control, Queueing Model; Supervisory Control; Unmanned Autonomous Vehicles M. O. Rodas U U U U 38 (619)

A Multi-User Virtual Environment for Building and Assessing Higher Order Inquiry Skills in Science

ERIC Educational Resources Information Center

Ketelhut, Diane Jass; Nelson, Brian C.; Clarke, Jody; Dede, Chris

2010-01-01

This study investigated novel pedagogies for helping teachers infuse inquiry into a standards-based science curriculum. Using a multi-user virtual environment (MUVE) as a pedagogical vehicle, teams of middle-school students collaboratively solved problems around disease in a virtual town called River City. The students interacted with "avatars" of…

A Cross-Disciplinary Literature Review: Examining Trust on Virtual Teams

ERIC Educational Resources Information Center

Berry, Gregory R.

2011-01-01

Effective and efficient teams communicate, collaborate, and perform, even if these teams are not co-located. Although much is known about enabling effectiveness on face-to-face teams, considerably less is known about similarly enabling effectiveness on virtual teams. Yet the use of virtual teams is common and will likely become more commonplace as…

Enhance Learning on Software Project Management through a Role-Play Game in a Virtual World

ERIC Educational Resources Information Center

Maratou, Vicky; Chatzidaki, Eleni; Xenos, Michalis

2016-01-01

This article presents a role-play game for software project management (SPM) in a three-dimensional online multiuser virtual world. The Opensimulator platform is used for the creation of an immersive virtual environment that facilitates students' collaboration and realistic interaction, in order to manage unexpected events occurring during the…

A Study of the Relationship of Communication Technology Configurations in Virtual Research Environments and Effectiveness of Collaborative Research

ERIC Educational Resources Information Center

Ahmed, Iftekhar

2009-01-01

Virtual Research Environments (VRE) are electronic meeting places for interaction among scientists created by combining software tools and computer networking. Virtual teams are enjoying increased importance in the conduct of scientific research because of the rising cost of traditional scientific scholarly communication, the growing importance of…

Designing Teaching--Teaching Designing: Teacher's Guidance in a Virtual Design Studio

ERIC Educational Resources Information Center

Lahti, Henna; Seitamaa-Hakkarainen, Pirita

2014-01-01

This study examined pedagogical aspects of virtual designing. It focused on how an industrial design teacher organised a university course in plastic product design and how the teacher guided student teams' design processes in a virtual design studio. The model of Learning by Collaborative Design was used as a pedagogical and analytical framework.…

Virtual First Impressions Matter: The Effect of Social Networking Sites on Impression Formation in Virtual Teams

ERIC Educational Resources Information Center

Cummings, Jeffrey

2012-01-01

The introduction of social media has changed the way individuals communicate and collaborate both within and outside the organization. While social media has the potential to change how organizations interact internally, minimal research has examined the impact this media may have within a virtual team environment. This dissertation examines a…

New Library, New Librarian, New Student: Using LibGuides to Reach the Virtual Student

ERIC Educational Resources Information Center

Roberts, Sara; Hunter, Dwight

2011-01-01

This article examines the virtual pathfinder and its relationship with distance education students. Various topics are addressed in relation to virtual students, LibGuides and collaborative efforts between librarians and teaching faculty. A brief history of the subject guide is presented, advantages and disadvantages of LibGuides are discussed and…

Students' First Impression of Second Life: A Case from the United Arab Emirates

ERIC Educational Resources Information Center

Abdallah, Salam; Douglas, Jamal

2010-01-01

Emerging 3D virtual worlds such as Second Life can offer students with opportunities to enhance learning using rich collaborative asynchronous media. Virtual worlds are believed to impact the future of higher education and therefore, universities across the world are immersing themselves inside virtual worlds to establish a unique learning and…

Virtual Teams and International Business Teaching and Learning: The Case of the Global Enterprise Experience (GEE)

ERIC Educational Resources Information Center

Gonzalez-Perez, Maria Alejandra; Velez-Calle, Andres; Cathro, Virginia; Caprar, Dan V.; Taras, Vasyl

2014-01-01

The increasing importance of global virtual teams in business is reflected in the classroom by the increased adoption of activities that facilitate real-time cross-cultural interaction. This article documents the experience of students from two Colombian universities who participated in a collaborative international project using virtual teams as…

Collaborative Problem Solving in Shared Space

ERIC Educational Resources Information Center

Lin, Lin; Mills, Leila A.; Ifenthaler, Dirk

2015-01-01

The purpose of this study was to examine collaborative problem solving in a shared virtual space. The main question asked was: How will the performance and processes differ between collaborative problem solvers and independent problem solvers over time? A total of 104 university students (63 female and 41 male) participated in an experimental…

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

PubMed

Dunne, James R; McDonald, Claudia L

2010-07-01

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

Study on Collaborative Object Manipulation in Virtual Environment

NASA Astrophysics Data System (ADS)

Mayangsari, Maria Niken; Yong-Moo, Kwon

This paper presents comparative study on network collaboration performance in different immersion. Especially, the relationship between user collaboration performance and degree of immersion provided by the system is addressed and compared based on several experiments. The user tests on our system include several cases: 1) Comparison between non-haptics and haptics collaborative interaction over LAN, 2) Comparison between non-haptics and haptics collaborative interaction over Internet, and 3) Analysis of collaborative interaction between non-immersive and immersive display environments.

Secure environment for real-time tele-collaboration on virtual simulation of radiation treatment planning.

PubMed

Ntasis, Efthymios; Maniatis, Theofanis A; Nikita, Konstantina S

2003-01-01

A secure framework is described for real-time tele-collaboration on Virtual Simulation procedure of Radiation Treatment Planning. An integrated approach is followed clustering the security issues faced by the system into organizational issues, security issues over the LAN and security issues over the LAN-to-LAN connection. The design and the implementation of the security services are performed according to the identified security requirements, along with the need for real time communication between the collaborating health care professionals. A detailed description of the implementation is given, presenting a solution, which can directly be tailored to other tele-collaboration services in the field of health care. The pilot study of the proposed security components proves the feasibility of the secure environment, and the consistency with the high performance demands of the application.

Research on Collaborative Technology in Distributed Virtual Reality System

NASA Astrophysics Data System (ADS)

Lei, ZhenJiang; Huang, JiJie; Li, Zhao; Wang, Lei; Cui, JiSheng; Tang, Zhi

2018-01-01

Distributed virtual reality technology applied to the joint training simulation needs the CSCW (Computer Supported Cooperative Work) terminal multicast technology to display and the HLA (high-level architecture) technology to ensure the temporal and spatial consistency of the simulation, in order to achieve collaborative display and collaborative computing. In this paper, the CSCW’s terminal multicast technology has been used to modify and expand the implementation framework of HLA. During the simulation initialization period, this paper has used the HLA statement and object management service interface to establish and manage the CSCW network topology, and used the HLA data filtering mechanism for each federal member to establish the corresponding Mesh tree. During the simulation running period, this paper has added a new thread for the RTI and the CSCW real-time multicast interactive technology into the RTI, so that the RTI can also use the window message mechanism to notify the application update the display screen. Through many applications of submerged simulation training in substation under the operation of large power grid, it is shown that this paper has achieved satisfactory training effect on the collaborative technology used in distributed virtual reality simulation.

Research on a Queue Scheduling Algorithm in Wireless Communications Network

NASA Astrophysics Data System (ADS)

Yang, Wenchuan; Hu, Yuanmei; Zhou, Qiancai

This paper proposes a protocol QS-CT, Queue Scheduling Mechanism based on Multiple Access in Ad hoc net work, which adds queue scheduling mechanism to RTS-CTS-DATA using multiple access protocol. By endowing different queues different scheduling mechanisms, it makes networks access to the channel much more fairly and effectively, and greatly enhances the performance. In order to observe the final performance of the network with QS-CT protocol, we simulate it and compare it with MACA/C-T without QS-CT protocol. Contrast to MACA/C-T, the simulation result shows that QS-CT has greatly improved the throughput, delay, rate of packets' loss and other key indicators.

Parallel integer sorting with medium and fine-scale parallelism

NASA Technical Reports Server (NTRS)

Dagum, Leonardo

1993-01-01

Two new parallel integer sorting algorithms, queue-sort and barrel-sort, are presented and analyzed in detail. These algorithms do not have optimal parallel complexity, yet they show very good performance in practice. Queue-sort designed for fine-scale parallel architectures which allow the queueing of multiple messages to the same destination. Barrel-sort is designed for medium-scale parallel architectures with a high message passing overhead. The performance results from the implementation of queue-sort on a Connection Machine CM-2 and barrel-sort on a 128 processor iPSC/860 are given. The two implementations are found to be comparable in performance but not as good as a fully vectorized bucket sort on the Cray YMP.

Optimal Service Capacities in a Competitive Multiple-Server Queueing Environment

NASA Astrophysics Data System (ADS)

Ching, Wai-Ki; Choi, Sin-Man; Huang, Min

The study of economic behavior of service providers in a competition environment is an important and interesting research issue. A two-server queueing model has been proposed in Kalai et al. [11] for this purpose. Their model aims at studying the role and impact of service capacity in capturing larger market share so as to maximize the long-run expected profit. They formulate the problem as a two-person strategic game and analyze the equilibrium solutions. The main aim of this paper is to extend the results of the two-server queueing model in [11] to the case of multiple servers. We will only focus on the case when the queueing system is stable.

Predicting clinical image delivery time by monitoring PACS queue behavior.

PubMed

King, Nelson E; Documet, Jorge; Liu, Brent

2006-01-01

The expectation of rapid image retrieval from PACS users contributes to increased information technology (IT) infrastructure investments to increase performance as well as continuing demands upon PACS administrators to respond to "slow" system performance. The ability to provide predicted delivery times to a PACS user may curb user expectations for "fastest" response especially during peak hours. This, in turn, could result in a PACS infrastructure tailored to more realistic performance demands. A PACS with a stand-alone architecture under peak load typically holds study requests in a queue until the DICOM C-Move command can take place. We investigate the contents of a stand-alone architecture PACS RetrieveSend queue and identified parameters and behaviors that enable a more accurate prediction of delivery time. A prediction algorithm for studies delayed in a stand-alone PACS queue can be extendible to other potential bottlenecks such as long-term storage archives. Implications of a queue monitor in other PACS architectures are also discussed.

British Columbia sends patients to Seattle for coronary artery surgery. Bypassing the queue in Canada.

PubMed

Katz, S J; Mizgala, H F; Welch, H G

1991-08-28

Concern about waiting lists for elective procedures has become a highly visible challenge to the universal health insurance program in Canada. In response to lengthening queues for patients waiting for cardiac surgery, British Columbia made contracts with four Seattle hospitals to send a total of 200 patients for coronary artery bypass surgery. This article examines the cause of the queue for cardiac surgery in British Columbia and the events that led to outside contracting. Global hospital budgets and restrictions on capital expansion have limited hospital capacity for cardiac surgery. This constrained supply, combined with periodic shortages in critical care nurses and cardiac perfusion technologists, has resulted in a rapid increase in the waiting list. Reducing wide variations in the lengths of queues for individual surgeons may afford an opportunity to reduce long waits. While the patient queue for cardiac surgery has sparked a public debate about budget limits and health care needs, its clinical impact remains uncertain.

A Virtual Mission Operations Center: Collaborative Environment

NASA Technical Reports Server (NTRS)

Medina, Barbara; Bussman, Marie; Obenschain, Arthur F. (Technical Monitor)

2002-01-01

The Virtual Mission Operations Center - Collaborative Environment (VMOC-CE) intent is to have a central access point for all the resources used in a collaborative mission operations environment to assist mission operators in communicating on-site and off-site in the investigation and resolution of anomalies. It is a framework that as a minimum incorporates online chat, realtime file sharing and remote application sharing components in one central location. The use of a collaborative environment in mission operations opens up the possibilities for a central framework for other project members to access and interact with mission operations staff remotely. The goal of the Virtual Mission Operations Center (VMOC) Project is to identify, develop, and infuse technology to enable mission control by on-call personnel in geographically dispersed locations. In order to achieve this goal, the following capabilities are needed: Autonomous mission control systems Automated systems to contact on-call personnel Synthesis and presentation of mission control status and history information Desktop tools for data and situation analysis Secure mechanism for remote collaboration commanding Collaborative environment for remote cooperative work The VMOC-CE is a collaborative environment that facilitates remote cooperative work. It is an application instance of the Virtual System Design Environment (VSDE), developed by NASA Goddard Space Flight Center's (GSFC) Systems Engineering Services & Advanced Concepts (SESAC) Branch. The VSDE is a web-based portal that includes a knowledge repository and collaborative environment to serve science and engineering teams in product development. It is a "one stop shop" for product design, providing users real-time access to product development data, engineering and management tools, and relevant design specifications and resources through the Internet. The initial focus of the VSDE has been to serve teams working in the early portion of the system/product lifecycle - concept development, proposal preparation, and formulation. The VMOC-CE expands the application of the VSDE into the operations portion of the system lifecycle. It will enable meaningful and real-time collaboration regardless of the geographical distribution of project team members. Team members will be able to interact in satellite operations, specifically for resolving anomalies, through access to a desktop computer and the Internet. Mission Operations Management will be able to participate and monitor up to the minute status of anomalies or other mission operations issues. In this paper we present the VMOC-CE project, system capabilities, and technologies.

Queued History based Mediator Identification for an Incentive Attached peer to peer Electronic Coupon System

NASA Astrophysics Data System (ADS)

Shojima, Taiki; Ikkai, Yoshitomo; Komoda, Norihisa

An incentive attached peer to peer (P2P) electronic coupon system is proposed in which users forward e-coupons to potential users by providing incentives to those mediators. A service provider needs to acquire distribution history for incentive payment by recording UserIDs (UIDs) in the e-coupons, since this system is intended for pure P2P environment. This causes problems of dishonestly altering distribution history. In order to solve such problems, distribution history is realized in a couple of queues structure. They are the UID queue, and the public key queue. Each element of the UID queue at the initial state consists of index, a secret key, and a digital signature. In recording one's UID, the encrypted UID is enqueued to the UID queue with a new digital signature created by a secret key of the dequeued element, so that each UID cannot be altered. The public key queue provides the functionality of validating digital signatures on mobile devices. This method makes it possible both each UID and sequence of them to be certificated. The availability of the method is evaluated by quantifying risk reduction using Fault Tree Analysis (FTA). And it's recognized that the method is better than common encryption methods.

Social stability and helping in small animal societies

PubMed Central

Field, Jeremy; Cant, Michael A.

2009-01-01

In primitively eusocial societies, all individuals can potentially reproduce independently. The key fact that we focus on in this paper is that individuals in such societies instead often queue to inherit breeding positions. Queuing leads to systematic differences in expected future fitness. We first discuss the implications this has for variation in behaviour. For example, because helpers nearer to the front of the queue have more to lose, they should work less hard to rear the dominant's offspring. However, higher rankers may be more aggressive than low rankers, even if they risk injury in the process, if aggression functions to maintain or enhance queue position. Second, we discuss how queuing rules may be enforced through hidden threats that rarely have to be carried out. In fishes, rule breakers face the threat of eviction from the group. In contrast, subordinate paper wasps are not injured or evicted during escalated challenges against the dominant, perhaps because they are more valuable to the dominant. We discuss evidence that paper-wasp dominants avoid escalated conflicts by ceding reproduction to subordinates. Queuing rules appear usually to be enforced by individuals adjacent in the queue rather than by dominants. Further manipulative studies are required to reveal mechanisms underlying queue stability and to elucidate what determines queue position in the first place. PMID:19805426

BioQueue: a novel pipeline framework to accelerate bioinformatics analysis.

PubMed

Yao, Li; Wang, Heming; Song, Yuanyuan; Sui, Guangchao

2017-10-15

With the rapid development of Next-Generation Sequencing, a large amount of data is now available for bioinformatics research. Meanwhile, the presence of many pipeline frameworks makes it possible to analyse these data. However, these tools concentrate mainly on their syntax and design paradigms, and dispatch jobs based on users' experience about the resources needed by the execution of a certain step in a protocol. As a result, it is difficult for these tools to maximize the potential of computing resources, and avoid errors caused by overload, such as memory overflow. Here, we have developed BioQueue, a web-based framework that contains a checkpoint before each step to automatically estimate the system resources (CPU, memory and disk) needed by the step and then dispatch jobs accordingly. BioQueue possesses a shell command-like syntax instead of implementing a new script language, which means most biologists without computer programming background can access the efficient queue system with ease. BioQueue is freely available at https://github.com/liyao001/BioQueue. The extensive documentation can be found at http://bioqueue.readthedocs.io. li_yao@outlook.com or gcsui@nefu.edu.cn. Supplementary data are available at Bioinformatics online. © The Author (2017). Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Queues on a Dynamically Evolving Graph

NASA Astrophysics Data System (ADS)

Mandjes, Michel; Starreveld, Nicos J.; Bekker, René

2018-04-01

This paper considers a population process on a dynamically evolving graph, which can be alternatively interpreted as a queueing network. The queues are of infinite-server type, entailing that at each node all customers present are served in parallel. The links that connect the queues have the special feature that they are unreliable, in the sense that their status alternates between `up' and `down'. If a link between two nodes is down, with a fixed probability each of the clients attempting to use that link is lost; otherwise the client remains at the origin node and reattempts using the link (and jumps to the destination node when it finds the link restored). For these networks we present the following results: (a) a system of coupled partial differential equations that describes the joint probability generating function corresponding to the queues' time-dependent behavior (and a system of ordinary differential equations for its stationary counterpart), (b) an algorithm to evaluate the (time-dependent and stationary) moments, and procedures to compute user-perceived performance measures which facilitate the quantification of the impact of the links' outages, (c) a diffusion limit for the joint queue length process. We include explicit results for a series relevant special cases, such as tandem networks and symmetric fully connected networks.

Collaborative voxel-based surgical virtual environments.

PubMed

Acosta, Eric; Muniz, Gilbert; Armonda, Rocco; Bowyer, Mark; Liu, Alan

2008-01-01

Virtual Reality-based surgical simulators can utilize Collaborative Virtual Environments (C-VEs) to provide team-based training. To support real-time interactions, C-VEs are typically replicated on each user's local computer and a synchronization method helps keep all local copies consistent. This approach does not work well for voxel-based C-VEs since large and frequent volumetric updates make synchronization difficult. This paper describes a method that allows multiple users to interact within a voxel-based C-VE for a craniotomy simulator being developed. Our C-VE method requires smaller update sizes and provides faster synchronization update rates than volumetric-based methods. Additionally, we address network bandwidth/latency issues to simulate networked haptic and bone drilling tool interactions with a voxel-based skull C-VE.

The Prototype of the Virtual Classroom.

ERIC Educational Resources Information Center

Wilson, Jack M.; Mosher, David N.

1994-01-01

Introduces an interactive distance learning environment prototype developed jointly by Rensselaer Polytechnic Institute (RPI) and AT&T which allows students to participate in virtual classroom environments by using computer teleconferencing. Student collaboration, note taking, question answering capabilities, project background, learning…

Application of Queueing Theory to the Analysis of Changes in Outpatients' Waiting Times in Hospitals Introducing EMR

PubMed Central

Cho, Kyoung Won; Kim, Seong Min; Chae, Young Moon

2017-01-01

Objectives This research used queueing theory to analyze changes in outpatients' waiting times before and after the introduction of Electronic Medical Record (EMR) systems. Methods We focused on the exact drawing of two fundamental parameters for queueing analysis, arrival rate (λ) and service rate (µ), from digital data to apply queueing theory to the analysis of outpatients' waiting times. We used outpatients' reception times and consultation finish times to calculate the arrival and service rates, respectively. Results Using queueing theory, we could calculate waiting time excluding distorted values from the digital data and distortion factors, such as arrival before the hospital open time, which occurs frequently in the initial stage of a queueing system. We analyzed changes in outpatients' waiting times before and after the introduction of EMR using the methodology proposed in this paper, and found that the outpatients' waiting time decreases after the introduction of EMR. More specifically, the outpatients' waiting times in the target public hospitals have decreased by rates in the range between 44% and 78%. Conclusions It is possible to analyze waiting times while minimizing input errors and limitations influencing consultation procedures if we use digital data and apply the queueing theory. Our results verify that the introduction of EMR contributes to the improvement of patient services by decreasing outpatients' waiting time, or by increasing efficiency. It is also expected that our methodology or its expansion could contribute to the improvement of hospital service by assisting the identification and resolution of bottlenecks in the outpatient consultation process. PMID:28261529

Application of Queueing Theory to the Analysis of Changes in Outpatients' Waiting Times in Hospitals Introducing EMR.

PubMed

Cho, Kyoung Won; Kim, Seong Min; Chae, Young Moon; Song, Yong Uk

2017-01-01

This research used queueing theory to analyze changes in outpatients' waiting times before and after the introduction of Electronic Medical Record (EMR) systems. We focused on the exact drawing of two fundamental parameters for queueing analysis, arrival rate (λ) and service rate (µ), from digital data to apply queueing theory to the analysis of outpatients' waiting times. We used outpatients' reception times and consultation finish times to calculate the arrival and service rates, respectively. Using queueing theory, we could calculate waiting time excluding distorted values from the digital data and distortion factors, such as arrival before the hospital open time, which occurs frequently in the initial stage of a queueing system. We analyzed changes in outpatients' waiting times before and after the introduction of EMR using the methodology proposed in this paper, and found that the outpatients' waiting time decreases after the introduction of EMR. More specifically, the outpatients' waiting times in the target public hospitals have decreased by rates in the range between 44% and 78%. It is possible to analyze waiting times while minimizing input errors and limitations influencing consultation procedures if we use digital data and apply the queueing theory. Our results verify that the introduction of EMR contributes to the improvement of patient services by decreasing outpatients' waiting time, or by increasing efficiency. It is also expected that our methodology or its expansion could contribute to the improvement of hospital service by assisting the identification and resolution of bottlenecks in the outpatient consultation process.

The Bridge: Experiments in Science and Art, Experiences from the 2017 SciArt Center Cross-Disciplinary Residency Program

NASA Astrophysics Data System (ADS)

Shipman, J. S.; Chalmers, R.; Buntaine, J.

2017-12-01

Cross-disciplinary programs create the opportunity to explore new realms for scientists and artists alike. Through the collaborative process, artistic insights enable innovative approaches to emotionally connect to and visualize the world around us. Likewise, engagement across the art-science spectrum can lead to shifts in scientific thinking that create new connections in data and drive discoveries in research. The SciArt Center "The Bridge Residency Program" is a four-month long virtual residency open internationally for professionals in the arts and sciences to facilitate cross-disciplinary work and to bring together like-minded participants. The SciArt Center provides a virtual space to record and showcase the process and products of each collaboration. The work is facilitated with biweekly Skype calls and documented with weekly blog posts. Residents create either digital or physical products and share via video, images, or direct mailing with their collaborators. Past projects have produced call and response discussion, websites, skills and conference presentations, science-art studies, virtual exhibits, art shows, dance performances, and research exchange. Here we present the creative process and outcomes of one of the four collaborative teams selected for the 2017 residency. Jill Shipman, a Ph.D. Candidate in Volcanology who is also active in filmmaking and theatrical productions and Rosemary Chalmers, a UK-based lecturer, concept artist, and illustrator with a specialty in creature design. They were paired together for their shared interest in storytelling, illustration, and unique geological and environmental habitats and the life that occupies them. We will discuss the collaborative project developed by this team during their recent residency and illustrate how a virtual program can bridge the distance between geographical location to foster science and art collaboration. To follow the progress of the residency please visit: http://www.sciartcenter.org/the-bridge.html

Inquiry-Based Learning for a Virtual Learning Community to Enhance Problem-Solving Ability of Applied Thai Traditional Medicine Students

ERIC Educational Resources Information Center

Chanprasitchai, Ong-art; Khlaisang, Jintavee

2016-01-01

The recent growth in collaborative and interactive virtual learning communities integrating innovative digital technologies and contemporary learning frameworks is contributing enormously to the use of e-learning in higher education in the twenty-first century. The purpose of this study was to describe the development of a virtual learning…

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

ERIC Educational Resources Information Center

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

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

Advanced Collaborative Environments Supporting Systems Integration and Design

DTIC Science & Technology

2003-03-01

concurrently view a virtual system or product model while maintaining natural, human communication . These virtual systems operate within a computer-generated...These environments allow multiple individuals to concurrently view a virtual system or product model while simultaneously maintaining natural, human ... communication . As a result, TARDEC researchers and system developers are using this advanced high-end visualization technology to develop future

Virtual Trust in US-India Global Outsource Teams: A Qualitative Exploratory Case Study

ERIC Educational Resources Information Center

Gugliotti, Domenic

2017-01-01

The purpose of this qualitative exploratory case study was to identify and analyze, trust behaviors used by members of an outsourced virtual team in an on and offshore engagement. The inability to build trust in outsourced engagements can cause serious damage to the collaboration within the virtual team causing it to fail. This study provides…

Virtual working systems to support R&D groups

NASA Astrophysics Data System (ADS)

Dew, Peter M.; Leigh, Christine; Drew, Richard S.; Morris, David; Curson, Jayne

1995-03-01

The paper reports on the progress at Leeds University to build a Virtual Science Park (VSP) to enhance the University's ability to interact with industry, grow its applied research and workplace learning activities. The VSP exploits the advances in real time collaborative computing and networking to provide an environment that meets the objectives of physically based science parks without the need for the organizations to relocate. It provides an integrated set of services (e.g. virtual consultancy, workbased learning) built around a structured person- centered information model. This model supports the integration of tools for: (a) navigating around the information space; (b) browsing information stored within the VSP database; (c) communicating through a variety of Person-to-Person collaborative tools; and (d) the ability to the information stored in the VSP including the relationships to other information that support the underlying model. The paper gives an overview of a generic virtual working system based on X.500 directory services and the World-Wide Web that can be used to support the Virtual Science Park. Finally the paper discusses some of the research issues that need to be addressed to fully realize a Virtual Science Park.

Emerging CAE technologies and their role in Future Ambient Intelligence Environments

NASA Astrophysics Data System (ADS)

Noor, Ahmed K.

2011-03-01

Dramatic improvements are on the horizon in Computer Aided Engineering (CAE) and various simulation technologies. The improvements are due, in part, to the developments in a number of leading-edge technologies and their synergistic combinations/convergence. The technologies include ubiquitous, cloud, and petascale computing; ultra high-bandwidth networks, pervasive wireless communication; knowledge based engineering; networked immersive virtual environments and virtual worlds; novel human-computer interfaces; and powerful game engines and facilities. This paper describes the frontiers and emerging simulation technologies, and their role in the future virtual product creation and learning/training environments. The environments will be ambient intelligence environments, incorporating a synergistic combination of novel agent-supported visual simulations (with cognitive learning and understanding abilities); immersive 3D virtual world facilities; development chain management systems and facilities (incorporating a synergistic combination of intelligent engineering and management tools); nontraditional methods; intelligent, multimodal and human-like interfaces; and mobile wireless devices. The Virtual product creation environment will significantly enhance the productivity and will stimulate creativity and innovation in future global virtual collaborative enterprises. The facilities in the learning/training environment will provide timely, engaging, personalized/collaborative and tailored visual learning.

Social Protocols for Agile Virtual Teams

NASA Astrophysics Data System (ADS)

Picard, Willy

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

Virtual worlds: a new frontier for nurse education?

PubMed

Green, Janet; Wyllie, Aileen; Jackson, Debra

2014-01-01

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

Using Wikis to Investigate Communication, Collaboration and Engagement in Capstone Engineering Design Projects

ERIC Educational Resources Information Center

Berthoud, L.; Gliddon, J.

2018-01-01

In today's global Aerospace industry, virtual workspaces are commonly used for collaboration between geographically distributed multidisciplinary teams. This study investigated the use of wikis to look at communication, collaboration and engagement in 'Capstone' team design projects at the end of an engineering degree. Wikis were set up for teams…

A Web 2.0-Based Collaborative Model for Multicultural Education

ERIC Educational Resources Information Center

Hossain, Md. Mokter; Aydin, Hasan

2011-01-01

Purpose: Web 2.0 is a collaborative web development platform that has had tremendous usage in building effective, interactive, and collaborative virtual societies at home and abroad. Multicultural study is another trend that has tremendous possibilities to help people in the fight against racism and enables them to become active members of a…

76 FR 45334 - Innovative Techniques for Delivering ITS Learning; Request for Information

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-28

... training opportunities and the desire to use emerging social media tools to better engage and collaborate...; Collaborative--through the use of social media or other `virtual' meeting spaces; Designed for the adult learner... ITS deployers? 6. How might social media collaboration tools be used to engage audiences in ITS...

User Satisfaction with Referrals at a Collaborative Virtual Reference Service

ERIC Educational Resources Information Center

Kwon, Nahyun

2006-01-01

Introduction: This study investigated unmonitored referrals in a nationwide, collaborative chat reference service. Specifically, it examined the extent to which questions are referred, the types of questions that are more likely to be referred than others, and the level of user satisfaction with the referrals in the collaborative chat reference…

Discussing the Factors Contributing to Students' Involvement in an EFL Collaborative Wiki Project

ERIC Educational Resources Information Center

Lee, Hsiao-chien; Wang, Pei-ling

2013-01-01

A growing number of researchers have acknowledged the potential for using wikis in online collaborative language learning. While researchers appreciate the wikis platform for engaging students in virtual team work and authentic language learning, many also have recognized the limitations of using wikis to promote student collaboration (Alyousef…

Dynamic Group Formation as an Approach to Collaborative Learning Support

ERIC Educational Resources Information Center

Srba, Ivan; Bielikova, Maria

2015-01-01

In the current time of globalization, collaboration among people in virtual environments is becoming an important precondition of success. This trend is reflected also in the educational domain where students collaborate in various short-term groups created repetitively but changing in each round (e.g. in MOOCs). Students in these kind of dynamic…

Fostering Collaborative Learning in Second Life: Metaphors and Affordances

ERIC Educational Resources Information Center

Andreas, Konstantinidis; Tsiatsos, Thrasyvoulos; Terzidou, Theodouli; Pomportsis, Andreas

2010-01-01

In this paper we examine the transferability of the Jigsaw and Fishbowl collaborative learning techniques to the Second Life platform. Our aim is to assess the applicability of Second Life for collaborative learning by developing virtual tools and metaphors and exploiting the representational richness of this novel medium. In order to enhance the…

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

ERIC Educational Resources Information Center

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

2008-01-01

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

Using Five Stage Model to Design of Collaborative Learning Environments in Second Life

ERIC Educational Resources Information Center

Orhan, Sevil; Karaman, M. Kemal

2014-01-01

Specifically Second Life (SL) among virtual worlds draws attention of researchers to form collaborative learning environments (Sutcliffe & Alrayes, 2012) since it could be used as a rich platform to simulate a real environment containing many collaborative learning characteristics and interaction tools within itself. Five Stage Model (FSM)…

Game-Based Virtual Worlds as Decentralized Virtual Activity Systems

NASA Astrophysics Data System (ADS)

Scacchi, Walt

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

Waiting for coronary angiography: is there a clinically ordered queue?

PubMed

Hemingway, H; Crook, A M; Feder, G; Dawson, J R; Timmis, A

2000-03-18

Among over 3000 patients undergoing coronary angiography in the absence of a formal queue-management system, we found that a-priori urgency scores were strongly associated with waiting times, prevalence of coronary-artery disease, rate of revascularisation, and mortality. These data challenge the widely held assumption that such waiting lists are not clinically ordered; however, the wide variation in waiting times within urgency categories suggests the need for further improvements in clinical queueing.

Cost Comparison of B-1B Non-Mission-Capable Drivers Using Finite Source Queueing with Spares

DTIC Science & Technology

2012-09-06

COMPARISON OF B-1B NON-MISSION-CAPABLE DRIVERS USING FINITE SOURCE QUEUEING WITH SPARES GRADUATE RESEARCH PAPER Presented to the Faculty...step into the lineup making large-number approximations unusable. Instead, a finite source queueing model including spares is incorporated...were reported as flying time accrued since last occurrence. Service time was given in both start-stop format and MX man-hours utilized. Service time was

Parallel discrete event simulation: A shared memory approach

NASA Technical Reports Server (NTRS)

Reed, Daniel A.; Malony, Allen D.; Mccredie, Bradley D.

1987-01-01

With traditional event list techniques, evaluating a detailed discrete event simulation model can often require hours or even days of computation time. Parallel simulation mimics the interacting servers and queues of a real system by assigning each simulated entity to a processor. By eliminating the event list and maintaining only sufficient synchronization to insure causality, parallel simulation can potentially provide speedups that are linear in the number of processors. A set of shared memory experiments is presented using the Chandy-Misra distributed simulation algorithm to simulate networks of queues. Parameters include queueing network topology and routing probabilities, number of processors, and assignment of network nodes to processors. These experiments show that Chandy-Misra distributed simulation is a questionable alternative to sequential simulation of most queueing network models.

An agent-based model for queue formation of powered two-wheelers in heterogeneous traffic

NASA Astrophysics Data System (ADS)

Lee, Tzu-Chang; Wong, K. I.

2016-11-01

This paper presents an agent-based model (ABM) for simulating the queue formation of powered two-wheelers (PTWs) in heterogeneous traffic at a signalized intersection. The main novelty is that the proposed interaction rule describing the position choice behavior of PTWs when queuing in heterogeneous traffic can capture the stochastic nature of the decision making process. The interaction rule is formulated as a multinomial logit model, which is calibrated by using a microscopic traffic trajectory dataset obtained from video footage. The ABM is validated against the survey data for the vehicular trajectory patterns, queuing patterns, queue lengths, and discharge rates. The results demonstrate that the proposed model is capable of replicating the observed queue formation process for heterogeneous traffic.

Leadership in practice: an analysis of collaborative leadership in the conception of a virtual ward.

PubMed

Stockham, Alayne

2016-09-30

The National Health Service (NHS) in the UK is evolving to meet the needs of society, but success depends on effective leadership. The World Health Organization identified intersectoral and multidisciplinary working as key to improving the quality and sustainability of the service, highlighting the need for a new leadership style. This article describes how collaborative leadership was used to successfully implement a virtual ward in the primary care setting in south-east Powys, Wales. The author describes the leadership style and addresses strategies used to manage the change process. The journey demonstrates how collaborative leadership and working collectively enabled a new service to be developed, and established a mutual respect for different professionals' roles.

Managing Distributed Innovation Processes in Virtual Organizations by Applying the Collaborative Network Relationship Analysis

NASA Astrophysics Data System (ADS)

Eschenbächer, Jens; Seifert, Marcus; Thoben, Klaus-Dieter

Distributed innovation processes are considered as a new option to handle both the complexity and the speed in which new products and services need to be prepared. Indeed most research on innovation processes was focused on multinational companies with an intra-organisational perspective. The phenomena of innovation processes in networks - with an inter-organisational perspective - have been almost neglected. Collaborative networks present a perfect playground for such distributed innovation processes whereas the authors highlight in specific Virtual Organisation because of their dynamic behaviour. Research activities supporting distributed innovation processes in VO are rather new so that little knowledge about the management of such research is available. With the presentation of the collaborative network relationship analysis this gap will be addressed. It will be shown that a qualitative planning of collaboration intensities can support real business cases by proving knowledge and planning data.

Surgical model-view-controller simulation software framework for local and collaborative applications

PubMed Central

Sankaranarayanan, Ganesh; Halic, Tansel; Arikatla, Venkata Sreekanth; Lu, Zhonghua; De, Suvranu

2010-01-01

Purpose Surgical simulations require haptic interactions and collaboration in a shared virtual environment. A software framework for decoupled surgical simulation based on a multi-controller and multi-viewer model-view-controller (MVC) pattern was developed and tested. Methods A software framework for multimodal virtual environments was designed, supporting both visual interactions and haptic feedback while providing developers with an integration tool for heterogeneous architectures maintaining high performance, simplicity of implementation, and straightforward extension. The framework uses decoupled simulation with updates of over 1,000 Hz for haptics and accommodates networked simulation with delays of over 1,000 ms without performance penalty. Results The simulation software framework was implemented and was used to support the design of virtual reality-based surgery simulation systems. The framework supports the high level of complexity of such applications and the fast response required for interaction with haptics. The efficacy of the framework was tested by implementation of a minimally invasive surgery simulator. Conclusion A decoupled simulation approach can be implemented as a framework to handle simultaneous processes of the system at the various frame rates each process requires. The framework was successfully used to develop collaborative virtual environments (VEs) involving geographically distributed users connected through a network, with the results comparable to VEs for local users. PMID:20714933

The impact of self-avatars on trust and collaboration in shared virtual environments.

PubMed

Pan, Ye; Steed, Anthony

2017-01-01

A self-avatar is known to have a potentially significant impact on the user's experience of the immersive content but it can also affect how users interact with each other in a shared virtual environment (SVE). We implemented an SVE for a consumer virtual reality system where each user's body could be represented by a jointed self-avatar that was dynamically controlled by head and hand controllers. We investigated the impact of a self-avatar on collaborative outcomes such as completion time and trust formation during competitive and cooperative tasks. We used two different embodiment levels: no self-avatar and self-avatar, and compared these to an in-person face to face version of the tasks. We found that participants could finish the task more quickly when they cooperated than when they competed, for both the self-avatar condition and the face to face condition, but not for the no self-avatar condition. In terms of trust formation, both the self-avatar condition and the face to face condition led to higher scores than the no self-avatar condition; however, collaboration style had no significant effect on trust built between partners. The results are further evidence of the importance of a self-avatar representation in immersive virtual reality.

The impact of self-avatars on trust and collaboration in shared virtual environments

PubMed Central

Steed, Anthony

2017-01-01

A self-avatar is known to have a potentially significant impact on the user’s experience of the immersive content but it can also affect how users interact with each other in a shared virtual environment (SVE). We implemented an SVE for a consumer virtual reality system where each user’s body could be represented by a jointed self-avatar that was dynamically controlled by head and hand controllers. We investigated the impact of a self-avatar on collaborative outcomes such as completion time and trust formation during competitive and cooperative tasks. We used two different embodiment levels: no self-avatar and self-avatar, and compared these to an in-person face to face version of the tasks. We found that participants could finish the task more quickly when they cooperated than when they competed, for both the self-avatar condition and the face to face condition, but not for the no self-avatar condition. In terms of trust formation, both the self-avatar condition and the face to face condition led to higher scores than the no self-avatar condition; however, collaboration style had no significant effect on trust built between partners. The results are further evidence of the importance of a self-avatar representation in immersive virtual reality. PMID:29240837

Surgical model-view-controller simulation software framework for local and collaborative applications.

PubMed

Maciel, Anderson; Sankaranarayanan, Ganesh; Halic, Tansel; Arikatla, Venkata Sreekanth; Lu, Zhonghua; De, Suvranu

2011-07-01

Surgical simulations require haptic interactions and collaboration in a shared virtual environment. A software framework for decoupled surgical simulation based on a multi-controller and multi-viewer model-view-controller (MVC) pattern was developed and tested. A software framework for multimodal virtual environments was designed, supporting both visual interactions and haptic feedback while providing developers with an integration tool for heterogeneous architectures maintaining high performance, simplicity of implementation, and straightforward extension. The framework uses decoupled simulation with updates of over 1,000 Hz for haptics and accommodates networked simulation with delays of over 1,000 ms without performance penalty. The simulation software framework was implemented and was used to support the design of virtual reality-based surgery simulation systems. The framework supports the high level of complexity of such applications and the fast response required for interaction with haptics. The efficacy of the framework was tested by implementation of a minimally invasive surgery simulator. A decoupled simulation approach can be implemented as a framework to handle simultaneous processes of the system at the various frame rates each process requires. The framework was successfully used to develop collaborative virtual environments (VEs) involving geographically distributed users connected through a network, with the results comparable to VEs for local users.

The relationship between (stigmatizing) views and lay public preferences regarding tuberculosis treatment in the Eastern Cape, South Africa.

PubMed

Cramm, Jane M; Nieboer, Anna P

2011-01-14

Tuberculosis (TB) and human immune virus/acquired immune deficiency syndrome (HIV/AIDS) stigmas affect public attitudes toward TB treatment and policy. This study examined 'stigmatizing' ideas and the view that 'TB patients should line-up in the chronic illness queue' in relation to preferences and attitudes toward TB treatment. Data were gathered through a survey administered to respondents from 1,020 households in Grahamstown. The survey measured stigmatization surrounding TB and HIV/AIDS, and determined perceptions of respondents whether TB patients should queue with other chronically ill patients. Respondents selected support and treatment options they felt would benefit TB patients. Statistical analysis identified the prevalence of TB and HIV/AIDS stigmas. Logistic regression analyses explored associations between stigmatizing ideas, views regarding TB patients in the chronic illness queue, and attitudes toward support and treatment. Respondents with TB stigmatizing ideas held positive attitudes toward volunteer support, special TB queues, and treatment at clinics; they held negative attitudes toward temporary disability grants, provision of information at work or school, and treatment at the TB hospital. Respondents who felt it beneficial for TB patients to queue with other chronically ill patients conversely held positive attitudes toward provision of porridge and disability grants, and treatment at the TB hospital; they held negative attitudes toward volunteer support, special TB queues, information provision at work or school, and treatment at clinics. These results showed that two varying views related to visibility factors that expose patients to stigmatization (one characterized by TB stigma, the other by the view that TB patients should queue with other chronically ill patients) are associated with opposing attitudes and preferences towards TB treatment. These opposing attitudes complicate treatment outcomes, and suggest that complex behaviors must be taken into account when designing health policy.

The Evolution of Constructivist Learning Environments: Immersion in Distributed, Virtual Worlds.

ERIC Educational Resources Information Center

Dede, Chris

1995-01-01

Discusses the evolution of constructivist learning environments and examines the collaboration of simulated software models, virtual environments, and evolving mental models via immersion in artificial realities. A sidebar gives a realistic example of a student navigating through cyberspace. (JMV)

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

NASA Astrophysics Data System (ADS)

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

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

Assessing the Success Rate of Students Using a Learning Management System Together with a Collaborative Tool in Web-Based Teaching of Programming Languages

ERIC Educational Resources Information Center

Cavus, Nadire; Ibrahim, Dogan

2007-01-01

The development of collaborative studies in learning has led to a renewed interest in the field of Web-based education. In this experimental study a highly interactive and collaborative virtual teaching environment has been created by supporting Moodle LMS with collaborative learning tool GREWPtool. The aim of this experimental study has been to…

The Supermarket Model with Bounded Queue Lengths in Equilibrium

NASA Astrophysics Data System (ADS)

Brightwell, Graham; Fairthorne, Marianne; Luczak, Malwina J.

2018-04-01

In the supermarket model, there are n queues, each with a single server. Customers arrive in a Poisson process with arrival rate λ n , where λ = λ (n) \\in (0,1) . Upon arrival, a customer selects d=d(n) servers uniformly at random, and joins the queue of a least-loaded server amongst those chosen. Service times are independent exponentially distributed random variables with mean 1. In this paper, we analyse the behaviour of the supermarket model in the regime where λ (n) = 1 - n^{-α } and d(n) = \\lfloor n^β \\rfloor , where α and β are fixed numbers in (0, 1]. For suitable pairs (α , β ) , our results imply that, in equilibrium, with probability tending to 1 as n → ∞, the proportion of queues with length equal to k = \\lceil α /β \\rceil is at least 1-2n^{-α + (k-1)β } , and there are no longer queues. We further show that the process is rapidly mixing when started in a good state, and give bounds on the speed of mixing for more general initial conditions.

Production Task Queue Optimization Based on Multi-Attribute Evaluation for Complex Product Assembly Workshop.

PubMed

Li, Lian-Hui; Mo, Rong

2015-01-01

The production task queue has a great significance for manufacturing resource allocation and scheduling decision. Man-made qualitative queue optimization method has a poor effect and makes the application difficult. A production task queue optimization method is proposed based on multi-attribute evaluation. According to the task attributes, the hierarchical multi-attribute model is established and the indicator quantization methods are given. To calculate the objective indicator weight, criteria importance through intercriteria correlation (CRITIC) is selected from three usual methods. To calculate the subjective indicator weight, BP neural network is used to determine the judge importance degree, and then the trapezoid fuzzy scale-rough AHP considering the judge importance degree is put forward. The balanced weight, which integrates the objective weight and the subjective weight, is calculated base on multi-weight contribution balance model. The technique for order preference by similarity to an ideal solution (TOPSIS) improved by replacing Euclidean distance with relative entropy distance is used to sequence the tasks and optimize the queue by the weighted indicator value. A case study is given to illustrate its correctness and feasibility.

Production Task Queue Optimization Based on Multi-Attribute Evaluation for Complex Product Assembly Workshop

PubMed Central

Li, Lian-hui; Mo, Rong

2015-01-01

The production task queue has a great significance for manufacturing resource allocation and scheduling decision. Man-made qualitative queue optimization method has a poor effect and makes the application difficult. A production task queue optimization method is proposed based on multi-attribute evaluation. According to the task attributes, the hierarchical multi-attribute model is established and the indicator quantization methods are given. To calculate the objective indicator weight, criteria importance through intercriteria correlation (CRITIC) is selected from three usual methods. To calculate the subjective indicator weight, BP neural network is used to determine the judge importance degree, and then the trapezoid fuzzy scale-rough AHP considering the judge importance degree is put forward. The balanced weight, which integrates the objective weight and the subjective weight, is calculated base on multi-weight contribution balance model. The technique for order preference by similarity to an ideal solution (TOPSIS) improved by replacing Euclidean distance with relative entropy distance is used to sequence the tasks and optimize the queue by the weighted indicator value. A case study is given to illustrate its correctness and feasibility. PMID:26414758

Collaborative Learning Processes in an Asynchronous Environment: An Analysis through Discourse and Social Networks

ERIC Educational Resources Information Center

Tirado, Ramon; Aguaded, Ignacio; Hernando, Angel

2011-01-01

This article analyses an experience in collaborative learning in an asynchronous writing environment through discussion forums on a WebCt platform of the University of Huelva's virtual campus, and was part of an innovative teaching project in 2007-08. The main objectives are to describe the processes of collaborative knowledge construction and the…

Collaborative Learning with Screen-Based Simulation in Health Care Education: An Empirical Study of Collaborative Patterns and Proficiency Development

ERIC Educational Resources Information Center

Hall, L. O.; Soderstrom, T.; Ahlqvist, J.; Nilsson, T.

2011-01-01

This article is about collaborative learning with educational computer-assisted simulation (ECAS) in health care education. Previous research on training with a radiological virtual reality simulator has indicated positive effects on learning when compared to a more conventional alternative. Drawing upon the field of Computer-Supported…

Combining multi-layered bitmap files using network specific hardware

DOEpatents

DuBois, David H [Los Alamos, NM; DuBois, Andrew J [Santa Fe, NM; Davenport, Carolyn Connor [Los Alamos, NM

2012-02-28

Images and video can be produced by compositing or alpha blending a group of image layers or video layers. Increasing resolution or the number of layers results in increased computational demands. As such, the available computational resources limit the images and videos that can be produced. A computational architecture in which the image layers are packetized and streamed through processors can be easily scaled so to handle many image layers and high resolutions. The image layers are packetized to produce packet streams. The packets in the streams are received, placed in queues, and processed. For alpha blending, ingress queues receive the packetized image layers which are then z sorted and sent to egress queues. The egress queue packets are alpha blended to produce an output image or video.

Virtuality and efficiency - overcoming past antinomy in the remote collaboration experience

NASA Astrophysics Data System (ADS)

Fernandes, Joao; Bjorkli, Knut; Clavo, David Martin; Baron, Thomas

2010-04-01

Several recent initiatives have been put in place by the CERN IT Department to improve the user experience in remote dispersed meetings and remote collaboration at large in the LHC communities worldwide. We will present an analysis of the factors which were historically limiting the efficiency of remote dispersed meetings and describe the consequent actions which were undertaken at CERN to overcome these limitations. After giving a status update of the different equipment available at CERN to enable the virtual sessions and the various collaborative tools which are currently proposed to users, we will focus on the evolution of this market: how can the new technological trends (among others, HD videoconferencing, Telepresence, Unified Communications, etc.) impact positively the user experience and how to attain the best usage of them. Finally, by projecting ourselves in the future, we will give some hints as to how to answer the difficult question of selecting the next generation of collaborative tools: which set of tools among the various offers (systems like Vidyo H264 SVC, next generation EVO, Groupware offers, standard H323 systems, etc.) is best suited for our environment and how to unify this set for the common user. This will finally allow us to definitively overcome the past antinomy between virtuality and efficiency.

Collaboration and Dialogue in Virtual Reality

ERIC Educational Resources Information Center

Jensen, Camilla Gyldendahl

2017-01-01

"Virtual reality" adds a new dimension to problem-based learning (PBL) environments in the architecture and building construction educations, where a realistic and lifelike presence in a building enables students to assess and discuss how the various solutions interact with each other. Combined with "Building Information…

Virtual patient care: an interprofessional education approach for physician assistant, physical therapy and occupational therapy students.

PubMed

Shoemaker, Michael J; Platko, Christina M; Cleghorn, Susan M; Booth, Andrew

2014-07-01

The purpose of this retrospective qualitative case report is to describe how a case-based, virtual patient interprofessional education (IPE) simulation activity was utilized to achieve physician assistant (PA), physical therapy (PT) and occupational therapy (OT) student IPE learning outcomes. Following completion of a virtual patient case, 30 PA, 46 PT and 24 OT students were required to develop a comprehensive, written treatment plan and respond to reflective questions. A qualitative analysis of the submitted written assignment was used to determine whether IPE learning objectives were met. Student responses revealed three themes that supported the learning objectives of the IPE experience: benefits of collaborative care, role clarification and relevance of the IPE experience for future practice. A case-based, IPE simulation activity for physician assistant and rehabilitation students using a computerized virtual patient software program effectively facilitated achievement of the IPE learning objectives, including development of greater student awareness of other professions and ways in which collaborative patient care can be provided.

The Virtual Test Bed Project

NASA Technical Reports Server (NTRS)

Rabelo, Luis C.

2002-01-01

This is a report of my activities as a NASA Fellow during the summer of 2002 at the NASA Kennedy Space Center (KSC). The core of these activities is the assigned project: the Virtual Test Bed (VTB) from the Spaceport Engineering and Technology Directorate. The VTB Project has its foundations in the NASA Ames Research Center (ARC) Intelligent Launch & Range Operations program. The objective of the VTB project is to develop a new and unique collaborative computing environment where simulation models can be hosted and integrated in a seamless fashion. This collaborative computing environment will be used to build a Virtual Range as well as a Virtual Spaceport. This project will work as a technology pipeline to research, develop, test and validate R&D efforts against real time operations without interfering with the actual operations or consuming the operational personnel s time. This report will also focus on the systems issues required to conceptualize and provide form to a systems architecture capable of handling the different demands.

Communication skills to develop trusting relationships on global virtual engineering capstone teams

NASA Astrophysics Data System (ADS)

Zaugg, Holt; Davies, Randall S.

2013-05-01

As universities seek to provide cost-effective, cross-cultural experiences using global virtual (GV) teams, the 'soft' communication skills typical of all teams, increases in importance for GV teams. Students need to be taught how to navigate through cultural issues and virtual tool issues to build strong trusting relationships with distant team members. Weekly team meetings provide an excellent opportunity to observe key team interactions that facilitate relationship and trust-building among team members. This study observed the weekly team meetings of engineering students attending two US universities and one Asian university as they collaborated as a single GV capstone GV team. In addition local team members were interviewed individually and collectively throughout the project to determine strategies that facilitated team relations and trust. Findings indicate the importance of student choice of virtual communication tools, the refining of communication practices, and specific actions to build trusting relationships. As student developed these attributes, collaboration and success was experienced on this GV team.

Ada Quality and Style: Guidelines for Professional Programmers, Version 02.01.01

DTIC Science & Technology

1992-12-01

47, 78, 79 predicate queue , entry not prioritized, 95 as function name, 22 for boolean object, 21 R preemptive scheduling. 118 race condition. 49...when lower priority tasks are given service while higher priority tasks remain blocked. In the above example, this occurred because entry queues are...from an entry queue 100 Ada QUALITY AND STYLE due to execution of an abort statement as well as expiration of a timed entry call. The use of this

Steady-State Algorithmic Analysis M/M/c Two-Priority Queues with Heterogeneous Rates.

DTIC Science & Technology

1981-04-21

ALGORITHMIC ANALYSIS OF M/M/c TWO-PRIORITY QUEUES WITH HETEROGENEOUS RATES by Douglas R. Miller An algorithm for steady-state analysis of M/M/c nonpreemptive ...practical algorithm for systems involving more than two priority classes. The preemptive case is simpler than the nonpreemptive case; an algorithm for it...priority nonpreemptive queueing system with arrival rates 1 and X2 and service rates V and p42 * The state space can be described as follows. Let xi,j,k be

Convergence of a Queueing System in Heavy Traffic with General Abandonment Distributions

DTIC Science & Technology

2010-10-08

3 in Reiman [27]. We circumvent the use of Reiman’s “Snap-shot Principle” and a comparison result with a non-abandoning queue used in Reed and Ward...4):2606–2650, 2005. 37 [5] R. Atar, A. Mandelbaum, and M. I. Reiman . Scheduling a multi class queue with many exponential servers: asymptotic... Reiman Designing a call center with impatient cus- tomers. Manufacturing and Service Oper. Management, 4(1A):208–227, 2002. [15] J. M. George and J. M

Trust Building in Virtual Communities

NASA Astrophysics Data System (ADS)

Mezgár, István

By using different types of communication networks various groups of people can come together according to their private or business interest forming a Virtual Community. In these communities cooperation and collaboration plays an important role. As trust is the base of all human interactions this fact is even more valid in case of virtual communities. According to different experiments the level of trust in virtual communities is highly influenced by the way/mode of communication and by the duration of contact. The paper discusses the ways of trust building focusing on communication technologies and security aspects in virtual communities.

Building Virtual Communities in School Counseling.

ERIC Educational Resources Information Center

Sabella, Russell A.; Halverson, Bill

Current trends and issues in education, and especially in school counseling, indicate the importance of collaborating for student success. With the proliferation of computer and networking technologies at their fingertips, school counselors can effectively forge greater collaborations among various stakeholders by creating virtual…

Research on an IP disaster recovery storage system

NASA Astrophysics Data System (ADS)

Zeng, Dong; Wang, Yusheng; Zhu, Jianfeng

2008-12-01

According to both the Fibre Channel (FC) Storage Area Network (SAN) switch and Fabric Application Interface Standard (FAIS) mechanism, an iSCSI storage controller is put forward and based upon it, an internet Small Computer System Interface (iSCSI) SAN construction strategy for disaster recovery (DR) is proposed and some multiple sites replication models and a closed queue performance analysis method are also discussed in this paper. The iSCSI storage controller lies in the fabric level of the networked storage infrastructure, and it can be used to connect to both the hybrid storage applications and storage subsystems, besides, it can provide virtualized storage environment and support logical volume access control, and by cooperating with the remote peerparts, a disaster recovery storage system can be built on the basis of the data replication, block-level snapshot and Internet Protocol (IP) take-over functions.

Virtual Reality Simulation of the International Space Welding Experiment

NASA Technical Reports Server (NTRS)

Phillips, James A.

1996-01-01

Virtual Reality (VR) is a set of breakthrough technologies that allow a human being to enter and fully experience a 3-dimensional, computer simulated environment. A true virtual reality experience meets three criteria: (1) It involves 3-dimensional computer graphics; (2) It includes real-time feedback and response to user actions; and (3) It must provide a sense of immersion. Good examples of a virtual reality simulator are the flight simulators used by all branches of the military to train pilots for combat in high performance jet fighters. The fidelity of such simulators is extremely high -- but so is the price tag, typically millions of dollars. Virtual reality teaching and training methods are manifestly effective, and we have therefore implemented a VR trainer for the International Space Welding Experiment. My role in the development of the ISWE trainer consisted of the following: (1) created texture-mapped models of the ISWE's rotating sample drum, technology block, tool stowage assembly, sliding foot restraint, and control panel; (2) developed C code for control panel button selection and rotation of the sample drum; (3) In collaboration with Tim Clark (Antares Virtual Reality Systems), developed a serial interface box for the PC and the SGI Indigo so that external control devices, similar to ones actually used on the ISWE, could be used to control virtual objects in the ISWE simulation; (4) In collaboration with Peter Wang (SFFP) and Mark Blasingame (Boeing), established the interference characteristics of the VIM 1000 head-mounted-display and tested software filters to correct the problem; (5) In collaboration with Peter Wang and Mark Blasingame, established software and procedures for interfacing the VPL DataGlove and the Polhemus 6DOF position sensors to the SGI Indigo serial ports. The majority of the ISWE modeling effort was conducted on a PC-based VR Workstation, described below.

A network architecture supporting consistent rich behavior in collaborative interactive applications.

PubMed

Marsh, James; Glencross, Mashhuda; Pettifer, Steve; Hubbold, Roger

2006-01-01

Network architectures for collaborative virtual reality have traditionally been dominated by client-server and peer-to-peer approaches, with peer-to-peer strategies typically being favored where minimizing latency is a priority, and client-server where consistency is key. With increasingly sophisticated behavior models and the demand for better support for haptics, we argue that neither approach provides sufficient support for these scenarios and, thus, a hybrid architecture is required. We discuss the relative performance of different distribution strategies in the face of real network conditions and illustrate the problems they face. Finally, we present an architecture that successfully meets many of these challenges and demonstrate its use in a distributed virtual prototyping application which supports simultaneous collaboration for assembly, maintenance, and training applications utilizing haptics.

Inspiring Equal Contribution and Opportunity in a 3D Multi-User Virtual Environment: Bringing Together Men Gamers and Women Non-Gamers in Second Life[R

ERIC Educational Resources Information Center

deNoyelles, Aimee; Seo, Kay Kyeong-Ju

2012-01-01

A 3D multi-user virtual environment holds promise to support and enhance student online learning communities due to its ability to promote global synchronous interaction and collaboration, rich multisensory experience and expression, and elaborate design capabilities. Second Life[R], a multi-user virtual environment intended for adult users 18 and…

Enabling Research without Geographical Boundaries via Collaborative Research Infrastructures

NASA Astrophysics Data System (ADS)

Gesing, S.

2016-12-01

Collaborative research infrastructures on global scale for earth and space sciences face a plethora of challenges from technical implementations to organizational aspects. Science gateways - also known as virtual research environments (VREs) or virtual laboratories - address part of such challenges by providing end-to-end solutions to aid researchers to focus on their specific research questions without the need to become acquainted with the technical details of the complex underlying infrastructures. In general, they provide a single point of entry to tools and data irrespective of organizational boundaries and thus make scientific discoveries easier and faster. The importance of science gateways has been recognized on national as well as on international level by funding bodies and by organizations. For example, the US NSF has just funded a Science Gateways Community Institute, which offers support, consultancy and open accessible software repositories for users and developers; Horizon 2020 provides funding for virtual research environments in Europe, which has led to projects such as VRE4EIC (A Europe-wide Interoperable Virtual Research Environment to Empower Multidisciplinary Research Communities and Accelerate Innovation and Collaboration); national or continental research infrastructures such as XSEDE in the USA, Nectar in Australia or EGI in Europe support the development and uptake of science gateways; the global initiatives International Coalition on Science Gateways, the RDA Virtual Research Environment Interest Group as well as the IEEE Technical Area on Science Gateways have been founded to provide global leadership on future directions for science gateways in general and facilitate awareness for science gateways. This presentation will give an overview on these projects and initiatives aiming at supporting domain researchers and developers with measures for the efficient creation of science gateways, for increasing their usability and sustainability under consideration of the breadth of topics in the context of science gateways. It will go into detail for the challenges the community faces for collaborative research on global scale without geographical boundaries and will provide suggestions for further enhancing the outreach to domain researchers.

Virtual Representations in 3D Learning Environments

ERIC Educational Resources Information Center

Shonfeld, Miri; Kritz, Miki

2013-01-01

This research explores the extent to which virtual worlds can serve as online collaborative learning environments for students by increasing social presence and engagement. 3D environments enable learning, which simulates face-to-face encounters while retaining the advantages of online learning. Students in Education departments created avatars…

PC-Based Virtual Reality for CAD Model Viewing

ERIC Educational Resources Information Center

Seth, Abhishek; Smith, Shana S.-F.

2004-01-01

Virtual reality (VR), as an emerging visualization technology, has introduced an unprecedented communication method for collaborative design. VR refers to an immersive, interactive, multisensory, viewer-centered, 3D computer-generated environment and the combination of technologies required to build such an environment. This article introduces the…

Coordinated Implicitly? An Empirical Study on the Role of Social Media in Collaborative Learning

ERIC Educational Resources Information Center

Zhang, Xi; Chen, Hui; Ordóñez de Pablos, Patricia; Lytras, Miltiadis D.; Sun, Yongqiang

2016-01-01

As social media is widely adopted in collaborative learning, which places teams in a virtual environment, it is critical for teams to identify and leverage the knowledge of their members. Yet little is known about how social media influences teams to coordinate their knowledge and collaborate effectively. In this research, we explore the roles of…

E-Tutorial Support for Collaborative Online Learning: An Explorative Study on Experienced and Inexperienced E-Tutors

ERIC Educational Resources Information Center

Kopp, Birgitta; Matteucci, Maria Cristina; Tomasetto, Carlo

2012-01-01

The e-tutor plays a major role in supporting virtual collaborative learning, as he/she supervises learners in collaboratively solving tasks, acquiring new skills, and applying new knowledge. This study is aimed at gaining further insights into the daily support practices of e-tutors. Seventy-six e-tutors from 17 different European countries were…

Enhancing Collaborative Peer-to-Peer Systems Using Resource Aggregation and Caching: A Multi-Attribute Resource and Query Aware Approach

ERIC Educational Resources Information Center

Bandara, H. M. N. Dilum

2012-01-01

Resource-rich computing devices, decreasing communication costs, and Web 2.0 technologies are fundamentally changing the way distributed applications communicate and collaborate. With these changes, we envision Peer-to-Peer (P2P) systems that will allow for the integration and collaboration of peers with diverse capabilities to a virtual community…

Design and analysis of a model predictive controller for active queue management.

PubMed

Wang, Ping; Chen, Hong; Yang, Xiaoping; Ma, Yan

2012-01-01

Model predictive (MP) control as a novel active queue management (AQM) algorithm in dynamic computer networks is proposed. According to the predicted future queue length in the data buffer, early packets at the router are dropped reasonably by the MPAQM controller so that the queue length reaches the desired value with minimal tracking error. The drop probability is obtained by optimizing the network performance. Further, randomized algorithms are applied to analyze the robustness of MPAQM successfully, and also to provide the stability domain of systems with uncertain network parameters. The performances of MPAQM are evaluated through a series of simulations in NS2. The simulation results show that the MPAQM algorithm outperforms RED, PI, and REM algorithms in terms of stability, disturbance rejection, and robustness. Copyright © 2011 ISA. Published by Elsevier Ltd. All rights reserved.

Queueing for healthcare.

PubMed

Palvannan, R Kannapiran; Teow, Kiok Liang

2012-04-01

Patient queues are prevalent in healthcare and wait time is one measure of access to care. We illustrate Queueing Theory-an analytical tool that has provided many insights to service providers when designing new service systems and managing existing ones. This established theory helps us to quantify the appropriate service capacity to meet the patient demand, balancing system utilization and the patient's wait time. It considers four key factors that affect the patient's wait time: average patient demand, average service rate and the variation in both. We illustrate four basic insights that will be useful for managers and doctors who manage healthcare delivery systems, at hospital or department level. Two examples from local hospitals are shown where we have used queueing models to estimate the service capacity and analyze the impact of capacity configurations, while considering the inherent variation in healthcare.

Ordering of guarded and unguarded stores for no-sync I/O

DOEpatents

Gara, Alan; Ohmacht, Martin

2013-06-25

A parallel computing system processes at least one store instruction. A first processor core issues a store instruction. A first queue, associated with the first processor core, stores the store instruction. A second queue, associated with a first local cache memory device of the first processor core, stores the store instruction. The first processor core updates first data in the first local cache memory device according to the store instruction. The third queue, associated with at least one shared cache memory device, stores the store instruction. The first processor core invalidates second data, associated with the store instruction, in the at least one shared cache memory. The first processor core invalidates third data, associated with the store instruction, in other local cache memory devices of other processor cores. The first processor core flushing only the first queue.

Queue theory for triangular and weibull arrival distribution models (case study of Banyumanik toll)

NASA Astrophysics Data System (ADS)

Sugito; Rahmawati, Rita; Kusuma Wardhani, Jenesia

2018-05-01

Queuing is one of the most common phenomena in daily life. Queued also happens on highway during busy time. The Electronic Toll Collection (ETC) was the new system of the Banyumanik toll gate which operates in 2014. Before ETC, Banyumanik toll gate users got regular service (regular toll gate) by paying in cash only. The ETC benefits more than regular service, but automatic toll gate (ETC) users are still few compared to regular toll gate users. To know the effectiveness of substance service, this paper used analysis of queuing system. The research was conducted at Toll Gate Banyumanik with the implementation time on 26-28 December 2016 for Ungaran-Semarang direction, and 29-31 December 2016 for Semarang- Ungaran direction. In one day, observation was done for 11 hours. That was at 07.00 a.m. until 06.00 p.m. There are 4 models of queues at Banyumanik toll gate. Here the four models will be used on the number of arrival and service time. Based on the simulation with Arena, the result showed that queue model regular toll gate in Ugaran-Semarang direction is (Tria/G/3):(GD/∞/∞) and the queue model for automatic toll gate is (G/G/3):(GD/∞/∞). While the queue model for the direction of Semarang-Ungaran regular toll gate is (G/G/3):(GD/∞/∞) and the queue model of automatic toll gate is (Weib/G/3):(GD/∞/∞).

NQS - NETWORK QUEUING SYSTEM, VERSION 2.0 (UNIX VERSION)

NASA Technical Reports Server (NTRS)

Walter, H.

1994-01-01

The Network Queuing System, NQS, is a versatile batch and device queuing facility for a single Unix computer or a group of networked computers. With the Unix operating system as a common interface, the user can invoke the NQS collection of user-space programs to move batch and device jobs freely around the different computer hardware tied into the network. NQS provides facilities for remote queuing, request routing, remote status, queue status controls, batch request resource quota limits, and remote output return. This program was developed as part of an effort aimed at tying together diverse UNIX based machines into NASA's Numerical Aerodynamic Simulator Processing System Network. This revision of NQS allows for creating, deleting, adding and setting of complexes that aid in limiting the number of requests to be handled at one time. It also has improved device-oriented queues along with some revision of the displays. NQS was designed to meet the following goals: 1) Provide for the full support of both batch and device requests. 2) Support all of the resource quotas enforceable by the underlying UNIX kernel implementation that are relevant to any particular batch request and its corresponding batch queue. 3) Support remote queuing and routing of batch and device requests throughout the NQS network. 4) Support queue access restrictions through user and group access lists for all queues. 5) Enable networked output return of both output and error files to possibly remote machines. 6) Allow mapping of accounts across machine boundaries. 7) Provide friendly configuration and modification mechanisms for each installation. 8) Support status operations across the network, without requiring a user to log in on remote target machines. 9) Provide for file staging or copying of files for movement to the actual execution machine. To support batch and device requests, NQS v.2 implements three queue types--batch, device and pipe. Batch queues hold and prioritize batch requests; device queues hold and prioritize device requests; pipe queues transport both batch and device requests to other batch, device, or pipe queues at local or remote machines. Unique to batch queues are resource quota limits that restrict the amounts of different resources that a batch request can consume during execution. Unique to each device queue is a set of one or more devices, such as a line printer, to which requests can be sent for execution. Pipe queues have associated destinations to which they route and deliver requests. If the proper destination machine is down or unreachable, pipe queues are able to requeue the request and deliver it later when the destination is available. All NQS network conversations are performed using the Berkeley socket mechanism as ported into the respective vendor kernels. NQS is written in C language. The generic UNIX version (ARC-13179) has been successfully implemented on a variety of UNIX platforms, including Sun3 and Sun4 series computers, SGI IRIS computers running IRIX 3.3, DEC computers running ULTRIX 4.1, AMDAHL computers running UTS 1.3 and 2.1, platforms running BSD 4.3 UNIX. The IBM RS/6000 AIX version (COS-10042) is a vendor port. NQS 2.0 will also communicate with the Cray Research, Inc. and Convex, Inc. versions of NQS. The standard distribution medium for either machine version of NQS 2.0 is a 60Mb, QIC-24, .25 inch streaming magnetic tape cartridge in UNIX tar format. Upon request the generic UNIX version (ARC-13179) can be provided in UNIX tar format on alternate media. Please contact COSMIC to discuss the availability and cost of media to meet your specific needs. An electronic copy of the NQS 2.0 documentation is included on the program media. NQS 2.0 was released in 1991. The IBM RS/6000 port of NQS was developed in 1992. IRIX is a trademark of Silicon Graphics Inc. IRIS is a registered trademark of Silicon Graphics Inc. UNIX is a registered trademark of UNIX System Laboratories Inc. Sun3 and Sun4 are trademarks of Sun Microsystems Inc. DEC and ULTRIX are trademarks of Digital Equipment Corporation.

Collaboration in a Wireless Grid Innovation Testbed by Virtual Consortium

NASA Astrophysics Data System (ADS)

Treglia, Joseph; Ramnarine-Rieks, Angela; McKnight, Lee

This paper describes the formation of the Wireless Grid Innovation Testbed (WGiT) coordinated by a virtual consortium involving academic and non-academic entities. Syracuse University and Virginia Tech are primary university partners with several other academic, government, and corporate partners. Objectives include: 1) coordinating knowledge sharing, 2) defining key parameters for wireless grids network applications, 3) dynamically connecting wired and wireless devices, content and users, 4) linking to VT-CORNET, Virginia Tech Cognitive Radio Network Testbed, 5) forming ad hoc networks or grids of mobile and fixed devices without a dedicated server, 6) deepening understanding of wireless grid application, device, network, user and market behavior through academic, trade and popular publications including online media, 7) identifying policy that may enable evaluated innovations to enter US and international markets and 8) implementation and evaluation of the international virtual collaborative process.

Collaborative enterprise and virtual prototyping (CEVP): a product-centric approach to distributed simulation

NASA Astrophysics Data System (ADS)

Saunders, Vance M.

1999-06-01

The downsizing of the Department of Defense (DoD) and the associated reduction in budgets has re-emphasized the need for commonality, reuse, and standards with respect to the way DoD does business. DoD has implemented significant changes in how it buys weapon systems. The new emphasis is on concurrent engineering with Integrated Product and Process Development and collaboration with Integrated Product Teams. The new DoD vision includes Simulation Based Acquisition (SBA), a process supported by robust, collaborative use of simulation technology that is integrated across acquisition phases and programs. This paper discusses the Air Force Research Laboratory's efforts to use Modeling and Simulation (M&S) resources within a Collaborative Enterprise Environment to support SBA and other Collaborative Enterprise and Virtual Prototyping (CEVP) applications. The paper will discuss four technology areas: (1) a Processing Ontology that defines a hierarchically nested set of collaboration contexts needed to organize and support multi-disciplinary collaboration using M&S, (2) a partial taxonomy of intelligent agents needed to manage different M&S resource contributions to advancing the state of product development, (3) an agent- based process for interfacing disparate M&S resources into a CEVP framework, and (4) a Model-View-Control based approach to defining `a new way of doing business' for users of CEVP frameworks/systems.

Virtual Disaster Simulation: Lesson Learned from an International Collaboration That Can Be Leveraged for Disaster Education in Iran.

PubMed

Ardalan, Ali; Balikuddembe, Joseph Kimuli; Ingrassia, Pier Luigi; Carenzo, Luca; Della Corte, Francesco; Akbarisari, Ali; Djalali, Ahmadreza

2015-07-13

Disaster education needs innovative educational methods to be more effective compared to traditional approaches. This can be done by using virtual simulation method. This article presents an experience about using virtual simulation methods to teach health professional on disaster medicine in Iran. The workshop on the "Application of New Technologies in Disaster Management Simulation" was held in Tehran in January 2015. It was co-organized by the Disaster and Emergency Health Academy of Tehran University of Medical Sciences and Emergency and the Research Center in Disaster Medicine and Computer Science applied to Medicine (CRIMEDIM), Università del Piemonte Orientale. Different simulators were used by the participants, who were from the health system and other relevant fields, both inside and outside Iran. As a result of the workshop, all the concerned stakeholders are called on to support this new initiative of incorporating virtual training and exercise simulation in the field of disaster medicine, so that its professionals are endowed with field-based and practical skills in Iran and elsewhere. Virtual simulation technology is recommended to be used in education of disaster management. This requires capacity building of instructors, and provision of technologies. International collaboration can facilitate this process.

Fokker-Planck description for the queue dynamics of large tick stocks.

PubMed

Garèche, A; Disdier, G; Kockelkoren, J; Bouchaud, J-P

2013-09-01

Motivated by empirical data, we develop a statistical description of the queue dynamics for large tick assets based on a two-dimensional Fokker-Planck (diffusion) equation. Our description explicitly includes state dependence, i.e., the fact that the drift and diffusion depend on the volume present on both sides of the spread. "Jump" events, corresponding to sudden changes of the best limit price, must also be included as birth-death terms in the Fokker-Planck equation. All quantities involved in the equation can be calibrated using high-frequency data on the best quotes. One of our central findings is that the dynamical process is approximately scale invariant, i.e., the only relevant variable is the ratio of the current volume in the queue to its average value. While the latter shows intraday seasonalities and strong variability across stocks and time periods, the dynamics of the rescaled volumes is universal. In terms of rescaled volumes, we found that the drift has a complex two-dimensional structure, which is a sum of a gradient contribution and a rotational contribution, both stable across stocks and time. This drift term is entirely responsible for the dynamical correlations between the ask queue and the bid queue.

Fokker-Planck description for the queue dynamics of large tick stocks

NASA Astrophysics Data System (ADS)

Garèche, A.; Disdier, G.; Kockelkoren, J.; Bouchaud, J.-P.

2013-09-01

Motivated by empirical data, we develop a statistical description of the queue dynamics for large tick assets based on a two-dimensional Fokker-Planck (diffusion) equation. Our description explicitly includes state dependence, i.e., the fact that the drift and diffusion depend on the volume present on both sides of the spread. “Jump” events, corresponding to sudden changes of the best limit price, must also be included as birth-death terms in the Fokker-Planck equation. All quantities involved in the equation can be calibrated using high-frequency data on the best quotes. One of our central findings is that the dynamical process is approximately scale invariant, i.e., the only relevant variable is the ratio of the current volume in the queue to its average value. While the latter shows intraday seasonalities and strong variability across stocks and time periods, the dynamics of the rescaled volumes is universal. In terms of rescaled volumes, we found that the drift has a complex two-dimensional structure, which is a sum of a gradient contribution and a rotational contribution, both stable across stocks and time. This drift term is entirely responsible for the dynamical correlations between the ask queue and the bid queue.

Dynamic properties of chasers in a moving queue based on a delayed chasing model

NASA Astrophysics Data System (ADS)

Ning, Guo; Jian-Xun, Ding; Xiang, Ling; Qin, Shi; Reinhart, Kühne

2016-05-01

A delayed chasing model is proposed to simulate the chase behavior in the queue, where each member regards the closest one ahead as the target, and the leader is attracted to a target point with slight fluctuation. When the initial distances between neighbors possess an identical low value, the fluctuating target of the leader can cause an amplified disturbance in the queue. After a long period of time, the queue recovers the stable state from the disturbance, forming a straight-line-like pattern again, but distances between neighbors grow. Whether the queue can keep stable or not depends on initial distance, desired velocity, and relaxation time. Furthermore, we carry out convergence analysis to explain the divergence transformation behavior and confirm the convergence conditions, which is in approximate agreement with simulations. Project supported by the National Natural Science Foundation of China (Grant Nos. 71071044, 71001001, 71201041, and 11247291), the Doctoral Program of the Ministry of Education of China (Grant Nos. 20110111120023 and 20120111120022), the Postdoctoral Fund Project of China (Grant No. 2013M530295), the National Basic Research Program of China (Grant No. 2012CB725404), and 1000 Plan for Foreign Talent, China (Grant No. WQ20123400070).

A kinematic wave model in Lagrangian coordinates incorporating capacity drop: Application to homogeneous road stretches and discontinuities

NASA Astrophysics Data System (ADS)

Yuan, Kai; Knoop, Victor L.; Hoogendoorn, Serge P.

2017-01-01

On freeways, congestion always leads to capacity drop. This means the queue discharge rate is lower than the pre-queue capacity. Our recent research findings indicate that the queue discharge rate increases with the speed in congestion, that is the capacity drop is strongly correlated with the congestion state. Incorporating this varying capacity drop into a kinematic wave model is essential for assessing consequences of control strategies. However, to the best of authors' knowledge, no such a model exists. This paper fills the research gap by presenting a Lagrangian kinematic wave model. "Lagrangian" denotes that the new model is solved in Lagrangian coordinates. The new model can give capacity drops accompanying both of stop-and-go waves (on homogeneous freeway section) and standing queues (at nodes) in a network. The new model can be applied in a network operation. In this Lagrangian kinematic wave model, the queue discharge rate (or the capacity drop) is a function of vehicular speed in traffic jams. Four case studies on links as well as at lane-drop and on-ramp nodes show that the Lagrangian kinematic wave model can give capacity drops well, consistent with empirical observations.

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Team Leader: Tom Peters--TAP Information Services

ERIC Educational Resources Information Center

Library Journal, 2005

2005-01-01

Tom Peters packs 36 hours of work into the confines of a 24-hour day. Without breaking a sweat, he juggles multiple collaborative projects, which currently include an Illinois academic library shared storage facility; a multistate virtual reference and instruction service for blind and visually impaired individuals (InfoEyes); a virtual meeting…

Virtual Project Rooms for Education in Engineering

ERIC Educational Resources Information Center

van Vliet, Rudolf G.; Roeling, Monika M.; de Graaff, Rick; Pilot, Albert

2004-01-01

Virtual project rooms (VPRs) may support collaborative project-based learning groups by facilitating project management, documentation and communication. In this study a set of experiments was carried out at Eindhoven University of Technology using the MS Outlook/Exchange software as a groupware platform for design-oriented group projects. The…

Building Virtual Teams: Experiential Learning Using Emerging Technologies

ERIC Educational Resources Information Center

Hu, Haihong

2015-01-01

Currently, virtual teams are being used exponentially in higher education and business because of the development of technologies and globalization. These teams have become an essential approach for collaborative learning as well as task completion. Team learning, especially in an online format, can be challenging due to lack of effective…

Making the Most of Mobility: Virtual Mentoring and Education Practitioner Professional Development

ERIC Educational Resources Information Center

Owen, Hazel D.

2015-01-01

Learning provision, including professional learning, needs to embrace mobility (of knowledge, cultures and contexts--physical and cerebral) to enable education practitioners to interact locally and globally, engage with new literacies, access rich contexts, and to question, co-construct and collaborate. Virtual mentoring, also known as distance,…

Online Behavior in Virtual Space: An Empirical Study on Helping

ERIC Educational Resources Information Center

Hsu, Jung-Lung; Hwang, Wu-Yuin; Huang, Yueh-Min; Liu, Jui-Jung

2011-01-01

Although previous studies have acknowledged that helping behavior has many potential benefits, little research has aimed at understanding which factors would possibly enhance helping behaviors among team members in CSCL environment. Accordingly, this study was intended to identify underlying factors leading learners to collaborate in virtual CSCL…

Enhancing Student Collaboration in Global Virtual Teams

ERIC Educational Resources Information Center

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…

Networked Experiments and Scientific Resource Sharing in Cooperative Knowledge Spaces

ERIC Educational Resources Information Center

Cikic, Sabine; Jeschke, Sabina; Ludwig, Nadine; Sinha, Uwe; Thomsen, Christian

2007-01-01

Cooperative knowledge spaces create new potentials for the experimental fields in natural sciences and engineering because they enhance the accessibility of experimental setups through virtual laboratories and remote technology, opening them for collaborative and distributed usage. A concept for extending existing virtual knowledge spaces for the…

Revealing Preconditions for Trustful Collaboration in CSCL

ERIC Educational Resources Information Center

Gerdes, Anne

2010-01-01

This paper analyses preconditions for trust in virtual learning environments. The concept of trust is discussed with reference to cases reporting trust in cyberspace and through a philosophical clarification holding that trust in the form of self-surrender is a common characteristic of all human co-existence. In virtual learning environments,…

A Virtual World for Collaboration: The AETZone

ERIC Educational Resources Information Center

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

2009-01-01

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

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

ERIC Educational Resources Information Center

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

2011-01-01

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

Users and Union Catalogues

ERIC Educational Resources Information Center

Hartley, R. J.; Booth, Helen

2006-01-01

Union catalogues have had an important place in libraries for many years. Their use has been little investigated. Recent interest in the relative merits of physical and virtual union catalogues and a recent collaborative project between a physical and several virtual union catalogues in the United Kingdom led to the opportunity to study how users…

Phases and Patterns of Group Development in Virtual Learning Teams

ERIC Educational Resources Information Center

Yoon, Seung Won; Johnson, Scott D.

2008-01-01

With the advancement of Internet communication technologies, distributed work groups have great potential for remote collaboration and use of collective knowledge. Adopting the Complex Adaptive System (CAS) perspective (McGrath, Arrow, & Berdhal, "Personal Soc Psychol Rev" 4 (2000) 95), which views virtual learning teams as an adaptive and…

The Reality of Virtual Learning.

ERIC Educational Resources Information Center

Berman, Sheldon

1999-01-01

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

How Virtual Team Leaders Cope with Creativity Challenges

ERIC Educational Resources Information Center

Han, Soo Jeoung; Chae, Chungil; Macko, Patricia; Park, Woongbae; Beyerlein, Michael

2017-01-01

Purpose: As technology-mediated communication improves, many organizations increasingly use new types of collaborative online tools to promote team-based learning and performance. The purpose of this study is to explore how virtual team leaders cope with process challenges in developing a context for team creativity. Design/methodology/approach:…

Building a Collaborative Online Literary Experience

ERIC Educational Resources Information Center

Essid, Joe; Wilde, Fran

2011-01-01

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

The development of a collaborative virtual environment for finite element simulation

NASA Astrophysics Data System (ADS)

Abdul-Jalil, Mohamad Kasim

Communication between geographically distributed designers has been a major hurdle in traditional engineering design. Conventional methods of communication, such as video conferencing, telephone, and email, are less efficient especially when dealing with complex design models. Complex shapes, intricate features and hidden parts are often difficult to describe verbally or even using traditional 2-D or 3-D visual representations. Virtual Reality (VR) and Internet technologies have provided a substantial potential to bridge the present communication barrier. VR technology allows designers to immerse themselves in a virtual environment to view and manipulate this model just as in real-life. Fast Internet connectivity has enabled fast data transfer between remote locations. Although various collaborative virtual environment (CVE) systems have been developed in the past decade, they are limited to high-end technology that is not accessible to typical designers. The objective of this dissertation is to discover and develop a new approach to increase the efficiency of the design process, particularly for large-scale applications wherein participants are geographically distributed. A multi-platform and easily accessible collaborative virtual environment (CVRoom), is developed to accomplish the stated research objective. Geographically dispersed designers can meet in a single shared virtual environment to discuss issues pertaining to the engineering design process and to make trade-off decisions more quickly than before, thereby speeding the entire process. This 'faster' design process will be achieved through the development of capabilities to better enable the multidisciplinary and modeling the trade-off decisions that are so critical before launching into a formal detailed design. The features of the environment developed as a result of this research include the ability to view design models, use voice interaction, and to link engineering analysis modules (such as Finite Element Analysis module, such as is demonstrated in this work). One of the major issues in developing a CVE system for engineering design purposes is to obtain any pertinent simulation results in real-time. This is critical so that the designers can make decisions based on these results quickly. For example, in a finite element analysis, if a design model is changed or perturbed, the analysis results must be obtained in real-time or near real-time to make the virtual meeting environment realistic. In this research, the finite difference-based Design Sensitivity Analysis (DSA) approach is employed to approximate structural responses (i.e. stress, displacement, etc), so as to demonstrate the applicability of CVRoom for engineering design trade-offs. This DSA approach provides for fast approximation and is well-suited for the virtual meeting environment where fast response time is required. The DSA-based approach is tested on several example test problems to show its applicability and limitations. This dissertation demonstrates that an increase in efficiency and reduction of time required for a complex design processing can be accomplished using the approach developed in this dissertation research. Several implementations of CVRoom by students working on common design tasks were investigated. All participants confirmed the preference of using the collaborative virtual environment developed in this dissertation work (CVRoom) over other modes of interactions. It is proposed here that CVRoom is representative of the type of collaborative virtual environment that will be used by most designers in the future to reduce the time required in a design cycle and thereby reduce the associated cost.

A Queue Simulation Tool for a High Performance Scientific Computing Center

NASA Technical Reports Server (NTRS)

Spear, Carrie; McGalliard, James

2007-01-01

The NASA Center for Computational Sciences (NCCS) at the Goddard Space Flight Center provides high performance highly parallel processors, mass storage, and supporting infrastructure to a community of computational Earth and space scientists. Long running (days) and highly parallel (hundreds of CPUs) jobs are common in the workload. NCCS management structures batch queues and allocates resources to optimize system use and prioritize workloads. NCCS technical staff use a locally developed discrete event simulation tool to model the impacts of evolving workloads, potential system upgrades, alternative queue structures and resource allocation policies.

Optimal and Approximately Optimal Control Policies for Queues in Heavy Traffic,

DTIC Science & Technology

1987-03-01

optimal and ’nearly optimal’ control problems for the open queueing networks in heavy traffic of the type dealt with in the fundamental papers of Reiman ...then the covariance is precisely that obtained by Reiman [1] (with a different notation used there). It is evident from (4.4) and the cited...wU’ ’U, d A K . " -50- References [1] M.I. Reiman , "Open queueing networks in heavy traffic", Math. of Operations Research, 9, 1984, p. 441-458. [2] J

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

NASA Astrophysics Data System (ADS)

Zhan, Yihong; Bai, Yu; Liu, Ziheng

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

Virtual Collaborative Environments for System of Systems Engineering and Applications for ISAT

NASA Technical Reports Server (NTRS)

Dryer, David A.

2002-01-01

This paper describes an system of systems or metasystems approach and models developed to help prepare engineering organizations for distributed engineering environments. These changes in engineering enterprises include competition in increasingly global environments; new partnering opportunities caused by advances in information and communication technologies, and virtual collaboration issues associated with dispersed teams. To help address challenges and needs in this environment, a framework is proposed that can be customized and adapted for NASA to assist in improved engineering activities conducted in distributed, enhanced engineering environments. The approach is designed to prepare engineers for such distributed collaborative environments by learning and applying e-engineering methods and tools to a real-world engineering development scenario. The approach consists of two phases: an e-engineering basics phase and e-engineering application phase. The e-engineering basics phase addresses skills required for e-engineering. The e-engineering application phase applies these skills in a distributed collaborative environment to system development projects.

Multithreaded Stochastic PDES for Reactions and Diffusions in Neurons.

PubMed

Lin, Zhongwei; Tropper, Carl; Mcdougal, Robert A; Patoary, Mohammand Nazrul Ishlam; Lytton, William W; Yao, Yiping; Hines, Michael L

2017-07-01

Cells exhibit stochastic behavior when the number of molecules is small. Hence a stochastic reaction-diffusion simulator capable of working at scale can provide a more accurate view of molecular dynamics within the cell. This paper describes a parallel discrete event simulator, Neuron Time Warp-Multi Thread (NTW-MT), developed for the simulation of reaction diffusion models of neurons. To the best of our knowledge, this is the first parallel discrete event simulator oriented towards stochastic simulation of chemical reactions in a neuron. The simulator was developed as part of the NEURON project. NTW-MT is optimistic and thread-based, which attempts to capitalize on multi-core architectures used in high performance machines. It makes use of a multi-level queue for the pending event set and a single roll-back message in place of individual anti-messages to disperse contention and decrease the overhead of processing rollbacks. Global Virtual Time is computed asynchronously both within and among processes to get rid of the overhead for synchronizing threads. Memory usage is managed in order to avoid locking and unlocking when allocating and de-allocating memory and to maximize cache locality. We verified our simulator on a calcium buffer model. We examined its performance on a calcium wave model, comparing it to the performance of a process based optimistic simulator and a threaded simulator which uses a single priority queue for each thread. Our multi-threaded simulator is shown to achieve superior performance to these simulators. Finally, we demonstrated the scalability of our simulator on a larger CICR model and a more detailed CICR model.

Virtual Organizations: An Overview

NASA Astrophysics Data System (ADS)

Nami, Mohammad Reza

The need to remain competitive in the open market forces companies to concentrate on their core competencies while searching for alliances when additional skills or resources are needed to fulfill business opportunities. The changing business situation of companies and customer needs have motivated researchers to introduce Virtual Organization (VO) idea. A Virtual Organization is always a form of partnership and managing partners and handling partnerships are crucial. Virtual organizations are defined as a temporary collection of enterprises that cooperate and share resources, knowledge, and competencies to better respond to business opportunities. This paper presents base concepts of virtual organizations including properties, management concepts, operational concepts, and main issues in collaboration such as security and authentication.

Development of traffic control and queue management procedures for oversaturated arterials

DOT National Transportation Integrated Search

1997-01-01

The formulation and solution of a new algorithm for queue management and coordination of traffic signals along oversaturated arterials are presented. Existing traffic-control and signal-coordination algorithms deal only with undersaturated steady-sta...

Report on dynamic speed harmonization and queue warning algorithm design.

DOT National Transportation Integrated Search

2014-02-01

This report provides a detailed description of the algorithms that will be used to generate harmonized recommended speeds and queue warning information in the proposed Intelligent Network Flow Optimization (INFLO) prototype. This document describes t...

Estimating the waiting time of multi-priority emergency patients with downstream blocking.

PubMed

Lin, Di; Patrick, Jonathan; Labeau, Fabrice

2014-03-01

To characterize the coupling effect between patient flow to access the emergency department (ED) and that to access the inpatient unit (IU), we develop a model with two connected queues: one upstream queue for the patient flow to access the ED and one downstream queue for the patient flow to access the IU. Building on this patient flow model, we employ queueing theory to estimate the average waiting time across patients. Using priority specific wait time targets, we further estimate the necessary number of ED and IU resources. Finally, we investigate how an alternative way of accessing ED (Fast Track) impacts the average waiting time of patients as well as the necessary number of ED/IU resources. This model as well as the analysis on patient flow can help the designer or manager of a hospital make decisions on the allocation of ED/IU resources in a hospital.

Paying for Express Checkout: Competition and Price Discrimination in Multi-Server Queuing Systems

PubMed Central

Deck, Cary; Kimbrough, Erik O.; Mongrain, Steeve

2014-01-01

We model competition between two firms selling identical goods to customers who arrive in the market stochastically. Shoppers choose where to purchase based upon both price and the time cost associated with waiting for service. One seller provides two separate queues, each with its own server, while the other seller has a single queue and server. We explore the market impact of the multi-server seller engaging in waiting cost-based-price discrimination by charging a premium for express checkout. Specifically, we analyze this situation computationally and through the use of controlled laboratory experiments. We find that this form of price discrimination is harmful to sellers and beneficial to consumers. When the two-queue seller offers express checkout for impatient customers, the single queue seller focuses on the patient shoppers thereby driving down prices and profits while increasing consumer surplus. PMID:24667809

Job Scheduling Under the Portable Batch System

NASA Technical Reports Server (NTRS)

Henderson, Robert L.; Woodrow, Thomas S. (Technical Monitor)

1995-01-01

The typical batch queuing system schedules jobs for execution by a set of queue controls. The controls determine from which queues jobs may be selected. Within the queue, jobs are ordered first-in, first-run. This limits the set of scheduling policies available to a site. The Portable Batch System removes this limitation by providing an external scheduling module. This separate program has full knowledge of the available queued jobs, running jobs, and system resource usage. Sites are able to implement any policy expressible in one of several procedural language. Policies may range from "bet fit" to "fair share" to purely political. Scheduling decisions can be made over the full set of jobs regardless of queue or order. The scheduling policy can be changed to fit a wide variety of computing environments and scheduling goals. This is demonstrated by the use of PBS on an IBM SP-2 system at NASA Ames.

Synchronized flow in oversaturated city traffic.

PubMed

Kerner, Boris S; Klenov, Sergey L; Hermanns, Gerhard; Hemmerle, Peter; Rehborn, Hubert; Schreckenberg, Michael

2013-11-01

Based on numerical simulations with a stochastic three-phase traffic flow model, we reveal that moving queues (moving jams) in oversaturated city traffic dissolve at some distance upstream of the traffic signal while transforming into synchronized flow. It is found that, as in highway traffic [Kerner, Phys. Rev. E 85, 036110 (2012)], such a jam-absorption effect in city traffic is explained by a strong driver's speed adaptation: Time headways (space gaps) between vehicles increase upstream of a moving queue (moving jam), resulting in moving queue dissolution. It turns out that at given traffic signal parameters, the stronger the speed adaptation effect, the shorter the mean distance between the signal location and the road location at which moving queues dissolve fully and oversaturated traffic consists of synchronized flow only. A comparison of the synchronized flow in city traffic found in this Brief Report with synchronized flow in highway traffic is made.

Paying for express checkout: competition and price discrimination in multi-server queuing systems.

PubMed

Deck, Cary; Kimbrough, Erik O; Mongrain, Steeve

2014-01-01

We model competition between two firms selling identical goods to customers who arrive in the market stochastically. Shoppers choose where to purchase based upon both price and the time cost associated with waiting for service. One seller provides two separate queues, each with its own server, while the other seller has a single queue and server. We explore the market impact of the multi-server seller engaging in waiting cost-based-price discrimination by charging a premium for express checkout. Specifically, we analyze this situation computationally and through the use of controlled laboratory experiments. We find that this form of price discrimination is harmful to sellers and beneficial to consumers. When the two-queue seller offers express checkout for impatient customers, the single queue seller focuses on the patient shoppers thereby driving down prices and profits while increasing consumer surplus.

Parallel discrete-event simulation of FCFS stochastic queueing networks

NASA Technical Reports Server (NTRS)

Nicol, David M.

1988-01-01

Physical systems are inherently parallel. Intuition suggests that simulations of these systems may be amenable to parallel execution. The parallel execution of a discrete-event simulation requires careful synchronization of processes in order to ensure the execution's correctness; this synchronization can degrade performance. Largely negative results were recently reported in a study which used a well-known synchronization method on queueing network simulations. Discussed here is a synchronization method (appointments), which has proven itself to be effective on simulations of FCFS queueing networks. The key concept behind appointments is the provision of lookahead. Lookahead is a prediction on a processor's future behavior, based on an analysis of the processor's simulation state. It is shown how lookahead can be computed for FCFS queueing network simulations, give performance data that demonstrates the method's effectiveness under moderate to heavy loads, and discuss performance tradeoffs between the quality of lookahead, and the cost of computing lookahead.

Synchronized flow in oversaturated city traffic

NASA Astrophysics Data System (ADS)

Kerner, Boris S.; Klenov, Sergey L.; Hermanns, Gerhard; Hemmerle, Peter; Rehborn, Hubert; Schreckenberg, Michael

2013-11-01

Based on numerical simulations with a stochastic three-phase traffic flow model, we reveal that moving queues (moving jams) in oversaturated city traffic dissolve at some distance upstream of the traffic signal while transforming into synchronized flow. It is found that, as in highway traffic [Kerner, Phys. Rev. EPLEEE81539-375510.1103/PhysRevE.85.036110 85, 036110 (2012)], such a jam-absorption effect in city traffic is explained by a strong driver's speed adaptation: Time headways (space gaps) between vehicles increase upstream of a moving queue (moving jam), resulting in moving queue dissolution. It turns out that at given traffic signal parameters, the stronger the speed adaptation effect, the shorter the mean distance between the signal location and the road location at which moving queues dissolve fully and oversaturated traffic consists of synchronized flow only. A comparison of the synchronized flow in city traffic found in this Brief Report with synchronized flow in highway traffic is made.

Scripted Collaboration in Serious Gaming for Complex Learning: Effects of Multiple Perspectives when Acquiring Water Management Skills

ERIC Educational Resources Information Center

Hummel, Hans G. K.; van Houcke, Jasper; Nadolski, Rob J.; van der Hiele, Tony; Kurvers, Hub; Lohr, Ansje

2011-01-01

This paper examines how learning outcomes from playing serious games can be enhanced by including scripted collaboration in the game play. We compared the quality of advisory reports, that students in the domain of water management had to draw up for an authentic case problem, both before and after collaborating on the problem with (virtual) peer…

Framework for Deploying a Virtualized Computing Environment for Collaborative and Secure Data Analytics

PubMed Central

Meyer, Adrian; Green, Laura; Faulk, Ciearro; Galla, Stephen; Meyer, Anne-Marie

2016-01-01

Introduction: Large amounts of health data generated by a wide range of health care applications across a variety of systems have the potential to offer valuable insight into populations and health care systems, but robust and secure computing and analytic systems are required to leverage this information. Framework: We discuss our experiences deploying a Secure Data Analysis Platform (SeDAP), and provide a framework to plan, build and deploy a virtual desktop infrastructure (VDI) to enable innovation, collaboration and operate within academic funding structures. It outlines 6 core components: Security, Ease of Access, Performance, Cost, Tools, and Training. Conclusion: A platform like SeDAP is not simply successful through technical excellence and performance. It’s adoption is dependent on a collaborative environment where researchers and users plan and evaluate the requirements of all aspects. PMID:27683665

Improvements in multimedia data buffering using master/slave architecture

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

Sheikh, S.; Ganesan, R.

1996-12-31

Advances in the networking technology and multimedia technology has necessitated a need for multimedia servers to be robust and reliable. Existing solutions have direct limitations such as I/O bottleneck and reliability of data retrieval. The system can store the stream of incoming data if enough buffer space is available or the mass storage is clearing the buffer data faster than queue input. A single buffer queue is not sufficient to handle the large frames. Queue sizes are normally several megabytes in length and thus in turn will introduce a state of overflow. The system should also keep track of themore » rewind, fast forwarding, and pause requests, otherwise queue management will become intricate. In this paper, we present a master/slave (server that is designated to monitor the workflow of the complete system. This server holds every other information of slaves by maintaining a dynamic table. It also controls the workload on each of the systems by redistributing request to others or handles the request by itself) approach which will overcome the limitations of today`s storage and also satisfy tomorrow`s storage needs. This approach will maintain the system reliability and yield faster response by using more storage units in parallel. A network of master/slave can handle many requests and synchronize them at all times. Using dedicated CPU and a common pool of queues we explain how queues can be controlled and buffer overflow can be avoided. We propose a layered approach to the buffering problem and provide a read-ahead solution to ensure continuous storage and retrieval of multimedia data.« less

Pathogen transfer through environment-host contact: an agent-based queueing theoretic framework.

PubMed

Chen, Shi; Lenhart, Suzanne; Day, Judy D; Lee, Chihoon; Dulin, Michael; Lanzas, Cristina

2017-11-02

Queueing theory studies the properties of waiting queues and has been applied to investigate direct host-to-host transmitted disease dynamics, but its potential in modelling environmentally transmitted pathogens has not been fully explored. In this study, we provide a flexible and customizable queueing theory modelling framework with three major subroutines to study the in-hospital contact processes between environments and hosts and potential nosocomial pathogen transfer, where environments are servers and hosts are customers. Two types of servers with different parameters but the same utilization are investigated. We consider various forms of transfer functions that map contact duration to the amount of pathogen transfer based on existing literature. We propose a case study of simulated in-hospital contact processes and apply stochastic queues to analyse the amount of pathogen transfer under different transfer functions, and assume that pathogen amount decreases during the inter-arrival time. Different host behaviour (feedback and non-feedback) as well as initial pathogen distribution (whether in environment and/or in hosts) are also considered and simulated. We assess pathogen transfer and circulation under these various conditions and highlight the importance of the nonlinear interactions among contact processes, transfer functions and pathogen demography during the contact process. Our modelling framework can be readily extended to more complicated queueing networks to simulate more realistic situations by adjusting parameters such as the number and type of servers and customers, and adding extra subroutines. © The authors 2017. Published by Oxford University Press on behalf of the Institute of Mathematics and its Applications. All rights reserved.

Best practices for virtual participation in meetings: Experiences from synthesis centers

USGS Publications Warehouse

Hampton, Stephanie E.; Halpern, Benjamin S.; Winter, Marten; Balch, Jennifer K.; Parker, John N.; Baron, Jill S.; Palmer, Margaret; Schildhauer, Mark P.; Bishop, Pamela; Meagher, Thomas R.; Specht, Alison

2017-01-01

The earth environment is a complex system, in which collaborative scientific approaches can provide major benefits by bringing together diverse perspectives, methods, and data, to achieve robust, synthetic understanding (Fig. 1). Face-to-face scientific meetings remain extremely valuable because of the opportunity to build deep mutual trust and understanding, and develop new collaborations and sometimes even lifelong friendships (Alberts 2013, Cooke and Hilton 2015). However, it has been argued that ecologists should be particularly sensitive to the environmental footprint of travel (Fox et al. 2009); such concerns, along with the time demands for travel, particularly for multi-national working groups, provide strong motivation for exploring virtual attendance. While not replacing the richness of face-to-face interactions entirely, it is now feasible to virtually participate in meetings through services that allow video, audio, and file sharing, as well as other Web-enabled communication.

Computer-mediated interdisciplinary teams: theory and reality.

PubMed

Vroman, Kerryellen; Kovacich, Joann

2002-05-01

The benefit of experience, tempered with the wisdom of hindsight and 5 years of text-based, asynchronous, computer-mediated, interdisciplinary team communications, provides the energy, insights and data shared in this article. Through the theoretical lens of group dynamics and the epistemology of interdisciplinary teaming, we analyze the interactions of a virtual interdisciplinary team to provide an understanding and appreciation of collaborative interdisciplinary communication in the context of interactive technologies. Whilst interactive technologies may require new patterns of language similar to that of learning a foreign language, what is communicated in the interdisciplinary team process does not change. Most important is the recognition that virtual teams, similar to their face-to-face counterparts, undergo the same challenges of interdisciplinary teaming and group developmental processes of formation: forming, storming, norming, performing, and transforming. After examining these dynamics of communication and collaboration in the context of the virtual team, the article concludes with guidelines facilitating interdisciplinary team computer-mediated communication.

ASCOT: A Collaborative Platform for the Virtual Observatory

NASA Astrophysics Data System (ADS)

Marcos, D.; Connolly, A. J.; Krughoff, K. S.; Smith, I.; Wallace, S. C.

2012-09-01

The digital networks are changing the way that knowledge is created, structured, curated, consumed, archived and referenced. Projects like Wikipedia, Github or Galaxy Zoo have shown the potential of online communities to develop and communicate ideas. ASCOT is a web based framework that facilitates collaboration among astronomers providing a simple way to share, explore, interact and analyze large amounts of data from a broad range of sources available trough the Virtual Observatories (VO). Designed with a strong emphasis on usability, ASCOT takes advantage of the latest generation of web standards and cloud technologies to implement an extendable and customizable stack of web tools and services.

The Virtual Campus: Trends for Higher Education and Training.

ERIC Educational Resources Information Center

Verdejo, Felisa, Ed.; Davies, Gordon, Ed.

This volume presents 27 papers given at a conference on the virtual campus. Papers are grouped into five parts: (1) keynote presentations, (2) global approaches, (3) evaluation studies, (4) collaborative learning and group activities, and (5) web tools and web applications. The papers are: "New Wine and Old Bottles? Tele-learning, Telematics,…

Virtual Seminars and Their Impact on the Role of the Teaching Staff.

ERIC Educational Resources Information Center

Jelfs, Anne; Colbourn, Chris

2002-01-01

Discusses current demands on teaching staff in United Kingdom higher education and the impact these demands have when teaching through electronic resources. Topics include collaborative small-group learning; transferable skills; nontraditional students; the role of the tutor; social theories of education; and a case study of virtual seminars for…

The Best of All Worlds: Immersive Interfaces for Art Education in Virtual and Real World Teaching and Learning Environments

ERIC Educational Resources Information Center

Grenfell, Janette

2013-01-01

Selected ubiquitous technologies encourage collaborative participation between higher education students and educators within a virtual socially networked e-learning landscape. Multiple modes of teaching and learning, ranging from real world experiences, to text and digital images accessed within the Deakin studies online learning management…

Wiki Technology: A Virtual, Cooperative Learning Tool Used to Enhance Student Learning

ERIC Educational Resources Information Center

Barrera, Alessandra L.

2015-01-01

This study demonstrates the use of wiki technology (an editable webpage environment) to provide a virtual, asynchronous collaborative-learning environment for students for the purpose of working on course-content-focused study-guide questions. To analyze the effectiveness of this course tool, students' responses to various qualitative and…

Learning as "Knowing": Towards Retaining and Visualizing Use in Virtual Settings

ERIC Educational Resources Information Center

Akoumianakis, Demosthenes

2011-01-01

The paper elaborates on the assumption that in modern organisations collaborative learning is an enacted capability that is more about "acting" and co-engaging in shared practices. In such settings, virtual learning can be conceived as an emergent knowledge process with no pre-determined outcomes that occupies multiple online and offline…

We'll Take It from Here: Further Developments We'd Like To See in Virtual Reference Software.

ERIC Educational Resources Information Center

Coffman, Steven

2001-01-01

Discussion of virtual reference services focuses on software that is currently available and further developments that are needed. Topics include co-browsing and collaboration capabilities; communications technology, including chat technology and voice over Internet protocol (VoIP); networked reference services; and online reference collections…

Negotiation for Action: English Language Learning in Game-Based Virtual Worlds

ERIC Educational Resources Information Center

Zheng, Dongping; Young, Michael F.; Wagner, Manuela Maria; Brewer, Robert A.

2009-01-01

This study analyzes the user chat logs and other artifacts of a virtual world, "Quest Atlantis" (QA), and proposes the concept of Negotiation for Action (NfA) to explain how interaction, specifically, avatar-embodied collaboration between native English speakers and nonnative English speakers, provided resources for English language acquisition.…

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

ERIC Educational Resources Information Center

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

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

Free the Sheep: Improvised Song and Performance in and around a Minecraft Community

ERIC Educational Resources Information Center

Bailey, Chris

2016-01-01

Recent work around the use of virtual world video games in educational contexts has conceptualised literacies as communal processes, whilst considering complex notions of collaboration through participants' multiplicity of presence in hybrid virtual/physical locations. However, further research is necessary in order to help us understand how the…

Leadership in MMOGs: A Field of Research on Virtual Teams

ERIC Educational Resources Information Center

Mysirlaki, Sofia; Paraskeva, Fotini

2012-01-01

As our need for collaboration constantly grows, new tools have emerged to connect us in social networks, supporting the development of online communities, such as online games and virtual worlds. MMOGs (Massively Multiplayer Online Games) and MMORPGs (Massively Multiplayer Online Role-Playing Games) are complex systems, in which players are…

Belle2VR: A Virtual-Reality Visualization of Subatomic Particle Physics in the Belle II Experiment.

PubMed

Duer, Zach; Piilonen, Leo; Glasson, George

2018-05-01

Belle2VR is an interactive virtual-reality visualization of subatomic particle physics, designed by an interdisciplinary team as an educational tool for learning about and exploring subatomic particle collisions. This article describes the tool, discusses visualization design decisions, and outlines our process for collaborative development.

Enhancing Mathematical Communication for Virtual Math Teams

ERIC Educational Resources Information Center

Stahl, Gerry; Çakir, Murat Perit; Weimar, Stephen; Weusijana, Baba Kofi; Ou, Jimmy Xiantong

2010-01-01

The Math Forum is an online resource center for pre-algebra, algebra, geometry and pre-calculus. Its Virtual Math Teams (VMT) service provides an integrated web-based environment for small teams of people to discuss math and to work collaboratively on math problems or explore interesting mathematical micro-worlds together. The VMT Project studies…

Proposal for Implementing Multi-User Database (MUD) Technology in an Academic Library.

ERIC Educational Resources Information Center

Filby, A. M. Iliana

1996-01-01

Explores the use of MOO (multi-user object oriented) virtual environments in academic libraries to enhance reference services. Highlights include the development of multi-user database (MUD) technology from gaming to non-recreational settings; programming issues; collaborative MOOs; MOOs as distinguished from other types of virtual reality; audio…

Collaborative Learning in Architectural Education: Benefits of Combining Conventional Studio, Virtual Design Studio and Live Projects

ERIC Educational Resources Information Center

Rodriguez, Carolina; Hudson, Roland; Niblock, Chantelle

2018-01-01

Combinations of Conventional Studio and Virtual Design Studio (VDS) have created valuable learning environments that take advantage of different instruments of communication and interaction. However, past experiences have reported limitations in regards to student engagement and motivation, especially when the studio projects encourage abstraction…

"The Evolution of e-Learning in the Context of 3D Virtual Worlds"

ERIC Educational Resources Information Center

Kotsilieris, Theodore; Dimopoulou, Nikoletta

2013-01-01

Information and Communication Technologies (ICT) offer new approaches towards knowledge acquisition and collaboration through distance learning processes. Web-based Learning Management Systems (LMS) have transformed the way that education is conducted nowadays. At the same time, the adoption of Virtual Worlds in the educational process is of great…

A Theoretical Cybernetic Macro-Script to Articulate Collaborative Interactions of Cyber Entities in Virtual Worlds

ERIC Educational Resources Information Center

Pellas, Nikolaos

2014-01-01

Nowadays, the dissemination and exploitation of three-dimensional (3D) multi-user virtual worlds in higher education have been disclosed from their widespread acceptance as candidate learning platforms. However, it is still lacking a theoretical cybernetic macro-script to elaborate the coordination of multiple complex interactions among…

Measuring Flow Experience in an Immersive Virtual Environment for Collaborative Learning

ERIC Educational Resources Information Center

van Schaik, P.; Martin, S.; Vallance, M.

2012-01-01

In contexts other than immersive virtual environments, theoretical and empirical work has identified flow experience as a major factor in learning and human-computer interaction. Flow is defined as a "holistic sensation that people feel when they act with total involvement". We applied the concept of flow to modeling the experience of…

Creation of a virtual triage exercise: an interprofessional communication strategy.

PubMed

Farra, Sharon; Nicely, Stephanie; Hodgson, Eric

2014-10-01

Virtual reality simulation as a teaching method is gaining increased acceptance and presence in institutions of higher learning. This study presents an innovative strategy using the interdisciplinary development of a nonimmersive virtual reality simulation to facilitate interprofessional communication. The purpose of this pilot project was to describe nursing students' attitudes related to interprofessional communication following the collaborative development of a disaster triage virtual reality simulation. Collaboration between and among professionals is integral in enhancing patient outcomes. In addition, ineffective communication is linked to detrimental patient outcomes, especially during times of high stress. Poor communication has been identified as the root cause of the majority of negative sentinel events occurring in hospitals. The simulation-development teaching model proved useful in fostering interprofessional communication and mastering course content. Mean scores on the KidSIM Attitudes Towards Teamwork in Training Undergoing Designed Educational Simulation survey demonstrated that nursing students, after simulation experience,had agreement to strong agreement inall areas surveyed including interprofessional education, communication, roles and responsibilities of team members, and situational awareness. The findings indicate that students value interprofessional teamwork and the opportunity to work with other disciplines.

The Virtual Observatory as Critical Scientific Cyber Infrastructure.

NASA Astrophysics Data System (ADS)

Fox, P.

2006-12-01

Virtual Observatories can provide access to vast stores of scientific data: observations and models as well as services to analyze, visualize and assimilate multiple data sources. As these electronic resource become widely used, there is potential to improve the efficiency, interoperability, collaborative potential, and impact of a wide range of interdisciplinary scientific research. In addition, we know that as the diversity of collaborative science and volume of accompanying data and data generators/consumers grows so do the challenges. In order for Virtual Observatories to realize their potential and become indispensible infrastructure, social, political and technical challenges need to be addressed concerning (at least) roles and responsibilities, data and services policies, representations and interoperability of services, data search, access, and usability. In this presentation, we discuss several concepts and instances of the Virtual Observatory and related projects that may, and may not, be meeting the abovementioned challanges. We also argue that science driven needs and architecture development are critical in the development of sustainable (and thus agile) cyberinfrastructure. Finally we some present or emerging candidate technologies and organizational constructs that will need to be pursued.

Modeling Human Supervisory Control in Heterogeneous Unmanned Vehicle Systems

DTIC Science & Technology

2009-02-01

events through a queue, nominally due to another queue having reached its capacity limitation (Balsamo, Persone, & Onvural, 2001; Onvural, 1990; Perros ...Communication and Coordination, Athens, Greece. Perros , H. G. (1984). Queuing Networks with Blocking: A Bibliography. ACM Sigmetrics, Performance Evaluation

A new traffic control design method for large networks with signalized intersections

NASA Technical Reports Server (NTRS)

Leininger, G. G.; Colony, D. C.; Seldner, K.

1979-01-01

The paper presents a traffic control design technique for application to large traffic networks with signalized intersections. It is shown that the design method adopts a macroscopic viewpoint to establish a new traffic modelling procedure in which vehicle platoons are subdivided into main stream queues and turning queues. Optimization of the signal splits minimizes queue lengths in the steady state condition and improves traffic flow conditions, from the viewpoint of the traveling public. Finally, an application of the design method to a traffic network with thirty-three signalized intersections is used to demonstrate the effectiveness of the proposed technique.

Wiki Based Collaborative Learning in Interuniversity Scenarios

ERIC Educational Resources Information Center

Katzlinger, Elisabeth; Herzog, Michael A.

2014-01-01

In business education advanced collaboration skills and media literacy are important for surviving in a globalized business where virtual communication between enterprises is part of the day-by-day business. To transform these global working situations into higher education, a learning scenario between two universities in Germany and Austria was…

Analysing a Web-Based E-Commerce Learning Community: A Case Study in Brazil.

ERIC Educational Resources Information Center

Joia, Luiz Antonio

2002-01-01

Demonstrates the use of a Web-based participative virtual learning environment for graduate students in Brazil enrolled in an electronic commerce course in a Masters in Business Administration program. Discusses learning communities; computer-supported collaborative work and collaborative learning; influences on student participation; the role of…

Widget, Widget on the Wall, Am I Performing Well at All?

ERIC Educational Resources Information Center

Scheffel, Maren; Drachsler, Hendrik; de Kraker, Joop

2017-01-01

In collaborative learning environments, students work together on assignments in virtual teams and depend on each other's contribution to achieve their learning objectives. The online learning environment, however, may not only facilitate but also hamper group communication, coordination, and collaboration. Group awareness widgets that visualize…

Collaborative Learning: Theoretical Foundations and Applicable Strategies to University

ERIC Educational Resources Information Center

Roselli, Nestor D.

2016-01-01

Collaborative learning is a construct that identifies a current strong field, both in face-to-face and virtual education. Firstly, three converging theoretical sources are analyzed: socio-cognitive conflict theory, intersubjectivity theory and distributed cognition theory. Secondly, a model of strategies that can be implemented by teachers to…

Studying the Effectiveness of Multi-User Immersive Environments for Collaborative Evaluation Tasks

ERIC Educational Resources Information Center

Lorenzo, Carlos-Miguel; Sicilia, Miguel Angel; Sanchez, Salvador

2012-01-01

Massively Multiuser On-line Learning (MMOL) Platforms, often called "virtual learning worlds", constitute a still unexplored context for communication-enhanced learning, where synchronous communication skills in an explicit social setting enhance the potential of effective collaboration. In this paper, we report on an experimental study of…

Virtual Team Communication and Collaboration in Army and Corporate Applications

DTIC Science & Technology

2009-06-12

Sharmila Pixy Ferri , 49-75. Hershey, PA: Idea Group Inc. Brown, Frederic J. 2006. Building high-performing commander leader teams: Intensive collaboration...Process, Technologies and Practice eds. Susan Hayes Godar and Sharmila Pixy Ferri , 49- 75. Hershey, Pennsylvania: Idea Group Inc. DeMarie, Samuel M. 2000

From Real Challenges to Virtual Reality: Realizing Your Collection through Digital Partnership

ERIC Educational Resources Information Center

Johnson, Jennifer; Mandity, Edward

2010-01-01

In fall 2008, a collaborative partnership was formed between the libraries of two Indiana universities--Marian College's (now Marian University) Mother Theresa Hackelmeier Memorial Library, and the University Library at Indiana University-Purdue University Indianapolis (IUPUI). The authors discuss the digital nature of this collaboration, which…

InnoTube: A Video-Based Connection Tool Supporting Collaborative Innovation

ERIC Educational Resources Information Center

Angehrn, Albert A.; Luccini, Angelo Marco; Maxwell, Katrina

2009-01-01

Innovation is a key driver of organizational renewal and success. However, providing the right environment for innovative ideas to emerge and develop is not easy. This is further complicated by the fact that the professional environment is increasingly virtual as globally dispersed organizational and inter-organizational teams collaborate on…

Crowdsourcing Scientific Work: A Comparative Study of Technologies, Processes, and Outcomes in Citizen Science

ERIC Educational Resources Information Center

Wiggins, Andrea

2012-01-01

Citizen science projects involve the public with scientists in collaborative research. Information and communication technologies for citizen science can enable massive virtual collaborations based on voluntary contributions by diverse participants. As the popularity of citizen science increases, scientists need a more thorough understanding of…

Collaborative Wikipedia Projects in the Virtual Classroom

ERIC Educational Resources Information Center

Kenny, A. J.; Wolt, J. D.; Hurd, H. S.

2013-01-01

Wikipedia is a web-based, free-content encyclopedia that is openly editable and, thus, provides a unique platform for collaborations. Wikipedia projects are increasingly being integrated into upper-level courses across the country to explore advanced concepts, communicate science, and provide high-quality information to the public. Here we outline…

Learning Spaces and Collaborative Work: Barriers or Supports?

ERIC Educational Resources Information Center

King, Hayley

2016-01-01

Drawing on 18 months of fieldwork, this article discusses the use of physical, virtual and social space to support collaborative work in translator education programs. The study adopted a contrastive ethnography approach that incorporated single- and multiple-case design rationales for site selection. Extended observation, informal chats and…

EVA: Collaborative Distributed Learning Environment Based in Agents.

ERIC Educational Resources Information Center

Sheremetov, Leonid; Tellez, Rolando Quintero

In this paper, a Web-based learning environment developed within the project called Virtual Learning Spaces (EVA, in Spanish) is presented. The environment is composed of knowledge, collaboration, consulting, experimentation, and personal spaces as a collection of agents and conventional software components working over the knowledge domains. All…

EVA: An Interactive Web-Based Collaborative Learning Environment

ERIC Educational Resources Information Center

Sheremetov, Leonid; Arenas, Adolfo Guzman

2002-01-01

In this paper, a Web-based learning environment developed within the project called Virtual Learning Spaces (EVA, in Spanish) is described. The environment is composed of knowledge, collaboration, consulting and experimentation spaces as a collection of agents and conventional software components working over the knowledge domains. All user…

SLA-based optimisation of virtualised resource for multi-tier web applications in cloud data centres

NASA Astrophysics Data System (ADS)

Bi, Jing; Yuan, Haitao; Tie, Ming; Tan, Wei

2015-10-01

Dynamic virtualised resource allocation is the key to quality of service assurance for multi-tier web application services in cloud data centre. In this paper, we develop a self-management architecture of cloud data centres with virtualisation mechanism for multi-tier web application services. Based on this architecture, we establish a flexible hybrid queueing model to determine the amount of virtual machines for each tier of virtualised application service environments. Besides, we propose a non-linear constrained optimisation problem with restrictions defined in service level agreement. Furthermore, we develop a heuristic mixed optimisation algorithm to maximise the profit of cloud infrastructure providers, and to meet performance requirements from different clients as well. Finally, we compare the effectiveness of our dynamic allocation strategy with two other allocation strategies. The simulation results show that the proposed resource allocation method is efficient in improving the overall performance and reducing the resource energy cost.

The University of Hawaii NEO Follow-Up Program

NASA Astrophysics Data System (ADS)

Fohring, Dora; Tholen, David J.; Claytor, Zach; Ramanjooloo, Yudish; Hung, Denise; Aspin, Colin

2017-10-01

At the University of Hawaii, we carry out NEO follow-up observations for orbital refinement. We regularly observe eight nights a month using the University of Hawaii 88-inch (UH88) telescope and utilise Canada-France-Hawaii Telescope queue time for recovery of targets with large ephemeris uncertainties. Our focus is follow-up of Virtual Impactors and faint asteroids with magnitudes V>21. The combination of excellent atmospheric conditions on Mauna Kea and long integration times allow us to observe asteroids as faint as V=25. Recent extensive improvements to our workhorse UH88 telescope have included renovations to the telescope exterior, software upgrades, and the commissioning of the new monolithic STA-1600 10K CCD. Recent observational highlights include astrometry of 2017 JB2 during its diurnal retrograde loop and photometric observations 2016 HO3 which was measured to have a synodic period of 27.90 minutes.

Virtual Queue in a Centralized Database Environment

NASA Astrophysics Data System (ADS)

Kar, Amitava; Pal, Dibyendu Kumar

2010-10-01

Today is the era of the Internet. Every matter whether it be a gather of knowledge or planning a holiday or booking of ticket etc everything can be obtained from the internet. This paper intends to calculate the different queuing measures when some booking or purchase is done through the internet subject to the limitations in the number of tickets or seats. It involves a lot of database activities like read and write. This paper takes care of the time involved in the requests of a service, taken as arrival and the time involved in providing the required information, taken as service and thereby tries to calculate the distribution of arrival and service and the various measures of the queuing. This paper considers the database as centralized database for the sake of simplicity as the alternating concept of distributed database would rather complicate the calculation.

State of the Art Review of Human-Human Collaboration Research: An Integrated, Multidisciplinary Perspective

DTIC Science & Technology

2002-10-31

NJ: Lawrence Erlbaum. Jamal, T. B. & Getz, D. (1995). Collaboration Theory and Community Tourism Planning. Annals of Tourism Planning...Surveys, 31. Jamal, T. B. & Getz, D. (1995). Collaboration Theory and Community Tourism Planning. Annals of Tourism Planning Research, 22 (1...granum/altdocs/dav_alt.htm. Jorn, L. A., Duin, A. H., & Wahlstrom, B. J. (1996). Designing and Managing Virtual Learning ommunities . IEEE

Proposing a Wiki-Based Technique for Collaborative Essay Writing (Propuesta de un modelo pedagógico para la escritura colaborativa de ensayos en un entorno virtual wiki)

ERIC Educational Resources Information Center

Ortiz Navarrete, Mabel; Ferreira Cabrera, Anita

2014-01-01

This paper aims at proposing a technique for students learning English as a foreign language when they collaboratively write an argumentative essay in a wiki environment. A wiki environment and collaborative work play an important role within the academic writing task. Nevertheless, an appropriate and systematic work assignment is required in…

The effectiveness of integration of virtual patients in a collaborative learning activity.

PubMed

Marei, Hesham F; Donkers, Jeroen; Van Merrienboer, Jeroen J G

2018-05-07

Virtual patients (VPs) have been recently integrated within different learning activities. To compare between the effect of using VPs in a collaborative learning activity and using VPs in an independent learning activity on students' knowledge acquisition, retention and transfer. For two different topics, respectively 82 and 76 dental students participated in teaching, learning and assessment sessions with VPs. Students from a female campus and from a male campus have been randomly assigned to condition (collaborative and independent), yielding four experimental groups. Each group received a lecture followed by a learning session using two VPs per topic. Students were administrated immediate and delayed written tests as well as transfer tests using two VPs to assess their knowledge in diagnosis and treatment. For the treatment items of the immediate and delayed written tests, females outperformed males in the collaborative VP group but not in the independent VP group. On the female campus, the use of VPs in a collaborative learning activity is more effective than its use as an independent learning activity in enhancing students' knowledge acquisition and retention. However, the collaborative use of VPs by itself is not enough to produce consistent results across different groups of students and attention should be given to all the factors that would affect students' interaction.

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

PubMed

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

2004-01-01

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

An Inverse MOOC Model: Small Virtual Field Geology Classes with Many Teachers (Invited)

NASA Astrophysics Data System (ADS)

De Paor, D. G.; Whitmeyer, S. J.; Bentley, C.

2013-12-01

In the Massive Open Online Courses (MOOCs) mode of instruction, one or a small group of collaborating instructors lecture online to a large (often extremely large) number of students. We are experimenting with an inverse concept: an online classroom in which a small group of collaborating students are taught by dozens of collaborating instructors. This experiment is part of a new NSF TUES Type 3 project titled 'Google Earth for Onsite and Distance Education (GEODE).' Among the goals of the project are the development of an online course called the 'Grand Tour.' We are inviting dozens of colleagues to record virtual field trips (VFTs) and upload them to Google Earth. Students enrolled in the course will be assigned to a small group and tasked with a research project--for example to write a report on foreland thrust belts. They will select a small subset of available VFTs to follow and will be scaffolded by virtual specimens, emergent cross sections, analytical simulations (virtual tricorders), and a game style environment. Instant feedback based on auto-logging will enable adaptive learning. The design is suited to both onsite and distance education and will facilitate access to iconic geologic sites around the world to persons with mobility constraints. We invite input from the community to help guide the design phase of this project. Prototypes of the above-listed learning resources have already been developed and are freely available at http://www.DigitalPlanet.org.

Technical report on prototype intelligent network flow optimization (INFLO) dynamic speed harmonization and queue warning.

DOT National Transportation Integrated Search

2015-06-01

This Technical Report on Prototype Intelligent Network Flow Optimization (INFLO) Dynamic Speed Harmonization and Queue Warning is the final report for the project. It describes the prototyping, acceptance testing and small-scale demonstration of the ...

Research into Queueing Network Theory.

DTIC Science & Technology

1977-09-01

and Zeigler, B. (1975) "Equilibrium properties of arbitrarily interconnected queueing netowrks ," Tech. Report 75-4, Computer and Communication...Associate. The project was extremely fortunate to secure the services of Dr. Wendel. Dr. Wendel was a project member for one month in the summer of

Identifying effects and applications of fixed and variable speed limits.

DOT National Transportation Integrated Search

2016-08-01

In Indiana, distracted driving and unexpected queues have led to an increase in the amount of back-of-queue crashes, particularly on approach to : work zones. This report presents new strategies for the assessment of both transportation safety and tr...

Real-time prediction of queues at signalized intersections to support eco-driving applications.

DOT National Transportation Integrated Search

2014-10-01

The overall objective of this research is to develop models for predicting queue lengths at signalized intersections based on : the data from probe vehicles. The time and space coordinates of the probe vehicles going through signalized intersections ...

Virtual Laboratories and Virtual Worlds

NASA Astrophysics Data System (ADS)

Hut, Piet

2008-05-01

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).

Virtual Sensor Web Architecture

NASA Astrophysics Data System (ADS)

Bose, P.; Zimdars, A.; Hurlburt, N.; Doug, S.

2006-12-01

NASA envisions the development of smart sensor webs, intelligent and integrated observation network that harness distributed sensing assets, their associated continuous and complex data sets, and predictive observation processing mechanisms for timely, collaborative hazard mitigation and enhanced science productivity and reliability. This paper presents Virtual Sensor Web Infrastructure for Collaborative Science (VSICS) Architecture for sustained coordination of (numerical and distributed) model-based processing, closed-loop resource allocation, and observation planning. VSICS's key ideas include i) rich descriptions of sensors as services based on semantic markup languages like OWL and SensorML; ii) service-oriented workflow composition and repair for simple and ensemble models; event-driven workflow execution based on event-based and distributed workflow management mechanisms; and iii) development of autonomous model interaction management capabilities providing closed-loop control of collection resources driven by competing targeted observation needs. We present results from initial work on collaborative science processing involving distributed services (COSEC framework) that is being extended to create VSICS.

SciEthics Interactive: Science and Ethics Learning in a Virtual Environment

ERIC Educational Resources Information Center

Nadolny, Larysa; Woolfrey, Joan; Pierlott, Matthew; Kahn, Seth

2013-01-01

Learning in immersive 3D environments allows students to collaborate, build, and interact with difficult course concepts. This case study examines the design and development of the TransGen Island within the SciEthics Interactive project, a National Science Foundation-funded, 3D virtual world emphasizing learning science content in the context of…

Preparing Graduate Students for Virtual World Simulations: Exploring the Potential of an Emerging Technology

ERIC Educational Resources Information Center

Hewitt, Anne M.; Spencer, Susan; Mirliss, Danielle; Twal, Riad

2009-01-01

Anne M. Hewitt, Susan Spencer, Danielle Mirliss, and Riad Twal report on a collaborative team initiative to create a virtual world emergency preparedness simulation that focuses on crisis and emergency risk communication (CERC). CERC is a key competency for students enrolled in Seton Hall University's (SHU) Master of Healthcare Administration…

Virtual Conferencing in Global Design Education: Dreams and Realities

ERIC Educational Resources Information Center

Moldenhauer, Judith A.

2010-01-01

The concept and use of the synchronous and asynchronous forms of virtual conferencing is central to the experience of global design education. Easy and ready access to people and information worldwide is at the heart of a paradigm shift in design practice and education, defined by collaboration and digital technology. The dream of smooth, global…

The Iterative Design of a Virtual Design Studio

ERIC Educational Resources Information Center

Blevis, Eli; Lim, Youn-kyung; Stolterman, Erik; Makice, Kevin

2008-01-01

In this article, the authors explain how they implemented Design eXchange as a shared collaborative online and physical space for design for their students. Their notion for Design eXchange favors a complex mix of key elements namely: (1) a virtual online studio; (2) a forum for review of all things related to design, especially design with the…

Virtual Office Hours Using a Tablet PC: E-lluminating Biochemistry in an Online Environment

ERIC Educational Resources Information Center

Kohorst, Kelly; Cox, James R.

2007-01-01

The availability of online collaboration software has provided new opportunities for instructors to interact with students outside the classroom. This report describes how Elluminate "Live!"[R], a particular conferencing software package, can be used with a tablet PC to conduct virtual office hours in a biochemistry course. The educational value…

Design and Implementation of a Student-Generated Virtual Museum in a Language Curriculum to Enhance Collaborative Multimodal Meaning-Making

ERIC Educational Resources Information Center

Ho, Caroline M. L.; Nelson, Mark Evan; Mueller-Wittig, Wolfgang

2011-01-01

This paper reports on a study, "MUSE", which involved Secondary (Grade 7) students in designing and constructing a virtual museum. It presents a description and evaluation of the design and implementation of the technologically-mediated intervention within a language curriculum that emphasizes multimodal meaning-making and expression.…

Investigating the Affective Learning in a 3D Virtual Learning Environment: The Case Study of the Chatterdale Mystery

ERIC Educational Resources Information Center

Molka-Danielsen, Judith; Hadjistassou, Stella; Messl-Egghart, Gerhilde

2016-01-01

This research is motivated by the emergence of virtual technologies and their potential as engaging pedagogical tools for facilitating comprehension, interactions and collaborations for learning; and in particular as applied to learning second languages (L2). This paper provides a descriptive analysis of a case study that examines affective…

Designing Interactive and Collaborative Learning Tasks in a 3-D Virtual Environment

ERIC Educational Resources Information Center

Berns, Anke; Palomo-Duarte, Manuel; Fernández, David Camacho

2012-01-01

The aim of our study is to explore several possibilities to use virtual worlds (VWs) and game-applications with learners of the A1 level (CEFR) of German as a foreign language. Our interest focuses especially on designing those learning tools which increase firstly, learner motivation towards online-learning and secondly, enhance autonomous…

Synchronous and Asynchronous E-Language Learning: A Case Study of Virtual University of Pakistan

ERIC Educational Resources Information Center

Perveen, Ayesha

2016-01-01

This case study evaluated the impact of synchronous and asynchronous E-Language Learning activities (ELL-ivities) in an E-Language Learning Environment (ELLE) at Virtual University of Pakistan. The purpose of the study was to assess e-language learning analytics based on the constructivist approach of collaborative construction of knowledge. The…

Exploring Arizona K-12 Virtual Educator Experiences and Perspectives Developing Collaborative Learning Communities

ERIC Educational Resources Information Center

Cross, Deborah Iyron

2015-01-01

Arizona Online Instruction (AOI) provided an instructional alternative to nearly fifty thousand K-12 students in Arizona during the 2012-2013 school year. Growth in online education underscores the importance of evolving the role of the K-12 virtual teacher as the human agent (Turvey, 2008) demonstrating social learning theory (Bandura, 1977) by…

EFL Learner Collaborative Interaction in Second Life

ERIC Educational Resources Information Center

Peterson, Mark

2012-01-01

This paper reports on the task-based interaction of English as a Foreign Language (EFL) learners in the 3D multiuser virtual environment (MUVE) Second Life. The discussion first explores research on the precursors of MUVEs, text-based 2D virtual worlds known as MOOs. This is followed by an examination of studies on the use of MUVEs in Computer…

The Mentored Multigenre Project: Fostering Authentic Writing Interactions between High School Writers and Teacher Candidates

ERIC Educational Resources Information Center

West, Jessica A.; Saine, Paula

2017-01-01

This article describes the Mentored Multigenre Project, a virtual writing collaboration experience between high school writers and teacher candidates. Our goal was to create an authentic opportunity for our high school students to receive writing feedback from virtual writing mentors, while also creating an opportunity for our teacher candidates…

The Learning Outcomes of Mentoring Library Science Students in Virtual World Reference: A Case Study

ERIC Educational Resources Information Center

Purpur, Geraldine; Morris, Jon Levi

2015-01-01

This article reports on the cognitive and affective development of students being mentored in virtual reference interview skills by professional librarians. The authors present a case study which examines the impact on student learning resulting from librarian mentor participation and collaboration with students on a course assignment. This study…

The Global Classroom Project: Learning a Second Language in a Virtual Environment

ERIC Educational Resources Information Center

Knutzen, Brant; Kennedy, David

2012-01-01

This paper reports the progress of a pilot project exploring the integration of a collaborative virtual learning environment (Second Life) with the instruction of English courses at Lingnan University in Hong Kong. An educational partnership was developed with two TESOL teacher-training courses at Texas A&M University in the US. The project…

Impacts assessment of dynamic speed harmonization with queue warning : task 3, impacts assessment report.

DOT National Transportation Integrated Search

2015-06-01

This report assesses the impacts of a prototype of Dynamic Speed Harmonization (SPD-HARM) with Queue Warning (Q-WARN), which are two component applications of the Intelligent Network Flow Optimization (INFLO) bundle. The assessment is based on an ext...

A queueing theory description of fat-tailed price returns in imperfect financial markets

NASA Astrophysics Data System (ADS)

Lamba, H.

2010-09-01

In a financial market, for agents with long investment horizons or at times of severe market stress, it is often changes in the asset price that act as the trigger for transactions or shifts in investment position. This suggests the use of price thresholds to simulate agent behavior over much longer timescales than are currently used in models of order-books. We show that many phenomena, routinely ignored in efficient market theory, can be systematically introduced into an otherwise efficient market, resulting in models that robustly replicate the most important stylized facts. We then demonstrate a close link between such threshold models and queueing theory, with large price changes corresponding to the busy periods of a single-server queue. The distribution of the busy periods is known to have excess kurtosis and non-exponential decay under various assumptions on the queue parameters. Such an approach may prove useful in the development of mathematical models for rapid deleveraging and panics in financial markets, and the stress-testing of financial institutions.

Exclusive queueing model including the choice of service windows

NASA Astrophysics Data System (ADS)

Tanaka, Masahiro; Yanagisawa, Daichi; Nishinari, Katsuhiro

2018-01-01

In a queueing system involving multiple service windows, choice behavior is a significant concern. This paper incorporates the choice of service windows into a queueing model with a floor represented by discrete cells. We contrived a logit-based choice algorithm for agents considering the numbers of agents and the distances to all service windows. Simulations were conducted with various parameters of agent choice preference for these two elements and for different floor configurations, including the floor length and the number of service windows. We investigated the model from the viewpoint of transit times and entrance block rates. The influences of the parameters on these factors were surveyed in detail and we determined that there are optimum floor lengths that minimize the transit times. In addition, we observed that the transit times were determined almost entirely by the entrance block rates. The results of the presented model are relevant to understanding queueing systems including the choice of service windows and can be employed to optimize facility design and floor management.

An energy-efficient MAC protocol using dynamic queue management for delay-tolerant mobile sensor networks.

PubMed

Li, Jie; Li, Qiyue; Qu, Yugui; Zhao, Baohua

2011-01-01

Conventional MAC protocols for wireless sensor network perform poorly when faced with a delay-tolerant mobile network environment. Characterized by a highly dynamic and sparse topology, poor network connectivity as well as data delay-tolerance, delay-tolerant mobile sensor networks exacerbate the severe power constraints and memory limitations of nodes. This paper proposes an energy-efficient MAC protocol using dynamic queue management (EQ-MAC) for power saving and data queue management. Via data transfers initiated by the target sink and the use of a dynamic queue management strategy based on priority, EQ-MAC effectively avoids untargeted transfers, increases the chance of successful data transmission, and makes useful data reach the target terminal in a timely manner. Experimental results show that EQ-MAC has high energy efficiency in comparison with a conventional MAC protocol. It also achieves a 46% decrease in packet drop probability, 79% increase in system throughput, and 25% decrease in mean packet delay.

An Energy-Efficient MAC Protocol Using Dynamic Queue Management for Delay-Tolerant Mobile Sensor Networks

PubMed Central

Li, Jie; Li, Qiyue; Qu, Yugui; Zhao, Baohua

2011-01-01

Conventional MAC protocols for wireless sensor network perform poorly when faced with a delay-tolerant mobile network environment. Characterized by a highly dynamic and sparse topology, poor network connectivity as well as data delay-tolerance, delay-tolerant mobile sensor networks exacerbate the severe power constraints and memory limitations of nodes. This paper proposes an energy-efficient MAC protocol using dynamic queue management (EQ-MAC) for power saving and data queue management. Via data transfers initiated by the target sink and the use of a dynamic queue management strategy based on priority, EQ-MAC effectively avoids untargeted transfers, increases the chance of successful data transmission, and makes useful data reach the target terminal in a timely manner. Experimental results show that EQ-MAC has high energy efficiency in comparison with a conventional MAC protocol. It also achieves a 46% decrease in packet drop probability, 79% increase in system throughput, and 25% decrease in mean packet delay. PMID:22319385

Reducing queues: demand and capacity variations.

PubMed

Eriksson, Henrik; Bergbrant, Ing-Marie; Berrum, Ingela; Mörck, Boel

2011-01-01

The aim of this paper is to investigate how waiting lists or queues could be reduced without adding more resources; and to describe what factors sustain reduced waiting-times. Cases were selected according to successful and sustained queue reduction. The approach in this study is action research. Accessibility improved as out-patient waiting lists for two clinics were reduced. The main success was working towards matching demand and capacity. It has been possible to sustain the improvements. Results should be viewed cautiously. Transferring and generalizing outcomes from this study is for readers to consider. However, accessible healthcare may be possible by paying more attention to existing solutions. The study indicates that queue reduction activities should include acquiring knowledge about theories and methods to improve accessibility, finding ways to monitor varying demand and capacity, and to improve patient processing by reducing variations. Accessibility is considered an important dimension when measuring service quality. However, there are few articles on how clinic staff sustain reduces waiting lists. This paper contributes accessible knowledge to the field.

Rationale choosing interval of a piecewise-constant approximation of input rate of non-stationary queue system

NASA Astrophysics Data System (ADS)

Korelin, Ivan A.; Porshnev, Sergey V.

2018-01-01

The paper demonstrates the possibility of calculating the characteristics of the flow of visitors to objects carrying out mass events passing through checkpoints. The mathematical model is based on the non-stationary queuing system (NQS) where dependence of requests input rate from time is described by the function. This function was chosen in such way that its properties were similar to the real dependencies of speed of visitors arrival on football matches to the stadium. A piecewise-constant approximation of the function is used when statistical modeling of NQS performing. Authors calculated the dependencies of the queue length and waiting time for visitors to service (time in queue) on time for different laws. Time required to service the entire queue and the number of visitors entering the stadium at the beginning of the match were calculated too. We found the dependence for macroscopic quantitative characteristics of NQS from the number of averaging sections of the input rate.

Queue and stack sorting algorithm optimization and performance analysis

NASA Astrophysics Data System (ADS)

Qian, Mingzhu; Wang, Xiaobao

2018-04-01

Sorting algorithm is one of the basic operation of a variety of software development, in data structures course specializes in all kinds of sort algorithm. The performance of the sorting algorithm is directly related to the efficiency of the software. A lot of excellent scientific research queue is constantly optimizing algorithm, algorithm efficiency better as far as possible, the author here further research queue combined with stacks of sorting algorithms, the algorithm is mainly used for alternating operation queue and stack storage properties, Thus avoiding the need for a large number of exchange or mobile operations in the traditional sort. Before the existing basis to continue research, improvement and optimization, the focus on the optimization of the time complexity of the proposed optimization and improvement, The experimental results show that the improved effectively, at the same time and the time complexity and space complexity of the algorithm, the stability study corresponding research. The improvement and optimization algorithm, improves the practicability.

Accelerating list management for MPI.

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

Hemmert, K. Scott; Rodrigues, Arun F.; Underwood, Keith Douglas

2005-07-01

The latency and throughput of MPI messages are critically important to a range of parallel scientific applications. In many modern networks, both of these performance characteristics are largely driven by the performance of a processor on the network interface. Because of the semantics of MPI, this embedded processor is forced to traverse a linked list of posted receives each time a message is received. As this list grows long, the latency of message reception grows and the throughput of MPI messages decreases. This paper presents a novel hardware feature to handle list management functions on a network interface. By movingmore » functions such as list insertion, list traversal, and list deletion to the hardware unit, latencies are decreased by up to 20% in the zero length queue case with dramatic improvements in the presence of long queues. Similarly, the throughput is increased by up to 10% in the zero length queue case and by nearly 100% in the presence queues of 30 messages.« less

Improving queuing service at McDonald's

NASA Astrophysics Data System (ADS)

Koh, Hock Lye; Teh, Su Yean; Wong, Chin Keat; Lim, Hooi Kie; Migin, Melissa W.

2014-07-01

Fast food restaurants are popular among price-sensitive youths and working adults who value the conducive environment and convenient services. McDonald's chains of restaurants promote their sales during lunch hours by offering package meals which are perceived to be inexpensive. These promotional lunch meals attract good response, resulting in occasional long queues and inconvenient waiting times. A study is conducted to monitor the distribution of waiting time, queue length, customer arrival and departure patterns at a McDonald's restaurant located in Kuala Lumpur. A customer survey is conducted to gauge customers' satisfaction regarding waiting time and queue length. An android app named Que is developed to perform onsite queuing analysis and report key performance indices. The queuing theory in Que is based upon the concept of Poisson distribution. In this paper, Que is utilized to perform queuing analysis at this McDonald's restaurant with the aim of improving customer service, with particular reference to reducing queuing time and shortening queue length. Some results will be presented.

Characteristics of the Unexpected Message Queue of MPI applications

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

Keller, Rainer; Graham, Richard L

2010-01-01

High Performance Computing systems are used on a regular basis to run a myriad of application codes, yet a surprising dearth of information exists with respect to communications characteristics. Even less information is available on the low-level communication libraries, such as the length of MPI Unexpected Message Queues (UMQs) and the length of time such messages spend in these queues. Such information is vital to developing appropriate strategies for handling such data at the library and system level. In this paper we present data on the communication characteristics of three applications GTC, LSMS, and S3D. We present data on themore » size of their UMQ, the time spend searching the UMQ and the length of time such messages spend in these queues. We find that for the particular inputs used, these applications have widely varying characteristics with regard to UMQ length and show patterns for specific applications which persist over various scales.« less

Fast simulation of packet loss rates in a shared buffer communications switch

NASA Technical Reports Server (NTRS)

Chang, Cheng-Shang; Heidelberger, Philip; Shahabuddin, Perwez

1993-01-01

This paper describes an efficient technique for estimating, via simulation, the probability of buffer overflows in a queueing model that arises in the analysis of ATM (Asynchronous Transfer Mode) communication switches. There are multiple streams of (autocorrelated) traffic feeding the switch that has a buffer of finite capacity. Each stream is designated as either being of high or low priority. When the queue length reaches a certain threshold, only high priority packets are admitted to the switch's buffer. The problem is to estimate the loss rate of high priority packets. An asymptotically optimal importance sampling approach is developed for this rare event simulation problem. In this approach, the importance sampling is done in two distinct phases. In the first phase, an importance sampling change of measure is used to bring the queue length up to the threshold at which low priority packets get rejected. In the second phase, a different importance sampling change of measure is used to move the queue length from the threshold to the buffer capacity.

Monitoring System for the GRID Monte Carlo Mass Production in the H1 Experiment at DESY

NASA Astrophysics Data System (ADS)

Bystritskaya, Elena; Fomenko, Alexander; Gogitidze, Nelly; Lobodzinski, Bogdan

2014-06-01

The H1 Virtual Organization (VO), as one of the small VOs, employs most components of the EMI or gLite Middleware. In this framework, a monitoring system is designed for the H1 Experiment to identify and recognize within the GRID the best suitable resources for execution of CPU-time consuming Monte Carlo (MC) simulation tasks (jobs). Monitored resources are Computer Elements (CEs), Storage Elements (SEs), WMS-servers (WMSs), CernVM File System (CVMFS) available to the VO HONE and local GRID User Interfaces (UIs). The general principle of monitoring GRID elements is based on the execution of short test jobs on different CE queues using submission through various WMSs and directly to the CREAM-CEs as well. Real H1 MC Production jobs with a small number of events are used to perform the tests. Test jobs are periodically submitted into GRID queues, the status of these jobs is checked, output files of completed jobs are retrieved, the result of each job is analyzed and the waiting time and run time are derived. Using this information, the status of the GRID elements is estimated and the most suitable ones are included in the automatically generated configuration files for use in the H1 MC production. The monitoring system allows for identification of problems in the GRID sites and promptly reacts on it (for example by sending GGUS (Global Grid User Support) trouble tickets). The system can easily be adapted to identify the optimal resources for tasks other than MC production, simply by changing to the relevant test jobs. The monitoring system is written mostly in Python and Perl with insertion of a few shell scripts. In addition to the test monitoring system we use information from real production jobs to monitor the availability and quality of the GRID resources. The monitoring tools register the number of job resubmissions, the percentage of failed and finished jobs relative to all jobs on the CEs and determine the average values of waiting and running time for the involved GRID queues. CEs which do not meet the set criteria can be removed from the production chain by including them in an exception table. All of these monitoring actions lead to a more reliable and faster execution of MC requests.

Application of queuing theory to patient satisfaction at a tertiary hospital in Nigeria

PubMed Central

Ameh, Nkeiruka; Sabo, B.; Oyefabi, M. O.

2013-01-01

Background: Queuing theory is the mathematical approach to the analysis of waiting lines in any setting where arrival rate of subjects is faster than the system can handle. It is applicable to healthcare settings where the systems have excess capacity to accommodate random variations. Materials and Methods: A cross-sectional descriptive survey was done. Questionnaires were administered to patients who attended the general outpatient department. Observations were also made on the queuing model and the service discipline at the clinic. Questions were meant to obtain demographic characteristics and the time spent on the queue by patients before being seen by a doctor, time spent with the doctor, their views about the time spent on the queue and useful suggestions on how to reduce the time spent on the queue. A total of 210 patients were surveyed. Results: Majority of the patients (164, 78.1%) spent 2 h or less on the queue before being seen by a doctor and less than 1 h to see the doctor. Majority of the patients (144, 68.5%) were satisfied with the time they spent on the queue before being seen by a doctor. Useful suggestions proffered by the patients to decrease the time spent on the queue before seeing a doctor at the clinic included: that more doctors be employed (46, 21.9%), that doctors should come to work on time (25, 11.9%), that first-come-first served be observed strictly (32, 15.2%) and others suggested that the records staff should desist from collecting bribes from patients in order to place their cards before others. The queuing method employed at the clinic is the multiple single channel type and the service discipline is priority service. The patients who spent less time on the queue (<1 h) before seeing the doctor were more satisfied than those who spent more time (P < 0.05). Conclusion: The study has revealed that majority of the patients were satisfied with the practice at the general outpatient department. However, there is a need to employ measures to respond to the suggestions given by the patients who are the beneficiaries of the hospital services. PMID:23661902

Vroom: designing an augmented environment for remote collaboration in digital cinema production

NASA Astrophysics Data System (ADS)

Margolis, Todd; Cornish, Tracy

2013-03-01

As media technologies become increasingly affordable, compact and inherently networked, new generations of telecollaborative platforms continue to arise which integrate these new affordances. Virtual reality has been primarily concerned with creating simulations of environments that can transport participants to real or imagined spaces that replace the "real world". Meanwhile Augmented Reality systems have evolved to interleave objects from Virtual Reality environments into the physical landscape. Perhaps now there is a new class of systems that reverse this precept to enhance dynamic media landscapes and immersive physical display environments to enable intuitive data exploration through collaboration. Vroom (Virtual Room) is a next-generation reconfigurable tiled display environment in development at the California Institute for Telecommunications and Information Technology (Calit2) at the University of California, San Diego. Vroom enables freely scalable digital collaboratories, connecting distributed, high-resolution visualization resources for collaborative work in the sciences, engineering and the arts. Vroom transforms a physical space into an immersive media environment with large format interactive display surfaces, video teleconferencing and spatialized audio built on a highspeed optical network backbone. Vroom enables group collaboration for local and remote participants to share knowledge and experiences. Possible applications include: remote learning, command and control, storyboarding, post-production editorial review, high resolution video playback, 3D visualization, screencasting and image, video and multimedia file sharing. To support these various scenarios, Vroom features support for multiple user interfaces (optical tracking, touch UI, gesture interface, etc.), support for directional and spatialized audio, giga-pixel image interactivity, 4K video streaming, 3D visualization and telematic production. This paper explains the design process that has been utilized to make Vroom an accessible and intuitive immersive environment for remote collaboration specifically for digital cinema production.

A multi-group and preemptable scheduling of cloud resource based on HTCondor

NASA Astrophysics Data System (ADS)

Jiang, Xiaowei; Zou, Jiaheng; Cheng, Yaodong; Shi, Jingyan

2017-10-01

Due to the features of virtual machine-flexibility, easy controlling and various system environments, more and more fields utilize the virtualization technology to construct the distributed system with the virtual resources, also including high energy physics. This paper introduce a method used in high energy physics that supports multiple resource group and preemptable cloud resource scheduling, combining virtual machine with HTCondor (a batch system). It makes resource controlling more flexible and more efficient and makes resource scheduling independent of job scheduling. Firstly, the resources belong to different experiment-groups, and the type of user-groups mapping to resource-groups(same as experiment-group) is one-to-one or many-to-one. In order to make the confused group simply to be managed, we designed the permission controlling component to ensure that the different resource-groups can get the suitable jobs. Secondly, for the purpose of elastically allocating resources for suitable resource-group, it is necessary to schedule resources like scheduling jobs. So this paper designs the cloud resource scheduling to maintain a resource queue and allocate an appropriate amount of virtual resources to the request resource-group. Thirdly, in some kind of situations, because of the resource occupied for a long time, resources need to be preempted. This paper adds the preemption function for the resource scheduling that implement resource preemption based on the group priority. Additionally, the way to preempting is soft that when virtual resources are preempted, jobs will not be killed but also be held and rematched later. It is implemented with the help of HTCondor, storing the held job information in scheduler, releasing the job to idle status and doing second matcher. In IHEP (institute of high energy physics), we have built a batch system based on HTCondor with a virtual resources pool based on Openstack. And this paper will show some cases of experiment JUNO and LHAASO. The result indicates that multi-group and preemptable resource scheduling is efficient to support multi-group and soft preemption. Additionally, the permission controlling component has been used in the local computing cluster, supporting for experiment JUNO, CMS and LHAASO, and the scale will be expanded to more experiments at the first half year, including DYW, BES and so on. Its evidence that the permission controlling is efficient.

Parallel discrete event simulation using shared memory

NASA Technical Reports Server (NTRS)

Reed, Daniel A.; Malony, Allen D.; Mccredie, Bradley D.

1988-01-01

With traditional event-list techniques, evaluating a detailed discrete-event simulation-model can often require hours or even days of computation time. By eliminating the event list and maintaining only sufficient synchronization to ensure causality, parallel simulation can potentially provide speedups that are linear in the numbers of processors. A set of shared-memory experiments, using the Chandy-Misra distributed-simulation algorithm, to simulate networks of queues is presented. Parameters of the study include queueing network topology and routing probabilities, number of processors, and assignment of network nodes to processors. These experiments show that Chandy-Misra distributed simulation is a questionable alternative to sequential-simulation of most queueing network models.

Can Massive Communities of Teachers Facilitate Collaborative Reflection? Fractal Design as a Possible Answer

ERIC Educational Resources Information Center

Clarà, Marc; Kelly, Nick; Mauri, Teresa; Danaher, P. A.

2017-01-01

This paper explores the possibility that virtual communities of teachers with large numbers of members (referred to as "massive communities of teachers") can offer support to novice teachers by means of collaborative reflection. The paper examines and conceptualises some problems found in professional massive communities and proposes…

The Affordance of Online Multiuser Virtual Environments (MUVE) for Creative Collaboration

ERIC Educational Resources Information Center

Hong, Seung Wan

2013-01-01

Creativity is an important criterion for evaluating conceptual and design abilities of architects and their praxis. However, in recent years, the world has grown more complex. New problems have emerged that are often outside the architect's capacity. Given this challenge, architects collaborate with colleagues from architecture and other related…

Virtual Collaborations in the Spanish Class: From E-Mail to Web Design and CD-ROM Development.

ERIC Educational Resources Information Center

Hellebrandt, Josef

1999-01-01

Modern technologies can provide language students with authentic content and contextualized, collaborative learning situations. This article illustrates how e-mail exchanges, Web exercises, and CD-ROM development between students in the United States and organizations in Ecuador can promote contextualized and authentic practice of Spanish language…

Investigating Linguistic, Literary, and Social Affordances of L2 Collaborative Reading

ERIC Educational Resources Information Center

Thoms, Joshua J.; Poole, Frederick

2017-01-01

This exploratory study analyzes learner-learner interactions within a virtual environment when collaboratively reading Spanish poetry in a Hispanic literature course at the college level via an ecological theoretical perspective (van Lier, 2004). The goals of the study are (a) to present empirical data that illustrate the theoretical construct of…

Necessity Fuels Creativity: Adapting Long-Distance Collaborative Methods for the Classroom

ERIC Educational Resources Information Center

Sopoci Drake, Katie; Larson, Eliza; Rugh, Rachel; Tait, Barbara

2016-01-01

Improved technology has made it possible to virtually bridge distance between dance makers, rendering physical location another choreographic device to be manipulated. Long-distance collaboration as an artistic process is not only a fertile new ground for creation and necessary for many practicing dance artists in the field today, but there is…

Virtual Communities of Practice: Bridging Research and Practice Using Web 2.0

ERIC Educational Resources Information Center

Lewis, Laura A.; Koston, Zoe; Quartley, Marjorie; Adsit, Jason

2011-01-01

A significant dilemma for the health and human service professions continues to be the question of how best to bridge the divide between academic research and practice. Communities of practice have traditionally been a vehicle for collaborative research and for information exchange (Moore, 2008). Through collaboration, communities of practice have…

Creating a Collaborative Learning Community in the CIS Sandbox

ERIC Educational Resources Information Center

Frydenberg, Mark

2013-01-01

Purpose: The purpose of this paper is to investigate the impact of transforming a traditional university computer lab to create a collaborative learning community known as the CIS Sandbox, by remodeling a physical space and supporting it with a virtual presence through the use of social media tools. The discussion applies Selander's "designs for…

Programming for Fun: MUDs as a Context for Collaborative Learning.

ERIC Educational Resources Information Center

Bruckman, Amy

Multi-User Dungeons (MUDs), are text-based virtual reality environments in which participants separated by great physical distances can communicate and collaborate in programming. Most MUDs started out as adventure games but are quickly being adapted for more "serious" endeavors. This paper presents a case study of the experiences of a…

The Virtual Table: A Framework for Online Teamwork, Collaboration, and Communication.

PubMed

Endersby, Lisa; Phelps, Kirstin; Jenkins, Dan

2017-03-01

This chapter reviews the complex relationship between technology and leadership, focusing on how technology affects the development and demonstration of skills in communication, teamwork, and collaboration. The chapter also proposes a framework for identifying and assessing key leadership competencies in the digital space. © 2017 Wiley Periodicals, Inc., A Wiley Company.

Informatics for neglected diseases collaborations.

PubMed

Bost, Frederic; Jacobs, Robert T; Kowalczyk, Paul

2010-05-01

Many different public and private organizations from across the globe are collaborating on neglected diseases drug-discovery and development projects with the aim of identifying a cure for tropical infectious diseases. These neglected diseases collaborations require a global, secure, multi-organization data-management solution, combined with a platform that facilitates communication and supports collaborative work. This review discusses the solutions offered by 'Software as a Service' (SaaS) web-based platforms, despite notable challenges, and the evolution of these platforms required to foster efficient virtual research efforts by geographically dispersed scientists.

Multi-Resource Fair Queueing for Packet Processing

DTIC Science & Technology

2012-06-19

Huawei , Intel, MarkLogic, Microsoft, NetApp, Oracle, Quanta, Splunk, VMware and by DARPA (contract #FA8650-11-C-7136). Multi-Resource Fair Queueing for...Google PhD Fellowship, gifts from Amazon Web Services, Google, SAP, Blue Goji, Cisco, Cloud- era, Ericsson, General Electric, Hewlett Packard, Huawei

TIME SHARING WITH AN EXPLICIT PRIORITY QUEUING DISCIPLINE.

DTIC Science & Technology

exponentially distributed service times and an ordered priority queue. Each new arrival buys a position in this queue by offering a non-negative bribe to the...parameters is investigated through numerical examples. Finally, to maximize the expected revenue per unit time accruing from bribes , an optimization

32 CFR 299.5 - Procedures.

Code of Federal Regulations, 2011 CFR

2011-07-01

... PROGRAM NATIONAL SECURITY AGENCY/CENTRAL SECURITY SERVICE (NSA/CSS) FREEDOM OF INFORMATION ACT PROGRAM.../CSS by other government agencies shall be placed in the processing queue according to the date the... placed in the queue according to the date of the requester's letter. (d) The FOIA office shall maintain...

Specification and Verification of Communication Protocols in AFFIRM Using State Transition Models.

DTIC Science & Technology

1981-03-01

NewQueueOfftcket; theorem Pendnglnvariant, Remove(Pending(s)) = NewQueueOfPacket; Since the implementation is in keeping with the specification, its salp ...another communication line. The communication lines are unreliable; messages traveling in either direction can be lost, reordered, corrupted, or

Virtual day of the midwife: a global 'pyjama party'.

PubMed

Stewart, Sarah

2014-06-01

The Virtual International Day of the Midwife (VIDM) (www.vidm.org) is an annual online conference designed to break down traditional barriers to continuing professional development (CPD); provide online opportunities for international midwifery networking; and model open access communication and collaboration practices. Whilst the VIDM is designed to reach midwives all around the world, issues of access to the Internet, language and cultural differences prevent some midwives from attending, especially those who live in resource-poor countries. Nevertheless, the VIDM has successfully demonstrated how CPD can be delivered to midwives in a flexible and cost-effective way, as well as bring them together in a truly global open and collaborative environment.

A Mixed Integer Linear Program for Airport Departure Scheduling

NASA Technical Reports Server (NTRS)

Gupta, Gautam; Jung, Yoon Chul

2009-01-01

Aircraft departing from an airport are subject to numerous constraints while scheduling departure times. These constraints include wake-separation constraints for successive departures, miles-in-trail separation for aircraft bound for the same departure fixes, and time-window or prioritization constraints for individual flights. Besides these, emissions as well as increased fuel consumption due to inefficient scheduling need to be included. Addressing all the above constraints in a single framework while allowing for resequencing of the aircraft using runway queues is critical to the implementation of the Next Generation Air Transport System (NextGen) concepts. Prior work on airport departure scheduling has addressed some of the above. However, existing methods use pre-determined runway queues, and schedule aircraft from these departure queues. The source of such pre-determined queues is not explicit, and could potentially be a subjective controller input. Determining runway queues and scheduling within the same framework would potentially result in better scheduling. This paper presents a mixed integer linear program (MILP) for the departure-scheduling problem. The program takes as input the incoming sequence of aircraft for departure from a runway, along with their earliest departure times and an optional prioritization scheme based on time-window of departure for each aircraft. The program then assigns these aircraft to the available departure queues and schedules departure times, explicitly considering wake separation and departure fix restrictions to minimize total delay for all aircraft. The approach is generalized and can be used in a variety of situations, and allows for aircraft prioritization based on operational as well as environmental considerations. We present the MILP in the paper, along with benefits over the first-come-first-serve (FCFS) scheme for numerous randomized problems based on real-world settings. The MILP results in substantially reduced delays as compared to FCFS, and the magnitude of the savings depends on the queue and departure fix structure. The MILP assumes deterministic aircraft arrival times at the runway queues. However, due to taxi time uncertainty, aircraft might arrive either earlier or later than these deterministic times. Thus, to incorporate this uncertainty, we present a method for using the MILP with "overlap discounted rolling planning horizon". The approach is based on valuing near-term decision results more than future ones. We develop a model of taxitime uncertainty based on real-world data, and then compare the baseline FCFS delays with delays using the above MILP in a simple rolling-horizon method and in the overlap discounted scheme.

A lock-free priority queue design based on multi-dimensional linked lists

DOE PAGES

Dechev, Damian; Zhang, Deli

2015-04-03

The throughput of concurrent priority queues is pivotal to multiprocessor applications such as discrete event simulation, best-first search and task scheduling. Existing lock-free priority queues are mostly based on skiplists, which probabilistically create shortcuts in an ordered list for fast insertion of elements. The use of skiplists eliminates the need of global rebalancing in balanced search trees and ensures logarithmic sequential search time on average, but the worst-case performance is linear with respect to the input size. In this paper, we propose a quiescently consistent lock-free priority queue based on a multi-dimensional list that guarantees worst-case search time of O(logN)more » for key universe of size N. The novel multi-dimensional list (MDList) is composed of nodes that contain multiple links to child nodes arranged by their dimensionality. The insertion operation works by first injectively mapping the scalar key to a high-dimensional vector, then uniquely locating the target position by using the vector as coordinates. Nodes in MDList are ordered by their coordinate prefixes and the ordering property of the data structure is readily maintained during insertion without rebalancing nor randomization. Furthermore, in our experimental evaluation using a micro-benchmark, our priority queue achieves an average of 50% speedup over the state of the art approaches under high concurrency.« less

Moving toward queue operations at the Large Binocular Telescope Observatory

NASA Astrophysics Data System (ADS)

Edwards, Michelle L.; Summers, Doug; Astier, Joseph; Suarez Sola, Igor; Veillet, Christian; Power, Jennifer; Cardwell, Andrew; Walsh, Shane

2016-07-01

The Large Binocular Telescope Observatory (LBTO), a joint scientific venture between the Instituto Nazionale di Astrofisica (INAF), LBT Beteiligungsgesellschaft (LBTB), University of Arizona, Ohio State University (OSU), and the Research Corporation, is one of the newest additions to the world's collection of large optical/infrared ground-based telescopes. With its unique, twin 8.4m mirror design providing a 22.8 meter interferometric baseline and the collecting area of an 11.8m telescope, LBT has a window of opportunity to exploit its singular status as the "first" of the next generation of Extremely Large Telescopes (ELTs). Prompted by urgency to maximize scientific output during this favorable interval, LBTO recently re-evaluated its operations model and developed a new strategy that augments classical observing with queue. Aided by trained observatory staff, queue mode will allow for flexible, multi-instrument observing responsive to site conditions. Our plan is to implement a staged rollout that will provide many of the benefits of queue observing sooner rather than later - with more bells and whistles coming in future stages. In this paper, we outline LBTO's new scientific model, focusing specifically on our "lean" resourcing and development, reuse and adaptation of existing software, challenges presented from our one-of-a-kind binocular operations, and lessons learned. We also outline further stages of development and our ultimate goals for queue.

A lock-free priority queue design based on multi-dimensional linked lists

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

Dechev, Damian; Zhang, Deli

The throughput of concurrent priority queues is pivotal to multiprocessor applications such as discrete event simulation, best-first search and task scheduling. Existing lock-free priority queues are mostly based on skiplists, which probabilistically create shortcuts in an ordered list for fast insertion of elements. The use of skiplists eliminates the need of global rebalancing in balanced search trees and ensures logarithmic sequential search time on average, but the worst-case performance is linear with respect to the input size. In this paper, we propose a quiescently consistent lock-free priority queue based on a multi-dimensional list that guarantees worst-case search time of O(logN)more » for key universe of size N. The novel multi-dimensional list (MDList) is composed of nodes that contain multiple links to child nodes arranged by their dimensionality. The insertion operation works by first injectively mapping the scalar key to a high-dimensional vector, then uniquely locating the target position by using the vector as coordinates. Nodes in MDList are ordered by their coordinate prefixes and the ordering property of the data structure is readily maintained during insertion without rebalancing nor randomization. Furthermore, in our experimental evaluation using a micro-benchmark, our priority queue achieves an average of 50% speedup over the state of the art approaches under high concurrency.« less

System and method for implementing periodic early discard in on-chip buffer memories of network elements

DOEpatents

Francini, Andrea

2013-05-14

An advance is made over the prior art in accordance with the principles of the present invention that is directed to a new approach for a system and method for a buffer management scheme called Periodic Early Discard (PED). The invention builds on the observation that, in presence of TCP traffic, the length of a queue can be stabilized by selection of an appropriate frequency for packet dropping. For any combination of number of TCP connections and distribution of the respective RTT values, there exists an ideal packet drop frequency that prevents the queue from over-flowing or under-flowing. While the value of the ideal packet drop frequency may quickly change over time and is sensitive to the series of TCP connections affected by past packet losses, and most of all is impossible to compute inline, it is possible to approximate it with a margin of error that allows keeping the queue occupancy within a pre-defined range for extended periods of time. The PED scheme aims at tracking the (unknown) ideal packet drop frequency, adjusting the approximated value based on the evolution of the queue occupancy, with corrections of the approximated packet drop frequency that occur at a timescale that is comparable to the aggregate time constant of the set of TCP connections that traverse the queue.

Virtual Worlds for Virtual Organizing

NASA Astrophysics Data System (ADS)

Rhoten, Diana; Lutters, Wayne

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

Emerging technologies in education and training: applications for the laboratory animal science community.

PubMed

Ketelhut, Diane Jass; Niemi, Steven M

2007-01-01

This article examines several new and exciting communication technologies. Many of the technologies were developed by the entertainment industry; however, other industries are adopting and modifying them for their own needs. These new technologies allow people to collaborate across distance and time and to learn in simulated work contexts. The article explores the potential utility of these technologies for advancing laboratory animal care and use through better education and training. Descriptions include emerging technologies such as augmented reality and multi-user virtual environments, which offer new approaches with different capabilities. Augmented reality interfaces, characterized by the use of handheld computers to infuse the virtual world into the real one, result in deeply immersive simulations. In these simulations, users can access virtual resources and communicate with real and virtual participants. Multi-user virtual environments enable multiple participants to simultaneously access computer-based three-dimensional virtual spaces, called "worlds," and to interact with digital tools. They allow for authentic experiences that promote collaboration, mentoring, and communication. Because individuals may learn or train differently, it is advantageous to combine the capabilities of these technologies and applications with more traditional methods to increase the number of students who are served by using current methods alone. The use of these technologies in animal care and use programs can create detailed training and education environments that allow students to learn the procedures more effectively, teachers to assess their progress more objectively, and researchers to gain insights into animal care.

Robust kernel collaborative representation for face recognition

NASA Astrophysics Data System (ADS)

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

2015-05-01

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

A 360° Vision for Virtual Organizations Characterization and Modelling: Two Intentional Level Aspects

NASA Astrophysics Data System (ADS)

Priego-Roche, Luz-María; Rieu, Dominique; Front, Agnès

Nowadays, organizations aiming to be successful in an increasingly competitive market tend to group together into virtual organizations. Designing the information system (IS) of such virtual organizations on the basis of the IS of those participating is a real challenge. The IS of a virtual organization plays an important role in the collaboration and cooperation of the participants organizations and in reaching the common goal. This article proposes criteria allowing virtual organizations to be identified and classified at an intentional level, as well as the information necessary for designing the organizations’ IS. Instantiation of criteria for a specific virtual organization and its participants, will allow simple graphical models to be generated in a modelling tool. The models will be used as bases for the IS design at organizational and operational levels. The approach is illustrated by the example of the virtual organization UGRT (a regional stockbreeders union in Tabasco, Mexico).

Future Evolution of Virtual Worlds as Communication Environments

NASA Astrophysics Data System (ADS)

Prisco, Giulio

Extensive experience creating locations and activities inside virtual worlds provides the basis for contemplating their future. Users of virtual worlds are diverse in their goals for these online environments; for example, immersionists want them to be alternative realities disconnected from real life, whereas augmentationists want them to be communication media supporting real-life activities. As the technology improves, the diversity of virtual worlds will increase along with their significance. Many will incorporate more advanced virtual reality, or serve as major media for long-distance collaboration, or become the venues for futurist social movements. Key issues are how people can create their own virtual worlds, travel across worlds, and experience a variety of multimedia immersive environments. This chapter concludes by noting the view among some computer scientists that future technologies will permit uploading human personalities to artificial intelligence avatars, thereby enhancing human beings and rendering the virtual worlds entirely real.

Impacts Assessment of Dynamic Speed Harmonization with Queue Warning : Task 3, Impacts Assessment Report. [supporting datasets

DOT National Transportation Integrated Search

2015-05-31

The datasets in the .pdf and .zip attached to this record are in support of Intelligent Transportation Systems Joint Program Office (ITS JPO) report FHWA-JPO-15-222, "Impacts Assessment of Dynamic Speed Harmonization with Queue Warning : Task 3, Impa...

Routing in Networks with Random Topologies

NASA Technical Reports Server (NTRS)

Bambos, Nicholas

1997-01-01

We examine the problems of routing and server assignment in networks with random connectivities. In such a network the basic topology is fixed, but during each time slot and for each of tis input queues, each server (node) is either connected to or disconnected from each of its queues with some probability.

Building a High Performance Metadata Broker using Clojure, NoSQL and Message Queues

NASA Astrophysics Data System (ADS)

Truslove, I.; Reed, S.

2013-12-01

In practice, Earth and Space Science Informatics often relies on getting more done with less: fewer hardware resources, less IT staff, fewer lines of code. As a capacity-building exercise focused on rapid development of high-performance geoinformatics software, the National Snow and Ice Data Center (NSIDC) built a prototype metadata brokering system using a new JVM language, modern database engines and virtualized or cloud computing resources. The metadata brokering system was developed with the overarching goals of (i) demonstrating a technically viable product with as little development effort as possible, (ii) using very new yet very popular tools and technologies in order to get the most value from the least legacy-encumbered code bases, and (iii) being a high-performance system by using scalable subcomponents, and implementation patterns typically used in web architectures. We implemented the system using the Clojure programming language (an interactive, dynamic, Lisp-like JVM language), Redis (a fast in-memory key-value store) as both the data store for original XML metadata content and as the provider for the message queueing service, and ElasticSearch for its search and indexing capabilities to generate search results. On evaluating the results of the prototyping process, we believe that the technical choices did in fact allow us to do more for less, due to the expressive nature of the Clojure programming language and its easy interoperability with Java libraries, and the successful reuse or re-application of high performance products or designs. This presentation will describe the architecture of the metadata brokering system, cover the tools and techniques used, and describe lessons learned, conclusions, and potential next steps.

Virtual microscopy: merging of computer mediated communication and intuitive interfacing

NASA Astrophysics Data System (ADS)

de Ridder, Huib; de Ridder-Sluiter, Johanna G.; Kluin, Philip M.; Christiaans, Henri H. C. M.

2009-02-01

Ubiquitous computing (or Ambient Intelligence) is an upcoming technology that is usually associated with futuristic smart environments in which information is available anytime anywhere and with which humans can interact in a natural, multimodal way. However spectacular the corresponding scenarios may be, it is equally challenging to consider how this technology may enhance existing situations. This is illustrated by a case study from the Dutch medical field: central quality reviewing for pathology in child oncology. The main goal of the review is to assess the quality of the diagnosis based on patient material. The sharing of knowledge in social face-to-face interaction during such meeting is an important advantage. At the same time there is the disadvantage that the experts from the seven Dutch academic medical centers have to travel to the review meeting and that the required logistics to collect and bring patient material and data to the meeting is cumbersome and time-consuming. This paper focuses on how this time-consuming, nonefficient way of reviewing can be replaced by a virtual collaboration system by merging technology supporting Computer Mediated Collaboration and intuitive interfacing. This requires insight in the preferred way of communication and collaboration as well as knowledge about preferred interaction style with a virtual shared workspace.

The right view from the wrong location: depth perception in stereoscopic multi-user virtual environments.

PubMed

Pollock, Brice; Burton, Melissa; Kelly, Jonathan W; Gilbert, Stephen; Winer, Eliot

2012-04-01

Stereoscopic depth cues improve depth perception and increase immersion within virtual environments (VEs). However, improper display of these cues can distort perceived distances and directions. Consider a multi-user VE, where all users view identical stereoscopic images regardless of physical location. In this scenario, cues are typically customized for one "leader" equipped with a head-tracking device. This user stands at the center of projection (CoP) and all other users ("followers") view the scene from other locations and receive improper depth cues. This paper examines perceived depth distortion when viewing stereoscopic VEs from follower perspectives and the impact of these distortions on collaborative spatial judgments. Pairs of participants made collaborative depth judgments of virtual shapes viewed from the CoP or after displacement forward or backward. Forward and backward displacement caused perceived depth compression and expansion, respectively, with greater compression than expansion. Furthermore, distortion was less than predicted by a ray-intersection model of stereo geometry. Collaboration times were significantly longer when participants stood at different locations compared to the same location, and increased with greater perceived depth discrepancy between the two viewing locations. These findings advance our understanding of spatial distortions in multi-user VEs, and suggest a strategy for reducing distortion.

Improved Learning Efficiency and Increased Student Collaboration through Use of Virtual Microscopy in the Teaching of Human Pathology

ERIC Educational Resources Information Center

Braun, Mark W.; Kearns, Katherine D.

2008-01-01

The implementation of virtual microscopy in the teaching of pathology at the Bloomington, Indiana extension of the Indiana University School of Medicine permitted the assessment of student attitudes, use and academic performance with respect to this new technology. A gradual and integrated approach allowed the parallel assessment with respect to…

Navigating Massively Multiplayer Online Games: Evaluating 21st Century Skills for Learning within Virtual Environments

ERIC Educational Resources Information Center

McCreery, Michael P.; Schrader, P. G.; Krach, S. Kathleen

2011-01-01

There is a substantial and growing interest in immersive virtual spaces as contexts for 21st century skills like problem solving, communication, and collaboration. However, little consideration has been given to the ways in which users become proficient in these environments or what types of target behaviors are associated with 21st century…

Information Problem-Solving Skills in Small Virtual Groups and Learning Outcomes

ERIC Educational Resources Information Center

Garcia, Consuelo; Badia, Antoni

2017-01-01

This study investigated the frequency of use of information problem-solving (IPS) skills and its relationship with learning outcomes. During the course of the study, 40 teachers carried out a collaborative IPS task in small virtual groups in a 4-week online training course. The status of IPS skills was collected through self-reports handed in over…

Communication Modes, Persuasiveness, and Decision-Making Quality: A Comparison of Audio Conferencing, Video Conferencing, and a Virtual Environment

ERIC Educational Resources Information Center

Lockwood, Nicholas S.

2011-01-01

Geographically dispersed teams rely on information and communication technologies (ICTs) to communicate and collaborate. Three ICTs that have received attention are audio conferencing (AC), video conferencing (VC), and, recently, 3D virtual environments (3D VEs). These ICTs offer modes of communication that differ primarily in the number and type…

SSERVI: Merging Science and Human Exploration

NASA Technical Reports Server (NTRS)

Schmidt, Gregory; Gibbs, Kristina

2017-01-01

The NASA Solar System Exploration Research Virtual Institute (SSERVI) is a virtual institute focused on research and the intersection of science and exploration, training the next generation of lunar scientists, and community development. As part of the SSERVI mission, we act as a hub for the opportunities that engage the larger scientific and exploration communities in order to form a new interdisciplinary, research-focused collaborations.

Real-Life Migrants on the MUVE: Stories of Virtual Transitions

ERIC Educational Resources Information Center

Perkins, Ross A.; Arreguin, Cathy

2007-01-01

The communication and collaborative interface known as a multi-user virtual environment (MUVE), has existed since as early as the late 1970s. MUVEs refer to programs that have an animated character ("avatar") controlled by a user within a wider environment that can be explored--or built--at will. Second Life, a MUVE created by San Francisco-based…

Collaboration, Reflection and Selective Neglect: Campus-Based Marketing Students' Experiences of Using a Virtual Learning Environment

ERIC Educational Resources Information Center

Molesworth, Mike

2004-01-01

Previous studies have suggested significant benefits to using computer-mediated communication in higher education and the development of the relevant skills may also be important for preparing students for their working careers. This study is a review of the introduction of a virtual learning environment to support a group of 60 campus-based,…

Scottish and Austrian Perspectives on Delivering a Master's: From Paper to Virtual and from Individual to Collaborative

ERIC Educational Resources Information Center

McLuckie, Joseph A.; Naulty, Michael; Luchoomun, Dharmadeo; Wahl, Harald

2009-01-01

This article explores the transition in course delivery from a paper-based format to blended learning, and highlights the role of the virtual learning environment (VLE) in this process. Professional practice in postgraduate programmes in particular is investigated during this transition stage at the University of Dundee (UoD) in Scotland, and the…

Eco-Dialogical Learning and Translanguaging in Open-Ended 3D Virtual Learning Environments: Where Place, Time, and Objects Matter

ERIC Educational Resources Information Center

Zheng, Dongping; Schmidt, Matthew; Hu, Ying; Liu, Min; Hsu, Jesse

2017-01-01

The purpose of this research was to explore the relationships between design, learning, and translanguaging in a 3D collaborative virtual learning environment for adolescent learners of Chinese and English. We designed an open-ended space congruent with ecological and dialogical perspectives on second language acquisition. In such a space,…

Virtual laboratories: new opportunities for collaborative water science

NASA Astrophysics Data System (ADS)

Ceola, Serena; Arheimer, Berit; Bloeschl, Guenter; Baratti, Emanuele; Capell, Rene; Castellarin, Attilio; Freer, Jim; Han, Dawei; Hrachowitz, Markus; Hundecha, Yeshewatesfa; Hutton, Christopher; Lindström, Goran; Montanari, Alberto; Nijzink, Remko; Parajka, Juraj; Toth, Elena; Viglione, Alberto; Wagener, Thorsten

2015-04-01

Reproducibility and repeatability of experiments are the fundamental prerequisites that allow researchers to validate results and share hydrological knowledge, experience and expertise in the light of global water management problems. Virtual laboratories offer new opportunities to enable these prerequisites since they allow experimenters to share data, tools and pre-defined experimental procedures (i.e. protocols). Here we present the outcomes of a first collaborative numerical experiment undertaken by five different international research groups in a virtual laboratory to address the key issues of reproducibility and repeatability. Moving from the definition of accurate and detailed experimental protocols, a rainfall-runoff model was independently applied to 15 European catchments by the research groups and model results were collectively examined through a web-based discussion. We found that a detailed modelling protocol was crucial to ensure the comparability and reproducibility of the proposed experiment across groups. Our results suggest that sharing comprehensive and precise protocols and running the experiments within a controlled environment (e.g. virtual laboratory) is as fundamental as sharing data and tools for ensuring experiment repeatability and reproducibility across the broad scientific community and thus advancing hydrology in a more coherent way.

Method and Apparatus for Virtual Interactive Medical Imaging by Multiple Remotely-Located Users

NASA Technical Reports Server (NTRS)

Ross, Muriel D. (Inventor); Twombly, Ian Alexander (Inventor); Senger, Steven O. (Inventor)

2003-01-01

A virtual interactive imaging system allows the displaying of high-resolution, three-dimensional images of medical data to a user and allows the user to manipulate the images, including rotation of images in any of various axes. The system includes a mesh component that generates a mesh to represent a surface of an anatomical object, based on a set of data of the object, such as from a CT or MRI scan or the like. The mesh is generated so as to avoid tears, or holes, in the mesh, providing very high-quality representations of topographical features of the object, particularly at high- resolution. The system further includes a virtual surgical cutting tool that enables the user to simulate the removal of a piece or layer of a displayed object, such as a piece of skin or bone, view the interior of the object, manipulate the removed piece, and reattach the removed piece if desired. The system further includes a virtual collaborative clinic component, which allows the users of multiple, remotely-located computer systems to collaboratively and simultaneously view and manipulate the high-resolution, three-dimensional images of the object in real-time.

Co-creation and Co-innovation in a Collaborative Networked Environment

NASA Astrophysics Data System (ADS)

Klen, Edmilson Rampazzo

Leveraged by the advances in communication and information Technologies, producers and consumers are developing a new behavior. Together with the new emerging collaborative manifestations this behavior may directly impact the way products are developed. This powerful combination indicates that consumers will be involved in a very early stage in product development processes supporting even more the creation and innovation of products. This new way of collaboration gives rise to a new collaborative networked environment based on co-creation and co-innovation. This work will present some evolutionary steps that point to the development of this environment where prosumer communities and virtual organizations interact and collaborate.

"Juxtapose": An Exploration of Mobile Augmented Reality Collaborations and Professional Practices in a Creative Learning Environment

ERIC Educational Resources Information Center

Menorath, Darren; Antonczak, Laurent

2017-01-01

This paper examines the state of the art of mobile Augmented Reality (AR) and mobile Virtual Reality (VR) in relation to collaboration and professional practices in a creative digital environment and higher education. To support their discussion, the authors use a recent design-based research project named "Juxtapose," which explores…

Using the Cognitive Apprenticeship Model with a Chat Tool to Enhance Online Collaborative Learning

ERIC Educational Resources Information Center

Rodríguez-Bonces, Mónica; Ortiz, Kris

2016-01-01

In Colombia, many institutions are in the firm quest of virtual learning environments to improve instruction, and making the most of online tools is clearly linked to offering quality learning. Thus, the purpose of this action research was to identify how the Cognitive Apprenticeship Model enhances online collaborative learning by using a chat…

"CityVille": Collaborative Game Play, Communication and Skill Development in Social Networks

ERIC Educational Resources Information Center

Del-Moral, María-Esther; Guzmán-Duque, Alba-Patricia

2014-01-01

This paper has as its aim to analyze how CityVille, a videogame hosted on Facebook and oriented to the construction of a virtual city, can favor collaboration between gamers along with the exchange of strategies, equally contributing to learning transfer and skill acquisition. The first step consists in identifying the opportunities which the said…