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Sample records for large-scale telework programme

  1. Evaluating Large-Scale Interactive Radio Programmes

    ERIC Educational Resources Information Center

    Potter, Charles; Naidoo, Gordon

    2009-01-01

    This article focuses on the challenges involved in conducting evaluations of interactive radio programmes in South Africa with large numbers of schools, teachers, and learners. It focuses on the role such large-scale evaluation has played during the South African radio learning programme's development stage, as well as during its subsequent…

  2. Evaluating Large-Scale Interactive Radio Programmes

    ERIC Educational Resources Information Center

    Potter, Charles; Naidoo, Gordon

    2009-01-01

    This article focuses on the challenges involved in conducting evaluations of interactive radio programmes in South Africa with large numbers of schools, teachers, and learners. It focuses on the role such large-scale evaluation has played during the South African radio learning programme's development stage, as well as during its subsequent…

  3. Examining the Invisible Loop: Tutors in Large Scale Teacher Development Programmes

    ERIC Educational Resources Information Center

    Bansilal, Sarah

    2014-01-01

    The recent curriculum changes in the South African education system have necessitated the development of large scale in-service training programmes for teachers. For some teacher training providers this has resulted in utilizing the services of tutors or facilitators from the various regions to deliver the programme. This article examines the role…

  4. Examining the Invisible Loop: Tutors in Large Scale Teacher Development Programmes

    ERIC Educational Resources Information Center

    Bansilal, Sarah

    2014-01-01

    The recent curriculum changes in the South African education system have necessitated the development of large scale in-service training programmes for teachers. For some teacher training providers this has resulted in utilizing the services of tutors or facilitators from the various regions to deliver the programme. This article examines the role…

  5. Studying large-scale programmes to improve patient safety in whole care systems: challenges for research.

    PubMed

    Benn, Jonathan; Burnett, Susan; Parand, Anam; Pinto, Anna; Iskander, Sandra; Vincent, Charles

    2009-12-01

    Large-scale national and multi-institutional patient safety improvement programmes are being developed in the health care systems of several countries to address problems in the reliability of care delivered to patients. Drawing upon popular collaborative improvement models, these campaigns are ambitious in their aims to improve patient safety in macro-level systems such as whole health care organisations. This article considers the methodological issues involved in conducting research and evaluation of these programmes. Several specific research challenges are outlined, which result from the complexity of longitudinal, multi-level intervention programmes and the variable, highly sociotechnical care systems, with which they interact. Organisational-level improvement programmes are often underspecified due to local variations in context and organisational readiness for improvement work. The result is variable implementation patterns and local adaptations. Programme effects span levels and other boundaries within a system, vary dynamically or are cumulative over time and are problematic to understand in terms of cause and effect, where concurrent external influences exist and the impact upon study endpoints may be mediated by a range of organisational and social factors. We outline the methodological approach to research in the United Kingdom Safer Patients Initiative, to exemplify how some of the challenges for research in this area can be met through a multi-method, longitudinal research design. Specifically, effective research designs must be sensitive to complex variation, through employing multiple qualitative and quantitative measures, collect data over time to understand change and utilise descriptive techniques to capture specific interactions between programme and context for implementation. When considering the long-term, sustained impact of an improvement programme, researchers must consider how to define and measure the capability for continuous safe and

  6. Evaluating large-scale health programmes at a district level in resource-limited countries

    PubMed Central

    Mate, Kedar S

    2011-01-01

    Abstract Recent experience in evaluating large-scale global health programmes has highlighted the need to consider contextual differences between sites implementing the same intervention. Traditional randomized controlled trials are ill-suited for this purpose, as they are designed to identify whether an intervention works, not how, when and why it works. In this paper we review several evaluation designs that attempt to account for contextual factors that contribute to intervention effectiveness. Using these designs as a base, we propose a set of principles that may help to capture information on context. Finally, we propose a tool, called a driver diagram, traditionally used in implementation that would allow evaluators to systematically monitor changing dynamics in project implementation and identify contextual variation across sites. We describe an implementation-related example from South Africa to underline the strengths of the tool. If used across multiple sites and multiple projects, the resulting driver diagrams could be pooled together to form a generalized theory for how, when and why a widely-used intervention works. Mechanisms similar to the driver diagram are urgently needed to complement existing evaluations of large-scale implementation efforts. PMID:22084529

  7. The development of new concepts for assessing reproductive toxicity applicable to large scale toxicological programmes.

    PubMed

    Bremer, S; Pellizzer, C; Hoffmann, S; Seidle, T; Hartung, T

    2007-01-01

    Large scale toxicological testing programmes which are currently ongoing such as the new European chemical legislation REACH require the development of new integrated testing strategies rather than applying traditional testing schemes to thousands of chemicals. The current practice of requiring in vivo testing for every possible adverse effect endanger the success of these programmes due (i) to limited testing facilities and sufficient capacity of scientific/technical knowledge for reproductive toxicity; (ii) an unacceptable number of laboratory animals involved (iii) an intolerable number of chemicals classified as false positive. A key aspect of the implementation of new testing strategies is the determination of prevalence of reproductive toxicity in the universe of industrial chemicals. Prevalences are relevant in order to be aware on the expected rate of false classification during the toxicological testing and to implement appropriate measures for their avoidance. Furthermore, a detailed understanding on the subendpoints affected by reproductive toxicants and the underlying mechanisms will lead to more science based testing strategies integrating alternative methods without compromising the protection of consumers.

  8. Teleworking and Gender.

    ERIC Educational Resources Information Center

    Huws, Ursula; And Others

    This report details a survey of 188 teleworkers throughout Europe that was supplemented by face-to-face interviews with 9 teleworkers in the United Kingdom, Sweden, and the Netherlands. The group of male and female home-based translators was chosen for two reasons: most surveys and case studies of teleworking have been company based and unable to…

  9. Multimethod study of a large-scale programme to improve patient safety using a harm-free care approach

    PubMed Central

    Power, Maxine; Brewster, Liz; Parry, Gareth; Brotherton, Ailsa; Minion, Joel; Ozieranski, Piotr; McNicol, Sarah; Harrison, Abigail; Dixon-Woods, Mary

    2016-01-01

    Objectives We aimed to evaluate whether a large-scale two-phase quality improvement programme achieved its aims and to characterise the influences on achievement. Setting National Health Service (NHS) in England. Participants NHS staff. Interventions The programme sought to (1) develop a shared national, regional and locally aligned safety focus for 4 high-cost, high volume harms; (2) establish a new measurement system based on a composite measure of ‘harm-free’ care and (3) deliver improved outcomes. Phase I involved a quality improvement collaborative intended to involve 100 organisations; phase II used financial incentives for data collection. Measures Multimethod evaluation of the programme. In phase I, analysis of regional plans and of rates of data submission and clinical outcomes reported to the programme. A concurrent process evaluation was conducted of phase I, but only data on submission rates and clinical outcomes were available for phase II. Results A context of extreme policy-related structural turbulence impacted strongly on phase I. Most regions' plans did not demonstrate full alignment with the national programme; most fell short of recruitment targets and attrition in attendance at the collaborative meetings occurred over time. Though collaborative participants saw the principles underlying the programme as attractive, useful and innovative, they often struggled to convert enthusiasm into change. Developing the measurement system was arduous, yet continued to be met by controversy. Data submission rates remained patchy throughout phase I but improved in reach and consistency in phase II in response to financial incentives. Some evidence of improvement in clinical outcomes over time could be detected but was hard to interpret owing to variability in the denominators. Conclusions These findings offer important lessons for large-scale improvement programmes, particularly when they seek to develop novel concepts and measures. External contexts may

  10. Time Discounting and Credit Market Access in a Large-Scale Cash Transfer Programme

    PubMed Central

    Handa, Sudhanshu; Martorano, Bruno; Halpern, Carolyn; Pettifor, Audrey; Thirumurthy, Harsha

    2017-01-01

    Summary Time discounting is thought to influence decision-making in almost every sphere of life, including personal finances, diet, exercise and sexual behavior. In this article we provide evidence on whether a national poverty alleviation program in Kenya can affect inter-temporal decisions. We administered a preferences module as part of a large-scale impact evaluation of the Kenyan Government’s Cash Transfer for Orphans and Vulnerable Children. Four years into the program we find that individuals in the treatment group are only marginally more likely to wait for future money, due in part to the erosion of the value of the transfer by inflation. However among the poorest households for whom the value of transfer is still relatively large we find significant program effects on the propensity to wait. We also find strong program effects among those who have access to credit markets though the program itself does not improve access to credit. PMID:28260842

  11. Time Discounting and Credit Market Access in a Large-Scale Cash Transfer Programme.

    PubMed

    Handa, Sudhanshu; Martorano, Bruno; Halpern, Carolyn; Pettifor, Audrey; Thirumurthy, Harsha

    2016-06-01

    Time discounting is thought to influence decision-making in almost every sphere of life, including personal finances, diet, exercise and sexual behavior. In this article we provide evidence on whether a national poverty alleviation program in Kenya can affect inter-temporal decisions. We administered a preferences module as part of a large-scale impact evaluation of the Kenyan Government's Cash Transfer for Orphans and Vulnerable Children. Four years into the program we find that individuals in the treatment group are only marginally more likely to wait for future money, due in part to the erosion of the value of the transfer by inflation. However among the poorest households for whom the value of transfer is still relatively large we find significant program effects on the propensity to wait. We also find strong program effects among those who have access to credit markets though the program itself does not improve access to credit.

  12. Large-Scale Programmable Synthesis of PbS Quantum Dots.

    PubMed

    Preske, Amanda; Liu, Jin; Prezhdo, Oleg V; Krauss, Todd D

    2016-03-03

    The most common method of synthesizing colloidal quantum dots (QDs) relies on an increasing particle size through increasing reaction time. We demonstrate a synthesis where the QD size is programmable through the use of a secondary phosphine sulfide precursor. The reaction runs to thermodynamic completion, resulting in a desired PbS diameter for a given set of specific reaction conditions, with no need for reaction quenching or post-synthesis size-separation. Moreover, this method is shown to produce high-quality PbS QDs on the grams scale. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. What can transaction costs tell us about governance in the delivery of large scale HIV prevention programmes in southern India?

    PubMed Central

    Guinness, Lorna

    2011-01-01

    This paper aims to understand the transaction costs implications of two different governance modes for large scale contracting of HIV prevention services to non-governmental organisations (NGOs) in 2 states in India as part of the National AIDS Control Programme between 2001 and 2003. Interviews at purposively selected case study NGOs, contracting agencies and key informants as well as document review were used to compile qualitative data and make comparisons between the states on five themes theoretically proposed to shape transaction costs: institutional environment, informational problems, opportunism, scale of activity and asset specificity (the degree to which investments made specifically for the contract have value elsewhere). The State AIDS Control Society (SACS) in state Y used a management agency to manage the NGO contracts whereas the SACS in state X contracted directly with the NGOs. A high level of uncertainty, endemic corruption and weak information systems served to weaken the contractual relationships in both states. The management agency in state Y enabled the development of a strong NGO network, greater transparency and control over corrupt practises than the contract model in state X. State X’s contractual process was further weakened by inadequate human resources. The application of the transaction cost framework to contracting out public services to NGOs identified the key costs associated with the governance of HIV prevention services through NGO contracts in India. A more successful form of relational contract evolved within the network of the contract management agency and the NGOs. This led to improved flows of information and perceived quality, and limited corrupt practises. It is unlikely that the SACS on its own, with broader responsibilities and limited autonomy can achieve the same ends. The management agency approach therefore appears to be both transaction cost reducing and better able to cope with the large scale of these

  14. What can transaction costs tell us about governance in the delivery of large scale HIV prevention programmes in southern India?

    PubMed

    Guinness, Lorna

    2011-06-01

    This paper aims to understand the transaction costs implications of two different governance modes for large scale contracting of HIV prevention services to non-governmental organisations (NGOs) in 2 states in India as part of the National AIDS Control Programme between 2001 and 2003. Interviews at purposively selected case study NGOs, contracting agencies and key informants as well as document review were used to compile qualitative data and make comparisons between the states on five themes theoretically proposed to shape transaction costs: institutional environment, informational problems, opportunism, scale of activity and asset specificity (the degree to which investments made specifically for the contract have value elsewhere). The State AIDS Control Society (SACS) in state Y used a management agency to manage the NGO contracts whereas the SACS in state X contracted directly with the NGOs. A high level of uncertainty, endemic corruption and weak information systems served to weaken the contractual relationships in both states. The management agency in state Y enabled the development of a strong NGO network, greater transparency and control over corrupt practises than the contract model in state X. State X's contractual process was further weakened by inadequate human resources. The application of the transaction cost framework to contracting out public services to NGOs identified the key costs associated with the governance of HIV prevention services through NGO contracts in India. A more successful form of relational contract evolved within the network of the contract management agency and the NGOs. This led to improved flows of information and perceived quality, and limited corrupt practises. It is unlikely that the SACS on its own, with broader responsibilities and limited autonomy can achieve the same ends. The management agency approach therefore appears to be both transaction cost reducing and better able to cope with the large scale of these

  15. The North Coast Cholesterol Check Campaign. Results of the first three years of a large-scale public screening programme.

    PubMed

    van Beurden, E K; James, R; Henrikson, D; Tyler, C; Christian, J

    1991-03-18

    Although cardiovascular disease (CVD) mortality has been declining, CVD is still the major cause of death in Australia and an elevated blood cholesterol level is considered a major contributor. Large-scale community-based screening programmes in other countries have demonstrated that a population approach can be effective in reducing cholesterol levels and the risk of CVD. The North Coast Cholesterol Check Campaign is the largest community-based cholesterol intervention programme in Australia. Since its inception in 1987, 13% of the Region's adult population (over 29,000 persons) have been screened. About half had elevated blood cholesterol levels (greater than or equal to 5.5 mmol/L) and were given dietary counselling to reduce fat intake. Mean blood cholesterol levels were significantly reduced between initial screening and follow-up in all three years. Reductions, after correction for regression, were 8%, 6% and 10%, respectively, in 1987, 1988 and 1989. There was also a consistent and significant 1.5% to 2% reduction in weight. All age/sex cohorts above age 35 were well represented each year although self-referral did bias both initial and follow-up samples towards women and the aged. Nevertheless, the proportion of men and men in their middle age increased during the three years. The proportion of participants with elevated cholesterol levels increased in each successive year while the proportion of participants who complied with referrals to visit their general practitioner and with requests to return for follow-up decreased. Over half of the North Coast adult population has now had a cholesterol test. The rate of increase in testing since the inception of the Campaign has been approximately four times the national rate. North Coast general practitioners have played a major role by catering for the increased community demand for cholesterol testing and by providing an effective referral service for the Campaign. Community-based screening programmes in

  16. Implementing large-scale programmes to optimise the health workforce in low- and middle-income settings: a multicountry case study synthesis.

    PubMed

    Gopinathan, Unni; Lewin, Simon; Glenton, Claire

    2014-12-01

    To identify factors affecting the implementation of large-scale programmes to optimise the health workforce in low- and middle-income countries. We conducted a multicountry case study synthesis. Eligible programmes were identified through consultation with experts and using Internet searches. Programmes were selected purposively to match the inclusion criteria. Programme documents were gathered via Google Scholar and PubMed and from key informants. The SURE Framework - a comprehensive list of factors that may influence the implementation of health system interventions - was used to organise the data. Thematic analysis was used to identify the key issues that emerged from the case studies. Programmes from Brazil, Ethiopia, India, Iran, Malawi, Venezuela and Zimbabwe were selected. Key system-level factors affecting the implementation of the programmes were related to health worker training and continuing education, management and programme support structures, the organisation and delivery of services, community participation, and the sociopolitical environment. Existing weaknesses in health systems may undermine the implementation of large-scale programmes to optimise the health workforce. Changes in the roles and responsibilities of cadres may also, in turn, impact the health system throughout. © 2014 John Wiley & Sons Ltd.

  17. Interprofessional Education and Practice Guide No. 7: Development, implementation, and evaluation of a large-scale required interprofessional education foundational programme.

    PubMed

    Shrader, Sarah; Hodgkins, Renee; Laverentz, Delois; Zaudke, Jana; Waxman, Michael; Johnston, Kristy; Jernigan, Stephen

    2016-09-01

    Health profession educators and administrators are interested in how to develop an effective and sustainable interprofessional education (IPE) programme. We describe the approach used at the University of Kansas Medical Centre, Kansas City, United States. This approach is a foundational programme with multiple large-scale, half-day events each year. The programme is threaded with common curricular components that build in complexity over time and assures that each learner is exposed to IPE. In this guide, lessons learned and general principles related to the development of IPE programming are discussed. Important areas that educators should consider include curriculum development, engaging leadership, overcoming scheduling barriers, providing faculty development, piloting the programming, planning for logistical coordination, intentionally pairing IP facilitators, anticipating IP conflict, setting clear expectations for learners, publicising the programme, debriefing with faculty, planning for programme evaluation, and developing a scholarship and dissemination plan.

  18. Early initiation of and exclusive breastfeeding in large-scale community-based programmes in Bolivia and Madagascar.

    PubMed

    Baker, Elizabeth Jean; Sanei, Linda C; Franklin, Nadra

    2006-12-01

    About one-fourth to one-half of all infant deaths in developing countries occur in the first week of life. Immediate breastfeeding within the first hour, followed by early exclusive breastfeeding, improves the health and survival status of newborns. The aim of this study was to demonstrate that breastfeeding practices, crucial to infant health, can be improved at scale in developing countries. During 1999-2003, the LINKAGES Project, funded by the United States Agency for International Development, implemented its community-based model to bring about rapid change in individual behaviours and community norms regarding early and exclusive breastfeeding, at a scale [LINKAGES' definition of 'scale' was adapted from a CORE Group background paper on 'Scaling-up' maternal, newborn, and child health services, 11 July 2005] that could achieve significant public-health impact. 'Scale' was defined as bringing improved infant-feeding practices to more people over a wider geographic area, more quickly, more equitably, and with sustainability as a goal. During this time, country-specific programmes were designed and implemented in Bolivia and Madagascar, with catchment populations of one million and six million respectively. These country programmes were implemented with multiple local government, private voluntary organizations, and partners of non-governmental organizations (NGOs) through existing health and nutrition activities. Breastfeeding was an entry point to work at all levels of the healthcare system and, within communities, using policy/advocacy and training for healthcare workers, with a particular emphasis on front-line health workers and community members. Harmonized messages and materials, including mass media, were developed and used by partners. Timely initiation of breastfeeding was one indicator measured. Data collected through rapid assessment surveys showed statistically significant increases (p<0.001) in timely initiation of breastfeeding in both the

  19. Evaluation of a large scale implementation of disease management programmes in various Dutch regions: a study protocol.

    PubMed

    Lemmens, Karin M M; Rutten-Van Mölken, Maureen P M H; Cramm, Jane M; Huijsman, Robbert; Bal, Roland A; Nieboer, Anna P

    2011-01-10

    Disease management programmes (DMPs) have been developed to improve effectiveness and economic efficiency within chronic care delivery by combining patient-related, professional-directed, and organisational interventions. The benefits of DMPs within different settings, patient groups, and versions remain unclear. In this article we propose a protocol to evaluate a range of current DMPs by capturing them in a single conceptual framework, employing comparable structure, process, and outcome measures, and combining qualitative and quantitative research methods. To assess DMP effectiveness a practical clinical trial will be conducted. Twenty-two disease management experiments will be studied in various Dutch regions consisting of a variety of collaborations between organisations and/or professionals. Patient cohorts include those with cardiovascular diseases, chronic obstructive pulmonary disease, diabetes, stroke, depression, psychotic diseases, and eating disorders. Our methodological approach combines qualitative and quantitative research methods to enable a comprehensive evaluation of complex programmes. Process indicators will be collected from health care providers' data registries and measured via physician and staff questionnaires. Patient questionnaires include health care experiences, health care utilisation, and quality of life. Qualitative data will be gathered by means of interviews and document analysis for an in depth description of project interventions and the contexts in which DMPs are embedded, and an ethnographic process evaluation in five DMPs. Such a design will provide insight into ongoing DMPs and demonstrate which elements of the intervention are potentially (cost)-effective for which patient populations. It will also enable sound comparison of the results of the different programmes. The study will lead to a better understanding of (1) the mechanisms of disease management, (2) the feasibility, and cost-effectiveness of a disease management

  20. Evaluation of a large scale implementation of disease management programmes in various Dutch regions: a study protocol

    PubMed Central

    2011-01-01

    Background Disease management programmes (DMPs) have been developed to improve effectiveness and economic efficiency within chronic care delivery by combining patient-related, professional-directed, and organisational interventions. The benefits of DMPs within different settings, patient groups, and versions remain unclear. In this article we propose a protocol to evaluate a range of current DMPs by capturing them in a single conceptual framework, employing comparable structure, process, and outcome measures, and combining qualitative and quantitative research methods. Methods To assess DMP effectiveness a practical clinical trial will be conducted. Twenty-two disease management experiments will be studied in various Dutch regions consisting of a variety of collaborations between organisations and/or professionals. Patient cohorts include those with cardiovascular diseases, chronic obstructive pulmonary disease, diabetes, stroke, depression, psychotic diseases, and eating disorders. Our methodological approach combines qualitative and quantitative research methods to enable a comprehensive evaluation of complex programmes. Process indicators will be collected from health care providers' data registries and measured via physician and staff questionnaires. Patient questionnaires include health care experiences, health care utilisation, and quality of life. Qualitative data will be gathered by means of interviews and document analysis for an in depth description of project interventions and the contexts in which DMPs are embedded, and an ethnographic process evaluation in five DMPs. Such a design will provide insight into ongoing DMPs and demonstrate which elements of the intervention are potentially (cost)-effective for which patient populations. It will also enable sound comparison of the results of the different programmes. Discussion The study will lead to a better understanding of (1) the mechanisms of disease management, (2) the feasibility, and cost

  1. A Correlational Study of Telework Frequency, Information Communication Technology, and Job Satisfaction of Home-Based Teleworkers

    ERIC Educational Resources Information Center

    Webster-Trotman, Shana P.

    2010-01-01

    In 2008, 33.7 million Americans teleworked from home. The Telework Enhancement Act (S. 707) and the Telework Improvements Act (H.R. 1722) of 2009 were designed to increase the number of teleworkers. The research problem addressed was the lack of understanding of factors that influence home-based teleworkers' job satisfaction. Job dissatisfaction…

  2. A Correlational Study of Telework Frequency, Information Communication Technology, and Job Satisfaction of Home-Based Teleworkers

    ERIC Educational Resources Information Center

    Webster-Trotman, Shana P.

    2010-01-01

    In 2008, 33.7 million Americans teleworked from home. The Telework Enhancement Act (S. 707) and the Telework Improvements Act (H.R. 1722) of 2009 were designed to increase the number of teleworkers. The research problem addressed was the lack of understanding of factors that influence home-based teleworkers' job satisfaction. Job dissatisfaction…

  3. Gauging policy-driven large-scale vegetation restoration programmes under a changing environment: Their effectiveness and socio-economic relationships.

    PubMed

    Li, Ting; Lü, Yihe; Fu, Bojie; Comber, Alexis J; Harris, Paul; Wu, Lianhai

    2017-12-31

    Large-scale ecological restoration has been widely accepted globally as an effective strategy for combating environmental crises and to facilitate sustainability. Assessing the effectiveness of ecological restoration is vital for researchers, practitioners, and policy-makers. However, few practical tools are available to perform such tasks, particularly for large-scale restoration programmes in complex socio-ecological systems. By taking a "before and after" design, this paper formulates a composite index (Ej) based on comparing the trends of vegetation cover and vegetation productivity to assess ecological restoration effectiveness. The index reveals the dynamic and spatially heterogenic process of vegetation restoration across different time periods, which can be informative for ecological restoration management at regional scales. Effectiveness together with its relationship to socio-economic factors is explored via structural equation modeling for three time periods. The results indicate that the temporal scale is a crucial factor in representing restoration effectiveness, and that the effects of socio-economic factors can also vary with time providing insight for improving restoration effectiveness. A dual-track strategy, which promotes the development of tertiary industry in absorbing the rural labor force together with improvements in agricultural practices, is proposed as a promising strategy for enhancing restoration effectiveness. In this process, timely and long-term ecological restoration monitoring is advocated, so that the success and sustainability of such programmes is ensured, together with more informative decision making where socio-ecological interactions at differing temporal scales are key concerns. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. "It's a complex mesh"- how large-scale health system reorganisation affected the delivery of the immunisation programme in England: a qualitative study.

    PubMed

    Chantler, Tracey; Lwembe, Saumu; Saliba, Vanessa; Raj, Thara; Mays, Nicholas; Ramsay, Mary; Mounier-Jack, Sandra

    2016-09-15

    The English health system experienced a large-scale reorganisation in April 2013. A national tri-partite delivery framework involving the Department of Health, NHS England and Public Health England was agreed and a new local operational model applied. Evidence about how health system re-organisations affect constituent public health programmes is sparse and focused on low and middle income countries. We conducted an in-depth analysis of how the English immunisation programme adapted to the April 2013 health system reorganisation, and what facilitated or hindered the delivery of immunisation services in this context. A qualitative case study methodology involving interviews and observations at national and local level was applied. Three sites were selected to represent different localities, varying levels of immunisation coverage and a range of changes in governance. Study participants included 19 national decision-makers and 56 local implementers. Two rounds of interviews and observations (immunisation board/committee meetings) occurred between December 2014 and June 2015, and September and December 2015. Interviews were audio recorded and transcribed verbatim and written accounts of observed events compiled. Data was imported into NVIVO 10 and analysed thematically. The new immunisation programme in the new health system was described as fragmented, and significant effort was expended to regroup. National tripartite arrangements required joint working and accountability; a shift from the simpler hierarchical pre-reform structure, typical of many public health programmes. New local inter-organisational arrangements resulted in ambiguity about organisational responsibilities and hindered data-sharing. Whilst making immunisation managers responsible for larger areas supported equitable resource distribution and strengthened service commissioning, it also reduced their ability to apply clinical expertise, support and evaluate immunisation providers' performance

  5. The transition of a large-scale quality improvement initiative: a bibliometric analysis of the Productive Ward: Releasing Time to Care programme.

    PubMed

    White, Mark; Wells, John S G; Butterworth, Tony

    2014-09-01

    To examine the literature related to a large-scale quality improvement initiative, the 'Productive Ward: Releasing Time to Care', providing a bibliometric profile that tracks the level of interest and scale of roll-out and adoption, discussing the implications for sustainability. Productive Ward: Releasing Time to Care (aka Productive Ward) is probably one of the most ambitious quality improvement efforts engaged by the UK-NHS. Politically and financially supported, its main driver was the NHS Institute for Innovation and Improvement. The NHS institute closed in early 2013 leaving a void of resources, knowledge and expertise. UK roll-out of the initiative is well established and has arguably peaked. International interest in the initiative however continues to develop. A comprehensive literature review was undertaken to identify the literature related to the Productive Ward and its implementation (January 2006-June 2013). A bibliometric analysis examined/reviewed the trends and identified/measured interest, spread and uptake. Overall distribution patterns identify a declining trend of interest, with reduced numbers of grey literature and evaluation publications. However, detailed examination of the data shows no reduction in peer-reviewed outputs. There is some evidence that international uptake of the initiative continues to generate publications and create interest. Sustaining this initiative in the UK will require re-energising, a new focus and financing. The transition period created by the closure of its creator may well contribute to further reduced levels of interest and publication outputs in the UK. However, international implementation, evaluation and associated publications could serve to attract professional/academic interest in this well-established, positively reported, quality improvement initiative. This paper provides nurses and ward teams involved in quality improvement programmes with a detailed, current-state, examination and analysis of the

  6. The impact of a large-scale quality improvement programme on work engagement: preliminary results from a national cross-sectional-survey of the 'Productive Ward'.

    PubMed

    White, Mark; Wells, John S G; Butterworth, Tony

    2014-12-01

    Quality improvement (QI) Programmes, like the Productive Ward: Releasing-time-to-care initiative, aim to 'engage' and 'empower' ward teams to actively participate, innovate and lead quality improvement at the front line. However, little is known about the relationship and impact that QI work has on the 'engagement' of the clinical teams who participate and vice-versa. This paper explores and examines the impact of a large-scale QI programme, the Productive Ward, on the 'work engagement' of the nurses and ward teams involved. Using the Utrecht Work Engagement Scale (UWES), we surveyed, measured and analysed work engagement in a representative test group of hospital-based ward teams who had recently commenced the latest phase of the national 'Productive Ward' initiative in Ireland and compared them to a control group of similar size and matched (as far as is possible) on variables such as ward size, employment grade and clinical specialty area. 338 individual datasets were recorded, n=180 (53.6%) from the Productive Ward group, and n=158 (46.4%) from the control group; the overall response rate was 67%, and did not differ significantly between the Productive Ward and control groups. The work engagement mean score (±standard deviation) in the Productive group was 4.33(±0.88), and 4.07(±1.06) in the control group, representing a modest but statistically significant between-group difference (p=0.013, independent samples t-test). Similarly modest differences were observed in all three dimensions of the work engagement construct. Employment grade and the clinical specialty area were also significantly related to the work engagement score (p<0.001, general linear model) and (for the most part), to its components, with both clerical and nurse manager grades, and the elderly specialist areas, exhibiting substantially higher scores. The findings demonstrate how QI activities, like those integral to the Productive Ward programme, appear to positively impact on the work

  7. LSI/VLSI (Large Scale Integration/Very Large Scale Integration) ion implanted GaAs (Gallium Arsenide) IC processing. Appendix A: Feasibility analysis of Gallium-Arsenide mask programmable functions and logic arrays for high performance communications systems

    NASA Astrophysics Data System (ADS)

    Zucca, R. R.; Kirkpatrick, C. G.; Asbeck, P. M.; Eisen, F. H.; Lee, C. P.

    1984-01-01

    Circuits critical to the performance of advanced radio, radar and spread spectrum communications systems require advances in the state-of-the-art in semiconductor technology to meet the demands of advanced systems. As these systems increase in complexity, extensive digital circuitry is required in addition to the typical linear signal processing circuits. The power, size and weight of advanced systems also becomes unacceptable without continuous advances in semiconductor technology. Moreover an increasing trend is seen in the use of metal mask selectable functions, programmable logic arrays and gate arrays to implement system specific circuitry in an attempt to lower non-recurring costs, minimize risk and shorten development times. GaAs and other technologies with very high speed power-performance figures-of-merit are critical ingredients in systems implementations which satisfy these needs. To meet these advanced system requirements this project was initiated as a multi-phase/year program to develop a group of mask programmable gallium arsenide (GaAs) circuit elements applicable to high speed/performance communications systems.

  8. "Tele"working in Higher Education: What Managers Should Know "before" Developing Teleworking Policies

    ERIC Educational Resources Information Center

    Waters, Kristin Albright

    2015-01-01

    Over the last several decades, changes in the workplace within higher education has led to the notion of teleworking: the opportunity for employees to complete work in a remote location. This article will review the various concepts of teleworking, as well as the pros, cons, and implications for the work environment within higher education.

  9. "Tele"working in Higher Education: What Managers Should Know "before" Developing Teleworking Policies

    ERIC Educational Resources Information Center

    Waters, Kristin Albright

    2015-01-01

    Over the last several decades, changes in the workplace within higher education has led to the notion of teleworking: the opportunity for employees to complete work in a remote location. This article will review the various concepts of teleworking, as well as the pros, cons, and implications for the work environment within higher education.

  10. The Value of Large-Scale Randomised Control Trials in System-Wide Improvement: The Case of the Reading Catch-Up Programme

    ERIC Educational Resources Information Center

    Fleisch, Brahm; Taylor, Stephen; Schöer, Volker; Mabogoane, Thabo

    2017-01-01

    This article illustrates the value of large-scale impact evaluations with counterfactual components. It begins by exploring the limitations of small-scale impact studies, which do not allow reliable inference to a wider population or which do not use valid comparison groups. The paper then describes the design features of a recent large-scale…

  11. Teleworking: Guidelines for Good Practice. IES Report 329.

    ERIC Educational Resources Information Center

    Huws, Ursula; And Others

    Because teleworking presents major new challenges to human resource managers, trade unions, and others involved in the development of good employment practices, this book provides practical guidelines for good practice in regard to teleworkers that recognize that teleworking is not a single category, but covers at least five distinct groups with…

  12. Telework: A New Way of Working and Living.

    ERIC Educational Resources Information Center

    Di Martino, Vittorio; Wirth, Linda

    1990-01-01

    Defines telework as online or offline electronic work performed at home or in central offices, customer sites, and satellite centers. Examines the nature, extent, and impact of telework on working conditions, work organization and explores the legal status of teleworkers, changing attitudes of employers and trade unions, and government…

  13. Proposed teleworking platform for workstations supporting multimedia medical applications

    NASA Astrophysics Data System (ADS)

    Orphanos, George; Kanellopoulos, Dimitris; Prentzas, Lambros; Koubias, Stavros

    1993-09-01

    Teleworking refers to the usage of telecommunication facilities to improve human to human collaboration and enhance performance of work. This paper focuses on the way teleworking affects medicine. In particular, a teleworking platform is proposed to support multimedia medical applications embedded into RISC-based workstations. In order to support the teleworking platform, current commercially available products have to be taken into consideration and a range of new technologies need to be developed and made available. In this paper, we put emphasis on a RISC-based workstation, UNIXTM operating system, communication protocols capable to support the teleworking platform, and ISDN network capabilities.

  14. Large scale dynamic systems

    NASA Technical Reports Server (NTRS)

    Doolin, B. F.

    1975-01-01

    Classes of large scale dynamic systems were discussed in the context of modern control theory. Specific examples discussed were in the technical fields of aeronautics, water resources and electric power.

  15. Method and infrastructure for cycle-reproducible simulation on large scale digital circuits on a coordinated set of field-programmable gate arrays (FPGAs)

    DOEpatents

    Asaad, Sameh W; Bellofatto, Ralph E; Brezzo, Bernard; Haymes, Charles L; Kapur, Mohit; Parker, Benjamin D; Roewer, Thomas; Tierno, Jose A

    2014-01-28

    A plurality of target field programmable gate arrays are interconnected in accordance with a connection topology and map portions of a target system. A control module is coupled to the plurality of target field programmable gate arrays. A balanced clock distribution network is configured to distribute a reference clock signal, and a balanced reset distribution network is coupled to the control module and configured to distribute a reset signal to the plurality of target field programmable gate arrays. The control module and the balanced reset distribution network are cooperatively configured to initiate and control a simulation of the target system with the plurality of target field programmable gate arrays. A plurality of local clock control state machines reside in the target field programmable gate arrays. The local clock state machines are configured to generate a set of synchronized free-running and stoppable clocks to maintain cycle-accurate and cycle-reproducible execution of the simulation of the target system. A method is also provided.

  16. The Whole Is Greater than the Sum of Its Parts: A Large-Scale Study of Students' Learning in Response to Different Programme Assessment Patterns

    ERIC Educational Resources Information Center

    Jessop, Tansy; El Hakim, Yassein; Gibbs, Graham

    2014-01-01

    Audits of 23 degree programmes in eight universities showed wide variations in assessment patterns and feedback. Scores from Assessment Experience Questionnaire returns revealed consistent relationships between characteristics of assessment and student learning responses, including a strong relationship between quantity and quality of feedback and…

  17. Large scale scientific computing

    SciTech Connect

    Deuflhard, P. ); Engquist, B. )

    1987-01-01

    This book presents papers on large scale scientific computing. It includes: Initial value problems of ODE's and parabolic PDE's; Boundary value problems of ODE's and elliptic PDE's; Hyperbolic PDE's; Inverse problems; Optimization and optimal control problems; and Algorithm adaptation on supercomputers.

  18. Knowledge Work and Telework: An Exploratory Study.

    ERIC Educational Resources Information Center

    Bentley, Kaye; Yoong, Pak

    2000-01-01

    Describes a case study conducted in New Zealand that investigated how knowledge workers used home-based teleworking, using information and Internet technology. Discusses findings that indicate a preference for doing most work at the office, and considers implications for human resources management, practice, and research. (Contains 26 references.)…

  19. Design and baseline findings of a large-scale rapid response to an HIV outbreak in people who inject drugs in Athens, Greece: the ARISTOTLE programme.

    PubMed

    Hatzakis, Angelos; Sypsa, Vana; Paraskevis, Dimitrios; Nikolopoulos, Georgios; Tsiara, Chrissa; Micha, Katerina; Panopoulos, Anastasios; Malliori, Meni; Psichogiou, Mina; Pharris, Anastasia; Wiessing, Lucas; van de Laar, Marita; Donoghoe, Martin; Heckathorn, Douglas D; Friedman, Samuel R; Des Jarlais, Don C

    2015-09-01

    To (i) describe an intervention implemented in response to the HIV-1 outbreak among people who inject drugs (PWIDs) in Greece (ARISTOTLE programme), (ii) assess its success in identifying and testing this population and (iii) describe socio-demographic characteristics, risk behaviours and access to treatment/prevention, estimate HIV prevalence and identify risk factors, as assessed at the first participation of PWIDs. A 'seek, test, treat, retain' intervention employing five rounds of respondent-driven sampling. Athens, Greece (2012-13). A total of 3320 individuals who had injected drugs in the past 12 months. ARISTOTLE is an intervention that involves reaching out to high-risk, hard-to-reach PWIDs ('seek'), engaging them in HIV testing and providing information and materials to prevent HIV ('test') and initiating and maintaining anti-retroviral and opioid substitution treatment for those testing positive ('treat' and 'retain'). Blood samples were collected for HIV testing and personal interviews were conducted. ARISTOTLE recruited 3320 PWIDs during the course of 13.5 months. More than half (54%) participated in multiple rounds, resulting in 7113 visits. HIV prevalence was 15.1%. At their first contact with the programme, 12.5% were on opioid substitution treatment programmes and the median number of free syringes they had received in the preceding month was 0. In the multivariable analysis, apart from injection-related variables, homelessness was a risk factor for HIV infection in male PWIDs [odds ratio (OR) yes versus no = 1.89, 95% confidence interval (CI) = 1.41, 2.52] while, in female PWIDS, the number of sexual partners (OR for > 5 versus one partner in the past year = 4.12, 95% CI = 1.93, 8.77) and history of imprisonment (OR yes versus no = 2.76, 95% CI = 1.43, 5.31) were associated with HIV. In Athens, Greece, the ARISTOTLE intervention for identifying HIV-positive people among people who inject drugs (PWID) facilitated rapid

  20. Design and baseline findings of a large-scale rapid response to an HIV outbreak in people who inject drugs in Athens, Greece: the ARISTOTLE programme

    PubMed Central

    Hatzakis, Angelos; Sypsa, Vana; Paraskevis, Dimitrios; Nikolopoulos, Georgios; Tsiara, Chrissa; Micha, Katerina; Panopoulos, Anastasios; Malliori, Meni; Psichogiou, Mina; Pharris, Anastasia; Wiessing, Lucas; van de Laar, Marita; Donoghoe, Martin; Heckathorn, Douglas D.; Friedman, Samuel R.; Des Jarlais, Don C.

    2016-01-01

    Aims To (i) describe an intervention implemented in response to the HIV-1 outbreak among people who inject drugs (PWIDs) in Greece (ARISTOTLE programme), (ii) assess its success in identifying and testing this population and (iii) describe socio-demographic characteristics, risk behaviours and access to treatment/prevention, estimate HIV prevalence and identify risk factors, as assessed at the first participation of PWIDs. Design A ‘seek, test, treat, retain’ intervention employing five rounds of respondent-driven sampling. Setting Athens, Greece (2012–13). Participants A total of 3320 individuals who had injected drugs in the past 12 months. Intervention ARISTOTLE is an intervention that involves reaching out to high-risk, hard-to-reach PWIDs (‘seek’), engaging them in HIV testing and providing information and materials to prevent HIV (‘test’) and initiating and maintaining anti-retroviral and opioid substitution treatment for those testing positive (‘treat’ and ‘retain’). Measurements Blood samples were collected for HIV testing and personal interviews were conducted. Findings ARISTOTLE recruited 3320 PWIDs during the course of 13.5 months. More than half (54%) participated in multiple rounds, resulting in 7113 visits. HIV prevalence was 15.1%. At their first contact with the programme, 12.5% were on opioid substitution treatment programmes and the median number of free syringes they had received in the preceding month was 0. In the multivariable analysis, apart from injection-related variables, homelessness was a risk factor for HIV infection in male PWIDs [odds ratio (OR) yes versus no=1.89, 95% confidence interval (CI)=1.41, 2.52]while, in female PWIDS, the number of sexual partners (OR for >5 versus one partner in the past year=4.12, 95% CI=1.93, 8.77) and history of imprisonment (OR yes versus no=2.76, 95% CI=1.43, 5.31) were associated with HIV. Conclusions In Athens, Greece, the ARISTOTLE intervention for identifying HIV

  1. Large-Scale Disasters

    NASA Astrophysics Data System (ADS)

    Gad-El-Hak, Mohamed

    "Extreme" events - including climatic events, such as hurricanes, tornadoes, and drought - can cause massive disruption to society, including large death tolls and property damage in the billions of dollars. Events in recent years have shown the importance of being prepared and that countries need to work together to help alleviate the resulting pain and suffering. This volume presents a review of the broad research field of large-scale disasters. It establishes a common framework for predicting, controlling and managing both manmade and natural disasters. There is a particular focus on events caused by weather and climate change. Other topics include air pollution, tsunamis, disaster modeling, the use of remote sensing and the logistics of disaster management. It will appeal to scientists, engineers, first responders and health-care professionals, in addition to graduate students and researchers who have an interest in the prediction, prevention or mitigation of large-scale disasters.

  2. The cost of large-scale school health programmes which deliver anthelmintics to children in Ghana and Tanzania. The Partnership for Child Development.

    PubMed

    1999-07-30

    It has been argued that the delivery of anthelmintics to school-children through existing education infrastructure can be one of the most cost-effective approaches to controlling parasitic worm infection. This paper examines the actual costs of a combination of mass and selective treatment for schistosomiasis using praziquantel and mass treatment for intestinal nematodes using albendazole, as an integral part of school health programmes reaching 80442 pupils in 577 schools in Volta Region, Ghana, and reaching 109099 pupils in 350 schools in Tanga Region, Tanzania. The analysis shows that financial delivery costs per child treated using praziquantel, which involved a dose related to body mass and a prior screening at the school level, were US$ 0.67 in Ghana and US$ 0.21 in Tanzania, while the delivery costs for albendazole, which was given as a fixed dose to all children, were US$ 0.04 in Ghana and US$ 0.03 in Tanzania. The higher unit costs in Ghana reflect the epidemiology of infection; overall, fixed costs were similar in both countries, but fewer children required treatment in Ghana. Analysis of economic costs-which includes the cost of unpaid days of labour--indicates that the financial costs are increased in Ghana by 78% and in Tanzania by 44%. It is these additional costs which are avoided by integration into an existing infrastructure. It is concluded that: the base cost of delivering a universal, standard, school-based health intervention can be as low as US$ 0.03 per child treated; that even a slight increase in the complexity of delivery can have a significant impact on the cost of intervention; and that the use of the education infrastructure does indeed offer significant savings in delivery costs.

  3. Large Scale Nonlinear Programming.

    DTIC Science & Technology

    1978-06-15

    KEY WORDS (Conhinu. as, t.n.t.. aid. if nic••iary aid ld.ntify by block n,a,b.r) L. In,~~~ IP!CIE LARGE SCALE OPTIMIZATION APPLICATIONS OF NONLINEAR ... NONLINEAR PROGRAMMING by Garth P. McCormick 1. Introduction The general mathematical programming ( optimization ) problem can be stated in the following form...because the difficulty in solving a general nonlinear optimization problem has a~ much to do with the nature of the functions involved as it does with the

  4. Large-scale spatial pollution patterns around the North Sea indicated by coastal bird eggs within an EcoQO programme.

    PubMed

    Dittmann, Tobias; Becker, Peter H; Bakker, Joop; Bignert, Anders; Nyberg, Elisabeth; Pereira, M Glória; Pijanowska, Ursula; Shore, Richard F; Stienen, Eric; Toft, Geir Olav; Marencic, Harald

    2012-11-01

    To categorize the marine environmental health status, the Oslo and Paris commissions have recently formulated Ecological Quality Objectives (EcoQOs) for many ecological features including the contamination of coastal bird eggs with mercury and organochlorines. In this study, we describe spatial and temporal patterns of egg contamination around the North Sea and compared them to the EcoQOs. Concentrations of mercury, polychlorinated biphenyl (ΣPCB) congeners, dichlorodiphenyltrichloroethane (ΣDDT) and derivatives, hexachlorobenzene (HCB) and hexachlorocyclohexane (ΣHCH) isomers were analysed in two tern species (Sterna hirundo and Sterna paradisaea) and Oystercatcher (Haematopus ostralegus) eggs collected between 2008 and 2010 in a total of 21 sites in seven countries surrounding the North Sea. Hg, ΣPCB and HCB were highest in the southern sites, while ΣDDT and ΣHCH concentrations were greatest in eggs from the western North Sea and the Elbe estuary. There were rarely any consistent decreases over time for any compounds. In the terns, Hg, HCB and ΣHCH increased at most sites, ΣPCB and ΣDDT in Sweden and Norway. In the Oystercatcher, HCB and ΣHCH increased at more than the half of the sites, ΣPCB, ΣDDT and Hg at several German sites. In the terns, Hg, ΣPCB and ΣDDT exceeded the EcoQO in all, HCB in most years and sites. At most sites, ΣHCH fulfilled the EcoQO in some study years. In the Oystercatcher, Hg, ΣPCB and ΣDDT exceeded the EcoQO in all or most years and sites. HCB and ΣHCH fulfilled the EcoQO in some or all years at most sites. The EcoQO was exceeded most frequently in estuaries. We conclude that EcoQOs are suitable for drawing contamination patterns of the coastal North Sea in an easily understandable manner, offering the opportunity to harmonize the EcoQOs with coordinated environmental monitoring programmes.

  5. Telework in Australia: Findings from a National Survey in Selected Industries.

    ERIC Educational Resources Information Center

    Lafferty, George; Whitehouse, Gillian

    2000-01-01

    A survey of 2,528 Australian organizations found that 44% had used some teleworkers, 15% did regularly. Larger organizations were more likely to use them. Most telework was done at home. In one-third of companies all teleworkers were male, in one-fourth over 75% were female. Teleworkers were most likely to be in management, information technology,…

  6. Interpersonal communication and creativity in journalistic telework.

    PubMed

    Manssour, Ana Beatriz Benites

    2003-02-01

    Man and work histories are interlaced to tell us how the interaction among different human groups have helped in the development of intellectual capacities of our species. Creativity is mostly seen as a gift or an individual quality, for whose bloom and exercise there are internal and external factors, understood as stimulants of the creative process. Research for a master's thesis had, as its principal aim, the analysis of the subjective impact of telework on the workers personal satisfaction. Our second category authenticates the importance of interpersonal communication among fellow workers as incentive to personal creativity. The study was developed with columnists of a great newspaper with a big circulation in the south of Brazil, because telework is a tool of the press media, and creativity is a requirement for journalistic employment.

  7. Electronically Distributed Work Communities: Implications for Research on Telework.

    ERIC Educational Resources Information Center

    Hesse, Bradford W.; Grantham, Charles E.

    1991-01-01

    Describes the concept of telework, or telecommuting, and its influence on the electronic community and organizational structures. The electronically distributed organization is discussed, and implications for research on telework are suggested in the areas of privacy regulation, self-efficacy, temporal aspects of employee behavior, communication…

  8. Large scale tracking algorithms

    SciTech Connect

    Hansen, Ross L.; Love, Joshua Alan; Melgaard, David Kennett; Karelitz, David B.; Pitts, Todd Alan; Zollweg, Joshua David; Anderson, Dylan Z.; Nandy, Prabal; Whitlow, Gary L.; Bender, Daniel A.; Byrne, Raymond Harry

    2015-01-01

    Low signal-to-noise data processing algorithms for improved detection, tracking, discrimination and situational threat assessment are a key research challenge. As sensor technologies progress, the number of pixels will increase signi cantly. This will result in increased resolution, which could improve object discrimination, but unfortunately, will also result in a significant increase in the number of potential targets to track. Many tracking techniques, like multi-hypothesis trackers, suffer from a combinatorial explosion as the number of potential targets increase. As the resolution increases, the phenomenology applied towards detection algorithms also changes. For low resolution sensors, "blob" tracking is the norm. For higher resolution data, additional information may be employed in the detection and classfication steps. The most challenging scenarios are those where the targets cannot be fully resolved, yet must be tracked and distinguished for neighboring closely spaced objects. Tracking vehicles in an urban environment is an example of such a challenging scenario. This report evaluates several potential tracking algorithms for large-scale tracking in an urban environment.

  9. Large scale traffic simulations

    SciTech Connect

    Nagel, K.; Barrett, C.L. |; Rickert, M. |

    1997-04-01

    Large scale microscopic (i.e. vehicle-based) traffic simulations pose high demands on computational speed in at least two application areas: (i) real-time traffic forecasting, and (ii) long-term planning applications (where repeated {open_quotes}looping{close_quotes} between the microsimulation and the simulated planning of individual person`s behavior is necessary). As a rough number, a real-time simulation of an area such as Los Angeles (ca. 1 million travellers) will need a computational speed of much higher than 1 million {open_quotes}particle{close_quotes} (= vehicle) updates per second. This paper reviews how this problem is approached in different projects and how these approaches are dependent both on the specific questions and on the prospective user community. The approaches reach from highly parallel and vectorizable, single-bit implementations on parallel supercomputers for Statistical Physics questions, via more realistic implementations on coupled workstations, to more complicated driving dynamics implemented again on parallel supercomputers. 45 refs., 9 figs., 1 tab.

  10. A comparison of the effectiveness of three parenting programmes in improving parenting skills, parent mental-well being and children's behaviour when implemented on a large scale in community settings in 18 English local authorities: the parenting early intervention pathfinder (PEIP)

    PubMed Central

    2011-01-01

    Background There is growing evidence that parenting programmes can improve parenting skills and thereby the behaviour of children exhibiting or at risk of developing antisocial behaviour. Given the high prevalence of childhood behaviour problems the task is to develop large scale application of effective programmes. The aim of this study was to evaluate the UK government funded implementation of the Parenting Early Intervention Pathfinder (PEIP). This involved the large scale rolling out of three programmes to parents of children 8-13 years in 18 local authorities (LAs) over a 2 year period. Methods The UK government's Department for Education allocated each programme (Incredible Years, Triple P and Strengthening Families Strengthening Communities) to six LAs which then developed systems to intervene using parenting groups. Implementation fidelity was supported by the training of group facilitators by staff of the appropriate parenting programme supplemented by supervision. Parents completed measures of parenting style, efficacy, satisfaction, and mental well-being, and also child behaviour. Results A total of 1121 parents completed pre- and post-course measures. There were significant improvements on all measures for each programme; effect sizes (Cohen's d) ranged across the programmes from 0.57 to 0.93 for parenting style; 0.33 to 0.77 for parenting satisfaction and self-efficacy; and from 0.49 to 0.88 for parental mental well-being. Effectiveness varied between programmes: Strengthening Families Strengthening Communities was significantly less effective than both the other two programmes in improving parental efficacy, satisfaction and mental well-being. Improvements in child behaviour were found for all programmes: effect sizes for reduction in conduct problems ranged from -0.44 to -0.71 across programmes, with Strengthening Families Strengthening Communities again having significantly lower reductions than Incredible Years. Conclusions Evidence-based parenting

  11. A comparison of the effectiveness of three parenting programmes in improving parenting skills, parent mental-well being and children's behaviour when implemented on a large scale in community settings in 18 English local authorities: the parenting early intervention pathfinder (PEIP).

    PubMed

    Lindsay, Geoff; Strand, Steve; Davis, Hilton

    2011-12-30

    There is growing evidence that parenting programmes can improve parenting skills and thereby the behaviour of children exhibiting or at risk of developing antisocial behaviour. Given the high prevalence of childhood behaviour problems the task is to develop large scale application of effective programmes. The aim of this study was to evaluate the UK government funded implementation of the Parenting Early Intervention Pathfinder (PEIP). This involved the large scale rolling out of three programmes to parents of children 8-13 years in 18 local authorities (LAs) over a 2 year period. The UK government's Department for Education allocated each programme (Incredible Years, Triple P and Strengthening Families Strengthening Communities) to six LAs which then developed systems to intervene using parenting groups. Implementation fidelity was supported by the training of group facilitators by staff of the appropriate parenting programme supplemented by supervision. Parents completed measures of parenting style, efficacy, satisfaction, and mental well-being, and also child behaviour. A total of 1121 parents completed pre- and post-course measures. There were significant improvements on all measures for each programme; effect sizes (Cohen's d) ranged across the programmes from 0.57 to 0.93 for parenting style; 0.33 to 0.77 for parenting satisfaction and self-efficacy; and from 0.49 to 0.88 for parental mental well-being. Effectiveness varied between programmes: Strengthening Families Strengthening Communities was significantly less effective than both the other two programmes in improving parental efficacy, satisfaction and mental well-being. Improvements in child behaviour were found for all programmes: effect sizes for reduction in conduct problems ranged from -0.44 to -0.71 across programmes, with Strengthening Families Strengthening Communities again having significantly lower reductions than Incredible Years. Evidence-based parenting programmes can be implemented

  12. Notification: Assessment of EPA Telework Policies and Tools

    EPA Pesticide Factsheets

    Project #OPE-FY16-0028, August 23, 2016. The EPA OIG plans to begin preliminary research to assess the agency's compliance with and implementation of relevant teleworking policies and guidance issued by the Office of Personnel Management.

  13. Programme coverage, condom use and STI treatment among FSWs in a large-scale HIV prevention programme: results from cross-sectional surveys in 22 districts in southern India

    PubMed Central

    Gautam, Abhishek; Goswami, Prabuddhagopal; Kallam, Srinivasan; Adhikary, Rajatashuvra; Mainkar, Mandar K; Ramesh, Banadakoppa M; Morineau, Guy; George, Bitra; Paranjape, Ramesh S

    2010-01-01

    Objective This paper evaluates Avahan programme's coverage of female sex workers (FSWs), focus on high-risk FSWs and intermediate outcomes. Methods First round of cross-sectional survey data, Integrated Behavioral and Biological Assessments (IBBA), conducted in 22 districts, were aggregated into district categories: Solo, where Avahan was the sole service provider covering all FSWs and Major or Minor where Avahan was not the sole provider, but intended coverage was >50% or ≤ 50% of FSWs respectively. Multivariate logistic regression was applied to compare exposure by district categories, vulnerability factors and intermediate outcomes associated with exposure. Results Reported exposure, evaluated on basis of having received any of three core services, was higher in Solo (75%) compared with Minor (66%) districts. Logistic regression showed that FSWs in solo districts were more likely to be exposed (adjusted odds ratio (AOR)=1.5; 95% CI 1.20 to 1.86) compared with FSWs in Minor districts. Multivariate analysis in Solo districts revealed that FSW with ≥15 clients in the past week had a higher chance of being exposed to core services (AOR=1.56; 95% CI 1.03 to 2.35). Exposure to the three services in Solo Avahan districts was significantly associated with correct knowledge on condom use (AOR=1.36; 95% CI 1.05 to 1.78), consistent condom use with occasional clients (AOR=3.17; 95% CI 2.17 to 4.63) and regular clients (AOR=2.47; 95% CI 1.86 to 3.28) and STI treatment-seeking behaviour (AOR=3.00; 95% CI 1.94 to 4.65). Conclusions Higher coverage of FSWs was achieved in districts where Avahan was the only intervention compared with districts having multiple and longstanding non-Avahan programmes. Exposure in Solo districts was associated with intermediate outcomes; this need to be further evaluated in comparison with non Avahan areas and substantiated through data from next IBBA. PMID:20167734

  14. Teleworking: Work/Life Balance of Online Instructors with Disabilities: A Phenomenological Study

    ERIC Educational Resources Information Center

    Heisey, Allyson G.

    2012-01-01

    Since the mid-1970s, teleworking has been recognized as being beneficial to organizations, individuals, and communities. In the 1980s and 1990s, advancements in technology made teleworking an attractive option for many workers, including those with disabilities. Teleworking has gained popularity and has been heralded as a method of accommodation…

  15. The role of organisational support in teleworker wellbeing: a socio-technical systems approach.

    PubMed

    Bentley, T A; Teo, S T T; McLeod, L; Tan, F; Bosua, R; Gloet, M

    2016-01-01

    The prevalence of telework and other forms of mobile working enabled by digital technology is increasing markedly. Following a socio-technical systems approach, this study aims to examine the role of organisational social support and specific support for teleworkers in influencing teleworker wellbeing, the mediating role of social isolation, potentially resulting from a person-environment mismatch in these relationships, and possible differences in these relationships between low-intensity and hybrid teleworkers. Teleworkers' (n = 804) perceptions of support and telework outcomes (psychological strain, job satisfaction, and social isolation) were collected using an on-line survey of teleworking employees distributed within 28 New Zealand organisations where knowledge work was undertaken. Organisational social support and teleworker support was associated with increased job satisfaction and reduced psychological strain. Social isolation mediated the relationship between organisational social support and the two outcome variables, and some differences were observed in the structural relationships for hybrid and low-intensity teleworker sub-samples. These findings suggest that providing the necessary organisational and teleworker support is important for enhancing the teleworker-environment fit and thereby ensuring desirable telework outcomes.

  16. Teleworking: Work/Life Balance of Online Instructors with Disabilities: A Phenomenological Study

    ERIC Educational Resources Information Center

    Heisey, Allyson G.

    2012-01-01

    Since the mid-1970s, teleworking has been recognized as being beneficial to organizations, individuals, and communities. In the 1980s and 1990s, advancements in technology made teleworking an attractive option for many workers, including those with disabilities. Teleworking has gained popularity and has been heralded as a method of accommodation…

  17. Large-scale studies of marked birds in North America

    USGS Publications Warehouse

    Tautin, J.; Metras, L.; Smith, G.

    1999-01-01

    The first large-scale, co-operative, studies of marked birds in North America were attempted in the 1950s. Operation Recovery, which linked numerous ringing stations along the east coast in a study of autumn migration of passerines, and the Preseason Duck Ringing Programme in prairie states and provinces, conclusively demonstrated the feasibility of large-scale projects. The subsequent development of powerful analytical models and computing capabilities expanded the quantitative potential for further large-scale projects. Monitoring Avian Productivity and Survivorship, and Adaptive Harvest Management are current examples of truly large-scale programmes. Their exemplary success and the availability of versatile analytical tools are driving changes in the North American bird ringing programme. Both the US and Canadian ringing offices are modifying operations to collect more and better data to facilitate large-scale studies and promote a more project-oriented ringing programme. New large-scale programmes such as the Cornell Nest Box Network are on the horizon.

  18. Large-scale structural optimization

    NASA Technical Reports Server (NTRS)

    Sobieszczanski-Sobieski, J.

    1983-01-01

    Problems encountered by aerospace designers in attempting to optimize whole aircraft are discussed, along with possible solutions. Large scale optimization, as opposed to component-by-component optimization, is hindered by computational costs, software inflexibility, concentration on a single, rather than trade-off, design methodology and the incompatibility of large-scale optimization with single program, single computer methods. The software problem can be approached by placing the full analysis outside of the optimization loop. Full analysis is then performed only periodically. Problem-dependent software can be removed from the generic code using a systems programming technique, and then embody the definitions of design variables, objective function and design constraints. Trade-off algorithms can be used at the design points to obtain quantitative answers. Finally, decomposing the large-scale problem into independent subproblems allows systematic optimization of the problems by an organization of people and machines.

  19. Large-scale circuit simulation

    NASA Astrophysics Data System (ADS)

    Wei, Y. P.

    1982-12-01

    The simulation of VLSI (Very Large Scale Integration) circuits falls beyond the capabilities of conventional circuit simulators like SPICE. On the other hand, conventional logic simulators can only give the results of logic levels 1 and 0 with the attendent loss of detail in the waveforms. The aim of developing large-scale circuit simulation is to bridge the gap between conventional circuit simulation and logic simulation. This research is to investigate new approaches for fast and relatively accurate time-domain simulation of MOS (Metal Oxide Semiconductors), LSI (Large Scale Integration) and VLSI circuits. New techniques and new algorithms are studied in the following areas: (1) analysis sequencing (2) nonlinear iteration (3) modified Gauss-Seidel method (4) latency criteria and timestep control scheme. The developed methods have been implemented into a simulation program PREMOS which could be used as a design verification tool for MOS circuits.

  20. Large Scale Dynamos in Stars

    NASA Astrophysics Data System (ADS)

    Vishniac, Ethan T.

    2015-01-01

    We show that a differentially rotating conducting fluid automatically creates a magnetic helicity flux with components along the rotation axis and in the direction of the local vorticity. This drives a rapid growth in the local density of current helicity, which in turn drives a large scale dynamo. The dynamo growth rate derived from this process is not constant, but depends inversely on the large scale magnetic field strength. This dynamo saturates when buoyant losses of magnetic flux compete with the large scale dynamo, providing a simple prediction for magnetic field strength as a function of Rossby number in stars. Increasing anisotropy in the turbulence produces a decreasing magnetic helicity flux, which explains the flattening of the B/Rossby number relation at low Rossby numbers. We also show that the kinetic helicity is always a subdominant effect. There is no kinematic dynamo in real stars.

  1. Very Large Scale Integration (VLSI).

    ERIC Educational Resources Information Center

    Yeaman, Andrew R. J.

    Very Large Scale Integration (VLSI), the state-of-the-art production techniques for computer chips, promises such powerful, inexpensive computing that, in the future, people will be able to communicate with computer devices in natural language or even speech. However, before full-scale VLSI implementation can occur, certain salient factors must be…

  2. Galaxy clustering on large scales.

    PubMed Central

    Efstathiou, G

    1993-01-01

    I describe some recent observations of large-scale structure in the galaxy distribution. The best constraints come from two-dimensional galaxy surveys and studies of angular correlation functions. Results from galaxy redshift surveys are much less precise but are consistent with the angular correlations, provided the distortions in mapping between real-space and redshift-space are relatively weak. The galaxy two-point correlation function, rich-cluster two-point correlation function, and galaxy-cluster cross-correlation function are all well described on large scales ( greater, similar 20h-1 Mpc, where the Hubble constant, H0 = 100h km.s-1.Mpc; 1 pc = 3.09 x 10(16) m) by the power spectrum of an initially scale-invariant, adiabatic, cold-dark-matter Universe with Gamma = Omegah approximately 0.2. I discuss how this fits in with the Cosmic Background Explorer (COBE) satellite detection of large-scale anisotropies in the microwave background radiation and other measures of large-scale structure in the Universe. PMID:11607400

  3. Managing Complex Distance Education Projects in a Telework Environment

    ERIC Educational Resources Information Center

    Ally, Mohamed; Cleveland-Innes, Marti; Wiseman, Colin

    2010-01-01

    The advances of communication technologies have allowed professionals to work on distance education projects in a telework environment. Managers of these projects must have the skills to manage the projects from a distance. They must be able to select the appropriate team members to work on the project, orient team members, and monitor team…

  4. Teleworking: Benefits and Pitfalls as Perceived by Professionals and Managers.

    ERIC Educational Resources Information Center

    Baruch, Yehuda

    2000-01-01

    Interviews with 60 British teleworkers showed that working at home did not change their employee identity; time management skills were crucial; reduction of distractions was a prime benefit; and the home environment provided better relationships and support. Telecommuting resulted in changed attitudes, satisfaction, less stress, and better…

  5. Teleworking: Benefits and Pitfalls as Perceived by Professionals and Managers.

    ERIC Educational Resources Information Center

    Baruch, Yehuda

    2000-01-01

    Interviews with 60 British teleworkers showed that working at home did not change their employee identity; time management skills were crucial; reduction of distractions was a prime benefit; and the home environment provided better relationships and support. Telecommuting resulted in changed attitudes, satisfaction, less stress, and better…

  6. Getting It "Better": The Importance of Improving Background Questionnaires in International Large-Scale Assessment

    ERIC Educational Resources Information Center

    Rutkowski, Leslie; Rutkowski, David

    2010-01-01

    In addition to collecting achievement data, international large-scale assessment programmes gather auxiliary information from students and schools regarding the context of teaching and learning. In an effort to clarify some of the opacity surrounding international large-scale assessment programmes and the potential problems associated with less…

  7. Getting It "Better": The Importance of Improving Background Questionnaires in International Large-Scale Assessment

    ERIC Educational Resources Information Center

    Rutkowski, Leslie; Rutkowski, David

    2010-01-01

    In addition to collecting achievement data, international large-scale assessment programmes gather auxiliary information from students and schools regarding the context of teaching and learning. In an effort to clarify some of the opacity surrounding international large-scale assessment programmes and the potential problems associated with less…

  8. Army Contracting Command--Picatinny Telework Policy: Applying Lessons Learned from the Federal Government

    DTIC Science & Technology

    2011-09-01

    Telecommuting Initiative OPM Office of Personnel Management OMB Office of Management and Budget OSHA Occupational Safety and Health Administration...telework, such as telecommuting , flexible workplace, remote work, virtual work, and mobile work, which it states “are all used to refer to work done...gives a basic explanation of telework similar to that of OPM’s and again includes with the definition of telework terms like telecommuting , flexible

  9. Cosmology with Large Scale Structure

    NASA Astrophysics Data System (ADS)

    Ho, Shirley; Cuesta, A.; Ross, A.; Seo, H.; DePutter, R.; Padmanabhan, N.; White, M.; Myers, A.; Bovy, J.; Blanton, M.; Hernandez, C.; Mena, O.; Percival, W.; Prada, F.; Ross, N. P.; Saito, S.; Schneider, D.; Skibba, R.; Smith, K.; Slosar, A.; Strauss, M.; Verde, L.; Weinberg, D.; Bachall, N.; Brinkmann, J.; da Costa, L. A.

    2012-01-01

    The Sloan Digital Sky Survey I-III surveyed 14,000 square degrees, and delivered over a trillion pixels of imaging data. I present cosmological results from this unprecedented data set which contains over a million galaxies distributed between redshift of 0.45 to 0.70. With such a large volume of data set, high precision cosmological constraints can be obtained given a careful control and understanding of observational systematics. I present a novel treatment of observational systematics and its application to the clustering signals from the data set. I will present cosmological constraints on dark components of the Universe and tightest constraints of the non-gaussianity of early Universe to date utilizing Large Scale Structure.

  10. Large scale biomimetic membrane arrays.

    PubMed

    Hansen, Jesper S; Perry, Mark; Vogel, Jörg; Groth, Jesper S; Vissing, Thomas; Larsen, Marianne S; Geschke, Oliver; Emneús, Jenny; Bohr, Henrik; Nielsen, Claus H

    2009-10-01

    To establish planar biomimetic membranes across large scale partition aperture arrays, we created a disposable single-use horizontal chamber design that supports combined optical-electrical measurements. Functional lipid bilayers could easily and efficiently be established across CO(2) laser micro-structured 8 x 8 aperture partition arrays with average aperture diameters of 301 +/- 5 microm. We addressed the electro-physical properties of the lipid bilayers established across the micro-structured scaffold arrays by controllable reconstitution of biotechnological and physiological relevant membrane peptides and proteins. Next, we tested the scalability of the biomimetic membrane design by establishing lipid bilayers in rectangular 24 x 24 and hexagonal 24 x 27 aperture arrays, respectively. The results presented show that the design is suitable for further developments of sensitive biosensor assays, and furthermore demonstrate that the design can conveniently be scaled up to support planar lipid bilayers in large square-centimeter partition arrays.

  11. Challenges for Large Scale Simulations

    NASA Astrophysics Data System (ADS)

    Troyer, Matthias

    2010-03-01

    With computational approaches becoming ubiquitous the growing impact of large scale computing on research influences both theoretical and experimental work. I will review a few examples in condensed matter physics and quantum optics, including the impact of computer simulations in the search for supersolidity, thermometry in ultracold quantum gases, and the challenging search for novel phases in strongly correlated electron systems. While only a decade ago such simulations needed the fastest supercomputers, many simulations can now be performed on small workstation clusters or even a laptop: what was previously restricted to a few experts can now potentially be used by many. Only part of the gain in computational capabilities is due to Moore's law and improvement in hardware. Equally impressive is the performance gain due to new algorithms - as I will illustrate using some recently developed algorithms. At the same time modern peta-scale supercomputers offer unprecedented computational power and allow us to tackle new problems and address questions that were impossible to solve numerically only a few years ago. While there is a roadmap for future hardware developments to exascale and beyond, the main challenges are on the algorithmic and software infrastructure side. Among the problems that face the computational physicist are: the development of new algorithms that scale to thousands of cores and beyond, a software infrastructure that lifts code development to a higher level and speeds up the development of new simulation programs for large scale computing machines, tools to analyze the large volume of data obtained from such simulations, and as an emerging field provenance-aware software that aims for reproducibility of the complete computational workflow from model parameters to the final figures. Interdisciplinary collaborations and collective efforts will be required, in contrast to the cottage-industry culture currently present in many areas of computational

  12. Large-scale PACS implementation.

    PubMed

    Carrino, J A; Unkel, P J; Miller, I D; Bowser, C L; Freckleton, M W; Johnson, T G

    1998-08-01

    The transition to filmless radiology is a much more formidable task than making the request for proposal to purchase a (Picture Archiving and Communications System) PACS. The Department of Defense and the Veterans Administration have been pioneers in the transformation of medical diagnostic imaging to the electronic environment. Many civilian sites are expected to implement large-scale PACS in the next five to ten years. This presentation will related the empirical insights gleaned at our institution from a large-scale PACS implementation. Our PACS integration was introduced into a fully operational department (not a new hospital) in which work flow had to continue with minimal impact. Impediments to user acceptance will be addressed. The critical components of this enormous task will be discussed. The topics covered during this session will include issues such as phased implementation, DICOM (digital imaging and communications in medicine) standard-based interaction of devices, hospital information system (HIS)/radiology information system (RIS) interface, user approval, networking, workstation deployment and backup procedures. The presentation will make specific suggestions regarding the implementation team, operating instructions, quality control (QC), training and education. The concept of identifying key functional areas is relevant to transitioning the facility to be entirely on line. Special attention must be paid to specific functional areas such as the operating rooms and trauma rooms where the clinical requirements may not match the PACS capabilities. The printing of films may be necessary for certain circumstances. The integration of teleradiology and remote clinics into a PACS is a salient topic with respect to the overall role of the radiologists providing rapid consultation. A Web-based server allows a clinician to review images and reports on a desk-top (personal) computer and thus reduce the number of dedicated PACS review workstations. This session

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

    ERIC Educational Resources Information Center

    Golden, Timothy D.

    2006-01-01

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

  14. Telework Centers. An Evaluation of the North American and Japanese Experience. Workscape 21: The Ecology of New Ways of Working.

    ERIC Educational Resources Information Center

    Becker, Franklin; Rappaport, Andrew J.; Quinn, Kristen L.; Sims, William R.

    Telework Centers are work locations used by firms to acommodate staff who live near the telework center location. A study examined the impact of using telework centers on communication, work groups/departments, performance, supervision, travel/environment, and type of work done in various locations. A case study approach was used to investigate 10…

  15. Implementation factors affecting the large-scale deployment of digital health and well-being technologies: A qualitative study of the initial phases of the ‘Living-It-Up’ programme

    PubMed Central

    Agbakoba, Ruth; McGee-Lennon, Marilyn; Bouamrane, Matt-Mouley; Watson, Nicholas; Mair, Frances S

    2015-01-01

    Little is known about the factors which facilitate or impede the large-scale deployment of health and well-being consumer technologies. The Living-It-Up project is a large-scale digital intervention led by NHS 24, aiming to transform health and well-being services delivery throughout Scotland. We conducted a qualitative study of the factors affecting the implementation and deployment of the Living-It-Up services. We collected a range of data during the initial phase of deployment, including semi-structured interviews (N = 6); participant observation sessions (N = 5) and meetings with key stakeholders (N = 3). We used the Normalisation Process Theory as an explanatory framework to interpret the social processes at play during the initial phases of deployment. Initial findings illustrate that it is clear − and perhaps not surprising − that the size and diversity of the Living-It-Up consortium made implementation processes more complex within a ‘multi-stakeholder’ environment. To overcome these barriers, there is a need to clearly define roles, tasks and responsibilities among the consortium partners. Furthermore, varying levels of expectations and requirements, as well as diverse cultures and ways of working, must be effectively managed. Factors which facilitated implementation included extensive stakeholder engagement, such as co-design activities, which can contribute to an increased ‘buy-in’ from users in the long term. An important lesson from the Living-It-Up initiative is that attempting to co-design innovative digital services, but at the same time, recruiting large numbers of users is likely to generate conflicting implementation priorities which hinder − or at least substantially slow down − the effective rollout of services at scale. The deployment of Living-It-Up services is ongoing, but our results to date suggest that − in order to be successful − the roll-out of digital health and well-being technologies at scale requires a delicate

  16. Implementation factors affecting the large-scale deployment of digital health and well-being technologies: A qualitative study of the initial phases of the 'Living-It-Up' programme.

    PubMed

    Agbakoba, Ruth; McGee-Lennon, Marilyn; Bouamrane, Matt-Mouley; Watson, Nicholas; Mair, Frances S

    2016-12-01

    Little is known about the factors which facilitate or impede the large-scale deployment of health and well-being consumer technologies. The Living-It-Up project is a large-scale digital intervention led by NHS 24, aiming to transform health and well-being services delivery throughout Scotland. We conducted a qualitative study of the factors affecting the implementation and deployment of the Living-It-Up services. We collected a range of data during the initial phase of deployment, including semi-structured interviews (N = 6); participant observation sessions (N = 5) and meetings with key stakeholders (N = 3). We used the Normalisation Process Theory as an explanatory framework to interpret the social processes at play during the initial phases of deployment.Initial findings illustrate that it is clear - and perhaps not surprising - that the size and diversity of the Living-It-Up consortium made implementation processes more complex within a 'multi-stakeholder' environment. To overcome these barriers, there is a need to clearly define roles, tasks and responsibilities among the consortium partners. Furthermore, varying levels of expectations and requirements, as well as diverse cultures and ways of working, must be effectively managed. Factors which facilitated implementation included extensive stakeholder engagement, such as co-design activities, which can contribute to an increased 'buy-in' from users in the long term. An important lesson from the Living-It-Up initiative is that attempting to co-design innovative digital services, but at the same time, recruiting large numbers of users is likely to generate conflicting implementation priorities which hinder - or at least substantially slow down - the effective rollout of services at scale.The deployment of Living-It-Up services is ongoing, but our results to date suggest that - in order to be successful - the roll-out of digital health and well-being technologies at scale requires a delicate and pragmatic trade

  17. Large scale cluster computing workshop

    SciTech Connect

    Dane Skow; Alan Silverman

    2002-12-23

    Recent revolutions in computer hardware and software technologies have paved the way for the large-scale deployment of clusters of commodity computers to address problems heretofore the domain of tightly coupled SMP processors. Near term projects within High Energy Physics and other computing communities will deploy clusters of scale 1000s of processors and be used by 100s to 1000s of independent users. This will expand the reach in both dimensions by an order of magnitude from the current successful production facilities. The goals of this workshop were: (1) to determine what tools exist which can scale up to the cluster sizes foreseen for the next generation of HENP experiments (several thousand nodes) and by implication to identify areas where some investment of money or effort is likely to be needed. (2) To compare and record experimences gained with such tools. (3) To produce a practical guide to all stages of planning, installing, building and operating a large computing cluster in HENP. (4) To identify and connect groups with similar interest within HENP and the larger clustering community.

  18. Large-Scale Sequence Comparison.

    PubMed

    Lal, Devi; Verma, Mansi

    2017-01-01

    There are millions of sequences deposited in genomic databases, and it is an important task to categorize them according to their structural and functional roles. Sequence comparison is a prerequisite for proper categorization of both DNA and protein sequences, and helps in assigning a putative or hypothetical structure and function to a given sequence. There are various methods available for comparing sequences, alignment being first and foremost for sequences with a small number of base pairs as well as for large-scale genome comparison. Various tools are available for performing pairwise large sequence comparison. The best known tools either perform global alignment or generate local alignments between the two sequences. In this chapter we first provide basic information regarding sequence comparison. This is followed by the description of the PAM and BLOSUM matrices that form the basis of sequence comparison. We also give a practical overview of currently available methods such as BLAST and FASTA, followed by a description and overview of tools available for genome comparison including LAGAN, MumMER, BLASTZ, and AVID.

  19. Large Scale Homing in Honeybees

    PubMed Central

    Pahl, Mario; Zhu, Hong; Tautz, Jürgen; Zhang, Shaowu

    2011-01-01

    Honeybee foragers frequently fly several kilometres to and from vital resources, and communicate those locations to their nest mates by a symbolic dance language. Research has shown that they achieve this feat by memorizing landmarks and the skyline panorama, using the sun and polarized skylight as compasses and by integrating their outbound flight paths. In order to investigate the capacity of the honeybees' homing abilities, we artificially displaced foragers to novel release spots at various distances up to 13 km in the four cardinal directions. Returning bees were individually registered by a radio frequency identification (RFID) system at the hive entrance. We found that homing rate, homing speed and the maximum homing distance depend on the release direction. Bees released in the east were more likely to find their way back home, and returned faster than bees released in any other direction, due to the familiarity of global landmarks seen from the hive. Our findings suggest that such large scale homing is facilitated by global landmarks acting as beacons, and possibly the entire skyline panorama. PMID:21602920

  20. Large Scale Magnetostrictive Valve Actuator

    NASA Technical Reports Server (NTRS)

    Richard, James A.; Holleman, Elizabeth; Eddleman, David

    2008-01-01

    Marshall Space Flight Center's Valves, Actuators and Ducts Design and Development Branch developed a large scale magnetostrictive valve actuator. The potential advantages of this technology are faster, more efficient valve actuators that consume less power and provide precise position control and deliver higher flow rates than conventional solenoid valves. Magnetostrictive materials change dimensions when a magnetic field is applied; this property is referred to as magnetostriction. Magnetostriction is caused by the alignment of the magnetic domains in the material s crystalline structure and the applied magnetic field lines. Typically, the material changes shape by elongating in the axial direction and constricting in the radial direction, resulting in no net change in volume. All hardware and testing is complete. This paper will discuss: the potential applications of the technology; overview of the as built actuator design; discuss problems that were uncovered during the development testing; review test data and evaluate weaknesses of the design; and discuss areas for improvement for future work. This actuator holds promises of a low power, high load, proportionally controlled actuator for valves requiring 440 to 1500 newtons load.

  1. Large-scale implementation of disease control programmes: a cost-effectiveness analysis of long-lasting insecticide-treated bed net distribution channels in a malaria-endemic area of western Kenya—a study protocol

    PubMed Central

    Gama, Elvis; Were, Vincent; Ouma, Peter; Desai, Meghna; Niessen, Louis; Buff, Ann M; Kariuki, Simon

    2016-01-01

    Introduction Historically, Kenya has used various distribution models for long-lasting insecticide-treated bed nets (LLINs) with variable results in population coverage. The models presently vary widely in scale, target population and strategy. There is limited information to determine the best combination of distribution models, which will lead to sustained high coverage and are operationally efficient and cost-effective. Standardised cost information is needed in combination with programme effectiveness estimates to judge the efficiency of LLIN distribution models and options for improvement in implementing malaria control programmes. The study aims to address the information gap, estimating distribution cost and the effectiveness of different LLIN distribution models, and comparing them in an economic evaluation. Methods and analysis Evaluation of cost and coverage will be determined for 5 different distribution models in Busia County, an area of perennial malaria transmission in western Kenya. Cost data will be collected retrospectively from health facilities, the Ministry of Health, donors and distributors. Programme-effectiveness data, defined as the number of people with access to an LLIN per 1000 population, will be collected through triangulation of data from a nationally representative, cross-sectional malaria survey, a cross-sectional survey administered to a subsample of beneficiaries in Busia County and LLIN distributors’ records. Descriptive statistics and regression analysis will be used for the evaluation. A cost-effectiveness analysis will be performed from a health-systems perspective, and cost-effectiveness ratios will be calculated using bootstrapping techniques. Ethics and dissemination The study has been evaluated and approved by Kenya Medical Research Institute, Scientific and Ethical Review Unit (SERU number 2997). All participants will provide written informed consent. The findings of this economic evaluation will be disseminated through

  2. Methane emissions on large scales

    NASA Astrophysics Data System (ADS)

    Beswick, K. M.; Simpson, T. W.; Fowler, D.; Choularton, T. W.; Gallagher, M. W.; Hargreaves, K. J.; Sutton, M. A.; Kaye, A.

    with previous results from the area, indicating that this method of data analysis provided good estimates of large scale methane emissions.

  3. Large Scale Nanolaminate Deformable Mirror

    SciTech Connect

    Papavasiliou, A; Olivier, S; Barbee, T; Miles, R; Chang, K

    2005-11-30

    This work concerns the development of a technology that uses Nanolaminate foils to form light-weight, deformable mirrors that are scalable over a wide range of mirror sizes. While MEMS-based deformable mirrors and spatial light modulators have considerably reduced the cost and increased the capabilities of adaptive optic systems, there has not been a way to utilize the advantages of lithography and batch-fabrication to produce large-scale deformable mirrors. This technology is made scalable by using fabrication techniques and lithography that are not limited to the sizes of conventional MEMS devices. Like many MEMS devices, these mirrors use parallel plate electrostatic actuators. This technology replicates that functionality by suspending a horizontal piece of nanolaminate foil over an electrode by electroplated nickel posts. This actuator is attached, with another post, to another nanolaminate foil that acts as the mirror surface. Most MEMS devices are produced with integrated circuit lithography techniques that are capable of very small line widths, but are not scalable to large sizes. This technology is very tolerant of lithography errors and can use coarser, printed circuit board lithography techniques that can be scaled to very large sizes. These mirrors use small, lithographically defined actuators and thin nanolaminate foils allowing them to produce deformations over a large area while minimizing weight. This paper will describe a staged program to develop this technology. First-principles models were developed to determine design parameters. Three stages of fabrication will be described starting with a 3 x 3 device using conventional metal foils and epoxy to a 10-across all-metal device with nanolaminate mirror surfaces.

  4. Large-Scale Information Systems

    SciTech Connect

    D. M. Nicol; H. R. Ammerlahn; M. E. Goldsby; M. M. Johnson; D. E. Rhodes; A. S. Yoshimura

    2000-12-01

    Large enterprises are ever more dependent on their Large-Scale Information Systems (LSLS), computer systems that are distinguished architecturally by distributed components--data sources, networks, computing engines, simulations, human-in-the-loop control and remote access stations. These systems provide such capabilities as workflow, data fusion and distributed database access. The Nuclear Weapons Complex (NWC) contains many examples of LSIS components, a fact that motivates this research. However, most LSIS in use grew up from collections of separate subsystems that were not designed to be components of an integrated system. For this reason, they are often difficult to analyze and control. The problem is made more difficult by the size of a typical system, its diversity of information sources, and the institutional complexities associated with its geographic distribution across the enterprise. Moreover, there is no integrated approach for analyzing or managing such systems. Indeed, integrated development of LSIS is an active area of academic research. This work developed such an approach by simulating the various components of the LSIS and allowing the simulated components to interact with real LSIS subsystems. This research demonstrated two benefits. First, applying it to a particular LSIS provided a thorough understanding of the interfaces between the system's components. Second, it demonstrated how more rapid and detailed answers could be obtained to questions significant to the enterprise by interacting with the relevant LSIS subsystems through simulated components designed with those questions in mind. In a final, added phase of the project, investigations were made on extending this research to wireless communication networks in support of telemetry applications.

  5. The Employability of Older Workers as Teleworkers: An Appraisal of Issues and an Empirical Study

    PubMed Central

    Sharit, Joseph; Czaja, Sara J.; Hernandez, Mario A.; Nair, Sankaran N.

    2009-01-01

    The aging of the population and, concomitantly, of the workforce has a number of important implications for governments, businesses, and workers. In this article, we examine the prospects for the employability of older workers as home-based teleworkers. This alternative work could accommodate many of the needs and preferences of older workers and at the same time benefit organizations. However, before telework can be considered a viable work option for many older workers there are a number of issues to consider, including the ability of older workers to adapt to the technological demands that are typically associated with telework jobs and managerial attitudes about older workers and about telework. Through an integrated examination of these and other issues, our goal is to provide a comprehensive understanding of the challenges associated with employing older workers as teleworkers. We also present findings from a questionnaire study that assessed managers’ perceptions of worker attributes desirable for telework and how older workers compare to younger workers on these attributes. The sample included 314 managers with varying degrees of managerial experience from a large variety of companies in the United States. The results presented a mixed picture with respect to the employability of older workers as teleworkers, and strongly suggested that less experienced managers would be more resistant to hiring older people as teleworkers. We conclude with a number of recommendations for improving the prospects for employment of older workers for this type of work arrangement. PMID:20090856

  6. 78 FR 73702 - Federal Travel Regulation (FTR); Telework Travel Expenses Test Programs

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-09

    ...] RIN 3090-AJ23 Federal Travel Regulation (FTR); Telework Travel Expenses Test Programs AGENCY: Office... 2010, which establishes and authorizes telework travel expenses test programs, authorizes reimbursement for any necessary travel expenses in conjunction with such a test program in lieu of any payment...

  7. The Employability of Older Workers as Teleworkers: An Appraisal of Issues and an Empirical Study.

    PubMed

    Sharit, Joseph; Czaja, Sara J; Hernandez, Mario A; Nair, Sankaran N

    2009-01-01

    The aging of the population and, concomitantly, of the workforce has a number of important implications for governments, businesses, and workers. In this article, we examine the prospects for the employability of older workers as home-based teleworkers. This alternative work could accommodate many of the needs and preferences of older workers and at the same time benefit organizations. However, before telework can be considered a viable work option for many older workers there are a number of issues to consider, including the ability of older workers to adapt to the technological demands that are typically associated with telework jobs and managerial attitudes about older workers and about telework. Through an integrated examination of these and other issues, our goal is to provide a comprehensive understanding of the challenges associated with employing older workers as teleworkers. We also present findings from a questionnaire study that assessed managers' perceptions of worker attributes desirable for telework and how older workers compare to younger workers on these attributes. The sample included 314 managers with varying degrees of managerial experience from a large variety of companies in the United States. The results presented a mixed picture with respect to the employability of older workers as teleworkers, and strongly suggested that less experienced managers would be more resistant to hiring older people as teleworkers. We conclude with a number of recommendations for improving the prospects for employment of older workers for this type of work arrangement.

  8. Comparing Teleworker Performance, Satisfaction, and Retention in the Joint Interoperability Test Command

    ERIC Educational Resources Information Center

    Hurd, Danny A.

    2010-01-01

    Telework is becoming one of the best options available to help organizations gain a competitive advantage. When management considers the fluctuating cost of fuel, emphasis on employee flexibility, and need to retain the most-qualified workforce, telework can be advantageous for solving problems. This quantitative comparative (non-experimental)…

  9. Virtual exclusion and telework: barriers and opportunities of technocentric workplace accommodation policy.

    PubMed

    Baker, Paul M A; Moon, Nathan W; Ward, Andrew C

    2006-01-01

    Teleworking, a restructuring of the manner in which work occurs, based on information communication technologies (ICTs), is a promising way of further integrating people with disabilities into the workplace. In contrast to telecommuting, in which the work is primarily shifted in locale, telework is a restructuring of the tasks to be accomplished within the larger work setting which could result in "work" being done remotely, or collaboratively with coworkers (remotely or not) using ICTs. Drawing upon a review of the literature, this paper explores the relationship between telework and people with disabilities. While the advent of telecommuting and subsequently "teleworking" might open increased opportunities for the hiring of people with disabilities, it may also place severe constraints on the type of work, workplace environment and interactions, and accumulation of social capital for people with disabilities. Whereas much of the prevailing literature on telework and disability is often proscriptive in nature and is written with an audience of employers in mind, it is just as important to consider policy options from the standpoint of the employee as well. This paper proposes a number of policy approaches for the creation of an inclusive work environment for teleworkers with disabilities that can minimize, as much as possible, the social isolation faced by teleworkers with disabilities while maximizing their participation within the workplace community. Policy objectives for enhancing telework for people with disabilities fall into three general categories: 1) research, 2) outreach, and 3) interventions.

  10. Throw Away that Telework Manual!’ - the Limitations of Existing Telework Literature in the B2C e-Business Context

    DTIC Science & Technology

    2004-06-01

    Manual!’ – the Limitations of Existing Telework Literature in the B2C e -Business Context Zoohan Gani Faculty of Business, Department of...literature, that are unique to the B2C e -business application. This consequentially gives future research a new direction by identifying factors of...business- to-consumer ( B2C ) e -business application, drawing out success factors that will be applicable to teleworking organisations from similar contexts

  11. Outbreaks of Pox Disease Due to Canarypox-Like and Fowlpox-Like Viruses in Large-Scale Houbara Bustard Captive-Breeding Programmes, in Morocco and the United Arab Emirates.

    PubMed

    Le Loc'h, G; Paul, M C; Camus-Bouclainville, C; Bertagnoli, S

    2016-12-01

    Infectious diseases can be serious threats for the success of reinforcement programmes of endangered species. Houbara Bustard species (Chlamydotis undulata and Chlamydotis macqueenii), whose populations declined in the last decades, have been captive-bred for conservation purposes for more than 15 years in North Africa and the Middle East. Field observations show that pox disease, caused by avipoxviruses (APV), regularly emerges in conservation projects of Houbara Bustard, despite a very strict implementation of both vaccination and biosecurity. Data collected from captive flocks of Houbara Bustard in Morocco from 2006 through 2013 and in the United Arab Emirates from 2011 through 2013 were analysed, and molecular investigations were carried out to define the virus strains involved. Pox cases (n = 2311) were observed during more than half of the year (88% of the months in Morocco, 54% in the United Arab Emirates). Monthly morbidity rates showed strong variations across the time periods considered, species and study sites: Four outbreaks were described during the study period on both sites. Molecular typing revealed that infections were mostly due to canarypox-like viruses in Morocco while fowlpox-like viruses were predominant in the United Arab Emirates. This study highlights that APV remain a major threat to consider in bird conservation initiatives.

  12. Large-Scale Reform Comes of Age

    ERIC Educational Resources Information Center

    Fullan, Michael

    2009-01-01

    This article reviews the history of large-scale education reform and makes the case that large-scale or whole system reform policies and strategies are becoming increasingly evident. The review briefly addresses the pre 1997 period concluding that while the pressure for reform was mounting that there were very few examples of deliberate or…

  13. Automating large-scale reactor systems

    SciTech Connect

    Kisner, R.A.

    1985-01-01

    This paper conveys a philosophy for developing automated large-scale control systems that behave in an integrated, intelligent, flexible manner. Methods for operating large-scale systems under varying degrees of equipment degradation are discussed, and a design approach that separates the effort into phases is suggested. 5 refs., 1 fig.

  14. 41 CFR 102-74.600 - Should Federal agencies utilize telework centers?

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... flexiplace work telecommuting program (i.e., to pay telework center program user fees): (a) Department of Agriculture. (b) Department of Commerce. (c) Department of Defense. (d) Department of Education....

  15. The home as a workplace: work-family interaction and psychological well-being in telework.

    PubMed

    Standen, P; Daniels, K; Lamond, D

    1999-10-01

    Home-based telework is a growing phenomenon with great potential to affect employees' psychological well-being. Although prior studies show both positive and negative effects on work-family interaction, conclusions are limited by the way telework, well-being, and work-family interaction have been modeled. The authors present a conceptual framework that describes telework as a multidimensional phenomenon and separates the effects of the home environment from those of distance from the organization. Propositions concerning work-family interaction are developed from P. Warr's (1987) model of the environmental antecedents of well-being, prior telework studies, and the work-family literature. Spillover between work and nonwork domains of well-being is discussed, and suggestions for future research on this complex issue are presented.

  16. Future Large - Scale Projects and Programmes in Astronomy and Astrophysics

    NASA Astrophysics Data System (ADS)

    Corbett, I.

    2004-03-01

    This workshop was proposed by Germany, which invited ESO to act as host, and took place on December 1-3, at the Deutsches Museum (December 1) and at the Ludwig- Maximilians-Universität (December 2, 3). It was attended by government-appointed delegates from fifteen Global Science Forum Member countries and Observers, three non- OECD countries, representatives of ESO, the President of the International Astronomical Union, invited speakers, and the OECD secretariat, and was chaired by Ian Corbett of ESO.

  17. Large Scale Metal Additive Techniques Review

    SciTech Connect

    Nycz, Andrzej; Adediran, Adeola I; Noakes, Mark W; Love, Lonnie J

    2016-01-01

    In recent years additive manufacturing made long strides toward becoming a main stream production technology. Particularly strong progress has been made in large-scale polymer deposition. However, large scale metal additive has not yet reached parity with large scale polymer. This paper is a review study of the metal additive techniques in the context of building large structures. Current commercial devices are capable of printing metal parts on the order of several cubic feet compared to hundreds of cubic feet for the polymer side. In order to follow the polymer progress path several factors are considered: potential to scale, economy, environment friendliness, material properties, feedstock availability, robustness of the process, quality and accuracy, potential for defects, and post processing as well as potential applications. This paper focuses on current state of art of large scale metal additive technology with a focus on expanding the geometric limits.

  18. Large-scale regions of antimatter

    SciTech Connect

    Grobov, A. V. Rubin, S. G.

    2015-07-15

    Amodified mechanism of the formation of large-scale antimatter regions is proposed. Antimatter appears owing to fluctuations of a complex scalar field that carries a baryon charge in the inflation era.

  19. The Large -scale Distribution of Galaxies

    NASA Astrophysics Data System (ADS)

    Flin, Piotr

    A review of the Large-scale structure of the Universe is given. A connection is made with the titanic work by Johannes Kepler in many areas of astronomy and cosmology. A special concern is made to spatial distribution of Galaxies, voids and walls (cellular structure of the Universe). Finaly, the author is concluding that the large scale structure of the Universe can be observed in much greater scale that it was thought twenty years ago.

  20. Large-scale cortical networks and cognition.

    PubMed

    Bressler, S L

    1995-03-01

    The well-known parcellation of the mammalian cerebral cortex into a large number of functionally distinct cytoarchitectonic areas presents a problem for understanding the complex cortical integrative functions that underlie cognition. How do cortical areas having unique individual functional properties cooperate to accomplish these complex operations? Do neurons distributed throughout the cerebral cortex act together in large-scale functional assemblages? This review examines the substantial body of evidence supporting the view that complex integrative functions are carried out by large-scale networks of cortical areas. Pathway tracing studies in non-human primates have revealed widely distributed networks of interconnected cortical areas, providing an anatomical substrate for large-scale parallel processing of information in the cerebral cortex. Functional coactivation of multiple cortical areas has been demonstrated by neurophysiological studies in non-human primates and several different cognitive functions have been shown to depend on multiple distributed areas by human neuropsychological studies. Electrophysiological studies on interareal synchronization have provided evidence that active neurons in different cortical areas may become not only coactive, but also functionally interdependent. The computational advantages of synchronization between cortical areas in large-scale networks have been elucidated by studies using artificial neural network models. Recent observations of time-varying multi-areal cortical synchronization suggest that the functional topology of a large-scale cortical network is dynamically reorganized during visuomotor behavior.

  1. Survey on large scale system control methods

    NASA Technical Reports Server (NTRS)

    Mercadal, Mathieu

    1987-01-01

    The problem inherent to large scale systems such as power network, communication network and economic or ecological systems were studied. The increase in size and flexibility of future spacecraft has put those dynamical systems into the category of large scale systems, and tools specific to the class of large systems are being sought to design control systems that can guarantee more stability and better performance. Among several survey papers, reference was found to a thorough investigation on decentralized control methods. Especially helpful was the classification made of the different existing approaches to deal with large scale systems. A very similar classification is used, even though the papers surveyed are somehow different from the ones reviewed in other papers. Special attention is brought to the applicability of the existing methods to controlling large mechanical systems like large space structures. Some recent developments are added to this survey.

  2. Large-scale nanophotonic phased array.

    PubMed

    Sun, Jie; Timurdogan, Erman; Yaacobi, Ami; Hosseini, Ehsan Shah; Watts, Michael R

    2013-01-10

    Electromagnetic phased arrays at radio frequencies are well known and have enabled applications ranging from communications to radar, broadcasting and astronomy. The ability to generate arbitrary radiation patterns with large-scale phased arrays has long been pursued. Although it is extremely expensive and cumbersome to deploy large-scale radiofrequency phased arrays, optical phased arrays have a unique advantage in that the much shorter optical wavelength holds promise for large-scale integration. However, the short optical wavelength also imposes stringent requirements on fabrication. As a consequence, although optical phased arrays have been studied with various platforms and recently with chip-scale nanophotonics, all of the demonstrations so far are restricted to one-dimensional or small-scale two-dimensional arrays. Here we report the demonstration of a large-scale two-dimensional nanophotonic phased array (NPA), in which 64 × 64 (4,096) optical nanoantennas are densely integrated on a silicon chip within a footprint of 576 μm × 576 μm with all of the nanoantennas precisely balanced in power and aligned in phase to generate a designed, sophisticated radiation pattern in the far field. We also show that active phase tunability can be realized in the proposed NPA by demonstrating dynamic beam steering and shaping with an 8 × 8 array. This work demonstrates that a robust design, together with state-of-the-art complementary metal-oxide-semiconductor technology, allows large-scale NPAs to be implemented on compact and inexpensive nanophotonic chips. In turn, this enables arbitrary radiation pattern generation using NPAs and therefore extends the functionalities of phased arrays beyond conventional beam focusing and steering, opening up possibilities for large-scale deployment in applications such as communication, laser detection and ranging, three-dimensional holography and biomedical sciences, to name just a few.

  3. The large-scale distribution of galaxies

    NASA Technical Reports Server (NTRS)

    Geller, Margaret J.

    1989-01-01

    The spatial distribution of galaxies in the universe is characterized on the basis of the six completed strips of the Harvard-Smithsonian Center for Astrophysics redshift-survey extension. The design of the survey is briefly reviewed, and the results are presented graphically. Vast low-density voids similar to the void in Bootes are found, almost completely surrounded by thin sheets of galaxies. Also discussed are the implications of the results for the survey sampling problem, the two-point correlation function of the galaxy distribution, the possibility of detecting large-scale coherent flows, theoretical models of large-scale structure, and the identification of groups and clusters of galaxies.

  4. The impact of professional isolation on teleworker job performance and turnover intentions: does time spent teleworking, interacting face-to-face, or having access to communication-enhancing technology matter?

    PubMed

    Golden, Timothy D; Veiga, John F; Dino, Richard N

    2008-11-01

    Although the teleworking literature continues to raise concerns regarding the adverse consequences of professional isolation, researchers have not examined its impact on work outcomes. Consequently, the authors first examine professional isolation's direct impact on job performance and turnover intentions among teleworkers and then investigate the contingent role of 3 salient work-mode-related factors. Survey data from a matched sample of 261 professional-level teleworkers and their managers revealed that professional isolation negatively impacts job performance and, contrary to expectations, reduces turnover intentions. Moreover, professional isolation's impact on these work outcomes is increased by the amount of time spent teleworking, whereas more face-to-face interactions and access to communication-enhancing technology tend to decrease its impact. On the basis of these findings, an agenda for future research on professional isolation is offered that takes into account telework's growing popularity as a work modality.

  5. Management of large-scale technology

    NASA Technical Reports Server (NTRS)

    Levine, A.

    1985-01-01

    Two major themes are addressed in this assessment of the management of large-scale NASA programs: (1) how a high technology agency was a decade marked by a rapid expansion of funds and manpower in the first half and almost as rapid contraction in the second; and (2) how NASA combined central planning and control with decentralized project execution.

  6. Large-scale multimedia modeling applications

    SciTech Connect

    Droppo, J.G. Jr.; Buck, J.W.; Whelan, G.; Strenge, D.L.; Castleton, K.J.; Gelston, G.M.

    1995-08-01

    Over the past decade, the US Department of Energy (DOE) and other agencies have faced increasing scrutiny for a wide range of environmental issues related to past and current practices. A number of large-scale applications have been undertaken that required analysis of large numbers of potential environmental issues over a wide range of environmental conditions and contaminants. Several of these applications, referred to here as large-scale applications, have addressed long-term public health risks using a holistic approach for assessing impacts from potential waterborne and airborne transport pathways. Multimedia models such as the Multimedia Environmental Pollutant Assessment System (MEPAS) were designed for use in such applications. MEPAS integrates radioactive and hazardous contaminants impact computations for major exposure routes via air, surface water, ground water, and overland flow transport. A number of large-scale applications of MEPAS have been conducted to assess various endpoints for environmental and human health impacts. These applications are described in terms of lessons learned in the development of an effective approach for large-scale applications.

  7. "Home is at work and work is at home": telework and individuals who use augmentative and alternative communication.

    PubMed

    McNaughton, David; Rackensperger, Tracy; Dorn, Dana; Wilson, Natasha

    2014-01-01

    Telework, the use of distance communication technologies to participate in the workforce, has been suggested as a promising employment strategy for individuals with disabilities. The goal of this study was to obtain a better understanding of the benefits and negative impacts of telework, as well as the supports and challenges to telework activities, for persons who use augmentative and alternative communication (AAC). This study used a series of focus group discussions, conducted on the internet, to examine the employment experiences of nine individuals with disabilities who used AAC and who held jobs that involved the use of telework. Four major themes emerged from the discussion: (a) benefits of telework, (b) negative impacts of telework, (c) strategies for addressing negative impacts of telework, and (d) recommendations for improving employment outcomes for individuals who use AAC. In summary, while participants identified the elimination of travel time and flexible work schedules as key strengths of telework, concerns were expressed regarding feelings of isolation and the difficulty in separating home and work environments. The participants also emphasized the important role of educational programs in supporting the acquisition of literacy and self-advocacy skills, and the need for post-secondary programs to support the school-to-workplace transition.

  8. 29 CFR 15.206 - What claims arising at a residence or Telework location may be covered under the MPCECA?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 1 2014-07-01 2013-07-01 true What claims arising at a residence or Telework location may... ADMINISTRATIVE CLAIMS UNDER THE FEDERAL TORT CLAIMS ACT AND RELATED CLAIMS STATUTES Claims Under the Military Personnel and Civilian Employees' Claims Act of 1964 § 15.206 What claims arising at a residence or Telework...

  9. 29 CFR 15.206 - What claims arising at a residence or Telework location may be covered under the MPCECA?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 1 2013-07-01 2013-07-01 false What claims arising at a residence or Telework location may... ADMINISTRATIVE CLAIMS UNDER THE FEDERAL TORT CLAIMS ACT AND RELATED CLAIMS STATUTES Claims Under the Military Personnel and Civilian Employees' Claims Act of 1964 § 15.206 What claims arising at a residence or Telework...

  10. Health circles for teleworkers: selective results on stress, strain and coping styles.

    PubMed

    Konradt, U; Schmook, R; Wilm, A; Hertel, G

    2000-06-01

    Telework is decentralized computer-mediated performance of work activities at a location distant from the employing organization. In order to improve well-being at such remote workplaces, we developed a health circle (HC) concept for teleworkers. Three HC sessions were conducted with a total of 17 teleworkers from diverse organizations and branches. The sessions were moderated by a professional facilitator, while the participants selected the discussion issues. Typical issues were technical problems at the home-based computer, time management, communication with supervisors, colleagues and customers, and feelings of isolation from the main company. Besides discussing these stress factors, participants developed concrete coping strategies based on the exchange of experiences and additional informational input by external experts. Process evaluation at the end of each meeting revealed that participants found the exchange of personal experiences and the informational input during the HCs very helpful, as well as the common development of coping strategies. Moreover, a questionnaire 2 months after the last HC session revealed that participants reported significantly more positive changes in typical stress factors than teleworkers in a control group. The implications of these results for preventive and corrective strategies of telework design are discussed.

  11. Condition Monitoring of Large-Scale Facilities

    NASA Technical Reports Server (NTRS)

    Hall, David L.

    1999-01-01

    This document provides a summary of the research conducted for the NASA Ames Research Center under grant NAG2-1182 (Condition-Based Monitoring of Large-Scale Facilities). The information includes copies of view graphs presented at NASA Ames in the final Workshop (held during December of 1998), as well as a copy of a technical report provided to the COTR (Dr. Anne Patterson-Hine) subsequent to the workshop. The material describes the experimental design, collection of data, and analysis results associated with monitoring the health of large-scale facilities. In addition to this material, a copy of the Pennsylvania State University Applied Research Laboratory data fusion visual programming tool kit was also provided to NASA Ames researchers.

  12. Large-scale Advanced Propfan (LAP) program

    NASA Technical Reports Server (NTRS)

    Sagerser, D. A.; Ludemann, S. G.

    1985-01-01

    The propfan is an advanced propeller concept which maintains the high efficiencies traditionally associated with conventional propellers at the higher aircraft cruise speeds associated with jet transports. The large-scale advanced propfan (LAP) program extends the research done on 2 ft diameter propfan models to a 9 ft diameter article. The program includes design, fabrication, and testing of both an eight bladed, 9 ft diameter propfan, designated SR-7L, and a 2 ft diameter aeroelastically scaled model, SR-7A. The LAP program is complemented by the propfan test assessment (PTA) program, which takes the large-scale propfan and mates it with a gas generator and gearbox to form a propfan propulsion system and then flight tests this system on the wing of a Gulfstream 2 testbed aircraft.

  13. Large-scale fibre-array multiplexing

    SciTech Connect

    Cheremiskin, I V; Chekhlova, T K

    2001-05-31

    The possibility of creating a fibre multiplexer/demultiplexer with large-scale multiplexing without any basic restrictions on the number of channels and the spectral spacing between them is shown. The operating capacity of a fibre multiplexer based on a four-fibre array ensuring a spectral spacing of 0.7 pm ({approx} 10 GHz) between channels is demonstrated. (laser applications and other topics in quantum electronics)

  14. Modeling Human Behavior at a Large Scale

    DTIC Science & Technology

    2012-01-01

    Discerning intentions in dynamic human action. Trends in Cognitive Sciences , 5(4):171 – 178, 2001. Shirli Bar-David, Israel Bar-David, Paul C. Cross, Sadie...Limits of predictability in human mobility. Science , 327(5968):1018, 2010. S.A. Stouffer. Intervening opportunities: a theory relating mobility and...Modeling Human Behavior at a Large Scale by Adam Sadilek Submitted in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy

  15. Large-Scale Aerosol Modeling and Analysis

    DTIC Science & Technology

    2008-09-30

    aerosol species up to six days in advance anywhere on the globe. NAAPS and COAMPS are particularly useful for forecasts of dust storms in areas...impact cloud processes globally. With increasing dust storms due to climate change and land use changes in desert regions, the impact of the...bacteria in large-scale dust storms is expected to significantly impact warm ice cloud formation, human health, and ecosystems globally. In Niemi et al

  16. Large-scale instabilities of helical flows

    NASA Astrophysics Data System (ADS)

    Cameron, Alexandre; Alexakis, Alexandros; Brachet, Marc-Étienne

    2016-10-01

    Large-scale hydrodynamic instabilities of periodic helical flows of a given wave number K are investigated using three-dimensional Floquet numerical computations. In the Floquet formalism the unstable field is expanded in modes of different spacial periodicity. This allows us (i) to clearly distinguish large from small scale instabilities and (ii) to study modes of wave number q of arbitrarily large-scale separation q ≪K . Different flows are examined including flows that exhibit small-scale turbulence. The growth rate σ of the most unstable mode is measured as a function of the scale separation q /K ≪1 and the Reynolds number Re. It is shown that the growth rate follows the scaling σ ∝q if an AKA effect [Frisch et al., Physica D: Nonlinear Phenomena 28, 382 (1987), 10.1016/0167-2789(87)90026-1] is present or a negative eddy viscosity scaling σ ∝q2 in its absence. This holds both for the Re≪1 regime where previously derived asymptotic results are verified but also for Re=O (1 ) that is beyond their range of validity. Furthermore, for values of Re above a critical value ReSc beyond which small-scale instabilities are present, the growth rate becomes independent of q and the energy of the perturbation at large scales decreases with scale separation. The nonlinear behavior of these large-scale instabilities is also examined in the nonlinear regime where the largest scales of the system are found to be the most dominant energetically. These results are interpreted by low-order models.

  17. Economically viable large-scale hydrogen liquefaction

    NASA Astrophysics Data System (ADS)

    Cardella, U.; Decker, L.; Klein, H.

    2017-02-01

    The liquid hydrogen demand, particularly driven by clean energy applications, will rise in the near future. As industrial large scale liquefiers will play a major role within the hydrogen supply chain, production capacity will have to increase by a multiple of today’s typical sizes. The main goal is to reduce the total cost of ownership for these plants by increasing energy efficiency with innovative and simple process designs, optimized in capital expenditure. New concepts must ensure a manageable plant complexity and flexible operability. In the phase of process development and selection, a dimensioning of key equipment for large scale liquefiers, such as turbines and compressors as well as heat exchangers, must be performed iteratively to ensure technological feasibility and maturity. Further critical aspects related to hydrogen liquefaction, e.g. fluid properties, ortho-para hydrogen conversion, and coldbox configuration, must be analysed in detail. This paper provides an overview on the approach, challenges and preliminary results in the development of efficient as well as economically viable concepts for large-scale hydrogen liquefaction.

  18. Large-Scale Visual Data Analysis

    NASA Astrophysics Data System (ADS)

    Johnson, Chris

    2014-04-01

    Modern high performance computers have speeds measured in petaflops and handle data set sizes measured in terabytes and petabytes. Although these machines offer enormous potential for solving very large-scale realistic computational problems, their effectiveness will hinge upon the ability of human experts to interact with their simulation results and extract useful information. One of the greatest scientific challenges of the 21st century is to effectively understand and make use of the vast amount of information being produced. Visual data analysis will be among our most most important tools in helping to understand such large-scale information. Our research at the Scientific Computing and Imaging (SCI) Institute at the University of Utah has focused on innovative, scalable techniques for large-scale 3D visual data analysis. In this talk, I will present state- of-the-art visualization techniques, including scalable visualization algorithms and software, cluster-based visualization methods and innovate visualization techniques applied to problems in computational science, engineering, and medicine. I will conclude with an outline for a future high performance visualization research challenges and opportunities.

  19. Large-scale neuromorphic computing systems

    NASA Astrophysics Data System (ADS)

    Furber, Steve

    2016-10-01

    Neuromorphic computing covers a diverse range of approaches to information processing all of which demonstrate some degree of neurobiological inspiration that differentiates them from mainstream conventional computing systems. The philosophy behind neuromorphic computing has its origins in the seminal work carried out by Carver Mead at Caltech in the late 1980s. This early work influenced others to carry developments forward, and advances in VLSI technology supported steady growth in the scale and capability of neuromorphic devices. Recently, a number of large-scale neuromorphic projects have emerged, taking the approach to unprecedented scales and capabilities. These large-scale projects are associated with major new funding initiatives for brain-related research, creating a sense that the time and circumstances are right for progress in our understanding of information processing in the brain. In this review we present a brief history of neuromorphic engineering then focus on some of the principal current large-scale projects, their main features, how their approaches are complementary and distinct, their advantages and drawbacks, and highlight the sorts of capabilities that each can deliver to neural modellers.

  20. Experimental Simulations of Large-Scale Collisions

    NASA Technical Reports Server (NTRS)

    Housen, Kevin R.

    2002-01-01

    This report summarizes research on the effects of target porosity on the mechanics of impact cratering. Impact experiments conducted on a centrifuge provide direct simulations of large-scale cratering on porous asteroids. The experiments show that large craters in porous materials form mostly by compaction, with essentially no deposition of material into the ejecta blanket that is a signature of cratering in less-porous materials. The ratio of ejecta mass to crater mass is shown to decrease with increasing crater size or target porosity. These results are consistent with the observation that large closely-packed craters on asteroid Mathilde appear to have formed without degradation to earlier craters.

  1. What is a large-scale dynamo?

    NASA Astrophysics Data System (ADS)

    Nigro, G.; Pongkitiwanichakul, P.; Cattaneo, F.; Tobias, S. M.

    2017-01-01

    We consider kinematic dynamo action in a sheared helical flow at moderate to high values of the magnetic Reynolds number (Rm). We find exponentially growing solutions which, for large enough shear, take the form of a coherent part embedded in incoherent fluctuations. We argue that at large Rm large-scale dynamo action should be identified by the presence of structures coherent in time, rather than those at large spatial scales. We further argue that although the growth rate is determined by small-scale processes, the period of the coherent structures is set by mean-field considerations.

  2. Large-scale brightenings associated with flares

    NASA Technical Reports Server (NTRS)

    Mandrini, Cristina H.; Machado, Marcos E.

    1992-01-01

    It is shown that large-scale brightenings (LSBs) associated with solar flares, similar to the 'giant arches' discovered by Svestka et al. (1982) in images obtained by the SSM HXIS hours after the onset of two-ribbon flares, can also occur in association with confined flares in complex active regions. For these events, a clear link between the LSB and the underlying flare is clearly evident from the active-region magnetic field topology. The implications of these findings are discussed within the framework of the interacting loops of flares and the giant arch phenomenology.

  3. Large scale phononic metamaterials for seismic isolation

    SciTech Connect

    Aravantinos-Zafiris, N.; Sigalas, M. M.

    2015-08-14

    In this work, we numerically examine structures that could be characterized as large scale phononic metamaterials. These novel structures could have band gaps in the frequency spectrum of seismic waves when their dimensions are chosen appropriately, thus raising the belief that they could be serious candidates for seismic isolation structures. Different and easy to fabricate structures were examined made from construction materials such as concrete and steel. The well-known finite difference time domain method is used in our calculations in order to calculate the band structures of the proposed metamaterials.

  4. Large-scale planar lightwave circuits

    NASA Astrophysics Data System (ADS)

    Bidnyk, Serge; Zhang, Hua; Pearson, Matt; Balakrishnan, Ashok

    2011-01-01

    By leveraging advanced wafer processing and flip-chip bonding techniques, we have succeeded in hybrid integrating a myriad of active optical components, including photodetectors and laser diodes, with our planar lightwave circuit (PLC) platform. We have combined hybrid integration of active components with monolithic integration of other critical functions, such as diffraction gratings, on-chip mirrors, mode-converters, and thermo-optic elements. Further process development has led to the integration of polarization controlling functionality. Most recently, all these technological advancements have been combined to create large-scale planar lightwave circuits that comprise hundreds of optical elements integrated on chips less than a square inch in size.

  5. Large-Scale PV Integration Study

    SciTech Connect

    Lu, Shuai; Etingov, Pavel V.; Diao, Ruisheng; Ma, Jian; Samaan, Nader A.; Makarov, Yuri V.; Guo, Xinxin; Hafen, Ryan P.; Jin, Chunlian; Kirkham, Harold; Shlatz, Eugene; Frantzis, Lisa; McClive, Timothy; Karlson, Gregory; Acharya, Dhruv; Ellis, Abraham; Stein, Joshua; Hansen, Clifford; Chadliev, Vladimir; Smart, Michael; Salgo, Richard; Sorensen, Rahn; Allen, Barbara; Idelchik, Boris

    2011-07-29

    This research effort evaluates the impact of large-scale photovoltaic (PV) and distributed generation (DG) output on NV Energy’s electric grid system in southern Nevada. It analyzes the ability of NV Energy’s generation to accommodate increasing amounts of utility-scale PV and DG, and the resulting cost of integrating variable renewable resources. The study was jointly funded by the United States Department of Energy and NV Energy, and conducted by a project team comprised of industry experts and research scientists from Navigant Consulting Inc., Sandia National Laboratories, Pacific Northwest National Laboratory and NV Energy.

  6. Colloquium: Large scale simulations on GPU clusters

    NASA Astrophysics Data System (ADS)

    Bernaschi, Massimo; Bisson, Mauro; Fatica, Massimiliano

    2015-06-01

    Graphics processing units (GPU) are currently used as a cost-effective platform for computer simulations and big-data processing. Large scale applications require that multiple GPUs work together but the efficiency obtained with cluster of GPUs is, at times, sub-optimal because the GPU features are not exploited at their best. We describe how it is possible to achieve an excellent efficiency for applications in statistical mechanics, particle dynamics and networks analysis by using suitable memory access patterns and mechanisms like CUDA streams, profiling tools, etc. Similar concepts and techniques may be applied also to other problems like the solution of Partial Differential Equations.

  7. Neutrinos and large-scale structure

    SciTech Connect

    Eisenstein, Daniel J.

    2015-07-15

    I review the use of cosmological large-scale structure to measure properties of neutrinos and other relic populations of light relativistic particles. With experiments to measure the anisotropies of the cosmic microwave anisotropies and the clustering of matter at low redshift, we now have securely measured a relativistic background with density appropriate to the cosmic neutrino background. Our limits on the mass of the neutrino continue to shrink. Experiments coming in the next decade will greatly improve the available precision on searches for the energy density of novel relativistic backgrounds and the mass of neutrinos.

  8. Large-scale Heterogeneous Network Data Analysis

    DTIC Science & Technology

    2012-07-31

    Data for Multi-Player Influence Maximization on Social Networks.” KDD 2012 (Demo).  Po-Tzu Chang , Yen-Chieh Huang, Cheng-Lun Yang, Shou-De Lin, Pu...Jen Cheng. “Learning-Based Time-Sensitive Re-Ranking for Web Search.” SIGIR 2012 (poster)  Hung -Che Lai, Cheng-Te Li, Yi-Chen Lo, and Shou-De Lin...Exploiting and Evaluating MapReduce for Large-Scale Graph Mining.” ASONAM 2012 (Full, 16% acceptance ratio).  Hsun-Ping Hsieh , Cheng-Te Li, and Shou

  9. NIC-based Reduction Algorithms for Large-scale Clusters

    SciTech Connect

    Petrini, F; Moody, A T; Fernandez, J; Frachtenberg, E; Panda, D K

    2004-07-30

    Efficient algorithms for reduction operations across a group of processes are crucial for good performance in many large-scale, parallel scientific applications. While previous algorithms limit processing to the host CPU, we utilize the programmable processors and local memory available on modern cluster network interface cards (NICs) to explore a new dimension in the design of reduction algorithms. In this paper, we present the benefits and challenges, design issues and solutions, analytical models, and experimental evaluations of a family of NIC-based reduction algorithms. Performance and scalability evaluations were conducted on the ASCI Linux Cluster (ALC), a 960-node, 1920-processor machine at Lawrence Livermore National Laboratory, which uses the Quadrics QsNet interconnect. We find NIC-based reductions on modern interconnects to be more efficient than host-based implementations in both scalability and consistency. In particular, at large-scale--1812 processes--NIC-based reductions of small integer and floating-point arrays provided respective speedups of 121% and 39% over the host-based, production-level MPI implementation.

  10. Internationalization Measures in Large Scale Research Projects

    NASA Astrophysics Data System (ADS)

    Soeding, Emanuel; Smith, Nancy

    2017-04-01

    Internationalization measures in Large Scale Research Projects Large scale research projects (LSRP) often serve as flagships used by universities or research institutions to demonstrate their performance and capability to stakeholders and other interested parties. As the global competition among universities for the recruitment of the brightest brains has increased, effective internationalization measures have become hot topics for universities and LSRP alike. Nevertheless, most projects and universities are challenged with little experience on how to conduct these measures and make internationalization an cost efficient and useful activity. Furthermore, those undertakings permanently have to be justified with the Project PIs as important, valuable tools to improve the capacity of the project and the research location. There are a variety of measures, suited to support universities in international recruitment. These include e.g. institutional partnerships, research marketing, a welcome culture, support for science mobility and an effective alumni strategy. These activities, although often conducted by different university entities, are interlocked and can be very powerful measures if interfaced in an effective way. On this poster we display a number of internationalization measures for various target groups, identify interfaces between project management, university administration, researchers and international partners to work together, exchange information and improve processes in order to be able to recruit, support and keep the brightest heads to your project.

  11. Local gravity and large-scale structure

    NASA Technical Reports Server (NTRS)

    Juszkiewicz, Roman; Vittorio, Nicola; Wyse, Rosemary F. G.

    1990-01-01

    The magnitude and direction of the observed dipole anisotropy of the galaxy distribution can in principle constrain the amount of large-scale power present in the spectrum of primordial density fluctuations. This paper confronts the data, provided by a recent redshift survey of galaxies detected by the IRAS satellite, with the predictions of two cosmological models with very different levels of large-scale power: the biased Cold Dark Matter dominated model (CDM) and a baryon-dominated model (BDM) with isocurvature initial conditions. Model predictions are investigated for the Local Group peculiar velocity, v(R), induced by mass inhomogeneities distributed out to a given radius, R, for R less than about 10,000 km/s. Several convergence measures for v(R) are developed, which can become powerful cosmological tests when deep enough samples become available. For the present data sets, the CDM and BDM predictions are indistinguishable at the 2 sigma level and both are consistent with observations. A promising discriminant between cosmological models is the misalignment angle between v(R) and the apex of the dipole anisotropy of the microwave background.

  12. Large-scale Intelligent Transporation Systems simulation

    SciTech Connect

    Ewing, T.; Canfield, T.; Hannebutte, U.; Levine, D.; Tentner, A.

    1995-06-01

    A prototype computer system has been developed which defines a high-level architecture for a large-scale, comprehensive, scalable simulation of an Intelligent Transportation System (ITS) capable of running on massively parallel computers and distributed (networked) computer systems. The prototype includes the modelling of instrumented ``smart`` vehicles with in-vehicle navigation units capable of optimal route planning and Traffic Management Centers (TMC). The TMC has probe vehicle tracking capabilities (display position and attributes of instrumented vehicles), and can provide 2-way interaction with traffic to provide advisories and link times. Both the in-vehicle navigation module and the TMC feature detailed graphical user interfaces to support human-factors studies. The prototype has been developed on a distributed system of networked UNIX computers but is designed to run on ANL`s IBM SP-X parallel computer system for large scale problems. A novel feature of our design is that vehicles will be represented by autonomus computer processes, each with a behavior model which performs independent route selection and reacts to external traffic events much like real vehicles. With this approach, one will be able to take advantage of emerging massively parallel processor (MPP) systems.

  13. Local gravity and large-scale structure

    NASA Technical Reports Server (NTRS)

    Juszkiewicz, Roman; Vittorio, Nicola; Wyse, Rosemary F. G.

    1990-01-01

    The magnitude and direction of the observed dipole anisotropy of the galaxy distribution can in principle constrain the amount of large-scale power present in the spectrum of primordial density fluctuations. This paper confronts the data, provided by a recent redshift survey of galaxies detected by the IRAS satellite, with the predictions of two cosmological models with very different levels of large-scale power: the biased Cold Dark Matter dominated model (CDM) and a baryon-dominated model (BDM) with isocurvature initial conditions. Model predictions are investigated for the Local Group peculiar velocity, v(R), induced by mass inhomogeneities distributed out to a given radius, R, for R less than about 10,000 km/s. Several convergence measures for v(R) are developed, which can become powerful cosmological tests when deep enough samples become available. For the present data sets, the CDM and BDM predictions are indistinguishable at the 2 sigma level and both are consistent with observations. A promising discriminant between cosmological models is the misalignment angle between v(R) and the apex of the dipole anisotropy of the microwave background.

  14. Large-scale Globally Propagating Coronal Waves.

    PubMed

    Warmuth, Alexander

    Large-scale, globally propagating wave-like disturbances have been observed in the solar chromosphere and by inference in the corona since the 1960s. However, detailed analysis of these phenomena has only been conducted since the late 1990s. This was prompted by the availability of high-cadence coronal imaging data from numerous spaced-based instruments, which routinely show spectacular globally propagating bright fronts. Coronal waves, as these perturbations are usually referred to, have now been observed in a wide range of spectral channels, yielding a wealth of information. Many findings have supported the "classical" interpretation of the disturbances: fast-mode MHD waves or shocks that are propagating in the solar corona. However, observations that seemed inconsistent with this picture have stimulated the development of alternative models in which "pseudo waves" are generated by magnetic reconfiguration in the framework of an expanding coronal mass ejection. This has resulted in a vigorous debate on the physical nature of these disturbances. This review focuses on demonstrating how the numerous observational findings of the last one and a half decades can be used to constrain our models of large-scale coronal waves, and how a coherent physical understanding of these disturbances is finally emerging.

  15. Conceptualizing the Science Curriculum: 40 Years of Developing Assessment Frameworks in Three Large-Scale Assessments

    ERIC Educational Resources Information Center

    Kind, Per Morten

    2013-01-01

    The paper analyzes conceptualizations in the science frameworks in three large-scale assessments, Trends in Mathematics and Science Study (TIMSS), Programme for International Student Assessment (PISA), and National Assessment of Educational Progress (NAEP). The assessments have a shared history, but have developed different conceptualizations. The…

  16. The Politics of Literacy in the Context of Large-Scale Education Reform

    ERIC Educational Resources Information Center

    Moss, Gemma

    2009-01-01

    In this paper, I will consider the lessons that can be learnt about literacy policy and its role in large-scale education reform programmes, with particular reference to policy-making in England since the election of New Labour in 1997. New Labour's promise to the electorate in 1997 was that state-funded education could be fixed and turned into a…

  17. Psychology in an Interdisciplinary Setting: A Large-Scale Project to Improve University Teaching

    ERIC Educational Resources Information Center

    Koch, Franziska D.; Vogt, Joachim

    2015-01-01

    At a German university of technology, a large-scale project was funded as a part of the "Quality Pact for Teaching", a programme launched by the German Federal Ministry of Education and Research to improve the quality of university teaching and study conditions. The project aims at intensifying interdisciplinary networking in teaching,…

  18. Conceptualizing the Science Curriculum: 40 Years of Developing Assessment Frameworks in Three Large-Scale Assessments

    ERIC Educational Resources Information Center

    Kind, Per Morten

    2013-01-01

    The paper analyzes conceptualizations in the science frameworks in three large-scale assessments, Trends in Mathematics and Science Study (TIMSS), Programme for International Student Assessment (PISA), and National Assessment of Educational Progress (NAEP). The assessments have a shared history, but have developed different conceptualizations. The…

  19. The Politics of Literacy in the Context of Large-Scale Education Reform

    ERIC Educational Resources Information Center

    Moss, Gemma

    2009-01-01

    In this paper, I will consider the lessons that can be learnt about literacy policy and its role in large-scale education reform programmes, with particular reference to policy-making in England since the election of New Labour in 1997. New Labour's promise to the electorate in 1997 was that state-funded education could be fixed and turned into a…

  20. Balancing Tensions in Educational Policy Reforms: Large-Scale Implementation of Assessment for Learning in Norway

    ERIC Educational Resources Information Center

    Hopfenbeck, Therese N.; Flórez Petour, María Teresa; Tolo, Astrid

    2015-01-01

    This study investigates how different stakeholders in Norway experienced a government-initiated, large-scale policy implementation programme on "Assessment for Learning" ("AfL"). Data were collected through 58 interviews with stakeholders in charge of the policy; Ministers of Education and members of the Directorate of…

  1. Psychology in an Interdisciplinary Setting: A Large-Scale Project to Improve University Teaching

    ERIC Educational Resources Information Center

    Koch, Franziska D.; Vogt, Joachim

    2015-01-01

    At a German university of technology, a large-scale project was funded as a part of the "Quality Pact for Teaching", a programme launched by the German Federal Ministry of Education and Research to improve the quality of university teaching and study conditions. The project aims at intensifying interdisciplinary networking in teaching,…

  2. Teaching, Tweeting, and Teleworking: Experiential and Cross-Institutional Learning through Social Media

    ERIC Educational Resources Information Center

    Madden, Stephanie; Briones Winkler, Rowena; Fraustino, Julia Daisy; Janoske, Melissa

    2016-01-01

    Today's college students increasingly need skills in social media and teleworking. To develop these skills, instructors at four institutions created and implemented a cross-institutional group project that required students to create and share online an instructional video about a social media topic. Students then discussed the videos and their…

  3. Knowledge Worker Perceptions of Telework Policy in the New York Metropolitan Area: A Qualitative Descriptive Study

    ERIC Educational Resources Information Center

    Slaughter, Sandra Lorraine Hawks

    2013-01-01

    This qualitative descriptive case study, "Knowledge Worker Perceptions of Telework in the New York Metropolitan Area," was conducted to explore the perceptions of knowledge workers who commute to a physical workplace in the New York Metropolitan area (NYMA). In-depth interviews were conducted with fourteen NYMA commuters who are…

  4. Knowledge Worker Perceptions of Telework Policy in the New York Metropolitan Area: A Qualitative Descriptive Study

    ERIC Educational Resources Information Center

    Slaughter, Sandra Lorraine Hawks

    2013-01-01

    This qualitative descriptive case study, "Knowledge Worker Perceptions of Telework in the New York Metropolitan Area," was conducted to explore the perceptions of knowledge workers who commute to a physical workplace in the New York Metropolitan area (NYMA). In-depth interviews were conducted with fourteen NYMA commuters who are…

  5. Teaching, Tweeting, and Teleworking: Experiential and Cross-Institutional Learning through Social Media

    ERIC Educational Resources Information Center

    Madden, Stephanie; Briones Winkler, Rowena; Fraustino, Julia Daisy; Janoske, Melissa

    2016-01-01

    Today's college students increasingly need skills in social media and teleworking. To develop these skills, instructors at four institutions created and implemented a cross-institutional group project that required students to create and share online an instructional video about a social media topic. Students then discussed the videos and their…

  6. Efficient, large scale separation of coal macerals

    SciTech Connect

    Dyrkacz, G.R.; Bloomquist, C.A.A.

    1988-01-01

    The authors believe that the separation of macerals by continuous flow centrifugation offers a simple technique for the large scale separation of macerals. With relatively little cost (/approximately/ $10K), it provides an opportunity for obtaining quite pure maceral fractions. Although they have not completely worked out all the nuances of this separation system, they believe that the problems they have indicated can be minimized to pose only minor inconvenience. It cannot be said that this system completely bypasses the disagreeable tedium or time involved in separating macerals, nor will it by itself overcome the mental inertia required to make maceral separation an accepted necessary fact in fundamental coal science. However, they find their particular brand of continuous flow centrifugation is considerably faster than sink/float separation, can provide a good quality product with even one separation cycle, and permits the handling of more material than a conventional sink/float centrifuge separation.

  7. Primer design for large scale sequencing.

    PubMed Central

    Haas, S; Vingron, M; Poustka, A; Wiemann, S

    1998-01-01

    We have developed PRIDE, a primer design program that automatically designs primers in single contigs or whole sequencing projects to extend the already known sequence and to double strand single-stranded regions. The program is fully integrated into the Staden package (GAP4) and accessible with a graphical user interface. PRIDE uses a fuzzy logic-based system to calculate primer qualities. The computational performance of PRIDE is enhanced by using suffix trees to store the huge amount of data being produced. A test set of 110 sequencing primers and 11 PCR primer pairs has been designed on genomic templates, cDNAs and sequences containing repetitive elements to analyze PRIDE's success rate. The high performance of PRIDE, combined with its minimal requirement of user interaction and its fast algorithm, make this program useful for the large scale design of primers, especially in large sequencing projects. PMID:9611248

  8. Grid sensitivity capability for large scale structures

    NASA Technical Reports Server (NTRS)

    Nagendra, Gopal K.; Wallerstein, David V.

    1989-01-01

    The considerations and the resultant approach used to implement design sensitivity capability for grids into a large scale, general purpose finite element system (MSC/NASTRAN) are presented. The design variables are grid perturbations with a rather general linking capability. Moreover, shape and sizing variables may be linked together. The design is general enough to facilitate geometric modeling techniques for generating design variable linking schemes in an easy and straightforward manner. Test cases have been run and validated by comparison with the overall finite difference method. The linking of a design sensitivity capability for shape variables in MSC/NASTRAN with an optimizer would give designers a powerful, automated tool to carry out practical optimization design of real life, complicated structures.

  9. Large-Scale Organization of Glycosylation Networks

    NASA Astrophysics Data System (ADS)

    Kim, Pan-Jun; Lee, Dong-Yup; Jeong, Hawoong

    2009-03-01

    Glycosylation is a highly complex process to produce a diverse repertoire of cellular glycans that are frequently attached to proteins and lipids. Glycans participate in fundamental biological processes including molecular trafficking and clearance, cell proliferation and apoptosis, developmental biology, immune response, and pathogenesis. N-linked glycans found on proteins are formed by sequential attachments of monosaccharides with the help of a relatively small number of enzymes. Many of these enzymes can accept multiple N-linked glycans as substrates, thus generating a large number of glycan intermediates and their intermingled pathways. Motivated by the quantitative methods developed in complex network research, we investigate the large-scale organization of such N-glycosylation pathways in a mammalian cell. The uncovered results give the experimentally-testable predictions for glycosylation process, and can be applied to the engineering of therapeutic glycoproteins.

  10. Large-scale optimization of neuron arbors

    NASA Astrophysics Data System (ADS)

    Cherniak, Christopher; Changizi, Mark; Won Kang, Du

    1999-05-01

    At the global as well as local scales, some of the geometry of types of neuron arbors-both dendrites and axons-appears to be self-organizing: Their morphogenesis behaves like flowing water, that is, fluid dynamically; waterflow in branching networks in turn acts like a tree composed of cords under tension, that is, vector mechanically. Branch diameters and angles and junction sites conform significantly to this model. The result is that such neuron tree samples globally minimize their total volume-rather than, for example, surface area or branch length. In addition, the arbors perform well at generating the cheapest topology interconnecting their terminals: their large-scale layouts are among the best of all such possible connecting patterns, approaching 5% of optimum. This model also applies comparably to arterial and river networks.

  11. Engineering management of large scale systems

    NASA Technical Reports Server (NTRS)

    Sanders, Serita; Gill, Tepper L.; Paul, Arthur S.

    1989-01-01

    The organization of high technology and engineering problem solving, has given rise to an emerging concept. Reasoning principles for integrating traditional engineering problem solving with system theory, management sciences, behavioral decision theory, and planning and design approaches can be incorporated into a methodological approach to solving problems with a long range perspective. Long range planning has a great potential to improve productivity by using a systematic and organized approach. Thus, efficiency and cost effectiveness are the driving forces in promoting the organization of engineering problems. Aspects of systems engineering that provide an understanding of management of large scale systems are broadly covered here. Due to the focus and application of research, other significant factors (e.g., human behavior, decision making, etc.) are not emphasized but are considered.

  12. Large scale cryogenic fluid systems testing

    NASA Technical Reports Server (NTRS)

    1992-01-01

    NASA Lewis Research Center's Cryogenic Fluid Systems Branch (CFSB) within the Space Propulsion Technology Division (SPTD) has the ultimate goal of enabling the long term storage and in-space fueling/resupply operations for spacecraft and reusable vehicles in support of space exploration. Using analytical modeling, ground based testing, and on-orbit experimentation, the CFSB is studying three primary categories of fluid technology: storage, supply, and transfer. The CFSB is also investigating fluid handling, advanced instrumentation, and tank structures and materials. Ground based testing of large-scale systems is done using liquid hydrogen as a test fluid at the Cryogenic Propellant Tank Facility (K-site) at Lewis' Plum Brook Station in Sandusky, Ohio. A general overview of tests involving liquid transfer, thermal control, pressure control, and pressurization is given.

  13. Large scale preparation of pure phycobiliproteins.

    PubMed

    Padgett, M P; Krogmann, D W

    1987-01-01

    This paper describes simple procedures for the purification of large amounts of phycocyanin and allophycocyanin from the cyanobacterium Microcystis aeruginosa. A homogeneous natural bloom of this organism provided hundreds of kilograms of cells. Large samples of cells were broken by freezing and thawing. Repeated extraction of the broken cells with distilled water released phycocyanin first, then allophycocyanin, and provides supporting evidence for the current models of phycobilisome structure. The very low ionic strength of the aqueous extracts allowed allophycocyanin release in a particulate form so that this protein could be easily concentrated by centrifugation. Other proteins in the extract were enriched and concentrated by large scale membrane filtration. The biliproteins were purified to homogeneity by chromatography on DEAE cellulose. Purity was established by HPLC and by N-terminal amino acid sequence analysis. The proteins were examined for stability at various pHs and exposures to visible light.

  14. Primer design for large scale sequencing.

    PubMed

    Haas, S; Vingron, M; Poustka, A; Wiemann, S

    1998-06-15

    We have developed PRIDE, a primer design program that automatically designs primers in single contigs or whole sequencing projects to extend the already known sequence and to double strand single-stranded regions. The program is fully integrated into the Staden package (GAP4) and accessible with a graphical user interface. PRIDE uses a fuzzy logic-based system to calculate primer qualities. The computational performance of PRIDE is enhanced by using suffix trees to store the huge amount of data being produced. A test set of 110 sequencing primers and 11 PCR primer pairs has been designed on genomic templates, cDNAs and sequences containing repetitive elements to analyze PRIDE's success rate. The high performance of PRIDE, combined with its minimal requirement of user interaction and its fast algorithm, make this program useful for the large scale design of primers, especially in large sequencing projects.

  15. Large-scale synthesis of peptides.

    PubMed

    Andersson, L; Blomberg, L; Flegel, M; Lepsa, L; Nilsson, B; Verlander, M

    2000-01-01

    Recent advances in the areas of formulation and delivery have rekindled the interest of the pharmaceutical community in peptides as drug candidates, which, in turn, has provided a challenge to the peptide industry to develop efficient methods for the manufacture of relatively complex peptides on scales of up to metric tons per year. This article focuses on chemical synthesis approaches for peptides, and presents an overview of the methods available and in use currently, together with a discussion of scale-up strategies. Examples of the different methods are discussed, together with solutions to some specific problems encountered during scale-up development. Finally, an overview is presented of issues common to all manufacturing methods, i.e., methods used for the large-scale purification and isolation of final bulk products and regulatory considerations to be addressed during scale-up of processes to commercial levels. Copyright 2000 John Wiley & Sons, Inc. Biopolymers (Pept Sci) 55: 227-250, 2000

  16. Large Scale Quantum Simulations of Nuclear Pasta

    NASA Astrophysics Data System (ADS)

    Fattoyev, Farrukh J.; Horowitz, Charles J.; Schuetrumpf, Bastian

    2016-03-01

    Complex and exotic nuclear geometries collectively referred to as ``nuclear pasta'' are expected to naturally exist in the crust of neutron stars and in supernovae matter. Using a set of self-consistent microscopic nuclear energy density functionals we present the first results of large scale quantum simulations of pasta phases at baryon densities 0 . 03 < ρ < 0 . 10 fm-3, proton fractions 0 . 05

  17. Jovian large-scale stratospheric circulation

    NASA Technical Reports Server (NTRS)

    West, R. A.; Friedson, A. J.; Appleby, J. F.

    1992-01-01

    An attempt is made to diagnose the annual-average mean meridional residual Jovian large-scale stratospheric circulation from observations of the temperature and reflected sunlight that reveal the morphology of the aerosol heating. The annual mean solar heating, total radiative flux divergence, mass stream function, and Eliassen-Palm flux divergence are shown. The stratospheric radiative flux divergence is dominated the high latitudes by aerosol absorption. Between the 270 and 100 mbar pressure levels, where there is no aerosol heating in the model, the structure of the circulation at low- to midlatitudes is governed by the meridional variation of infrared cooling in association with the variation of zonal mean temperatures observed by IRIS. The principal features of the vertical velocity profile found by Gierasch et al. (1986) are recovered in the present calculation.

  18. Large-scale parametric survival analysis.

    PubMed

    Mittal, Sushil; Madigan, David; Cheng, Jerry Q; Burd, Randall S

    2013-10-15

    Survival analysis has been a topic of active statistical research in the past few decades with applications spread across several areas. Traditional applications usually consider data with only a small numbers of predictors with a few hundreds or thousands of observations. Recent advances in data acquisition techniques and computation power have led to considerable interest in analyzing very-high-dimensional data where the number of predictor variables and the number of observations range between 10(4) and 10(6). In this paper, we present a tool for performing large-scale regularized parametric survival analysis using a variant of the cyclic coordinate descent method. Through our experiments on two real data sets, we show that application of regularized models to high-dimensional data avoids overfitting and can provide improved predictive performance and calibration over corresponding low-dimensional models.

  19. Large-Scale Parametric Survival Analysis†

    PubMed Central

    Mittal, Sushil; Madigan, David; Cheng, Jerry; Burd, Randall S.

    2013-01-01

    Survival analysis has been a topic of active statistical research in the past few decades with applications spread across several areas. Traditional applications usually consider data with only small numbers of predictors with a few hundreds or thousands of observations. Recent advances in data acquisition techniques and computation power has led to considerable interest in analyzing very high-dimensional data where the number of predictor variables and the number of observations range between 104 – 106. In this paper, we present a tool for performing large-scale regularized parametric survival analysis using a variant of cyclic coordinate descent method. Through our experiments on two real data sets, we show that application of regularized models to high-dimensional data avoids overfitting and can provide improved predictive performance and calibration over corresponding low-dimensional models. PMID:23625862

  20. Large scale study of tooth enamel

    SciTech Connect

    Bodart, F.; Deconninck, G.; Martin, M.Th.

    1981-04-01

    Human tooth enamel contains traces of foreign elements. The presence of these elements is related to the history and the environment of the human body and can be considered as the signature of perturbations which occur during the growth of a tooth. A map of the distribution of these traces on a large scale sample of the population will constitute a reference for further investigations of environmental effects. One hundred eighty samples of teeth were first analysed using PIXE, backscattering and nuclear reaction techniques. The results were analysed using statistical methods. Correlations between O, F, Na, P, Ca, Mn, Fe, Cu, Zn, Pb and Sr were observed and cluster analysis was in progress. The techniques described in the present work have been developed in order to establish a method for the exploration of very large samples of the Belgian population.

  1. The challenge of large-scale structure

    NASA Astrophysics Data System (ADS)

    Gregory, S. A.

    1996-03-01

    The tasks that I have assumed for myself in this presentation include three separate parts. The first, appropriate to the particular setting of this meeting, is to review the basic work of the founding of this field; the appropriateness comes from the fact that W. G. Tifft made immense contributions that are not often realized by the astronomical community. The second task is to outline the general tone of the observational evidence for large scale structures. (Here, in particular, I cannot claim to be complete. I beg forgiveness from any workers who are left out by my oversight for lack of space and time.) The third task is to point out some of the major aspects of the field that may represent the clues by which some brilliant sleuth will ultimately figure out how galaxies formed.

  2. Modeling the Internet's large-scale topology

    PubMed Central

    Yook, Soon-Hyung; Jeong, Hawoong; Barabási, Albert-László

    2002-01-01

    Network generators that capture the Internet's large-scale topology are crucial for the development of efficient routing protocols and modeling Internet traffic. Our ability to design realistic generators is limited by the incomplete understanding of the fundamental driving forces that affect the Internet's evolution. By combining several independent databases capturing the time evolution, topology, and physical layout of the Internet, we identify the universal mechanisms that shape the Internet's router and autonomous system level topology. We find that the physical layout of nodes form a fractal set, determined by population density patterns around the globe. The placement of links is driven by competition between preferential attachment and linear distance dependence, a marked departure from the currently used exponential laws. The universal parameters that we extract significantly restrict the class of potentially correct Internet models and indicate that the networks created by all available topology generators are fundamentally different from the current Internet. PMID:12368484

  3. Large-scale sequential quadratic programming algorithms

    SciTech Connect

    Eldersveld, S.K.

    1992-09-01

    The problem addressed is the general nonlinear programming problem: finding a local minimizer for a nonlinear function subject to a mixture of nonlinear equality and inequality constraints. The methods studied are in the class of sequential quadratic programming (SQP) algorithms, which have previously proved successful for problems of moderate size. Our goal is to devise an SQP algorithm that is applicable to large-scale optimization problems, using sparse data structures and storing less curvature information but maintaining the property of superlinear convergence. The main features are: 1. The use of a quasi-Newton approximation to the reduced Hessian of the Lagrangian function. Only an estimate of the reduced Hessian matrix is required by our algorithm. The impact of not having available the full Hessian approximation is studied and alternative estimates are constructed. 2. The use of a transformation matrix Q. This allows the QP gradient to be computed easily when only the reduced Hessian approximation is maintained. 3. The use of a reduced-gradient form of the basis for the null space of the working set. This choice of basis is more practical than an orthogonal null-space basis for large-scale problems. The continuity condition for this choice is proven. 4. The use of incomplete solutions of quadratic programming subproblems. Certain iterates generated by an active-set method for the QP subproblem are used in place of the QP minimizer to define the search direction for the nonlinear problem. An implementation of the new algorithm has been obtained by modifying the code MINOS. Results and comparisons with MINOS and NPSOL are given for the new algorithm on a set of 92 test problems.

  4. Supporting large-scale computational science

    SciTech Connect

    Musick, R., LLNL

    1998-02-19

    Business needs have driven the development of commercial database systems since their inception. As a result, there has been a strong focus on supporting many users, minimizing the potential corruption or loss of data, and maximizing performance metrics like transactions per second, or TPC-C and TPC-D results. It turns out that these optimizations have little to do with the needs of the scientific community, and in particular have little impact on improving the management and use of large-scale high-dimensional data. At the same time, there is an unanswered need in the scientific community for many of the benefits offered by a robust DBMS. For example, tying an ad-hoc query language such as SQL together with a visualization toolkit would be a powerful enhancement to current capabilities. Unfortunately, there has been little emphasis or discussion in the VLDB community on this mismatch over the last decade. The goal of the paper is to identify the specific issues that need to be resolved before large-scale scientific applications can make use of DBMS products. This topic is addressed in the context of an evaluation of commercial DBMS technology applied to the exploration of data generated by the Department of Energy`s Accelerated Strategic Computing Initiative (ASCI). The paper describes the data being generated for ASCI as well as current capabilities for interacting with and exploring this data. The attraction of applying standard DBMS technology to this domain is discussed, as well as the technical and business issues that currently make this an infeasible solution.

  5. Improving Recent Large-Scale Pulsar Surveys

    NASA Astrophysics Data System (ADS)

    Cardoso, Rogerio Fernando; Ransom, S.

    2011-01-01

    Pulsars are unique in that they act as celestial laboratories for precise tests of gravity and other extreme physics (Kramer 2004). There are approximately 2000 known pulsars today, which is less than ten percent of pulsars in the Milky Way according to theoretical models (Lorimer 2004). Out of these 2000 known pulsars, approximately ten percent are known millisecond pulsars, objects used for their period stability for detailed physics tests and searches for gravitational radiation (Lorimer 2008). As the field and instrumentation progress, pulsar astronomers attempt to overcome observational biases and detect new pulsars, consequently discovering new millisecond pulsars. We attempt to improve large scale pulsar surveys by examining three recent pulsar surveys. The first, the Green Bank Telescope 350MHz Drift Scan, a low frequency isotropic survey of the northern sky, has yielded a large number of candidates that were visually inspected and identified, resulting in over 34.000 thousands candidates viewed, dozens of detections of known pulsars, and the discovery of a new low-flux pulsar, PSRJ1911+22. The second, the PALFA survey, is a high frequency survey of the galactic plane with the Arecibo telescope. We created a processing pipeline for the PALFA survey at the National Radio Astronomy Observatory in Charlottesville- VA, in addition to making needed modifications upon advice from the PALFA consortium. The third survey examined is a new GBT 820MHz survey devoted to find new millisecond pulsars by observing the target-rich environment of unidentified sources in the FERMI LAT catalogue. By approaching these three pulsar surveys at different stages, we seek to improve the success rates of large scale surveys, and hence the possibility for ground-breaking work in both basic physics and astrophysics.

  6. Introducing Large-Scale Innovation in Schools

    NASA Astrophysics Data System (ADS)

    Sotiriou, Sofoklis; Riviou, Katherina; Cherouvis, Stephanos; Chelioti, Eleni; Bogner, Franz X.

    2016-08-01

    Education reform initiatives tend to promise higher effectiveness in classrooms especially when emphasis is given to e-learning and digital resources. Practical changes in classroom realities or school organization, however, are lacking. A major European initiative entitled Open Discovery Space (ODS) examined the challenge of modernizing school education via a large-scale implementation of an open-scale methodology in using technology-supported innovation. The present paper describes this innovation scheme which involved schools and teachers all over Europe, embedded technology-enhanced learning into wider school environments and provided training to teachers. Our implementation scheme consisted of three phases: (1) stimulating interest, (2) incorporating the innovation into school settings and (3) accelerating the implementation of the innovation. The scheme's impact was monitored for a school year using five indicators: leadership and vision building, ICT in the curriculum, development of ICT culture, professional development support, and school resources and infrastructure. Based on about 400 schools, our study produced four results: (1) The growth in digital maturity was substantial, even for previously high scoring schools. This was even more important for indicators such as vision and leadership" and "professional development." (2) The evolution of networking is presented graphically, showing the gradual growth of connections achieved. (3) These communities became core nodes, involving numerous teachers in sharing educational content and experiences: One out of three registered users (36 %) has shared his/her educational resources in at least one community. (4) Satisfaction scores ranged from 76 % (offer of useful support through teacher academies) to 87 % (good environment to exchange best practices). Initiatives such as ODS add substantial value to schools on a large scale.

  7. Supporting large-scale computational science

    SciTech Connect

    Musick, R

    1998-10-01

    A study has been carried out to determine the feasibility of using commercial database management systems (DBMSs) to support large-scale computational science. Conventional wisdom in the past has been that DBMSs are too slow for such data. Several events over the past few years have muddied the clarity of this mindset: 1. 2. 3. 4. Several commercial DBMS systems have demonstrated storage and ad-hoc quer access to Terabyte data sets. Several large-scale science teams, such as EOSDIS [NAS91], high energy physics [MM97] and human genome [Kin93] have adopted (or make frequent use of) commercial DBMS systems as the central part of their data management scheme. Several major DBMS vendors have introduced their first object-relational products (ORDBMSs), which have the potential to support large, array-oriented data. In some cases, performance is a moot issue. This is true in particular if the performance of legacy applications is not reduced while new, albeit slow, capabilities are added to the system. The basic assessment is still that DBMSs do not scale to large computational data. However, many of the reasons have changed, and there is an expiration date attached to that prognosis. This document expands on this conclusion, identifies the advantages and disadvantages of various commercial approaches, and describes the studies carried out in exploring this area. The document is meant to be brief, technical and informative, rather than a motivational pitch. The conclusions within are very likely to become outdated within the next 5-7 years, as market forces will have a significant impact on the state of the art in scientific data management over the next decade.

  8. Voids in the Large-Scale Structure

    NASA Astrophysics Data System (ADS)

    El-Ad, Hagai; Piran, Tsvi

    1997-12-01

    Voids are the most prominent feature of the large-scale structure of the universe. Still, their incorporation into quantitative analysis of it has been relatively recent, owing essentially to the lack of an objective tool to identify the voids and to quantify them. To overcome this, we present here the VOID FINDER algorithm, a novel tool for objectively quantifying voids in the galaxy distribution. The algorithm first classifies galaxies as either wall galaxies or field galaxies. Then, it identifies voids in the wall-galaxy distribution. Voids are defined as continuous volumes that do not contain any wall galaxies. The voids must be thicker than an adjustable limit, which is refined in successive iterations. In this way, we identify the same regions that would be recognized as voids by the eye. Small breaches in the walls are ignored, avoiding artificial connections between neighboring voids. We test the algorithm using Voronoi tesselations. By appropriate scaling of the parameters with the selection function, we apply it to two redshift surveys, the dense SSRS2 and the full-sky IRAS 1.2 Jy. Both surveys show similar properties: ~50% of the volume is filled by voids. The voids have a scale of at least 40 h-1 Mpc and an average -0.9 underdensity. Faint galaxies do not fill the voids, but they do populate them more than bright ones. These results suggest that both optically and IRAS-selected galaxies delineate the same large-scale structure. Comparison with the recovered mass distribution further suggests that the observed voids in the galaxy distribution correspond well to underdense regions in the mass distribution. This confirms the gravitational origin of the voids.

  9. Statistical Measures of Large-Scale Structure

    NASA Astrophysics Data System (ADS)

    Vogeley, Michael; Geller, Margaret; Huchra, John; Park, Changbom; Gott, J. Richard

    1993-12-01

    \\inv Mpc} To quantify clustering in the large-scale distribution of galaxies and to test theories for the formation of structure in the universe, we apply statistical measures to the CfA Redshift Survey. This survey is complete to m_{B(0)}=15.5 over two contiguous regions which cover one-quarter of the sky and include ~ 11,000 galaxies. The salient features of these data are voids with diameter 30-50\\hmpc and coherent dense structures with a scale ~ 100\\hmpc. Comparison with N-body simulations rules out the ``standard" CDM model (Omega =1, b=1.5, sigma_8 =1) at the 99% confidence level because this model has insufficient power on scales lambda >30\\hmpc. An unbiased open universe CDM model (Omega h =0.2) and a biased CDM model with non-zero cosmological constant (Omega h =0.24, lambda_0 =0.6) match the observed power spectrum. The amplitude of the power spectrum depends on the luminosity of galaxies in the sample; bright (L>L(*) ) galaxies are more strongly clustered than faint galaxies. The paucity of bright galaxies in low-density regions may explain this dependence. To measure the topology of large-scale structure, we compute the genus of isodensity surfaces of the smoothed density field. On scales in the ``non-linear" regime, <= 10\\hmpc, the high- and low-density regions are multiply-connected over a broad range of density threshold, as in a filamentary net. On smoothing scales >10\\hmpc, the topology is consistent with statistics of a Gaussian random field. Simulations of CDM models fail to produce the observed coherence of structure on non-linear scales (>95% confidence level). The underdensity probability (the frequency of regions with density contrast delta rho //lineρ=-0.8) depends strongly on the luminosity of galaxies; underdense regions are significantly more common (>2sigma ) in bright (L>L(*) ) galaxy samples than in samples which include fainter galaxies.

  10. Management of large-scale multimedia conferencing

    NASA Astrophysics Data System (ADS)

    Cidon, Israel; Nachum, Youval

    1998-12-01

    The goal of this work is to explore management strategies and algorithms for large-scale multimedia conferencing over a communication network. Since the use of multimedia conferencing is still limited, the management of such systems has not yet been studied in depth. A well organized and human friendly multimedia conference management should utilize efficiently and fairly its limited resources as well as take into account the requirements of the conference participants. The ability of the management to enforce fair policies and to quickly take into account the participants preferences may even lead to a conference environment that is more pleasant and more effective than a similar face to face meeting. We suggest several principles for defining and solving resource sharing problems in this context. The conference resources which are addressed in this paper are the bandwidth (conference network capacity), time (participants' scheduling) and limitations of audio and visual equipment. The participants' requirements for these resources are defined and translated in terms of Quality of Service requirements and the fairness criteria.

  11. Large-scale wind turbine structures

    NASA Technical Reports Server (NTRS)

    Spera, David A.

    1988-01-01

    The purpose of this presentation is to show how structural technology was applied in the design of modern wind turbines, which were recently brought to an advanced stage of development as sources of renewable power. Wind turbine structures present many difficult problems because they are relatively slender and flexible; subject to vibration and aeroelastic instabilities; acted upon by loads which are often nondeterministic; operated continuously with little maintenance in all weather; and dominated by life-cycle cost considerations. Progress in horizontal-axis wind turbines (HAWT) development was paced by progress in the understanding of structural loads, modeling of structural dynamic response, and designing of innovative structural response. During the past 15 years a series of large HAWTs was developed. This has culminated in the recent completion of the world's largest operating wind turbine, the 3.2 MW Mod-5B power plane installed on the island of Oahu, Hawaii. Some of the applications of structures technology to wind turbine will be illustrated by referring to the Mod-5B design. First, a video overview will be presented to provide familiarization with the Mod-5B project and the important components of the wind turbine system. Next, the structural requirements for large-scale wind turbines will be discussed, emphasizing the difficult fatigue-life requirements. Finally, the procedures used to design the structure will be presented, including the use of the fracture mechanics approach for determining allowable fatigue stresses.

  12. Large-scale tides in general relativity

    NASA Astrophysics Data System (ADS)

    Ip, Hiu Yan; Schmidt, Fabian

    2017-02-01

    Density perturbations in cosmology, i.e. spherically symmetric adiabatic perturbations of a Friedmann-Lemaȋtre-Robertson-Walker (FLRW) spacetime, are locally exactly equivalent to a different FLRW solution, as long as their wavelength is much larger than the sound horizon of all fluid components. This fact is known as the "separate universe" paradigm. However, no such relation is known for anisotropic adiabatic perturbations, which correspond to an FLRW spacetime with large-scale tidal fields. Here, we provide a closed, fully relativistic set of evolutionary equations for the nonlinear evolution of such modes, based on the conformal Fermi (CFC) frame. We show explicitly that the tidal effects are encoded by the Weyl tensor, and are hence entirely different from an anisotropic Bianchi I spacetime, where the anisotropy is sourced by the Ricci tensor. In order to close the system, certain higher derivative terms have to be dropped. We show that this approximation is equivalent to the local tidal approximation of Hui and Bertschinger [1]. We also show that this very simple set of equations matches the exact evolution of the density field at second order, but fails at third and higher order. This provides a useful, easy-to-use framework for computing the fully relativistic growth of structure at second order.

  13. Large scale mechanical metamaterials as seismic shields

    NASA Astrophysics Data System (ADS)

    Miniaci, Marco; Krushynska, Anastasiia; Bosia, Federico; Pugno, Nicola M.

    2016-08-01

    Earthquakes represent one of the most catastrophic natural events affecting mankind. At present, a universally accepted risk mitigation strategy for seismic events remains to be proposed. Most approaches are based on vibration isolation of structures rather than on the remote shielding of incoming waves. In this work, we propose a novel approach to the problem and discuss the feasibility of a passive isolation strategy for seismic waves based on large-scale mechanical metamaterials, including for the first time numerical analysis of both surface and guided waves, soil dissipation effects, and adopting a full 3D simulations. The study focuses on realistic structures that can be effective in frequency ranges of interest for seismic waves, and optimal design criteria are provided, exploring different metamaterial configurations, combining phononic crystals and locally resonant structures and different ranges of mechanical properties. Dispersion analysis and full-scale 3D transient wave transmission simulations are carried out on finite size systems to assess the seismic wave amplitude attenuation in realistic conditions. Results reveal that both surface and bulk seismic waves can be considerably attenuated, making this strategy viable for the protection of civil structures against seismic risk. The proposed remote shielding approach could open up new perspectives in the field of seismology and in related areas of low-frequency vibration damping or blast protection.

  14. Food appropriation through large scale land acquisitions

    NASA Astrophysics Data System (ADS)

    Rulli, Maria Cristina; D'Odorico, Paolo

    2014-05-01

    The increasing demand for agricultural products and the uncertainty of international food markets has recently drawn the attention of governments and agribusiness firms toward investments in productive agricultural land, mostly in the developing world. The targeted countries are typically located in regions that have remained only marginally utilized because of lack of modern technology. It is expected that in the long run large scale land acquisitions (LSLAs) for commercial farming will bring the technology required to close the existing crops yield gaps. While the extent of the acquired land and the associated appropriation of freshwater resources have been investigated in detail, the amount of food this land can produce and the number of people it could feed still need to be quantified. Here we use a unique dataset of land deals to provide a global quantitative assessment of the rates of crop and food appropriation potentially associated with LSLAs. We show how up to 300-550 million people could be fed by crops grown in the acquired land, should these investments in agriculture improve crop production and close the yield gap. In contrast, about 190-370 million people could be supported by this land without closing of the yield gap. These numbers raise some concern because the food produced in the acquired land is typically exported to other regions, while the target countries exhibit high levels of malnourishment. Conversely, if used for domestic consumption, the crops harvested in the acquired land could ensure food security to the local populations.

  15. Large scale structure of the sun's corona

    NASA Astrophysics Data System (ADS)

    Kundu, Mukul R.

    Results concerning the large-scale structure of the solar corona obtained by observations at meter-decameter wavelengths are reviewed. Coronal holes observed on the disk at multiple frequencies show the radial and azimuthal geometry of the hole. At the base of the hole there is good correspondence to the chromospheric signature in He I 10,830 A, but at greater heights the hole may show departures from symmetry. Two-dimensional imaging of weak-type III bursts simultaneously with the HAO SMM coronagraph/polarimeter measurements indicate that these bursts occur along elongated features emanating from the quiet sun, corresponding in position angle to the bright coronal streamers. It is shown that the densest regions of streamers and the regions of maximum intensity of type II bursts coincide closely. Non-flare-associated type II/type IV bursts associated with coronal streamer disruption events are studied along with correlated type II burst emissions originating from distant centers on the sun.

  16. Large-scale carbon fiber tests

    NASA Technical Reports Server (NTRS)

    Pride, R. A.

    1980-01-01

    A realistic release of carbon fibers was established by burning a minimum of 45 kg of carbon fiber composite aircraft structural components in each of five large scale, outdoor aviation jet fuel fire tests. This release was quantified by several independent assessments with various instruments developed specifically for these tests. The most likely values for the mass of single carbon fibers released ranged from 0.2 percent of the initial mass of carbon fiber for the source tests (zero wind velocity) to a maximum of 0.6 percent of the initial carbon fiber mass for dissemination tests (5 to 6 m/s wind velocity). Mean fiber lengths for fibers greater than 1 mm in length ranged from 2.5 to 3.5 mm. Mean diameters ranged from 3.6 to 5.3 micrometers which was indicative of significant oxidation. Footprints of downwind dissemination of the fire released fibers were measured to 19.1 km from the fire.

  17. Large-scale clustering of cosmic voids

    NASA Astrophysics Data System (ADS)

    Chan, Kwan Chuen; Hamaus, Nico; Desjacques, Vincent

    2014-11-01

    We study the clustering of voids using N -body simulations and simple theoretical models. The excursion-set formalism describes fairly well the abundance of voids identified with the watershed algorithm, although the void formation threshold required is quite different from the spherical collapse value. The void cross bias bc is measured and its large-scale value is found to be consistent with the peak background split results. A simple fitting formula for bc is found. We model the void auto-power spectrum taking into account the void biasing and exclusion effect. A good fit to the simulation data is obtained for voids with radii ≳30 Mpc h-1 , especially when the void biasing model is extended to 1-loop order. However, the best-fit bias parameters do not agree well with the peak-background results. Being able to fit the void auto-power spectrum is particularly important not only because it is the direct observable in galaxy surveys, but also our method enables us to treat the bias parameters as nuisance parameters, which are sensitive to the techniques used to identify voids.

  18. Large-scale autostereoscopic outdoor display

    NASA Astrophysics Data System (ADS)

    Reitterer, Jörg; Fidler, Franz; Saint Julien-Wallsee, Ferdinand; Schmid, Gerhard; Gartner, Wolfgang; Leeb, Walter; Schmid, Ulrich

    2013-03-01

    State-of-the-art autostereoscopic displays are often limited in size, effective brightness, number of 3D viewing zones, and maximum 3D viewing distances, all of which are mandatory requirements for large-scale outdoor displays. Conventional autostereoscopic indoor concepts like lenticular lenses or parallax barriers cannot simply be adapted for these screens due to the inherent loss of effective resolution and brightness, which would reduce both image quality and sunlight readability. We have developed a modular autostereoscopic multi-view laser display concept with sunlight readable effective brightness, theoretically up to several thousand 3D viewing zones, and maximum 3D viewing distances of up to 60 meters. For proof-of-concept purposes a prototype display with two pixels was realized. Due to various manufacturing tolerances each individual pixel has slightly different optical properties, and hence the 3D image quality of the display has to be calculated stochastically. In this paper we present the corresponding stochastic model, we evaluate the simulation and measurement results of the prototype display, and we calculate the achievable autostereoscopic image quality to be expected for our concept.

  19. Large Scale EOF Analysis of Climate Data

    NASA Astrophysics Data System (ADS)

    Prabhat, M.; Gittens, A.; Kashinath, K.; Cavanaugh, N. R.; Mahoney, M.

    2016-12-01

    We present a distributed approach towards extracting EOFs from 3D climate data. We implement the method in Apache Spark, and process multi-TB sized datasets on O(1000-10,000) cores. We apply this method to latitude-weighted ocean temperature data from CSFR, a 2.2 terabyte-sized data set comprising ocean and subsurface reanalysis measurements collected at 41 levels in the ocean, at 6 hour intervals over 31 years. We extract the first 100 EOFs of this full data set and compare to the EOFs computed simply on the surface temperature field. Our analyses provide evidence of Kelvin and Rossy waves and components of large-scale modes of oscillation including the ENSO and PDO that are not visible in the usual SST EOFs. Further, they provide information on the the most influential parts of the ocean, such as the thermocline, that exist below the surface. Work is ongoing to understand the factors determining the depth-varying spatial patterns observed in the EOFs. We will experiment with weighting schemes to appropriately account for the differing depths of the observations. We also plan to apply the same distributed approach to analysis of analysis of 3D atmospheric climatic data sets, including multiple variables. Because the atmosphere changes on a quicker time-scale than the ocean, we expect that the results will demonstrate an even greater advantage to computing 3D EOFs in lieu of 2D EOFs.

  20. Numerical Modeling for Large Scale Hydrothermal System

    NASA Astrophysics Data System (ADS)

    Sohrabi, Reza; Jansen, Gunnar; Malvoisin, Benjamin; Mazzini, Adriano; Miller, Stephen A.

    2017-04-01

    Moderate-to-high enthalpy systems are driven by multiphase and multicomponent processes, fluid and rock mechanics, and heat transport processes, all of which present challenges in developing realistic numerical models of the underlying physics. The objective of this work is to present an approach, and some initial results, for modeling and understanding dynamics of the birth of large scale hydrothermal systems. Numerical modeling of such complex systems must take into account a variety of coupled thermal, hydraulic, mechanical and chemical processes, which is numerically challenging. To provide first estimates of the behavior of this deep complex systems, geological structures must be constrained, and the fluid dynamics, mechanics and the heat transport need to be investigated in three dimensions. Modeling these processes numerically at adequate resolution and reasonable computation times requires a suite of tools that we are developing and/or utilizing to investigate such systems. Our long-term goal is to develop 3D numerical models, based on a geological models, which couples mechanics with the hydraulics and thermal processes driving hydrothermal system. Our first results from the Lusi hydrothermal system in East Java, Indonesia provide a basis for more sophisticated studies, eventually in 3D, and we introduce a workflow necessary to achieve these objectives. Future work focuses with the aim and parallelization suitable for High Performance Computing (HPC). Such developments are necessary to achieve high-resolution simulations to more fully understand the complex dynamics of hydrothermal systems.

  1. Large scale digital atlases in neuroscience

    NASA Astrophysics Data System (ADS)

    Hawrylycz, M.; Feng, D.; Lau, C.; Kuan, C.; Miller, J.; Dang, C.; Ng, L.

    2014-03-01

    Imaging in neuroscience has revolutionized our current understanding of brain structure, architecture and increasingly its function. Many characteristics of morphology, cell type, and neuronal circuitry have been elucidated through methods of neuroimaging. Combining this data in a meaningful, standardized, and accessible manner is the scope and goal of the digital brain atlas. Digital brain atlases are used today in neuroscience to characterize the spatial organization of neuronal structures, for planning and guidance during neurosurgery, and as a reference for interpreting other data modalities such as gene expression and connectivity data. The field of digital atlases is extensive and in addition to atlases of the human includes high quality brain atlases of the mouse, rat, rhesus macaque, and other model organisms. Using techniques based on histology, structural and functional magnetic resonance imaging as well as gene expression data, modern digital atlases use probabilistic and multimodal techniques, as well as sophisticated visualization software to form an integrated product. Toward this goal, brain atlases form a common coordinate framework for summarizing, accessing, and organizing this knowledge and will undoubtedly remain a key technology in neuroscience in the future. Since the development of its flagship project of a genome wide image-based atlas of the mouse brain, the Allen Institute for Brain Science has used imaging as a primary data modality for many of its large scale atlas projects. We present an overview of Allen Institute digital atlases in neuroscience, with a focus on the challenges and opportunities for image processing and computation.

  2. Large-scale quantum photonic circuits in silicon

    NASA Astrophysics Data System (ADS)

    Harris, Nicholas C.; Bunandar, Darius; Pant, Mihir; Steinbrecher, Greg R.; Mower, Jacob; Prabhu, Mihika; Baehr-Jones, Tom; Hochberg, Michael; Englund, Dirk

    2016-08-01

    Quantum information science offers inherently more powerful methods for communication, computation, and precision measurement that take advantage of quantum superposition and entanglement. In recent years, theoretical and experimental advances in quantum computing and simulation with photons have spurred great interest in developing large photonic entangled states that challenge today's classical computers. As experiments have increased in complexity, there has been an increasing need to transition bulk optics experiments to integrated photonics platforms to control more spatial modes with higher fidelity and phase stability. The silicon-on-insulator (SOI) nanophotonics platform offers new possibilities for quantum optics, including the integration of bright, nonclassical light sources, based on the large third-order nonlinearity (χ(3)) of silicon, alongside quantum state manipulation circuits with thousands of optical elements, all on a single phase-stable chip. How large do these photonic systems need to be? Recent theoretical work on Boson Sampling suggests that even the problem of sampling from e30 identical photons, having passed through an interferometer of hundreds of modes, becomes challenging for classical computers. While experiments of this size are still challenging, the SOI platform has the required component density to enable low-loss and programmable interferometers for manipulating hundreds of spatial modes. Here, we discuss the SOI nanophotonics platform for quantum photonic circuits with hundreds-to-thousands of optical elements and the associated challenges. We compare SOI to competing technologies in terms of requirements for quantum optical systems. We review recent results on large-scale quantum state evolution circuits and strategies for realizing high-fidelity heralded gates with imperfect, practical systems. Next, we review recent results on silicon photonics-based photon-pair sources and device architectures, and we discuss a path towards

  3. Sensitivity technologies for large scale simulation.

    SciTech Connect

    Collis, Samuel Scott; Bartlett, Roscoe Ainsworth; Smith, Thomas Michael; Heinkenschloss, Matthias; Wilcox, Lucas C.; Hill, Judith C.; Ghattas, Omar; Berggren, Martin Olof; Akcelik, Volkan; Ober, Curtis Curry; van Bloemen Waanders, Bart Gustaaf; Keiter, Eric Richard

    2005-01-01

    Sensitivity analysis is critically important to numerous analysis algorithms, including large scale optimization, uncertainty quantification,reduced order modeling, and error estimation. Our research focused on developing tools, algorithms and standard interfaces to facilitate the implementation of sensitivity type analysis into existing code and equally important, the work was focused on ways to increase the visibility of sensitivity analysis. We attempt to accomplish the first objective through the development of hybrid automatic differentiation tools, standard linear algebra interfaces for numerical algorithms, time domain decomposition algorithms and two level Newton methods. We attempt to accomplish the second goal by presenting the results of several case studies in which direct sensitivities and adjoint methods have been effectively applied, in addition to an investigation of h-p adaptivity using adjoint based a posteriori error estimation. A mathematical overview is provided of direct sensitivities and adjoint methods for both steady state and transient simulations. Two case studies are presented to demonstrate the utility of these methods. A direct sensitivity method is implemented to solve a source inversion problem for steady state internal flows subject to convection diffusion. Real time performance is achieved using novel decomposition into offline and online calculations. Adjoint methods are used to reconstruct initial conditions of a contamination event in an external flow. We demonstrate an adjoint based transient solution. In addition, we investigated time domain decomposition algorithms in an attempt to improve the efficiency of transient simulations. Because derivative calculations are at the root of sensitivity calculations, we have developed hybrid automatic differentiation methods and implemented this approach for shape optimization for gas dynamics using the Euler equations. The hybrid automatic differentiation method was applied to a first

  4. Large Scale Flame Spread Environmental Characterization Testing

    NASA Technical Reports Server (NTRS)

    Clayman, Lauren K.; Olson, Sandra L.; Gokoghi, Suleyman A.; Brooker, John E.; Ferkul, Paul V.; Kacher, Henry F.

    2013-01-01

    Under the Advanced Exploration Systems (AES) Spacecraft Fire Safety Demonstration Project (SFSDP), as a risk mitigation activity in support of the development of a large-scale fire demonstration experiment in microgravity, flame-spread tests were conducted in normal gravity on thin, cellulose-based fuels in a sealed chamber. The primary objective of the tests was to measure pressure rise in a chamber as sample material, burning direction (upward/downward), total heat release, heat release rate, and heat loss mechanisms were varied between tests. A Design of Experiments (DOE) method was imposed to produce an array of tests from a fixed set of constraints and a coupled response model was developed. Supplementary tests were run without experimental design to additionally vary select parameters such as initial chamber pressure. The starting chamber pressure for each test was set below atmospheric to prevent chamber overpressure. Bottom ignition, or upward propagating burns, produced rapid acceleratory turbulent flame spread. Pressure rise in the chamber increases as the amount of fuel burned increases mainly because of the larger amount of heat generation and, to a much smaller extent, due to the increase in gaseous number of moles. Top ignition, or downward propagating burns, produced a steady flame spread with a very small flat flame across the burning edge. Steady-state pressure is achieved during downward flame spread as the pressure rises and plateaus. This indicates that the heat generation by the flame matches the heat loss to surroundings during the longer, slower downward burns. One heat loss mechanism included mounting a heat exchanger directly above the burning sample in the path of the plume to act as a heat sink and more efficiently dissipate the heat due to the combustion event. This proved an effective means for chamber overpressure mitigation for those tests producing the most total heat release and thusly was determined to be a feasible mitigation

  5. Synchronization of coupled large-scale Boolean networks

    SciTech Connect

    Li, Fangfei

    2014-03-15

    This paper investigates the complete synchronization and partial synchronization of two large-scale Boolean networks. First, the aggregation algorithm towards large-scale Boolean network is reviewed. Second, the aggregation algorithm is applied to study the complete synchronization and partial synchronization of large-scale Boolean networks. Finally, an illustrative example is presented to show the efficiency of the proposed results.

  6. The School Principal's Role in Large-Scale Assessment

    ERIC Educational Resources Information Center

    Newton, Paul; Tunison, Scott; Viczko, Melody

    2010-01-01

    This paper reports on an interpretive study in which 25 elementary principals were asked about their assessment knowledge, the use of large-scale assessments in their schools, and principals' perceptions on their roles with respect to large-scale assessments. Principals in this study suggested that the current context of large-scale assessment and…

  7. Synchronization of coupled large-scale Boolean networks

    NASA Astrophysics Data System (ADS)

    Li, Fangfei

    2014-03-01

    This paper investigates the complete synchronization and partial synchronization of two large-scale Boolean networks. First, the aggregation algorithm towards large-scale Boolean network is reviewed. Second, the aggregation algorithm is applied to study the complete synchronization and partial synchronization of large-scale Boolean networks. Finally, an illustrative example is presented to show the efficiency of the proposed results.

  8. Large scale dynamics of protoplanetary discs

    NASA Astrophysics Data System (ADS)

    Béthune, William

    2017-08-01

    Planets form in the gaseous and dusty disks orbiting young stars. These protoplanetary disks are dispersed in a few million years, being accreted onto the central star or evaporated into the interstellar medium. To explain the observed accretion rates, it is commonly assumed that matter is transported through the disk by turbulence, although the mechanism sustaining turbulence is uncertain. On the other side, irradiation by the central star could heat up the disk surface and trigger a photoevaporative wind, but thermal effects cannot account for the observed acceleration and collimation of the wind into a narrow jet perpendicular to the disk plane. Both issues can be solved if the disk is sensitive to magnetic fields. Weak fields lead to the magnetorotational instability, whose outcome is a state of sustained turbulence. Strong fields can slow down the disk, causing it to accrete while launching a collimated wind. However, the coupling between the disk and the neutral gas is done via electric charges, each of which is outnumbered by several billion neutral molecules. The imperfect coupling between the magnetic field and the neutral gas is described in terms of "non-ideal" effects, introducing new dynamical behaviors. This thesis is devoted to the transport processes happening inside weakly ionized and weakly magnetized accretion disks; the role of microphysical effects on the large-scale dynamics of the disk is of primary importance. As a first step, I exclude the wind and examine the impact of non-ideal effects on the turbulent properties near the disk midplane. I show that the flow can spontaneously organize itself if the ionization fraction is low enough; in this case, accretion is halted and the disk exhibits axisymmetric structures, with possible consequences on planetary formation. As a second step, I study the launching of disk winds via a global model of stratified disk embedded in a warm atmosphere. This model is the first to compute non-ideal effects from

  9. Large-Scale Spacecraft Fire Safety Tests

    NASA Technical Reports Server (NTRS)

    Urban, David; Ruff, Gary A.; Ferkul, Paul V.; Olson, Sandra; Fernandez-Pello, A. Carlos; T'ien, James S.; Torero, Jose L.; Cowlard, Adam J.; Rouvreau, Sebastien; Minster, Olivier; hide

    2014-01-01

    An international collaborative program is underway to address open issues in spacecraft fire safety. Because of limited access to long-term low-gravity conditions and the small volume generally allotted for these experiments, there have been relatively few experiments that directly study spacecraft fire safety under low-gravity conditions. Furthermore, none of these experiments have studied sample sizes and environment conditions typical of those expected in a spacecraft fire. The major constraint has been the size of the sample, with prior experiments limited to samples of the order of 10 cm in length and width or smaller. This lack of experimental data forces spacecraft designers to base their designs and safety precautions on 1-g understanding of flame spread, fire detection, and suppression. However, low-gravity combustion research has demonstrated substantial differences in flame behavior in low-gravity. This, combined with the differences caused by the confined spacecraft environment, necessitates practical scale spacecraft fire safety research to mitigate risks for future space missions. To address this issue, a large-scale spacecraft fire experiment is under development by NASA and an international team of investigators. This poster presents the objectives, status, and concept of this collaborative international project (Saffire). The project plan is to conduct fire safety experiments on three sequential flights of an unmanned ISS re-supply spacecraft (the Orbital Cygnus vehicle) after they have completed their delivery of cargo to the ISS and have begun their return journeys to earth. On two flights (Saffire-1 and Saffire-3), the experiment will consist of a flame spread test involving a meter-scale sample ignited in the pressurized volume of the spacecraft and allowed to burn to completion while measurements are made. On one of the flights (Saffire-2), 9 smaller (5 x 30 cm) samples will be tested to evaluate NASAs material flammability screening tests

  10. Large scale simulations of Brownian suspensions

    NASA Astrophysics Data System (ADS)

    Viera, Marc Nathaniel

    Particle suspensions occur in a wide variety of natural and engineering materials. Some examples are colloids, polymers, paints, and slurries. These materials exhibit complex behavior owing to the forces which act among the particles and are transmitted through the fluid medium. Depending on the application, particle sizes range from large macroscopic molecules of 100mum to smaller colloidal particles in the range of 10nm to 1mum. Particles of this size interact though interparticle forces such as electrostatic and van der Waals, as well as hydrodynamic forces transmitted through the fluid medium. Additionally, the particles are subjected to random thermal fluctuations in the fluid giving rise to Brownian motion. The central objective of our research is to develop efficient numerical algorithms for the large scale dynamic simulation of particle suspensions. While previous methods have incurred a computational cost of O(N3), where N is the number of particles, we have developed a novel algorithm capable of solving this problem in O(N ln N) operations. This has allowed us to perform dynamic simulations with up to 64,000 particles and Monte Carlo realizations of up to 1 million particles. Our algorithm follows a Stokesian dynamics formulation by evaluating many-body hydrodynamic interactions using a far-field multipole expansion combined with a near-field lubrication correction. The breakthrough O(N ln N) scaling is obtained by employing a Particle-Mesh-Ewald (PME) approach whereby near-field interactions are evaluated directly and far-field interactions are evaluated using a grid based velocity computed with FFT's. This approach is readily extended to include the effects of Brownian motion. For interacting particles, the fluctuation-dissipation theorem requires that the individual Brownian forces satisfy a correlation based on the N body resistance tensor R. The accurate modeling of these forces requires the computation of a matrix square root R 1/2 for matrices up

  11. Scalable NIC-based reduction on large-scale clusters

    SciTech Connect

    Moody, A.; Fernández, J. C.; Petrini, F.; Panda, Dhabaleswar K.

    2003-01-01

    Many parallel algorithms require effiaent support for reduction mllectives. Over the years, researchers have developed optimal reduction algonduns by taking inm account system size, dam size, and complexities of reduction operations. However, all of these algorithm have assumed the faa that the reduction precessing takes place on the host CPU. Modem Network Interface Cards (NICs) sport programmable processors with substantial memory and thus introduce a fresh variable into the equation This raises the following intersting challenge: Can we take advantage of modern NICs to implementJost redudion operations? In this paper, we take on this challenge in the context of large-scale clusters. Through experiments on the 960-node, 1920-processor or ASCI Linux Cluster (ALC) located at the Lawrence Livermore National Laboratory, we show that NIC-based reductions indeed perform with reduced latency and immed consistency over host-based aleorithms for the wmmon case and that these benefits scale as the system grows. In the largest configuration tested--1812 processors-- our NIC-based algorithm can sum a single element vector in 73 ps with 32-bi integers and in 118 with Mbit floating-point numnbers. These results represent an improvement, respeaively, of 121% and 39% with resvect w the {approx}roductionle vel MPI library

  12. Large Scale Applications of HTS in New Zealand

    NASA Astrophysics Data System (ADS)

    Wimbush, Stuart C.

    New Zealand has one of the longest-running and most consistently funded (relative to GDP) programmes in high temperature superconductor (HTS) development and application worldwide. As a consequence, it has a sustained breadth of involvement in HTS technology development stretching from the materials discovery right through to burgeoning commercial exploitation. This review paper outlines the present large scale projects of the research team at the newly-established Robinson Research Institute of Victoria University of Wellington. These include the construction and grid-based testing of a three-phase 1 MVA 2G HTS distribution transformer utilizing Roebel cable for its high-current secondary windings and the development of a cryogen-free conduction-cooled 1.5 T YBCO-based human extremity magnetic resonance imaging system. Ongoing activities supporting applications development such as low-temperature full-current characterization of commercial superconducting wires and the implementation of inductive flux-pump technologies for efficient brushless coil excitation in superconducting magnets and rotating machines are also described.

  13. Bio-Inspired Wooden Actuators for Large Scale Applications

    PubMed Central

    Rüggeberg, Markus; Burgert, Ingo

    2015-01-01

    Implementing programmable actuation into materials and structures is a major topic in the field of smart materials. In particular the bilayer principle has been employed to develop actuators that respond to various kinds of stimuli. A multitude of small scale applications down to micrometer size have been developed, but up-scaling remains challenging due to either limitations in mechanical stiffness of the material or in the manufacturing processes. Here, we demonstrate the actuation of wooden bilayers in response to changes in relative humidity, making use of the high material stiffness and a good machinability to reach large scale actuation and application. Amplitude and response time of the actuation were measured and can be predicted and controlled by adapting the geometry and the constitution of the bilayers. Field tests in full weathering conditions revealed long-term stability of the actuation. The potential of the concept is shown by a first demonstrator. With the sensor and actuator intrinsically incorporated in the wooden bilayers, the daily change in relative humidity is exploited for an autonomous and solar powered movement of a tracker for solar modules. PMID:25835386

  14. Cryogenic Control Architecture for Large-Scale Quantum Computing

    NASA Astrophysics Data System (ADS)

    Hornibrook, J. M.; Colless, J. I.; Conway Lamb, I. D.; Pauka, S. J.; Lu, H.; Gossard, A. C.; Watson, J. D.; Gardner, G. C.; Fallahi, S.; Manfra, M. J.; Reilly, D. J.

    2015-02-01

    Solid-state qubits have recently advanced to the level that enables them, in principle, to be scaled up into fault-tolerant quantum computers. As these physical qubits continue to advance, meeting the challenge of realizing a quantum machine will also require the development of new supporting devices and control architectures with complexity far beyond the systems used in today's few-qubit experiments. Here, we report a microarchitecture for controlling and reading out qubits during the execution of a quantum algorithm such as an error-correcting code. We demonstrate the basic principles of this architecture using a cryogenic switch matrix implemented via high-electron-mobility transistors and a new kind of semiconductor device based on gate-switchable capacitance. The switch matrix is used to route microwave waveforms to qubits under the control of a field-programmable gate array, also operating at cryogenic temperatures. Taken together, these results suggest a viable approach for controlling large-scale quantum systems using semiconductor technology.

  15. Large-scale weather systems: A future research priority

    NASA Astrophysics Data System (ADS)

    Davies, Huw C.

    2006-12-01

    A brief assessment is provided of both the case against and the case for assigning priority to research on large-scale weather systems (LSWS). The three-fold case against is based upon: the emergence of new overarching themes in environmental science; the fresh emphasis upon other sub-disciplines of the atmospheric science; and the mature state of research and prediction of LSWS. The case for is also supported by three arguments. First is the assertion that LSWS research should not merely be an integral but a major component of future research related to both the new overarching themes and the other sub-disciplines. Second recent major developments in LSWS research, as epitomized by the paradigm shifts in the prediction strategy for LSWS and the emergence of the potential vorticity perspective, testify to the theme’s on-going vibrancy. Third the field’s future development, as exemplified by the new international THORPEX (The Observing System Research and Predictability Experiment) programme, embodies a perceptive dovetailing of intellectually challenging fundamental research with directed application(s) of societal and economic benefit. It is thus inferred that LSWS research, far from being in demise, will feature at the forefront of the new relationship between science and society.

  16. Bio-inspired wooden actuators for large scale applications.

    PubMed

    Rüggeberg, Markus; Burgert, Ingo

    2015-01-01

    Implementing programmable actuation into materials and structures is a major topic in the field of smart materials. In particular the bilayer principle has been employed to develop actuators that respond to various kinds of stimuli. A multitude of small scale applications down to micrometer size have been developed, but up-scaling remains challenging due to either limitations in mechanical stiffness of the material or in the manufacturing processes. Here, we demonstrate the actuation of wooden bilayers in response to changes in relative humidity, making use of the high material stiffness and a good machinability to reach large scale actuation and application. Amplitude and response time of the actuation were measured and can be predicted and controlled by adapting the geometry and the constitution of the bilayers. Field tests in full weathering conditions revealed long-term stability of the actuation. The potential of the concept is shown by a first demonstrator. With the sensor and actuator intrinsically incorporated in the wooden bilayers, the daily change in relative humidity is exploited for an autonomous and solar powered movement of a tracker for solar modules.

  17. Population generation for large-scale simulation

    NASA Astrophysics Data System (ADS)

    Hannon, Andrew C.; King, Gary; Morrison, Clayton; Galstyan, Aram; Cohen, Paul

    2005-05-01

    Computer simulation is used to research phenomena ranging from the structure of the space-time continuum to population genetics and future combat.1-3 Multi-agent simulations in particular are now commonplace in many fields.4, 5 By modeling populations whose complex behavior emerges from individual interactions, these simulations help to answer questions about effects where closed form solutions are difficult to solve or impossible to derive.6 To be useful, simulations must accurately model the relevant aspects of the underlying domain. In multi-agent simulation, this means that the modeling must include both the agents and their relationships. Typically, each agent can be modeled as a set of attributes drawn from various distributions (e.g., height, morale, intelligence and so forth). Though these can interact - for example, agent height is related to agent weight - they are usually independent. Modeling relations between agents, on the other hand, adds a new layer of complexity, and tools from graph theory and social network analysis are finding increasing application.7, 8 Recognizing the role and proper use of these techniques, however, remains the subject of ongoing research. We recently encountered these complexities while building large scale social simulations.9-11 One of these, the Hats Simulator, is designed to be a lightweight proxy for intelligence analysis problems. Hats models a "society in a box" consisting of many simple agents, called hats. Hats gets its name from the classic spaghetti western, in which the heroes and villains are known by the color of the hats they wear. The Hats society also has its heroes and villains, but the challenge is to identify which color hat they should be wearing based on how they behave. There are three types of hats: benign hats, known terrorists, and covert terrorists. Covert terrorists look just like benign hats but act like terrorists. Population structure can make covert hat identification significantly more

  18. Large-scale Fractal Motion of Clouds

    NASA Image and Video Library

    2017-09-27

    waters surrounding the island.) The “swallowed” gulps of clear island air get carried along within the vortices, but these are soon mixed into the surrounding clouds. Landsat is unique in its ability to image both the small-scale eddies that mix clear and cloudy air, down to the 30 meter pixel size of Landsat, but also having a wide enough field-of-view, 180 km, to reveal the connection of the turbulence to large-scale flows such as the subtropical oceanic gyres. Landsat 7, with its new onboard digital recorder, has extended this capability away from the few Landsat ground stations to remote areas such as Alejandro Island, and thus is gradually providing a global dynamic picture of evolving human-scale phenomena. For more details on von Karman vortices, refer to climate.gsfc.nasa.gov/~cahalan. Image and caption courtesy Bob Cahalan, NASA GSFC Instrument: Landsat 7 - ETM+ Credit: NASA/GSFC/Landsat NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Join us on Facebook

  19. Large-scale assembly of colloidal particles

    NASA Astrophysics Data System (ADS)

    Yang, Hongta

    This study reports a simple, roll-to-roll compatible coating technology for producing three-dimensional highly ordered colloidal crystal-polymer composites, colloidal crystals, and macroporous polymer membranes. A vertically beveled doctor blade is utilized to shear align silica microsphere-monomer suspensions to form large-area composites in a single step. The polymer matrix and the silica microspheres can be selectively removed to create colloidal crystals and self-standing macroporous polymer membranes. The thickness of the shear-aligned crystal is correlated with the viscosity of the colloidal suspension and the coating speed, and the correlations can be qualitatively explained by adapting the mechanisms developed for conventional doctor blade coating. Five important research topics related to the application of large-scale three-dimensional highly ordered macroporous films by doctor blade coating are covered in this study. The first topic describes the invention in large area and low cost color reflective displays. This invention is inspired by the heat pipe technology. The self-standing macroporous polymer films exhibit brilliant colors which originate from the Bragg diffractive of visible light form the three-dimensional highly ordered air cavities. The colors can be easily changed by tuning the size of the air cavities to cover the whole visible spectrum. When the air cavities are filled with a solvent which has the same refractive index as that of the polymer, the macroporous polymer films become completely transparent due to the index matching. When the solvent trapped in the cavities is evaporated by in-situ heating, the sample color changes back to brilliant color. This process is highly reversible and reproducible for thousands of cycles. The second topic reports the achievement of rapid and reversible vapor detection by using 3-D macroporous photonic crystals. Capillary condensation of a condensable vapor in the interconnected macropores leads to the

  20. Multitree Algorithms for Large-Scale Astrostatistics

    NASA Astrophysics Data System (ADS)

    March, William B.; Ozakin, Arkadas; Lee, Dongryeol; Riegel, Ryan; Gray, Alexander G.

    2012-03-01

    this number every week, resulting in billions of objects. At such scales, even linear-time analysis operations present challenges, particularly since statistical analyses are inherently interactive processes, requiring that computations complete within some reasonable human attention span. The quadratic (or worse) runtimes of straightforward implementations become quickly unbearable. Examples of applications. These analysis subroutines occur ubiquitously in astrostatistical work. We list just a few examples. The need to cross-match objects across different catalogs has led to various algorithms, which at some point perform an AllNN computation. 2-point and higher-order spatial correlations for the basis of spatial statistics, and are utilized in astronomy to compare the spatial structures of two datasets, such as an observed sample and a theoretical sample, for example, forming the basis for two-sample hypothesis testing. Friends-of-friends clustering is often used to identify halos in data from astrophysical simulations. Minimum spanning tree properties have also been proposed as statistics of large-scale structure. Comparison of the distributions of different kinds of objects requires accurate density estimation, for which KDE is the overall statistical method of choice. The prediction of redshifts from optical data requires accurate regression, for which kernel regression is a powerful method. The identification of objects of various types in astronomy, such as stars versus galaxies, requires accurate classification, for which KDA is a powerful method. Overview. In this chapter, we will briefly sketch the main ideas behind recent fast algorithms which achieve, for example, linear runtimes for pairwise-distance problems, or similarly dramatic reductions in computational growth. In some cases, the runtime orders for these algorithms are mathematically provable statements, while in others we have only conjectures backed by experimental observations for the time being

  1. Using Web-Based Testing for Large-Scale Assessment.

    ERIC Educational Resources Information Center

    Hamilton, Laura S.; Klein, Stephen P.; Lorie, William

    This paper describes an approach to large-scale assessment that uses tests that are delivered to students over the Internet and that are tailored (adapted) to each student's own level of proficiency. A brief background on large-scale assessment is followed by a description of this new technology and an example. Issues that need to be investigated…

  2. Distribution probability of large-scale landslides in central Nepal

    NASA Astrophysics Data System (ADS)

    Timilsina, Manita; Bhandary, Netra P.; Dahal, Ranjan Kumar; Yatabe, Ryuichi

    2014-12-01

    Large-scale landslides in the Himalaya are defined as huge, deep-seated landslide masses that occurred in the geological past. They are widely distributed in the Nepal Himalaya. The steep topography and high local relief provide high potential for such failures, whereas the dynamic geology and adverse climatic conditions play a key role in the occurrence and reactivation of such landslides. The major geoscientific problems related with such large-scale landslides are 1) difficulties in their identification and delineation, 2) sources of small-scale failures, and 3) reactivation. Only a few scientific publications have been published concerning large-scale landslides in Nepal. In this context, the identification and quantification of large-scale landslides and their potential distribution are crucial. Therefore, this study explores the distribution of large-scale landslides in the Lesser Himalaya. It provides simple guidelines to identify large-scale landslides based on their typical characteristics and using a 3D schematic diagram. Based on the spatial distribution of landslides, geomorphological/geological parameters and logistic regression, an equation of large-scale landslide distribution is also derived. The equation is validated by applying it to another area. For the new area, the area under the receiver operating curve of the landslide distribution probability in the new area is 0.699, and a distribution probability value could explain > 65% of existing landslides. Therefore, the regression equation can be applied to areas of the Lesser Himalaya of central Nepal with similar geological and geomorphological conditions.

  3. Organised convection embedded in a large-scale flow

    NASA Astrophysics Data System (ADS)

    Naumann, Ann Kristin; Stevens, Bjorn; Hohenegger, Cathy

    2017-04-01

    In idealised simulations of radiative convective equilibrium, convection aggregates spontaneously from randomly distributed convective cells into organized mesoscale convection despite homogeneous boundary conditions. Although these simulations apply very idealised setups, the process of self-aggregation is thought to be relevant for the development of tropical convective systems. One feature that idealised simulations usually neglect is the occurrence of a large-scale background flow. In the tropics, organised convection is embedded in a large-scale circulation system, which advects convection in along-wind direction and alters near surface convergence in the convective areas. A large-scale flow also modifies the surface fluxes, which are expected to be enhanced upwind of the convective area if a large-scale flow is applied. Convective clusters that are embedded in a large-scale flow therefore experience an asymmetric component of the surface fluxes, which influences the development and the pathway of a convective cluster. In this study, we use numerical simulations with explicit convection and add a large-scale flow to the established setup of radiative convective equilibrium. We then analyse how aggregated convection evolves when being exposed to wind forcing. The simulations suggest that convective line structures are more prevalent if a large-scale flow is present and that convective clusters move considerably slower than advection by the large-scale flow would suggest. We also study the asymmetric component of convective aggregation due to enhanced surface fluxes, and discuss the pathway and speed of convective clusters as a function of the large-scale wind speed.

  4. Why Do Countries Participate in International Large-Scale Assessments? The Case of PISA. Policy Research Working Paper 7447

    ERIC Educational Resources Information Center

    Lockheed, Marlaine E.

    2015-01-01

    The number of countries that regularly participate in international large-scale assessments has increased sharply over the past 15 years, with the share of countries participating in the Programme for International Student Assessment growing from one-fifth of countries in 2000 to over one-third of countries in 2015. What accounts for this…

  5. Projecting Images of the "Good" and the "Bad School": Top Scorers in Educational Large-Scale Assessments as Reference Societies

    ERIC Educational Resources Information Center

    Waldow, Florian

    2017-01-01

    Researchers interested in the global flow of educational ideas and programmes have long been interested in the role of so-called "reference societies." The article investigates how top scorers in large-scale assessments are framed as positive or negative reference societies in the education policy-making debate in German mass media and…

  6. Needs, opportunities, and options for large scale systems research

    SciTech Connect

    Thompson, G.L.

    1984-10-01

    The Office of Energy Research was recently asked to perform a study of Large Scale Systems in order to facilitate the development of a true large systems theory. It was decided to ask experts in the fields of electrical engineering, chemical engineering and manufacturing/operations research for their ideas concerning large scale systems research. The author was asked to distribute a questionnaire among these experts to find out their opinions concerning recent accomplishments and future research directions in large scale systems research. He was also requested to convene a conference which included three experts in each area as panel members to discuss the general area of large scale systems research. The conference was held on March 26--27, 1984 in Pittsburgh with nine panel members, and 15 other attendees. The present report is a summary of the ideas presented and the recommendations proposed by the attendees.

  7. Modified gravity and large scale flows, a review

    NASA Astrophysics Data System (ADS)

    Mould, Jeremy

    2017-02-01

    Large scale flows have been a challenging feature of cosmography ever since galaxy scaling relations came on the scene 40 years ago. The next generation of surveys will offer a serious test of the standard cosmology.

  8. Learning networks for sustainable, large-scale improvement.

    PubMed

    McCannon, C Joseph; Perla, Rocco J

    2009-05-01

    Large-scale improvement efforts known as improvement networks offer structured opportunities for exchange of information and insights into the adaptation of clinical protocols to a variety of settings.

  9. Amplification of large-scale magnetic field in nonhelical magnetohydrodynamics

    NASA Astrophysics Data System (ADS)

    Kumar, Rohit; Verma, Mahendra K.

    2017-09-01

    It is typically assumed that the kinetic and magnetic helicities play a crucial role in the growth of large-scale dynamo. In this paper, we demonstrate that helicity is not essential for the amplification of large-scale magnetic field. For this purpose, we perform nonhelical magnetohydrodynamic (MHD) simulation, and show that the large-scale magnetic field can grow in nonhelical MHD when random external forcing is employed at scale 1/10 the box size. The energy fluxes and shell-to-shell transfer rates computed using the numerical data show that the large-scale magnetic energy grows due to the energy transfers from the velocity field at the forcing scales.

  10. An Adaptive Multiscale Finite Element Method for Large Scale Simulations

    DTIC Science & Technology

    2015-09-28

    the method . Using the above definitions , the weak statement of the non-linear local problem at the kth 4 DISTRIBUTION A: Distribution approved for...AFRL-AFOSR-VA-TR-2015-0305 An Adaptive Multiscale Finite Element Method for Large Scale Simulations Carlos Duarte UNIVERSITY OF ILLINOIS CHAMPAIGN...14-07-2015 4. TITLE AND SUBTITLE An Adaptive Multiscale Generalized Finite Element Method for Large Scale Simulations 5a.  CONTRACT NUMBER 5b

  11. A study of MLFMA for large-scale scattering problems

    NASA Astrophysics Data System (ADS)

    Hastriter, Michael Larkin

    This research is centered in computational electromagnetics with a focus on solving large-scale problems accurately in a timely fashion using first principle physics. Error control of the translation operator in 3-D is shown. A parallel implementation of the multilevel fast multipole algorithm (MLFMA) was studied as far as parallel efficiency and scaling. The large-scale scattering program (LSSP), based on the ScaleME library, was used to solve ultra-large-scale problems including a 200lambda sphere with 20 million unknowns. As these large-scale problems were solved, techniques were developed to accurately estimate the memory requirements. Careful memory management is needed in order to solve these massive problems. The study of MLFMA in large-scale problems revealed significant errors that stemmed from inconsistencies in constants used by different parts of the algorithm. These were fixed to produce the most accurate data possible for large-scale surface scattering problems. Data was calculated on a missile-like target using both high frequency methods and MLFMA. This data was compared and analyzed to determine possible strategies to increase data acquisition speed and accuracy through multiple computation method hybridization.

  12. An Examination of a Virtual Private Network Implementation to Support a Teleworking Initiative: The Marcus Food Company Inc. Case Study

    ERIC Educational Resources Information Center

    Ferguson, Jason W.

    2010-01-01

    In this dissertation, the author examined the capabilities of virtual private networks (VPNs) in supporting teleworking environments for small businesses in the food marketing sector. The goal of this research was to develop an implementation model for small businesses in the food marketing sector that use a VPN solution to support teleworker…

  13. An Examination of a Virtual Private Network Implementation to Support a Teleworking Initiative: The Marcus Food Company Inc. Case Study

    ERIC Educational Resources Information Center

    Ferguson, Jason W.

    2010-01-01

    In this dissertation, the author examined the capabilities of virtual private networks (VPNs) in supporting teleworking environments for small businesses in the food marketing sector. The goal of this research was to develop an implementation model for small businesses in the food marketing sector that use a VPN solution to support teleworker…

  14. The large-scale removal of mammalian invasive alien species in Northern Europe.

    PubMed

    Robertson, Peter A; Adriaens, Tim; Lambin, Xavier; Mill, Aileen; Roy, Sugoto; Shuttleworth, Craig M; Sutton-Croft, Mike

    2017-02-01

    Numerous examples exist of successful mammalian invasive alien species (IAS) eradications from small islands (<10 km(2) ), but few from more extensive areas. We review 15 large-scale removals (mean area 2627 km(2) ) from Northern Europe since 1900, including edible dormouse, muskrat, coypu, Himalayan porcupine, Pallas' and grey squirrels and American mink, each primarily based on daily checking of static traps. Objectives included true eradication or complete removal to a buffer zone, as distinct from other programmes that involved local control to limit damage or spread. Twelve eradication/removal programmes (80%) were successful. Cost increased with and was best predicted by area, while the cost per unit area decreased; the number of individual animals removed did not add significantly to the model. Doubling the area controlled reduced cost per unit area by 10%, but there was no evidence that cost effectiveness had increased through time. Compared with small islands, larger-scale programmes followed similar patterns of effort in relation to area. However, they brought challenges when defining boundaries and consequent uncertainties around costs, the definition of their objectives, confirmation of success and different considerations for managing recolonisation. Novel technologies or increased use of volunteers may reduce costs. Rapid response to new incursions is recommended as best practice rather than large-scale control to reduce the environmental, financial and welfare costs. © 2016 Crown copyright. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

  15. EINSTEIN'S SIGNATURE IN COSMOLOGICAL LARGE-SCALE STRUCTURE

    SciTech Connect

    Bruni, Marco; Hidalgo, Juan Carlos; Wands, David

    2014-10-10

    We show how the nonlinearity of general relativity generates a characteristic nonGaussian signal in cosmological large-scale structure that we calculate at all perturbative orders in a large-scale limit. Newtonian gravity and general relativity provide complementary theoretical frameworks for modeling large-scale structure in ΛCDM cosmology; a relativistic approach is essential to determine initial conditions, which can then be used in Newtonian simulations studying the nonlinear evolution of the matter density. Most inflationary models in the very early universe predict an almost Gaussian distribution for the primordial metric perturbation, ζ. However, we argue that it is the Ricci curvature of comoving-orthogonal spatial hypersurfaces, R, that drives structure formation at large scales. We show how the nonlinear relation between the spatial curvature, R, and the metric perturbation, ζ, translates into a specific nonGaussian contribution to the initial comoving matter density that we calculate for the simple case of an initially Gaussian ζ. Our analysis shows the nonlinear signature of Einstein's gravity in large-scale structure.

  16. Recursive architecture for large-scale adaptive system

    NASA Astrophysics Data System (ADS)

    Hanahara, Kazuyuki; Sugiyama, Yoshihiko

    1994-09-01

    'Large scale' is one of major trends in the research and development of recent engineering, especially in the field of aerospace structural system. This term expresses the large scale of an artifact in general, however, it also implies the large number of the components which make up the artifact in usual. Considering a large scale system which is especially used in remote space or deep-sea, such a system should be adaptive as well as robust by itself, because its control as well as maintenance by human operators are not easy due to the remoteness. An approach to realizing this large scale, adaptive and robust system is to build the system as an assemblage of components which are respectively adaptive by themselves. In this case, the robustness of the system can be achieved by using a large number of such components and suitable adaptation as well as maintenance strategies. Such a system gathers many research's interest and their studies such as decentralized motion control, configurating algorithm and characteristics of structural elements are reported. In this article, a recursive architecture concept is developed and discussed towards the realization of large scale system which consists of a number of uniform adaptive components. We propose an adaptation strategy based on the architecture and its implementation by means of hierarchically connected processing units. The robustness and the restoration from degeneration of the processing unit are also discussed. Two- and three-dimensional adaptive truss structures are conceptually designed based on the recursive architecture.

  17. The Influence of Large-scale Environments on Galaxy Properties

    NASA Astrophysics Data System (ADS)

    Wei, Yu-qing; Wang, Lei; Dai, Cai-ping

    2017-07-01

    The star formation properties of galaxies and their dependence on environments play an important role for understanding the formation and evolution of galaxies. Using the galaxy sample of the Sloan Digital Sky Survey (SDSS), different research groups have studied the physical properties of galaxies and their large-scale environments. Here, using the filament catalog from Tempel et al. and the galaxy catalog of large-scale structure classification from Wang et al., and taking the influence of the galaxy morphology, high/low local density environment, and central (satellite) galaxy into consideration, we have found that the properties of galaxies are correlated with their residential large-scale environments: the SSFR (specific star formation rate) and SFR (star formation rate) strongly depend on the large-scale environment for spiral galaxies and satellite galaxies, but this dependence is very weak for elliptical galaxies and central galaxies, and the influence of large-scale environments on galaxies in low density region is more sensitive than that in high density region. The above conclusions remain valid even for the galaxies with the same mass. In addition, the SSFR distributions derived from the catalogs of Tempel et al. and Wang et al. are not entirely consistent.

  18. Toward Improved Support for Loosely Coupled Large Scale Simulation Workflows

    SciTech Connect

    Boehm, Swen; Elwasif, Wael R; Naughton, III, Thomas J; Vallee, Geoffroy R

    2014-01-01

    High-performance computing (HPC) workloads are increasingly leveraging loosely coupled large scale simula- tions. Unfortunately, most large-scale HPC platforms, including Cray/ALPS environments, are designed for the execution of long-running jobs based on coarse-grained launch capabilities (e.g., one MPI rank per core on all allocated compute nodes). This assumption limits capability-class workload campaigns that require large numbers of discrete or loosely coupled simulations, and where time-to-solution is an untenable pacing issue. This paper describes the challenges related to the support of fine-grained launch capabilities that are necessary for the execution of loosely coupled large scale simulations on Cray/ALPS platforms. More precisely, we present the details of an enhanced runtime system to support this use case, and report on initial results from early testing on systems at Oak Ridge National Laboratory.

  19. Seismic safety in conducting large-scale blasts

    NASA Astrophysics Data System (ADS)

    Mashukov, I. V.; Chaplygin, V. V.; Domanov, V. P.; Semin, A. A.; Klimkin, M. A.

    2017-09-01

    In mining enterprises to prepare hard rocks for excavation a drilling and blasting method is used. With the approach of mining operations to settlements the negative effect of large-scale blasts increases. To assess the level of seismic impact of large-scale blasts the scientific staff of Siberian State Industrial University carried out expertise for coal mines and iron ore enterprises. Determination of the magnitude of surface seismic vibrations caused by mass explosions was performed using seismic receivers, an analog-digital converter with recording on a laptop. The registration results of surface seismic vibrations during production of more than 280 large-scale blasts at 17 mining enterprises in 22 settlements are presented. The maximum velocity values of the Earth’s surface vibrations are determined. The safety evaluation of seismic effect was carried out according to the permissible value of vibration velocity. For cases with exceedance of permissible values recommendations were developed to reduce the level of seismic impact.

  20. PKI security in large-scale healthcare networks.

    PubMed

    Mantas, Georgios; Lymberopoulos, Dimitrios; Komninos, Nikos

    2012-06-01

    During the past few years a lot of PKI (Public Key Infrastructures) infrastructures have been proposed for healthcare networks in order to ensure secure communication services and exchange of data among healthcare professionals. However, there is a plethora of challenges in these healthcare PKI infrastructures. Especially, there are a lot of challenges for PKI infrastructures deployed over large-scale healthcare networks. In this paper, we propose a PKI infrastructure to ensure security in a large-scale Internet-based healthcare network connecting a wide spectrum of healthcare units geographically distributed within a wide region. Furthermore, the proposed PKI infrastructure facilitates the trust issues that arise in a large-scale healthcare network including multi-domain PKI infrastructures.

  1. Acoustic Studies of the Large Scale Ocean Circulation

    NASA Technical Reports Server (NTRS)

    Menemenlis, Dimitris

    1999-01-01

    Detailed knowledge of ocean circulation and its transport properties is prerequisite to an understanding of the earth's climate and of important biological and chemical cycles. Results from two recent experiments, THETIS-2 in the Western Mediterranean and ATOC in the North Pacific, illustrate the use of ocean acoustic tomography for studies of the large scale circulation. The attraction of acoustic tomography is its ability to sample and average the large-scale oceanic thermal structure, synoptically, along several sections, and at regular intervals. In both studies, the acoustic data are compared to, and then combined with, general circulation models, meteorological analyses, satellite altimetry, and direct measurements from ships. Both studies provide complete regional descriptions of the time-evolving, three-dimensional, large scale circulation, albeit with large uncertainties. The studies raise serious issues about existing ocean observing capability and provide guidelines for future efforts.

  2. Large-scale velocity structures in turbulent thermal convection.

    PubMed

    Qiu, X L; Tong, P

    2001-09-01

    A systematic study of large-scale velocity structures in turbulent thermal convection is carried out in three different aspect-ratio cells filled with water. Laser Doppler velocimetry is used to measure the velocity profiles and statistics over varying Rayleigh numbers Ra and at various spatial positions across the whole convection cell. Large velocity fluctuations are found both in the central region and near the cell boundary. Despite the large velocity fluctuations, the flow field still maintains a large-scale quasi-two-dimensional structure, which rotates in a coherent manner. This coherent single-roll structure scales with Ra and can be divided into three regions in the rotation plane: (1) a thin viscous boundary layer, (2) a fully mixed central core region with a constant mean velocity gradient, and (3) an intermediate plume-dominated buffer region. The experiment reveals a unique driving mechanism for the large-scale coherent rotation in turbulent convection.

  3. Large-scale simulations of complex physical systems

    NASA Astrophysics Data System (ADS)

    Belić, A.

    2007-04-01

    Scientific computing has become a tool as vital as experimentation and theory for dealing with scientific challenges of the twenty-first century. Large scale simulations and modelling serve as heuristic tools in a broad problem-solving process. High-performance computing facilities make possible the first step in this process - a view of new and previously inaccessible domains in science and the building up of intuition regarding the new phenomenology. The final goal of this process is to translate this newly found intuition into better algorithms and new analytical results. In this presentation we give an outline of the research themes pursued at the Scientific Computing Laboratory of the Institute of Physics in Belgrade regarding large-scale simulations of complex classical and quantum physical systems, and present recent results obtained in the large-scale simulations of granular materials and path integrals.

  4. Large-scale simulations of complex physical systems

    SciTech Connect

    Belic, A.

    2007-04-23

    Scientific computing has become a tool as vital as experimentation and theory for dealing with scientific challenges of the twenty-first century. Large scale simulations and modelling serve as heuristic tools in a broad problem-solving process. High-performance computing facilities make possible the first step in this process - a view of new and previously inaccessible domains in science and the building up of intuition regarding the new phenomenology. The final goal of this process is to translate this newly found intuition into better algorithms and new analytical results.In this presentation we give an outline of the research themes pursued at the Scientific Computing Laboratory of the Institute of Physics in Belgrade regarding large-scale simulations of complex classical and quantum physical systems, and present recent results obtained in the large-scale simulations of granular materials and path integrals.

  5. A relativistic signature in large-scale structure

    NASA Astrophysics Data System (ADS)

    Bartolo, Nicola; Bertacca, Daniele; Bruni, Marco; Koyama, Kazuya; Maartens, Roy; Matarrese, Sabino; Sasaki, Misao; Verde, Licia; Wands, David

    2016-09-01

    In General Relativity, the constraint equation relating metric and density perturbations is inherently nonlinear, leading to an effective non-Gaussianity in the dark matter density field on large scales-even if the primordial metric perturbation is Gaussian. Intrinsic non-Gaussianity in the large-scale dark matter overdensity in GR is real and physical. However, the variance smoothed on a local physical scale is not correlated with the large-scale curvature perturbation, so that there is no relativistic signature in the galaxy bias when using the simplest model of bias. It is an open question whether the observable mass proxies such as luminosity or weak lensing correspond directly to the physical mass in the simple halo bias model. If not, there may be observables that encode this relativistic signature.

  6. Magnetic Helicity and Large Scale Magnetic Fields: A Primer

    NASA Astrophysics Data System (ADS)

    Blackman, Eric G.

    2015-05-01

    Magnetic fields of laboratory, planetary, stellar, and galactic plasmas commonly exhibit significant order on large temporal or spatial scales compared to the otherwise random motions within the hosting system. Such ordered fields can be measured in the case of planets, stars, and galaxies, or inferred indirectly by the action of their dynamical influence, such as jets. Whether large scale fields are amplified in situ or a remnant from previous stages of an object's history is often debated for objects without a definitive magnetic activity cycle. Magnetic helicity, a measure of twist and linkage of magnetic field lines, is a unifying tool for understanding large scale field evolution for both mechanisms of origin. Its importance stems from its two basic properties: (1) magnetic helicity is typically better conserved than magnetic energy; and (2) the magnetic energy associated with a fixed amount of magnetic helicity is minimized when the system relaxes this helical structure to the largest scale available. Here I discuss how magnetic helicity has come to help us understand the saturation of and sustenance of large scale dynamos, the need for either local or global helicity fluxes to avoid dynamo quenching, and the associated observational consequences. I also discuss how magnetic helicity acts as a hindrance to turbulent diffusion of large scale fields, and thus a helper for fossil remnant large scale field origin models in some contexts. I briefly discuss the connection between large scale fields and accretion disk theory as well. The goal here is to provide a conceptual primer to help the reader efficiently penetrate the literature.

  7. Large Scale Processes and Extreme Floods in Brazil

    NASA Astrophysics Data System (ADS)

    Ribeiro Lima, C. H.; AghaKouchak, A.; Lall, U.

    2016-12-01

    Persistent large scale anomalies in the atmospheric circulation and ocean state have been associated with heavy rainfall and extreme floods in water basins of different sizes across the world. Such studies have emerged in the last years as a new tool to improve the traditional, stationary based approach in flood frequency analysis and flood prediction. Here we seek to advance previous studies by evaluating the dominance of large scale processes (e.g. atmospheric rivers/moisture transport) over local processes (e.g. local convection) in producing floods. We consider flood-prone regions in Brazil as case studies and the role of large scale climate processes in generating extreme floods in such regions is explored by means of observed streamflow, reanalysis data and machine learning methods. The dynamics of the large scale atmospheric circulation in the days prior to the flood events are evaluated based on the vertically integrated moisture flux and its divergence field, which are interpreted in a low-dimensional space as obtained by machine learning techniques, particularly supervised kernel principal component analysis. In such reduced dimensional space, clusters are obtained in order to better understand the role of regional moisture recycling or teleconnected moisture in producing floods of a given magnitude. The convective available potential energy (CAPE) is also used as a measure of local convection activities. We investigate for individual sites the exceedance probability in which large scale atmospheric fluxes dominate the flood process. Finally, we analyze regional patterns of floods and how the scaling law of floods with drainage area responds to changes in the climate forcing mechanisms (e.g. local vs large scale).

  8. [Issues of large scale tissue culture of medicinal plant].

    PubMed

    Lv, Dong-Mei; Yuan, Yuan; Zhan, Zhi-Lai

    2014-09-01

    In order to increase the yield and quality of the medicinal plant and enhance the competitive power of industry of medicinal plant in our country, this paper analyzed the status, problem and countermeasure of the tissue culture of medicinal plant on large scale. Although the biotechnology is one of the most efficient and promising means in production of medicinal plant, it still has problems such as stability of the material, safety of the transgenic medicinal plant and optimization of cultured condition. Establishing perfect evaluation system according to the characteristic of the medicinal plant is the key measures to assure the sustainable development of the tissue culture of medicinal plant on large scale.

  9. The CLASSgal code for relativistic cosmological large scale structure

    NASA Astrophysics Data System (ADS)

    Di Dio, Enea; Montanari, Francesco; Lesgourgues, Julien; Durrer, Ruth

    2013-11-01

    We present accurate and efficient computations of large scale structure observables, obtained with a modified version of the CLASS code which is made publicly available. This code includes all relativistic corrections and computes both the power spectrum Cl(z1,z2) and the corresponding correlation function ξ(θ,z1,z2) of the matter density and the galaxy number fluctuations in linear perturbation theory. For Gaussian initial perturbations, these quantities contain the full information encoded in the large scale matter distribution at the level of linear perturbation theory. We illustrate the usefulness of our code for cosmological parameter estimation through a few simple examples.

  10. Corridors Increase Plant Species Richness at Large Scales

    SciTech Connect

    Damschen, Ellen I.; Haddad, Nick M.; Orrock,John L.; Tewksbury, Joshua J.; Levey, Douglas J.

    2006-09-01

    Habitat fragmentation is one of the largest threats to biodiversity. Landscape corridors, which are hypothesized to reduce the negative consequences of fragmentation, have become common features of ecological management plans worldwide. Despite their popularity, there is little evidence documenting the effectiveness of corridors in preserving biodiversity at large scales. Using a large-scale replicated experiment, we showed that habitat patches connected by corridors retain more native plant species than do isolated patches, that this difference increases over time, and that corridors do not promote invasion by exotic species. Our results support the use of corridors in biodiversity conservation.

  11. Large-Scale Graph Processing Analysis using Supercomputer Cluster

    NASA Astrophysics Data System (ADS)

    Vildario, Alfrido; Fitriyani; Nugraha Nurkahfi, Galih

    2017-01-01

    Graph implementation is widely use in various sector such as automotive, traffic, image processing and many more. They produce graph in large-scale dimension, cause the processing need long computational time and high specification resources. This research addressed the analysis of implementation large-scale graph using supercomputer cluster. We impelemented graph processing by using Breadth-First Search (BFS) algorithm with single destination shortest path problem. Parallel BFS implementation with Message Passing Interface (MPI) used supercomputer cluster at High Performance Computing Laboratory Computational Science Telkom University and Stanford Large Network Dataset Collection. The result showed that the implementation give the speed up averages more than 30 times and eficiency almost 90%.

  12. Survey of decentralized control methods. [for large scale dynamic systems

    NASA Technical Reports Server (NTRS)

    Athans, M.

    1975-01-01

    An overview is presented of the types of problems that are being considered by control theorists in the area of dynamic large scale systems with emphasis on decentralized control strategies. Approaches that deal directly with decentralized decision making for large scale systems are discussed. It is shown that future advances in decentralized system theory are intimately connected with advances in the stochastic control problem with nonclassical information pattern. The basic assumptions and mathematical tools associated with the latter are summarized, and recommendations concerning future research are presented.

  13. Clearing and Labeling Techniques for Large-Scale Biological Tissues

    PubMed Central

    Seo, Jinyoung; Choe, Minjin; Kim, Sung-Yon

    2016-01-01

    Clearing and labeling techniques for large-scale biological tissues enable simultaneous extraction of molecular and structural information with minimal disassembly of the sample, facilitating the integration of molecular, cellular and systems biology across different scales. Recent years have witnessed an explosive increase in the number of such methods and their applications, reflecting heightened interest in organ-wide clearing and labeling across many fields of biology and medicine. In this review, we provide an overview and comparison of existing clearing and labeling techniques and discuss challenges and opportunities in the investigations of large-scale biological systems. PMID:27239813

  14. The Evolution of Baryons in Cosmic Large Scale Structure

    NASA Astrophysics Data System (ADS)

    Snedden, Ali; Arielle Phillips, Lara; Mathews, Grant James; Coughlin, Jared; Suh, In-Saeng; Bhattacharya, Aparna

    2015-01-01

    The environments of galaxies play a critical role in their formation and evolution. We study these environments using cosmological simulations with star formation and supernova feedback included. From these simulations, we parse the large scale structure into clusters, filaments and voids using a segmentation algorithm adapted from medical imaging. We trace the star formation history, gas phase and metal evolution of the baryons in the intergalactic medium as function of structure. We find that our algorithm reproduces the baryon fraction in the intracluster medium and that the majority of star formation occurs in cold, dense filaments. We present the consequences this large scale environment has for galactic halos and galaxy evolution.

  15. Large scale purification of RNA nanoparticles by preparative ultracentrifugation.

    PubMed

    Jasinski, Daniel L; Schwartz, Chad T; Haque, Farzin; Guo, Peixuan

    2015-01-01

    Purification of large quantities of supramolecular RNA complexes is of paramount importance due to the large quantities of RNA needed and the purity requirements for in vitro and in vivo assays. Purification is generally carried out by liquid chromatography (HPLC), polyacrylamide gel electrophoresis (PAGE), or agarose gel electrophoresis (AGE). Here, we describe an efficient method for the large-scale purification of RNA prepared by in vitro transcription using T7 RNA polymerase by cesium chloride (CsCl) equilibrium density gradient ultracentrifugation and the large-scale purification of RNA nanoparticles by sucrose gradient rate-zonal ultracentrifugation or cushioned sucrose gradient rate-zonal ultracentrifugation.

  16. The Large-Scale Structure of Scientific Method

    ERIC Educational Resources Information Center

    Kosso, Peter

    2009-01-01

    The standard textbook description of the nature of science describes the proposal, testing, and acceptance of a theoretical idea almost entirely in isolation from other theories. The resulting model of science is a kind of piecemeal empiricism that misses the important network structure of scientific knowledge. Only the large-scale description of…

  17. A bibliographical surveys of large-scale systems

    NASA Technical Reports Server (NTRS)

    Corliss, W. R.

    1970-01-01

    A limited, partly annotated bibliography was prepared on the subject of large-scale system control. Approximately 400 references are divided into thirteen application areas, such as large societal systems and large communication systems. A first-author index is provided.

  18. Mixing Metaphors: Building Infrastructure for Large Scale School Turnaround

    ERIC Educational Resources Information Center

    Peurach, Donald J.; Neumerski, Christine M.

    2015-01-01

    The purpose of this analysis is to increase understanding of the possibilities and challenges of building educational infrastructure--the basic, foundational structures, systems, and resources--to support large-scale school turnaround. Building educational infrastructure often exceeds the capacity of schools, districts, and state education…

  19. Firebrands and spotting ignition in large-scale fires

    Treesearch

    Eunmo Koo; Patrick J. Pagni; David R. Weise; John P. Woycheese

    2010-01-01

    Spotting ignition by lofted firebrands is a significant mechanism of fire spread, as observed in many largescale fires. The role of firebrands in fire propagation and the important parameters involved in spot fire development are studied. Historical large-scale fires, including wind-driven urban and wildland conflagrations and post-earthquake fires are given as...

  20. Large Scale Survey Data in Career Development Research

    ERIC Educational Resources Information Center

    Diemer, Matthew A.

    2008-01-01

    Large scale survey datasets have been underutilized but offer numerous advantages for career development scholars, as they contain numerous career development constructs with large and diverse samples that are followed longitudinally. Constructs such as work salience, vocational expectations, educational expectations, work satisfaction, and…

  1. Measurement, Sampling, and Equating Errors in Large-Scale Assessments

    ERIC Educational Resources Information Center

    Wu, Margaret

    2010-01-01

    In large-scale assessments, such as state-wide testing programs, national sample-based assessments, and international comparative studies, there are many steps involved in the measurement and reporting of student achievement. There are always sources of inaccuracies in each of the steps. It is of interest to identify the source and magnitude of…

  2. US National Large-scale City Orthoimage Standard Initiative

    USGS Publications Warehouse

    Zhou, G.; Song, C.; Benjamin, S.; Schickler, W.

    2003-01-01

    The early procedures and algorithms for National digital orthophoto generation in National Digital Orthophoto Program (NDOP) were based on earlier USGS mapping operations, such as field control, aerotriangulation (derived in the early 1920's), the quarter-quadrangle-centered (3.75 minutes of longitude and latitude in geographic extent), 1:40,000 aerial photographs, and 2.5 D digital elevation models. However, large-scale city orthophotos using early procedures have disclosed many shortcomings, e.g., ghost image, occlusion, shadow. Thus, to provide the technical base (algorithms, procedure) and experience needed for city large-scale digital orthophoto creation is essential for the near future national large-scale digital orthophoto deployment and the revision of the Standards for National Large-scale City Digital Orthophoto in National Digital Orthophoto Program (NDOP). This paper will report our initial research results as follows: (1) High-precision 3D city DSM generation through LIDAR data processing, (2) Spatial objects/features extraction through surface material information and high-accuracy 3D DSM data, (3) 3D city model development, (4) Algorithm development for generation of DTM-based orthophoto, and DBM-based orthophoto, (5) True orthophoto generation by merging DBM-based orthophoto and DTM-based orthophoto, and (6) Automatic mosaic by optimizing and combining imagery from many perspectives.

  3. DESIGN OF LARGE-SCALE AIR MONITORING NETWORKS

    EPA Science Inventory

    The potential effects of air pollution on human health have received much attention in recent years. In the U.S. and other countries, there are extensive large-scale monitoring networks designed to collect data to inform the public of exposure risks to air pollution. A major crit...

  4. Large-Scale Environmental Influences on Aquatic Animal Health

    EPA Science Inventory

    In the latter portion of the 20th century, North America experienced numerous large-scale mortality events affecting a broad diversity of aquatic animals. Short-term forensic investigations of these events have sometimes characterized a causative agent or condition, but have rare...

  5. DESIGN OF LARGE-SCALE AIR MONITORING NETWORKS

    EPA Science Inventory

    The potential effects of air pollution on human health have received much attention in recent years. In the U.S. and other countries, there are extensive large-scale monitoring networks designed to collect data to inform the public of exposure risks to air pollution. A major crit...

  6. Developing and Understanding Methods for Large-Scale Nonlinear Optimization

    DTIC Science & Technology

    2006-07-24

    algorithms for large-scale uncon- strained and constrained optimization problems, including limited-memory methods for problems with -2- many thousands...34Published in peer-reviewed journals" E. Eskow, B. Bader, R. Byrd, S. Crivelli, T. Head-Gordon, V. Lamberti and R. Schnabel, "An optimization approach to the

  7. Probabilistic Cuing in Large-Scale Environmental Search

    ERIC Educational Resources Information Center

    Smith, Alastair D.; Hood, Bruce M.; Gilchrist, Iain D.

    2010-01-01

    Finding an object in our environment is an important human ability that also represents a critical component of human foraging behavior. One type of information that aids efficient large-scale search is the likelihood of the object being in one location over another. In this study we investigated the conditions under which individuals respond to…

  8. Feasibility of large-scale aquatic microcosms. Final report

    SciTech Connect

    Pease, T.; Wyman, R.L.; Logan, D.T.; Logan, C.M.; Lispi, D.R.

    1982-02-01

    Microcosms have been used to study a number of fundamental ecological principles and more recently to investigate the effects of man-made perturbations on ecosystems. In this report the feasibility of using large-scale microcosms to access aquatic impacts of power generating facilities is evaluated. Aquatic problems of concern to utilities are outlined, and various research approaches, including large and small microcosms, bioassays, and other laboratory experiments, are discussed. An extensive critical review and synthesis of the literature on recent microcosm research, which includes a comparison of the factors influencing physical, chemical, and biological processes in small vs large microcosms and in microcosms vs nature, led the authors to conclude that large-scale microcosms offer several advantages over other study techniques for particular types of problems. A hypothetical large-scale facility simulating a lake ecosystem is presented to illustrate the size, cost, and complexity of such facilities. The rationale for designing a lake-simulating large-scale microcosm is presented.

  9. Assuring Quality in Large-Scale Online Course Development

    ERIC Educational Resources Information Center

    Parscal, Tina; Riemer, Deborah

    2010-01-01

    Student demand for online education requires colleges and universities to rapidly expand the number of courses and programs offered online while maintaining high quality. This paper outlines two universities respective processes to assure quality in large-scale online programs that integrate instructional design, eBook custom publishing, Quality…

  10. Improving the Utility of Large-Scale Assessments in Canada

    ERIC Educational Resources Information Center

    Rogers, W. Todd

    2014-01-01

    Principals and teachers do not use large-scale assessment results because the lack of distinct and reliable subtests prevents identifying strengths and weaknesses of students and instruction, the results arrive too late to be used, and principals and teachers need assistance to use the results to improve instruction so as to improve student…

  11. Research directions in large scale systems and decentralized control

    NASA Technical Reports Server (NTRS)

    Tenney, R. R.

    1980-01-01

    Control theory provides a well established framework for dealing with automatic decision problems and a set of techniques for automatic decision making which exploit special structure, but it does not deal well with complexity. The potential exists for combining control theoretic and knowledge based concepts into a unified approach. The elements of control theory are diagrammed, including modern control and large scale systems.

  12. Efficient On-Demand Operations in Large-Scale Infrastructures

    ERIC Educational Resources Information Center

    Ko, Steven Y.

    2009-01-01

    In large-scale distributed infrastructures such as clouds, Grids, peer-to-peer systems, and wide-area testbeds, users and administrators typically desire to perform "on-demand operations" that deal with the most up-to-date state of the infrastructure. However, the scale and dynamism present in the operating environment make it challenging to…

  13. Ecosystem resilience despite large-scale altered hydro climatic conditions

    USDA-ARS?s Scientific Manuscript database

    Climate change is predicted to increase both drought frequency and duration, and when coupled with substantial warming, will establish a new hydroclimatological paradigm for many regions. Large-scale, warm droughts have recently impacted North America, Africa, Europe, Amazonia, and Australia result...

  14. The Large-Scale Structure of Scientific Method

    ERIC Educational Resources Information Center

    Kosso, Peter

    2009-01-01

    The standard textbook description of the nature of science describes the proposal, testing, and acceptance of a theoretical idea almost entirely in isolation from other theories. The resulting model of science is a kind of piecemeal empiricism that misses the important network structure of scientific knowledge. Only the large-scale description of…

  15. Large-Scale Assessments and Educational Policies in Italy

    ERIC Educational Resources Information Center

    Damiani, Valeria

    2016-01-01

    Despite Italy's extensive participation in most large-scale assessments, their actual influence on Italian educational policies is less easy to identify. The present contribution aims at highlighting and explaining reasons for the weak and often inconsistent relationship between international surveys and policy-making processes in Italy.…

  16. Large-Scale Innovation and Change in UK Higher Education

    ERIC Educational Resources Information Center

    Brown, Stephen

    2013-01-01

    This paper reflects on challenges universities face as they respond to change. It reviews current theories and models of change management, discusses why universities are particularly difficult environments in which to achieve large scale, lasting change and reports on a recent attempt by the UK JISC to enable a range of UK universities to employ…

  17. Current Scientific Issues in Large Scale Atmospheric Dynamics

    NASA Technical Reports Server (NTRS)

    Miller, T. L. (Compiler)

    1986-01-01

    Topics in large scale atmospheric dynamics are discussed. Aspects of atmospheric blocking, the influence of transient baroclinic eddies on planetary-scale waves, cyclogenesis, the effects of orography on planetary scale flow, small scale frontal structure, and simulations of gravity waves in frontal zones are discussed.

  18. Large-Scale Assessments and Educational Policies in Italy

    ERIC Educational Resources Information Center

    Damiani, Valeria

    2016-01-01

    Despite Italy's extensive participation in most large-scale assessments, their actual influence on Italian educational policies is less easy to identify. The present contribution aims at highlighting and explaining reasons for the weak and often inconsistent relationship between international surveys and policy-making processes in Italy.…

  19. Large scale fire whirls: Can their formation be predicted?

    Treesearch

    J. Forthofer; Bret Butler

    2010-01-01

    Large scale fire whirls have not traditionally been recognized as a frequent phenomenon on wildland fires. However, there are anecdotal data suggesting that they can and do occur with some regularity. This paper presents a brief summary of this information and an analysis of the causal factors leading to their formation.

  20. Large-Scale Environmental Influences on Aquatic Animal Health

    EPA Science Inventory

    In the latter portion of the 20th century, North America experienced numerous large-scale mortality events affecting a broad diversity of aquatic animals. Short-term forensic investigations of these events have sometimes characterized a causative agent or condition, but have rare...

  1. International Large-Scale Assessments: What Uses, What Consequences?

    ERIC Educational Resources Information Center

    Johansson, Stefan

    2016-01-01

    Background: International large-scale assessments (ILSAs) are a much-debated phenomenon in education. Increasingly, their outcomes attract considerable media attention and influence educational policies in many jurisdictions worldwide. The relevance, uses and consequences of these assessments are often the focus of research scrutiny. Whilst some…

  2. Extracting Useful Semantic Information from Large Scale Corpora of Text

    ERIC Educational Resources Information Center

    Mendoza, Ray Padilla, Jr.

    2012-01-01

    Extracting and representing semantic information from large scale corpora is at the crux of computer-assisted knowledge generation. Semantic information depends on collocation extraction methods, mathematical models used to represent distributional information, and weighting functions which transform the space. This dissertation provides a…

  3. Large-Scale Innovation and Change in UK Higher Education

    ERIC Educational Resources Information Center

    Brown, Stephen

    2013-01-01

    This paper reflects on challenges universities face as they respond to change. It reviews current theories and models of change management, discusses why universities are particularly difficult environments in which to achieve large scale, lasting change and reports on a recent attempt by the UK JISC to enable a range of UK universities to employ…

  4. Mixing Metaphors: Building Infrastructure for Large Scale School Turnaround

    ERIC Educational Resources Information Center

    Peurach, Donald J.; Neumerski, Christine M.

    2015-01-01

    The purpose of this analysis is to increase understanding of the possibilities and challenges of building educational infrastructure--the basic, foundational structures, systems, and resources--to support large-scale school turnaround. Building educational infrastructure often exceeds the capacity of schools, districts, and state education…

  5. Individual Skill Differences and Large-Scale Environmental Learning

    ERIC Educational Resources Information Center

    Fields, Alexa W.; Shelton, Amy L.

    2006-01-01

    Spatial skills are known to vary widely among normal individuals. This project was designed to address whether these individual differences are differentially related to large-scale environmental learning from route (ground-level) and survey (aerial) perspectives. Participants learned two virtual environments (route and survey) with limited…

  6. Newton Methods for Large Scale Problems in Machine Learning

    ERIC Educational Resources Information Center

    Hansen, Samantha Leigh

    2014-01-01

    The focus of this thesis is on practical ways of designing optimization algorithms for minimizing large-scale nonlinear functions with applications in machine learning. Chapter 1 introduces the overarching ideas in the thesis. Chapters 2 and 3 are geared towards supervised machine learning applications that involve minimizing a sum of loss…

  7. Large-Scale Machine Learning for Classification and Search

    ERIC Educational Resources Information Center

    Liu, Wei

    2012-01-01

    With the rapid development of the Internet, nowadays tremendous amounts of data including images and videos, up to millions or billions, can be collected for training machine learning models. Inspired by this trend, this thesis is dedicated to developing large-scale machine learning techniques for the purpose of making classification and nearest…

  8. Global smoothing and continuation for large-scale molecular optimization

    SciTech Connect

    More, J.J.; Wu, Zhijun

    1995-10-01

    We discuss the formulation of optimization problems that arise in the study of distance geometry, ionic systems, and molecular clusters. We show that continuation techniques based on global smoothing are applicable to these molecular optimization problems, and we outline the issues that must be resolved in the solution of large-scale molecular optimization problems.

  9. Large-scale Eucalyptus energy farms and power cogeneration

    Treesearch

    Robert C. Noroña

    1983-01-01

    A thorough evaluation of all factors possibly affecting a large-scale planting of eucalyptus is foremost in determining the cost effectiveness of the planned operation. Seven basic areas of concern must be analyzed:1. Species Selection 2. Site Preparation 3. Planting 4. Weed Control 5....

  10. Probabilistic Cuing in Large-Scale Environmental Search

    ERIC Educational Resources Information Center

    Smith, Alastair D.; Hood, Bruce M.; Gilchrist, Iain D.

    2010-01-01

    Finding an object in our environment is an important human ability that also represents a critical component of human foraging behavior. One type of information that aids efficient large-scale search is the likelihood of the object being in one location over another. In this study we investigated the conditions under which individuals respond to…

  11. Lessons from Large-Scale Renewable Energy Integration Studies: Preprint

    SciTech Connect

    Bird, L.; Milligan, M.

    2012-06-01

    In general, large-scale integration studies in Europe and the United States find that high penetrations of renewable generation are technically feasible with operational changes and increased access to transmission. This paper describes other key findings such as the need for fast markets, large balancing areas, system flexibility, and the use of advanced forecasting.

  12. The large scale microwave background anisotropy in decaying particle cosmology

    SciTech Connect

    Panek, M.

    1987-06-01

    We investigate the large-scale anisotropy of the microwave background radiation in cosmological models with decaying particles. The observed value of the quadrupole moment combined with other constraints gives an upper limit on the redshift of the decay z/sub d/ < 3-5. 12 refs., 2 figs.

  13. Large-scale search for dark-matter axions

    SciTech Connect

    Kinion, D; van Bibber, K

    2000-08-30

    We review the status of two ongoing large-scale searches for axions which may constitute the dark matter of our Milky Way halo. The experiments are based on the microwave cavity technique proposed by Sikivie, and marks a ''second-generation'' to the original experiments performed by the Rochester-Brookhaven-Fermilab collaboration, and the University of Florida group.

  14. Resilience of Florida Keys coral communities following large scale disturbances

    EPA Science Inventory

    The decline of coral reefs in the Caribbean over the last 40 years has been attributed to multiple chronic stressors and episodic large-scale disturbances. This study assessed the resilience of coral communities in two different regions of the Florida Keys reef system between 199...

  15. Large Scale Survey Data in Career Development Research

    ERIC Educational Resources Information Center

    Diemer, Matthew A.

    2008-01-01

    Large scale survey datasets have been underutilized but offer numerous advantages for career development scholars, as they contain numerous career development constructs with large and diverse samples that are followed longitudinally. Constructs such as work salience, vocational expectations, educational expectations, work satisfaction, and…

  16. The Role of Plausible Values in Large-Scale Surveys

    ERIC Educational Resources Information Center

    Wu, Margaret

    2005-01-01

    In large-scale assessment programs such as NAEP, TIMSS and PISA, students' achievement data sets provided for secondary analysts contain so-called "plausible values." Plausible values are multiple imputations of the unobservable latent achievement for each student. In this article it has been shown how plausible values are used to: (1)…

  17. Large-scale silicon optical switches for optical interconnection

    NASA Astrophysics Data System (ADS)

    Qiao, Lei; Tang, Weijie; Chu, Tao

    2016-11-01

    Large-scale optical switches are greatly demanded in building optical interconnections in data centers and high performance computers (HPCs). Silicon optical switches have advantages of being compact and CMOS process compatible, which can be easily monolithically integrated. However, there are difficulties to construct large ports silicon optical switches. One of them is the non-uniformity of the switch units in large scale silicon optical switches, which arises from the fabrication error and causes confusion in finding the unit optimum operation points. In this paper, we proposed a method to detect the optimum operating point in large scale switch with limited build-in power monitors. We also propose methods for improving the unbalanced crosstalk of cross/bar states in silicon electro-optical MZI switches and insertion losses. Our recent progress in large scale silicon optical switches, including 64 × 64 thermal-optical and 32 × 32 electro-optical switches will be introduced. To the best our knowledge, both of them are the largest scale silicon optical switches in their sections, respectively. The switches were fabricated on 340-nm SOI substrates with CMOS 180- nm processes. The crosstalk of the 32 × 32 electro-optic switch was -19.2dB to -25.1 dB, while the value of the 64 × 64 thermal-optic switch was -30 dB to -48.3 dB.

  18. Assuring Quality in Large-Scale Online Course Development

    ERIC Educational Resources Information Center

    Parscal, Tina; Riemer, Deborah

    2010-01-01

    Student demand for online education requires colleges and universities to rapidly expand the number of courses and programs offered online while maintaining high quality. This paper outlines two universities respective processes to assure quality in large-scale online programs that integrate instructional design, eBook custom publishing, Quality…

  19. Computational Complexity, Efficiency and Accountability in Large Scale Teleprocessing Systems.

    DTIC Science & Technology

    1980-12-01

    COMPLEXITY, EFFICIENCY AND ACCOUNTABILITY IN LARGE SCALE TELEPROCESSING SYSTEMS DAAG29-78-C-0036 STANFORD UNIVERSITY JOHN T. GILL MARTIN E. BELLMAN...solve but easy to check. Ve have also suggested howy sucb random tapes can be simulated by determin- istically generating "pseudorandom" numbers by a

  20. Large-Scale Assessment and English Language Learners with Disabilities

    ERIC Educational Resources Information Center

    Liu, Kristin K.; Ward, Jenna M.; Thurlow, Martha L.; Christensen, Laurene L.

    2017-01-01

    This article highlights a set of principles and guidelines, developed by a diverse group of specialists in the field, for appropriately including English language learners (ELLs) with disabilities in large-scale assessments. ELLs with disabilities make up roughly 9% of the rapidly increasing ELL population nationwide. In spite of the small overall…

  1. Large-scale silviculture experiments of western Oregon and Washington.

    Treesearch

    Nathan J. Poage; Paul D. Anderson

    2007-01-01

    We review 12 large-scale silviculture experiments (LSSEs) in western Washington and Oregon with which the Pacific Northwest Research Station of the USDA Forest Service is substantially involved. We compiled and arrayed information about the LSSEs as a series of matrices in a relational database, which is included on the compact disc published with this report and...

  2. Newton Methods for Large Scale Problems in Machine Learning

    ERIC Educational Resources Information Center

    Hansen, Samantha Leigh

    2014-01-01

    The focus of this thesis is on practical ways of designing optimization algorithms for minimizing large-scale nonlinear functions with applications in machine learning. Chapter 1 introduces the overarching ideas in the thesis. Chapters 2 and 3 are geared towards supervised machine learning applications that involve minimizing a sum of loss…

  3. Efficient On-Demand Operations in Large-Scale Infrastructures

    ERIC Educational Resources Information Center

    Ko, Steven Y.

    2009-01-01

    In large-scale distributed infrastructures such as clouds, Grids, peer-to-peer systems, and wide-area testbeds, users and administrators typically desire to perform "on-demand operations" that deal with the most up-to-date state of the infrastructure. However, the scale and dynamism present in the operating environment make it challenging to…

  4. Large-Scale Machine Learning for Classification and Search

    ERIC Educational Resources Information Center

    Liu, Wei

    2012-01-01

    With the rapid development of the Internet, nowadays tremendous amounts of data including images and videos, up to millions or billions, can be collected for training machine learning models. Inspired by this trend, this thesis is dedicated to developing large-scale machine learning techniques for the purpose of making classification and nearest…

  5. Moon-based Earth Observation for Large Scale Geoscience Phenomena

    NASA Astrophysics Data System (ADS)

    Guo, Huadong; Liu, Guang; Ding, Yixing

    2016-07-01

    The capability of Earth observation for large-global-scale natural phenomena needs to be improved and new observing platform are expected. We have studied the concept of Moon as an Earth observation in these years. Comparing with manmade satellite platform, Moon-based Earth observation can obtain multi-spherical, full-band, active and passive information,which is of following advantages: large observation range, variable view angle, long-term continuous observation, extra-long life cycle, with the characteristics of longevity ,consistency, integrity, stability and uniqueness. Moon-based Earth observation is suitable for monitoring the large scale geoscience phenomena including large scale atmosphere change, large scale ocean change,large scale land surface dynamic change,solid earth dynamic change,etc. For the purpose of establishing a Moon-based Earth observation platform, we already have a plan to study the five aspects as follows: mechanism and models of moon-based observing earth sciences macroscopic phenomena; sensors' parameters optimization and methods of moon-based Earth observation; site selection and environment of moon-based Earth observation; Moon-based Earth observation platform; and Moon-based Earth observation fundamental scientific framework.

  6. Large-scale societal changes and intentionality - an uneasy marriage.

    PubMed

    Bodor, Péter; Fokas, Nikos

    2014-08-01

    Our commentary focuses on juxtaposing the proposed science of intentional change with facts and concepts pertaining to the level of large populations or changes on a worldwide scale. Although we find a unified evolutionary theory promising, we think that long-term and large-scale, scientifically guided - that is, intentional - social change is not only impossible, but also undesirable.

  7. Large-scale screening by the automated Wassermann reaction

    PubMed Central

    Wagstaff, W.; Firth, R.; Booth, J. R.; Bowley, C. C.

    1969-01-01

    In view of the drawbacks in the use of the Kahn test for large-scale screening of blood donors, mainly those of human error through work overload and fatiguability, an attempt was made to adapt an existing automated complement-fixation technique for this purpose. This paper reports the successful results of that adaptation. PMID:5776559

  8. International Large-Scale Assessments: What Uses, What Consequences?

    ERIC Educational Resources Information Center

    Johansson, Stefan

    2016-01-01

    Background: International large-scale assessments (ILSAs) are a much-debated phenomenon in education. Increasingly, their outcomes attract considerable media attention and influence educational policies in many jurisdictions worldwide. The relevance, uses and consequences of these assessments are often the focus of research scrutiny. Whilst some…

  9. Cosmic strings and the large-scale structure

    NASA Technical Reports Server (NTRS)

    Stebbins, Albert

    1988-01-01

    A possible problem for cosmic string models of galaxy formation is presented. If very large voids are common and if loop fragmentation is not much more efficient than presently believed, then it may be impossible for string scenarios to produce the observed large-scale structure with Omega sub 0 = 1 and without strong environmental biasing.

  10. Extracting Useful Semantic Information from Large Scale Corpora of Text

    ERIC Educational Resources Information Center

    Mendoza, Ray Padilla, Jr.

    2012-01-01

    Extracting and representing semantic information from large scale corpora is at the crux of computer-assisted knowledge generation. Semantic information depends on collocation extraction methods, mathematical models used to represent distributional information, and weighting functions which transform the space. This dissertation provides a…

  11. Large scale structure of the sun's radio corona

    NASA Technical Reports Server (NTRS)

    Kundu, M. R.

    1986-01-01

    Results of studies of large scale structures of the corona at long radio wavelengths are presented, using data obtained with the multifrequency radioheliograph of the Clark Lake Radio Observatory. It is shown that features corresponding to coronal streamers and coronal holes are readily apparent in the Clark Lake maps.

  12. Resilience of Florida Keys coral communities following large scale disturbances

    EPA Science Inventory

    The decline of coral reefs in the Caribbean over the last 40 years has been attributed to multiple chronic stressors and episodic large-scale disturbances. This study assessed the resilience of coral communities in two different regions of the Florida Keys reef system between 199...

  13. Electron drift in a large scale solid xenon

    SciTech Connect

    Yoo, J.; Jaskierny, W. F.

    2015-08-21

    A study of charge drift in a large scale optically transparent solid xenon is reported. A pulsed high power xenon light source is used to liberate electrons from a photocathode. The drift speeds of the electrons are measured using a 8.7 cm long electrode in both the liquid and solid phase of xenon. In the liquid phase (163 K), the drift speed is 0.193 ± 0.003 cm/μs while the drift speed in the solid phase (157 K) is 0.397 ± 0.006 cm/μs at 900 V/cm over 8.0 cm of uniform electric fields. Furthermore, it is demonstrated that a factor two faster electron drift speed in solid phase xenon compared to that in liquid in a large scale solid xenon.

  14. Electron drift in a large scale solid xenon

    DOE PAGES

    Yoo, J.; Jaskierny, W. F.

    2015-08-21

    A study of charge drift in a large scale optically transparent solid xenon is reported. A pulsed high power xenon light source is used to liberate electrons from a photocathode. The drift speeds of the electrons are measured using a 8.7 cm long electrode in both the liquid and solid phase of xenon. In the liquid phase (163 K), the drift speed is 0.193 ± 0.003 cm/μs while the drift speed in the solid phase (157 K) is 0.397 ± 0.006 cm/μs at 900 V/cm over 8.0 cm of uniform electric fields. Furthermore, it is demonstrated that a factor twomore » faster electron drift speed in solid phase xenon compared to that in liquid in a large scale solid xenon.« less

  15. GAIA: A WINDOW TO LARGE-SCALE MOTIONS

    SciTech Connect

    Nusser, Adi; Branchini, Enzo; Davis, Marc E-mail: branchin@fis.uniroma3.it

    2012-08-10

    Using redshifts as a proxy for galaxy distances, estimates of the two-dimensional (2D) transverse peculiar velocities of distant galaxies could be obtained from future measurements of proper motions. We provide the mathematical framework for analyzing 2D transverse motions and show that they offer several advantages over traditional probes of large-scale motions. They are completely independent of any intrinsic relations between galaxy properties; hence, they are essentially free of selection biases. They are free from homogeneous and inhomogeneous Malmquist biases that typically plague distance indicator catalogs. They provide additional information to traditional probes that yield line-of-sight peculiar velocities only. Further, because of their 2D nature, fundamental questions regarding vorticity of large-scale flows can be addressed. Gaia, for example, is expected to provide proper motions of at least bright galaxies with high central surface brightness, making proper motions a likely contender for traditional probes based on current and future distance indicator measurements.

  16. Large scale meteorological influence during the Geysers 1979 field experiment

    SciTech Connect

    Barr, S.

    1980-01-01

    A series of meteorological field measurements conducted during July 1979 near Cobb Mountain in Northern California reveals evidence of several scales of atmospheric circulation consistent with the climatic pattern of the area. The scales of influence are reflected in the structure of wind and temperature in vertically stratified layers at a given observation site. Large scale synoptic gradient flow dominates the wind field above about twice the height of the topographic ridge. Below that there is a mixture of effects with evidence of a diurnal sea breeze influence and a sublayer of katabatic winds. The July observations demonstrate that weak migratory circulations in the large scale synoptic meteorological pattern have a significant influence on the day-to-day gradient winds and must be accounted for in planning meteorological programs including tracer experiments.

  17. The Large Scale Synthesis of Aligned Plate Nanostructures

    PubMed Central

    Zhou, Yang; Nash, Philip; Liu, Tian; Zhao, Naiqin; Zhu, Shengli

    2016-01-01

    We propose a novel technique for the large-scale synthesis of aligned-plate nanostructures that are self-assembled and self-supporting. The synthesis technique involves developing nanoscale two-phase microstructures through discontinuous precipitation followed by selective etching to remove one of the phases. The method may be applied to any alloy system in which the discontinuous precipitation transformation goes to completion. The resulting structure may have many applications in catalysis, filtering and thermal management depending on the phase selection and added functionality through chemical reaction with the retained phase. The synthesis technique is demonstrated using the discontinuous precipitation of a γ′ phase, (Ni, Co)3Al, followed by selective dissolution of the γ matrix phase. The production of the nanostructure requires heat treatments on the order of minutes and can be performed on a large scale making this synthesis technique of great economic potential. PMID:27439672

  18. Lagrangian space consistency relation for large scale structure

    SciTech Connect

    Horn, Bart; Hui, Lam; Xiao, Xiao E-mail: lh399@columbia.edu

    2015-09-01

    Consistency relations, which relate the squeezed limit of an (N+1)-point correlation function to an N-point function, are non-perturbative symmetry statements that hold even if the associated high momentum modes are deep in the nonlinear regime and astrophysically complex. Recently, Kehagias and Riotto and Peloso and Pietroni discovered a consistency relation applicable to large scale structure. We show that this can be recast into a simple physical statement in Lagrangian space: that the squeezed correlation function (suitably normalized) vanishes. This holds regardless of whether the correlation observables are at the same time or not, and regardless of whether multiple-streaming is present. The simplicity of this statement suggests that an analytic understanding of large scale structure in the nonlinear regime may be particularly promising in Lagrangian space.

  19. The workshop on iterative methods for large scale nonlinear problems

    SciTech Connect

    Walker, H.F.; Pernice, M.

    1995-12-01

    The aim of the workshop was to bring together researchers working on large scale applications with numerical specialists of various kinds. Applications that were addressed included reactive flows (combustion and other chemically reacting flows, tokamak modeling), porous media flows, cardiac modeling, chemical vapor deposition, image restoration, macromolecular modeling, and population dynamics. Numerical areas included Newton iterative (truncated Newton) methods, Krylov subspace methods, domain decomposition and other preconditioning methods, large scale optimization and optimal control, and parallel implementations and software. This report offers a brief summary of workshop activities and information about the participants. Interested readers are encouraged to look into an online proceedings available at http://www.usi.utah.edu/logan.proceedings. In this, the material offered here is augmented with hypertext abstracts that include links to locations such as speakers` home pages, PostScript copies of talks and papers, cross-references to related talks, and other information about topics addresses at the workshop.

  20. Large Scale Deformation of the Western US Cordillera

    NASA Technical Reports Server (NTRS)

    Bennett, Richard A.

    2001-01-01

    Destructive earthquakes occur throughout the western US Cordillera (WUSC), not just within the San Andreas fault zone. But because we do not understand the present-day large-scale deformations of the crust throughout the WUSC, our ability to assess the potential for seismic hazards in this region remains severely limited. To address this problem, we are using a large collection of Global Positioning System (GPS) networks which spans the WUSC to precisely quantify present-day large-scale crustal deformations in a single uniform reference frame. Our work can roughly be divided into an analysis of the GPS observations to infer the deformation field across and within the entire plate boundary zone and an investigation of the implications of this deformation field regarding plate boundary dynamics.

  1. Large-scale linear nonparallel support vector machine solver.

    PubMed

    Tian, Yingjie; Ping, Yuan

    2014-02-01

    Twin support vector machines (TWSVMs), as the representative nonparallel hyperplane classifiers, have shown the effectiveness over standard SVMs from some aspects. However, they still have some serious defects restricting their further study and real applications: (1) They have to compute and store the inverse matrices before training, it is intractable for many applications where data appear with a huge number of instances as well as features; (2) TWSVMs lost the sparseness by using a quadratic loss function making the proximal hyperplane close enough to the class itself. This paper proposes a Sparse Linear Nonparallel Support Vector Machine, termed as L1-NPSVM, to deal with large-scale data based on an efficient solver-dual coordinate descent (DCD) method. Both theoretical analysis and experiments indicate that our method is not only suitable for large scale problems, but also performs as good as TWSVMs and SVMs.

  2. Instrumentation Development for Large Scale Hypersonic Inflatable Aerodynamic Decelerator Characterization

    NASA Technical Reports Server (NTRS)

    Swanson, Gregory T.; Cassell, Alan M.

    2011-01-01

    Hypersonic Inflatable Aerodynamic Decelerator (HIAD) technology is currently being considered for multiple atmospheric entry applications as the limitations of traditional entry vehicles have been reached. The Inflatable Re-entry Vehicle Experiment (IRVE) has successfully demonstrated this technology as a viable candidate with a 3.0 m diameter vehicle sub-orbital flight. To further this technology, large scale HIADs (6.0 8.5 m) must be developed and tested. To characterize the performance of large scale HIAD technology new instrumentation concepts must be developed to accommodate the flexible nature inflatable aeroshell. Many of the concepts that are under consideration for the HIAD FY12 subsonic wind tunnel test series are discussed below.

  3. Long gradient mode and large-scale structure observables

    NASA Astrophysics Data System (ADS)

    Allahyari, Alireza; Firouzjaee, Javad T.

    2017-03-01

    We extend the study of long-mode perturbations to other large-scale observables such as cosmic rulers, galaxy-number counts, and halo bias. The long mode is a pure gradient mode that is still outside an observer's horizon. We insist that gradient-mode effects on observables vanish. It is also crucial that the expressions for observables are relativistic. This allows us to show that the effects of a gradient mode on the large-scale observables vanish identically in a relativistic framework. To study the potential modulation effect of the gradient mode on halo bias, we derive a consistency condition to the first order in gradient expansion. We find that the matter variance at a fixed physical scale is not modulated by the long gradient mode perturbations when the consistency condition holds. This shows that the contribution of long gradient modes to bias vanishes in this framework.

  4. LARGE SCALE PURIFICATION OF PROTEINASES FROM CLOSTRIDIUM HISTOLYTICUM FILTRATES

    PubMed Central

    Conklin, David A.; Webster, Marion E.; Altieri, Patricia L.; Berman, Sanford; Lowenthal, Joseph P.; Gochenour, Raymond B.

    1961-01-01

    Conklin, David A. (Walter Reed Army Institute of Research, Washington, D. C.), Marion E. Webster, Patricia L. Altieri, Sanford Berman, Joseph P. Lowenthal, and Raymond B. Gochenour. Large scale purification of proteinases from Clostridium histolyticum filtrates. J. Bacteriol. 82:589–594. 1961.—A method for the large scale preparation and partial purification of Clostridium histolyticum proteinases by fractional precipitation with ammonium sulfate is described. Conditions for adequate separation and purification of the δ-proteinase and the gelatinase were obtained. Collagenase, on the other hand, was found distributed in four to five fractions and little increase in purity was achieved as compared to the crude ammonium sulfate precipitates. PMID:13880849

  5. Prototype Vector Machine for Large Scale Semi-Supervised Learning

    SciTech Connect

    Zhang, Kai; Kwok, James T.; Parvin, Bahram

    2009-04-29

    Practicaldataminingrarelyfalls exactlyinto the supervisedlearning scenario. Rather, the growing amount of unlabeled data poses a big challenge to large-scale semi-supervised learning (SSL). We note that the computationalintensivenessofgraph-based SSLarises largely from the manifold or graph regularization, which in turn lead to large models that are dificult to handle. To alleviate this, we proposed the prototype vector machine (PVM), a highlyscalable,graph-based algorithm for large-scale SSL. Our key innovation is the use of"prototypes vectors" for effcient approximation on both the graph-based regularizer and model representation. The choice of prototypes are grounded upon two important criteria: they not only perform effective low-rank approximation of the kernel matrix, but also span a model suffering the minimum information loss compared with the complete model. We demonstrate encouraging performance and appealing scaling properties of the PVM on a number of machine learning benchmark data sets.

  6. The Large Scale Synthesis of Aligned Plate Nanostructures

    NASA Astrophysics Data System (ADS)

    Zhou, Yang; Nash, Philip; Liu, Tian; Zhao, Naiqin; Zhu, Shengli

    2016-07-01

    We propose a novel technique for the large-scale synthesis of aligned-plate nanostructures that are self-assembled and self-supporting. The synthesis technique involves developing nanoscale two-phase microstructures through discontinuous precipitation followed by selective etching to remove one of the phases. The method may be applied to any alloy system in which the discontinuous precipitation transformation goes to completion. The resulting structure may have many applications in catalysis, filtering and thermal management depending on the phase selection and added functionality through chemical reaction with the retained phase. The synthesis technique is demonstrated using the discontinuous precipitation of a γ‧ phase, (Ni, Co)3Al, followed by selective dissolution of the γ matrix phase. The production of the nanostructure requires heat treatments on the order of minutes and can be performed on a large scale making this synthesis technique of great economic potential.

  7. Comparative study of large-scale nonlinear optimization methods

    SciTech Connect

    Alemzadeh, S.A.

    1987-01-01

    Solving large-scale nonlinear optimization problems has been one of the active research areas for the last twenty years. Several heuristic algorithms with codes have been developed and implemented since 1966. This study explores the motivation and basic mathematical ideas leading to the development of MINOS-1.0, GRG-2,and MINOS-5.0 algorithms and their codes. The reliability, accuracy, and complexity of the algorithms and software depend upon their use of the gradient, Jacobian, and the Hessian. MINOS-1.0 and GRG-2 incorporate all of the input and output features, while MINOS-1.0 is not able to handle the nonlinearly constrained problems, and GRG-2 is not able to handle large-scale problems, MINOS-5.0 is a robust and an efficient software that incorporates all input, output features.

  8. LARGE-SCALE MOTIONS IN THE PERSEUS GALAXY CLUSTER

    SciTech Connect

    Simionescu, A.; Werner, N.; Urban, O.; Allen, S. W.; Fabian, A. C.; Sanders, J. S.; Mantz, A.; Nulsen, P. E. J.; Takei, Y.

    2012-10-01

    By combining large-scale mosaics of ROSAT PSPC, XMM-Newton, and Suzaku X-ray observations, we present evidence for large-scale motions in the intracluster medium of the nearby, X-ray bright Perseus Cluster. These motions are suggested by several alternating and interleaved X-ray bright, low-temperature, low-entropy arcs located along the east-west axis, at radii ranging from {approx}10 kpc to over a Mpc. Thermodynamic features qualitatively similar to these have previously been observed in the centers of cool-core clusters, and were successfully modeled as a consequence of the gas sloshing/swirling motions induced by minor mergers. Our observations indicate that such sloshing/swirling can extend out to larger radii than previously thought, on scales approaching the virial radius.

  9. The CLASSgal code for relativistic cosmological large scale structure

    SciTech Connect

    Dio, Enea Di; Montanari, Francesco; Durrer, Ruth; Lesgourgues, Julien E-mail: Francesco.Montanari@unige.ch E-mail: Ruth.Durrer@unige.ch

    2013-11-01

    We present accurate and efficient computations of large scale structure observables, obtained with a modified version of the CLASS code which is made publicly available. This code includes all relativistic corrections and computes both the power spectrum C{sub ℓ}(z{sub 1},z{sub 2}) and the corresponding correlation function ξ(θ,z{sub 1},z{sub 2}) of the matter density and the galaxy number fluctuations in linear perturbation theory. For Gaussian initial perturbations, these quantities contain the full information encoded in the large scale matter distribution at the level of linear perturbation theory. We illustrate the usefulness of our code for cosmological parameter estimation through a few simple examples.

  10. Large-Scale Optimization for Bayesian Inference in Complex Systems

    SciTech Connect

    Willcox, Karen; Marzouk, Youssef

    2013-11-12

    The SAGUARO (Scalable Algorithms for Groundwater Uncertainty Analysis and Robust Optimization) Project focused on the development of scalable numerical algorithms for large-scale Bayesian inversion in complex systems that capitalize on advances in large-scale simulation-based optimization and inversion methods. The project was a collaborative effort among MIT, the University of Texas at Austin, Georgia Institute of Technology, and Sandia National Laboratories. The research was directed in three complementary areas: efficient approximations of the Hessian operator, reductions in complexity of forward simulations via stochastic spectral approximations and model reduction, and employing large-scale optimization concepts to accelerate sampling. The MIT--Sandia component of the SAGUARO Project addressed the intractability of conventional sampling methods for large-scale statistical inverse problems by devising reduced-order models that are faithful to the full-order model over a wide range of parameter values; sampling then employs the reduced model rather than the full model, resulting in very large computational savings. Results indicate little effect on the computed posterior distribution. On the other hand, in the Texas--Georgia Tech component of the project, we retain the full-order model, but exploit inverse problem structure (adjoint-based gradients and partial Hessian information of the parameter-to-observation map) to implicitly extract lower dimensional information on the posterior distribution; this greatly speeds up sampling methods, so that fewer sampling points are needed. We can think of these two approaches as ``reduce then sample'' and ``sample then reduce.'' In fact, these two approaches are complementary, and can be used in conjunction with each other. Moreover, they both exploit deterministic inverse problem structure, in the form of adjoint-based gradient and Hessian information of the underlying parameter-to-observation map, to achieve their

  11. Turbulent amplification of large-scale magnetic fields

    NASA Technical Reports Server (NTRS)

    Montgomery, D.; Chen, H.

    1984-01-01

    Previously-introduced methods for analytically estimating the effects of small-scale turbulent fluctuations on large-scale dynamics are extended to fully three-dimensional magnetohydrodynamics. The problem becomes algebraically tractable in the presence of sufficiently large spectral gaps. The calculation generalizes 'alpha dynamo' calculations, except that the velocity fluctuations and magnetic fluctuations are treated on an independent and equal footing. Earlier expressions for the 'alpha coefficients' of turbulent magnetic field amplification are recovered as a special case.

  12. Concurrent Programming Using Actors: Exploiting Large-Scale Parallelism,

    DTIC Science & Technology

    1985-10-07

    ORGANIZATION NAME AND ADDRESS 10. PROGRAM ELEMENT. PROJECT. TASK* Artificial Inteligence Laboratory AREA Is WORK UNIT NUMBERS 545 Technology Square...D-R162 422 CONCURRENT PROGRMMIZNG USING f"OS XL?ITP TEH l’ LARGE-SCALE PARALLELISH(U) NASI AC E Al CAMBRIDGE ARTIFICIAL INTELLIGENCE L. G AGHA ET AL...RESOLUTION TEST CHART N~ATIONAL BUREAU OF STANDA.RDS - -96 A -E. __ _ __ __’ .,*- - -- •. - MASSACHUSETTS INSTITUTE OF TECHNOLOGY ARTIFICIAL

  13. Host Immunity via Mutable Virtualized Large-Scale Network Containers

    DTIC Science & Technology

    2016-07-25

    migrate to different IP addresses multiple 6mes. We implement a virtual machine based system prototype and evaluate it using state-of-the-a1t scanning...entire !Pv4 address space within 5 Host Immunity via Mutable Virtualized Large-Scale Network Containers 45 minutes from a single machine . Second, when...that the attacker will be trapped into one decoy instead of the real server. We implement a virtual machine (VM)-based prototype that integrates

  14. Developing and Understanding Methods for Large Scale Nonlinear Optimization

    DTIC Science & Technology

    2001-12-01

    development of new algorithms for large-scale uncon- strained and constrained optimization problems, including limited-memory methods for problems with...analysis of tensor and SQP methods for singular con- strained optimization", to appear in SIAM Journal on Optimization. Published in peer-reviewed...Mathematica, Vol III, Journal der Deutschen Mathematiker-Vereinigung, 1998. S. Crivelli, B. Bader, R. Byrd, E. Eskow, V. Lamberti , R.Schnabel and T

  15. Wiggly cosmic strings, neutrinos and large-scale structure

    NASA Astrophysics Data System (ADS)

    Vachaspati, Tanmay

    1993-04-01

    We discuss the cosmic string scenario of large-scale structure formation in light of the result that the strings are not smooth but instead have a lot of sub-structure or wiggles on them. It appears from the results of Albrecht and Stebbins that the scenario works best if the universe is dominated by massive neutrinos or some other form of hot dark matter. Some unique features of the scenario, such as the generation of primordial magnetic fields, are also described.

  16. Analysis plan for 1985 large-scale tests. Technical report

    SciTech Connect

    McMullan, F.W.

    1983-01-01

    The purpose of this effort is to assist DNA in planning for large-scale (upwards of 5000 tons) detonations of conventional explosives in the 1985 and beyond time frame. Primary research objectives were to investigate potential means to increase blast duration and peak pressures. This report identifies and analyzes several candidate explosives. It examines several charge designs and identifies advantages and disadvantages of each. Other factors including terrain and multiburst techniques are addressed as are test site considerations.

  17. Multimodel Design of Large Scale Systems with Multiple Decision Makers.

    DTIC Science & Technology

    1982-08-01

    virtue. 5- , Lead me from darkneu to light. - Lead me from death to eternal Life. ( Vedic Payer) p. I, MULTIMODEL DESIGN OF LARGE SCALE SYSTEMS WITH...guidance during the course of *: this research . He would also like to thank Professors W. R. Perkins, P. V. Kokotovic, T. Basar, and T. N. Trick for...thesis concludes with Chapter 7 where we summarize the results obtained, outline the main contributions, and indicate directions for future research . 7- I

  18. Critical Problems in Very Large Scale Computer Systems

    DTIC Science & Technology

    1990-03-31

    MAY I i9cu( CRITICAL PROBLEMS IN VERY LARGE SCALE COMPUTER SYSTEMS Semiannual Technical Report for the Period October 1, 1989 to...suitability for supporting popular models of parallel computation . During the reporting period they have developed an interface definition. A simulator has...queries in computational geometry . Range queries are a fundamental problem in computational geometry with applications to computer graphics and

  19. Supporting large scale applications on networks of workstations

    NASA Technical Reports Server (NTRS)

    Cooper, Robert; Birman, Kenneth P.

    1989-01-01

    Distributed applications on networks of workstations are an increasingly common way to satisfy computing needs. However, existing mechanisms for distributed programming exhibit poor performance and reliability as application size increases. Extension of the ISIS distributed programming system to support large scale distributed applications by providing hierarchical process groups is discussed. Incorporation of hierarchy in the program structure and exploitation of this to limit the communication and storage required in any one component of the distributed system is examined.

  20. Large Scale Airflow Perturbations and Resultant Dune Dynamics

    NASA Astrophysics Data System (ADS)

    Smith, Alexander B.; Jackson, Derek W. T.; Cooper, J. Andrew G.; Beyers, Meiring

    2017-04-01

    Large-scale atmospheric turbulence can have a large impact on the regional wind regime effecting dune environments. Depending on the incident angle of mesoscale airflow, local topographic steering can also alter wind conditions and subsequent aeolian dynamics. This research analyses the influence of large-scale airflow perturbations occurring at the Maspalomas dunefield located on the southern coast of Gran Canaria, Spain. These perturbations in turn significantly influence the morphometry and migration rates of barchan dunes, monitored at the study site through time. The main meteorological station on Gran Canaria records highly uni-modal NNE wind conditions; however, simultaneously measured winds are highly variable around the island, showing a high degree of steering. Large Eddy Simulations (LES) were used to identify large-scale airflow perturbations around the island of Gran Canaria during NNE, N, and NNW incident flow directions. Results indicate that approaching surface airflow bifurcates around the island's coastline before converging at the lee coast. Winds in areas located around the islands lateral coast are controlled by these diverging flow patterns, whereas lee-side areas are influenced primarily by the islands upwind canyon topography leading to highly turbulent flow. Characteristic turbulent eddies show a complex wind environment at Maspalomas with winds diverging-converging up to 180° between the eastern and western sections of the dunefield. Multi-directional flow conditions lead to highly altered dune dynamics including the production of temporary slip faces on the stoss slopes, rapid reduction in crest height and slope length, and development of bi-crested dunes. This indicates a distinct bi-modality of airflow conditions that control the geomorphic evolution of the dunefield. Variability in wind conditions is not evident in the long-term meteorological records on the island, indicating the significance of large scale atmospheric steering on

  1. A Holistic Management Architecture for Large-Scale Adaptive Networks

    DTIC Science & Technology

    2007-09-01

    MANAGEMENT ARCHITECTURE FOR LARGE-SCALE ADAPTIVE NETWORKS by Michael R. Clement September 2007 Thesis Advisor: Alex Bordetsky Second Reader...TECHNOLOGY MANAGEMENT from the NAVAL POSTGRADUATE SCHOOL September 2007 Author: Michael R. Clement Approved by: Dr. Alex ...achieve in life is by His will. Ad Majorem Dei Gloriam. To my parents, my family, and Caitlin: For supporting me, listening to me when I got

  2. A Cloud Computing Platform for Large-Scale Forensic Computing

    NASA Astrophysics Data System (ADS)

    Roussev, Vassil; Wang, Liqiang; Richard, Golden; Marziale, Lodovico

    The timely processing of massive digital forensic collections demands the use of large-scale distributed computing resources and the flexibility to customize the processing performed on the collections. This paper describes MPI MapReduce (MMR), an open implementation of the MapReduce processing model that outperforms traditional forensic computing techniques. MMR provides linear scaling for CPU-intensive processing and super-linear scaling for indexing-related workloads.

  3. Large-Scale Weather Disturbances in Mars’ Southern Extratropics

    NASA Astrophysics Data System (ADS)

    Hollingsworth, Jeffery L.; Kahre, Melinda A.

    2015-11-01

    Between late autumn and early spring, Mars’ middle and high latitudes within its atmosphere support strong mean thermal gradients between the tropics and poles. Observations from both the Mars Global Surveyor (MGS) and Mars Reconnaissance Orbiter (MRO) indicate that this strong baroclinicity supports intense, large-scale eastward traveling weather systems (i.e., transient synoptic-period waves). These extratropical weather disturbances are key components of the global circulation. Such wave-like disturbances act as agents in the transport of heat and momentum, and generalized scalar/tracer quantities (e.g., atmospheric dust, water-vapor and ice clouds). The character of large-scale, traveling extratropical synoptic-period disturbances in Mars' southern hemisphere during late winter through early spring is investigated using a moderately high-resolution Mars global climate model (Mars GCM). This Mars GCM imposes interactively lifted and radiatively active dust based on a threshold value of the surface stress. The model exhibits a reasonable "dust cycle" (i.e., globally averaged, a dustier atmosphere during southern spring and summer occurs). Compared to their northern-hemisphere counterparts, southern synoptic-period weather disturbances and accompanying frontal waves have smaller meridional and zonal scales, and are far less intense. Influences of the zonally asymmetric (i.e., east-west varying) topography on southern large-scale weather are examined. Simulations that adapt Mars’ full topography compared to simulations that utilize synthetic topographies emulating key large-scale features of the southern middle latitudes indicate that Mars’ transient barotropic/baroclinic eddies are highly influenced by the great impact basins of this hemisphere (e.g., Argyre and Hellas). The occurrence of a southern storm zone in late winter and early spring appears to be anchored to the western hemisphere via orographic influences from the Tharsis highlands, and the Argyre

  4. The large-scale anisotropy with the PAMELA calorimeter

    NASA Astrophysics Data System (ADS)

    Karelin, A.; Adriani, O.; Barbarino, G.; Bazilevskaya, G.; Bellotti, R.; Boezio, M.; Bogomolov, E.; Bongi, M.; Bonvicini, V.; Bottai, S.; Bruno, A.; Cafagna, F.; Campana, D.; Carbone, R.; Carlson, P.; Casolino, M.; Castellini, G.; De Donato, C.; De Santis, C.; De Simone, N.; Di Felice, V.; Formato, V.; Galper, A.; Koldashov, S.; Koldobskiy, S.; Krut'kov, S.; Kvashnin, A.; Leonov, A.; Malakhov, V.; Marcelli, L.; Martucci, M.; Mayorov, A.; Menn, W.; Mergé, M.; Mikhailov, V.; Mocchiutti, E.; Monaco, A.; Mori, N.; Munini, R.; Osteria, G.; Palma, F.; Panico, B.; Papini, P.; Pearce, M.; Picozza, P.; Ricci, M.; Ricciarini, S.; Sarkar, R.; Simon, M.; Scotti, V.; Sparvoli, R.; Spillantini, P.; Stozhkov, Y.; Vacchi, A.; Vannuccini, E.; Vasilyev, G.; Voronov, S.; Yurkin, Y.; Zampa, G.; Zampa, N.

    2015-10-01

    The large-scale anisotropy (or the so-called star-diurnal wave) has been studied using the calorimeter of the space-born experiment PAMELA. The cosmic ray anisotropy has been obtained for the Southern and Northern hemispheres simultaneously in the equatorial coordinate system for the time period 2006-2014. The dipole amplitude and phase have been measured for energies 1-20 TeV n-1.

  5. Space transportation booster engine thrust chamber technology, large scale injector

    NASA Technical Reports Server (NTRS)

    Schneider, J. A.

    1993-01-01

    The objective of the Large Scale Injector (LSI) program was to deliver a 21 inch diameter, 600,000 lbf thrust class injector to NASA/MSFC for hot fire testing. The hot fire test program would demonstrate the feasibility and integrity of the full scale injector, including combustion stability, chamber wall compatibility (thermal management), and injector performance. The 21 inch diameter injector was delivered in September of 1991.

  6. Large Scale Density Estimation of Blue and Fin Whales (LSD)

    DTIC Science & Technology

    2014-09-30

    1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Large Scale Density Estimation of Blue and Fin Whales ...estimating blue and fin whale density that is effective over large spatial scales and is designed to cope with spatial variation in animal density utilizing...a density estimation methodology for quantifying blue and fin whale abundance from passive acoustic data recorded on sparse hydrophone arrays in the

  7. Relic vector field and CMB large scale anomalies

    SciTech Connect

    Chen, Xingang; Wang, Yi E-mail: yw366@cam.ac.uk

    2014-10-01

    We study the most general effects of relic vector fields on the inflationary background and density perturbations. Such effects are observable if the number of inflationary e-folds is close to the minimum requirement to solve the horizon problem. We show that this can potentially explain two CMB large scale anomalies: the quadrupole-octopole alignment and the quadrupole power suppression. We discuss its effect on the parity anomaly. We also provide analytical template for more detailed data comparison.

  8. Large-scale controls on convective extreme precipitation

    NASA Astrophysics Data System (ADS)

    Loriaux, Jessica M.; Lenderink, Geert; Pier Siebesma, A.

    2017-04-01

    The influence of large-scale conditions on extreme precipitation is not yet understood well enough. We will present the results of Loriaux et al. (2017), in which we investigate the role of large-scale dynamics and environmental conditions on precipitation and on the precipitation response to climate change. To this end, we have set up a composite LES case for convective precipitation using strong large-scale forcing based on idealized profiles for the highest 10 percentiles of peak intensities over the Netherlands, as described by Loriaux et al. (2016). In this setting, we have performed sensitivity analyses for atmospheric stability, large-scale moisture convergence, and relative humidity, and compared present-day climate to a warmer future climate. The results suggest that amplification of the moisture convergence and destabilization of the atmosphere both lead to an increase in precipitation, but due to different effects; Atmospheric stability mainly influences the precipitation intensity, while the moisture convergence mainly controls the precipitation area fraction. Extreme precipitation intensities show qualitatively similar sensitivities to atmospheric stability and moisture convergence. Precipitation increases with RH due to an increase in area fraction, despite a decrease in intensity. The precipitation response to the climate perturbation shows a stronger response for the precipitation intensity than the overall precipitation, with no clear dependency of changes in atmospheric stability, moisture convergence and relative humidity. The difference in response between the precipitation intensity and overall precipitation is caused by a decrease in the precipitation area fraction from present-day to future climate. In other words, our climate perturbation indicates that with warming, it will rain more intensely but in less places. Loriaux, J.M., G. Lenderink, and A.P. Siebesma, 2016, doi: 10.1002/2015JD024274 Loriaux, J.M., G. Lenderink, and A.P. Siebesma

  9. On a Game of Large-Scale Projects Competition

    NASA Astrophysics Data System (ADS)

    Nikonov, Oleg I.; Medvedeva, Marina A.

    2009-09-01

    The paper is devoted to game-theoretical control problems motivated by economic decision making situations arising in realization of large-scale projects, such as designing and putting into operations the new gas or oil pipelines. A non-cooperative two player game is considered with payoff functions of special type for which standard existence theorems and algorithms for searching Nash equilibrium solutions are not applicable. The paper is based on and develops the results obtained in [1]-[5].

  10. Measuring large scale space perception in literary texts

    NASA Astrophysics Data System (ADS)

    Rossi, Paolo

    2007-07-01

    A center and radius of “perception” (in the sense of environmental cognition) can be formally associated with a written text and operationally defined. Simple algorithms for their computation are presented, and indicators for anisotropy in large scale space perception are introduced. The relevance of these notions for the analysis of literary and historical records is briefly discussed and illustrated with an example taken from medieval historiography.

  11. Semantic Concept Discovery for Large Scale Zero Shot Event Detection

    DTIC Science & Technology

    2015-07-25

    NO. 0704-0188 3. DATES COVERED (From - To) - UU UU UU UU 18-08-2015 Approved for public release; distribution is unlimited. Semantic Concept Discovery ...Office P.O. Box 12211 Research Triangle Park, NC 27709-2211 zero shot event detection, semantic concept discovery REPORT DOCUMENTATION PAGE 11...Mellon University 5000 Forbes Avenue Pittsburgh, PA 15213 -3815 ABSTRACT Semantic Concept Discovery for Large-Scale Zero-Shot Event Detection Report

  12. Large-scale Alfvén vortices

    SciTech Connect

    Onishchenko, O. G.; Horton, W.; Scullion, E.; Fedun, V.

    2015-12-15

    The new type of large-scale vortex structures of dispersionless Alfvén waves in collisionless plasma is investigated. It is shown that Alfvén waves can propagate in the form of Alfvén vortices of finite characteristic radius and characterised by magnetic flux ropes carrying orbital angular momentum. The structure of the toroidal and radial velocity, fluid and magnetic field vorticity, the longitudinal electric current in the plane orthogonal to the external magnetic field are discussed.

  13. The Phoenix series large scale LNG pool fire experiments.

    SciTech Connect

    Simpson, Richard B.; Jensen, Richard Pearson; Demosthenous, Byron; Luketa, Anay Josephine; Ricks, Allen Joseph; Hightower, Marion Michael; Blanchat, Thomas K.; Helmick, Paul H.; Tieszen, Sheldon Robert; Deola, Regina Anne; Mercier, Jeffrey Alan; Suo-Anttila, Jill Marie; Miller, Timothy J.

    2010-12-01

    The increasing demand for natural gas could increase the number and frequency of Liquefied Natural Gas (LNG) tanker deliveries to ports across the United States. Because of the increasing number of shipments and the number of possible new facilities, concerns about the potential safety of the public and property from an accidental, and even more importantly intentional spills, have increased. While improvements have been made over the past decade in assessing hazards from LNG spills, the existing experimental data is much smaller in size and scale than many postulated large accidental and intentional spills. Since the physics and hazards from a fire change with fire size, there are concerns about the adequacy of current hazard prediction techniques for large LNG spills and fires. To address these concerns, Congress funded the Department of Energy (DOE) in 2008 to conduct a series of laboratory and large-scale LNG pool fire experiments at Sandia National Laboratories (Sandia) in Albuquerque, New Mexico. This report presents the test data and results of both sets of fire experiments. A series of five reduced-scale (gas burner) tests (yielding 27 sets of data) were conducted in 2007 and 2008 at Sandia's Thermal Test Complex (TTC) to assess flame height to fire diameter ratios as a function of nondimensional heat release rates for extrapolation to large-scale LNG fires. The large-scale LNG pool fire experiments were conducted in a 120 m diameter pond specially designed and constructed in Sandia's Area III large-scale test complex. Two fire tests of LNG spills of 21 and 81 m in diameter were conducted in 2009 to improve the understanding of flame height, smoke production, and burn rate and therefore the physics and hazards of large LNG spills and fires.

  14. Large-scale quantization from local correlations in space plasmas

    NASA Astrophysics Data System (ADS)

    Livadiotis, George; McComas, David J.

    2014-05-01

    This study examines the large-scale quantization that can characterize the phase space of certain physical systems. Plasmas are such systems where large-scale quantization, ħ*, is caused by Debye shielding that structures correlations between particles. The value of ħ* is constant—some 12 orders of magnitude larger than the Planck constant—across a wide range of space plasmas, from the solar wind in the inner heliosphere to the distant plasma in the inner heliosheath and the local interstellar medium. This paper develops the foundation and advances the understanding of the concept of plasma quantization; in particular, we (i) show the analogy of plasma to Planck quantization, (ii) show the key points of plasma quantization, (iii) construct some basic quantum mechanical concepts for the large-scale plasma quantization, (iv) investigate the correlation between plasma parameters that implies plasma quantization, when it is approximated by a relation between the magnetosonic energy and the plasma frequency, (v) analyze typical space plasmas throughout the heliosphere and show the constancy of plasma quantization over many orders of magnitude in plasma parameters, (vi) analyze Advanced Composition Explorer (ACE) solar wind measurements to develop another measurement of the value of ħ*, and (vii) apply plasma quantization to derive unknown plasma parameters when some key observable is missing.

  15. Large-scale investigation of genomic markers for severe periodontitis.

    PubMed

    Suzuki, Asami; Ji, Guijin; Numabe, Yukihiro; Ishii, Keisuke; Muramatsu, Masaaki; Kamoi, Kyuichi

    2004-09-01

    The purpose of the present study was to investigate the genomic markers for periodontitis, using large-scale single-nucleotide polymorphism (SNP) association studies comparing healthy volunteers and patients with periodontitis. Genomic DNA was obtained from 19 healthy volunteers and 22 patients with severe periodontitis, all of whom were Japanese. The subjects were genotyped at 637 SNPs in 244 genes on a large scale, using the TaqMan polymerase chain reaction (PCR) system. Statistically significant differences in allele and genotype frequencies were analyzed with Fisher's exact test. We found statistically significant differences (P < 0.01) between the healthy volunteers and patients with severe periodontitis in the following genes; gonadotropin-releasing hormone 1 (GNRH1), phosphatidylinositol 3-kinase regulatory 1 (PIK3R1), dipeptidylpeptidase 4 (DPP4), fibrinogen-like 2 (FGL2), and calcitonin receptor (CALCR). These results suggest that SNPs in the GNRH1, PIK3R1, DPP4, FGL2, and CALCR genes are genomic markers for severe periodontitis. Our findings indicate the necessity of analyzing SNPs in genes on a large scale (i.e., genome-wide approach), to identify genomic markers for periodontitis.

  16. Geospatial Optimization of Siting Large-Scale Solar Projects

    SciTech Connect

    Macknick, J.; Quinby, T.; Caulfield, E.; Gerritsen, M.; Diffendorfer, J.; Haines, S.

    2014-03-01

    Recent policy and economic conditions have encouraged a renewed interest in developing large-scale solar projects in the U.S. Southwest. However, siting large-scale solar projects is complex. In addition to the quality of the solar resource, solar developers must take into consideration many environmental, social, and economic factors when evaluating a potential site. This report describes a proof-of-concept, Web-based Geographical Information Systems (GIS) tool that evaluates multiple user-defined criteria in an optimization algorithm to inform discussions and decisions regarding the locations of utility-scale solar projects. Existing siting recommendations for large-scale solar projects from governmental and non-governmental organizations are not consistent with each other, are often not transparent in methods, and do not take into consideration the differing priorities of stakeholders. The siting assistance GIS tool we have developed improves upon the existing siting guidelines by being user-driven, transparent, interactive, capable of incorporating multiple criteria, and flexible. This work provides the foundation for a dynamic siting assistance tool that can greatly facilitate siting decisions among multiple stakeholders.

  17. Large-scale data mining pilot project in human genome

    SciTech Connect

    Musick, R.; Fidelis, R.; Slezak, T.

    1997-05-01

    This whitepaper briefly describes a new, aggressive effort in large- scale data Livermore National Labs. The implications of `large- scale` will be clarified Section. In the short term, this effort will focus on several @ssion-critical questions of Genome project. We will adapt current data mining techniques to the Genome domain, to quantify the accuracy of inference results, and lay the groundwork for a more extensive effort in large-scale data mining. A major aspect of the approach is that we will be fully-staffed data warehousing effort in the human Genome area. The long term goal is strong applications- oriented research program in large-@e data mining. The tools, skill set gained will be directly applicable to a wide spectrum of tasks involving a for large spatial and multidimensional data. This includes applications in ensuring non-proliferation, stockpile stewardship, enabling Global Ecology (Materials Database Industrial Ecology), advancing the Biosciences (Human Genome Project), and supporting data for others (Battlefield Management, Health Care).

  18. A model of plasma heating by large-scale flow

    NASA Astrophysics Data System (ADS)

    Pongkitiwanichakul, P.; Cattaneo, F.; Boldyrev, S.; Mason, J.; Perez, J. C.

    2015-12-01

    In this work, we study the process of energy dissipation triggered by a slow large-scale motion of a magnetized conducting fluid. Our consideration is motivated by the problem of heating the solar corona, which is believed to be governed by fast reconnection events set off by the slow motion of magnetic field lines anchored in the photospheric plasma. To elucidate the physics governing the disruption of the imposed laminar motion and the energy transfer to small scales, we propose a simplified model where the large-scale motion of magnetic field lines is prescribed not at the footpoints but rather imposed volumetrically. As a result, the problem can be treated numerically with an efficient, highly accurate spectral method, allowing us to use a resolution and statistical ensemble exceeding those of the previous work. We find that, even though the large-scale deformations are slow, they eventually lead to reconnection events that drive a turbulent state at smaller scales. The small-scale turbulence displays many of the universal features of field-guided magnetohydrodynamic turbulence like a well-developed inertial range spectrum. Based on these observations, we construct a phenomenological model that gives the scalings of the amplitude of the fluctuations and the energy-dissipation rate as functions of the input parameters. We find good agreement between the numerical results and the predictions of the model.

  19. Large-scale biodiversity patterns in freshwater phytoplankton.

    PubMed

    Stomp, Maayke; Huisman, Jef; Mittelbach, Gary G; Litchman, Elena; Klausmeier, Christopher A

    2011-11-01

    Our planet shows striking gradients in the species richness of plants and animals, from high biodiversity in the tropics to low biodiversity in polar and high-mountain regions. Recently, similar patterns have been described for some groups of microorganisms, but the large-scale biogeographical distribution of freshwater phytoplankton diversity is still largely unknown. We examined the species diversity of freshwater phytoplankton sampled from 540 lakes and reservoirs distributed across the continental United States and found strong latitudinal, longitudinal, and altitudinal gradients in phytoplankton biodiversity, demonstrating that microorganisms can show substantial geographic variation in biodiversity. Detailed analysis using structural equation models indicated that these large-scale biodiversity gradients in freshwater phytoplankton diversity were mainly driven by local environmental factors, although there were residual direct effects of latitude, longitude, and altitude as well. Specifically, we found that phytoplankton species richness was an increasing saturating function of lake chlorophyll a concentration, increased with lake surface area and possibly increased with water temperature, resembling effects of productivity, habitat area, and temperature on diversity patterns commonly observed for macroorganisms. In turn, these local environmental factors varied along latitudinal, longitudinal, and altitudinal gradients. These results imply that changes in land use or climate that affect these local environmental factors are likely to have major impacts on large-scale biodiversity patterns of freshwater phytoplankton.

  20. Homogenization of Large-Scale Movement Models in Ecology

    USGS Publications Warehouse

    Garlick, M.J.; Powell, J.A.; Hooten, M.B.; McFarlane, L.R.

    2011-01-01

    A difficulty in using diffusion models to predict large scale animal population dispersal is that individuals move differently based on local information (as opposed to gradients) in differing habitat types. This can be accommodated by using ecological diffusion. However, real environments are often spatially complex, limiting application of a direct approach. Homogenization for partial differential equations has long been applied to Fickian diffusion (in which average individual movement is organized along gradients of habitat and population density). We derive a homogenization procedure for ecological diffusion and apply it to a simple model for chronic wasting disease in mule deer. Homogenization allows us to determine the impact of small scale (10-100 m) habitat variability on large scale (10-100 km) movement. The procedure generates asymptotic equations for solutions on the large scale with parameters defined by small-scale variation. The simplicity of this homogenization procedure is striking when compared to the multi-dimensional homogenization procedure for Fickian diffusion,and the method will be equally straightforward for more complex models. ?? 2010 Society for Mathematical Biology.

  1. Channel capacity of next generation large scale MIMO systems

    NASA Astrophysics Data System (ADS)

    Alshammari, A.; Albdran, S.; Matin, M.

    2016-09-01

    Information rate that can be transferred over a given bandwidth is limited by the information theory. Capacity depends on many factors such as the signal to noise ratio (SNR), channel state information (CSI) and the spatial correlation in the propagation environment. It is very important to increase spectral efficiency in order to meet the growing demand for wireless services. Thus, Multiple input multiple output (MIMO) technology has been developed and applied in most of the wireless standards and it has been very successful in increasing capacity and reliability. As the demand is still increasing, attention now is shifting towards large scale multiple input multiple output (MIMO) which has a potential of bringing orders of magnitude of improvement in spectral and energy efficiency. It has been shown that users channels decorrelate after increasing the number of antennas. As a result, inter-user interference can be avoided since energy can be focused on precise directions. This paper investigates the limits of channel capacity for large scale MIMO. We study the relation between spectral efficiency and the number of antenna N. We use time division duplex (TDD) system in order to obtain CSI using training sequence in the uplink. The same CSI is used for the downlink because the channel is reciprocal. Spectral efficiency is measured for channel model that account for small scale fading while ignoring the effect of large scale fading. It is shown the spectral efficiency can be improved significantly when compared to single antenna systems in ideal circumstances.

  2. Sparse approximation through boosting for learning large scale kernel machines.

    PubMed

    Sun, Ping; Yao, Xin

    2010-06-01

    Recently, sparse approximation has become a preferred method for learning large scale kernel machines. This technique attempts to represent the solution with only a subset of original data points also known as basis vectors, which are usually chosen one by one with a forward selection procedure based on some selection criteria. The computational complexity of several resultant algorithms scales as O(NM(2)) in time and O(NM) in memory, where N is the number of training points and M is the number of basis vectors as well as the steps of forward selection. For some large scale data sets, to obtain a better solution, we are sometimes required to include more basis vectors, which means that M is not trivial in this situation. However, the limited computational resource (e.g., memory) prevents us from including too many vectors. To handle this dilemma, we propose to add an ensemble of basis vectors instead of only one at each forward step. The proposed method, closely related to gradient boosting, could decrease the required number M of forward steps significantly and thus a large fraction of computational cost is saved. Numerical experiments on three large scale regression tasks and a classification problem demonstrate the effectiveness of the proposed approach.

  3. Dispersal Mutualism Incorporated into Large-Scale, Infrequent Disturbances.

    PubMed

    Parker, V Thomas

    2015-01-01

    Because of their influence on succession and other community interactions, large-scale, infrequent natural disturbances also should play a major role in mutualistic interactions. Using field data and experiments, I test whether mutualisms have been incorporated into large-scale wildfire by whether the outcomes of a mutualism depend on disturbance. In this study a seed dispersal mutualism is shown to depend on infrequent, large-scale disturbances. A dominant shrubland plant (Arctostaphylos species) produces seeds that make up a persistent soil seed bank and requires fire to germinate. In post-fire stands, I show that seedlings emerging from rodent caches dominate sites experiencing higher fire intensity. Field experiments show that rodents (Perimyscus californicus, P. boylii) do cache Arctostaphylos fruit and bury most seed caches to a sufficient depth to survive a killing heat pulse that a fire might drive into the soil. While the rodent dispersal and caching behavior itself has not changed compared to other habitats, the environmental transformation caused by wildfire converts the caching burial of seed from a dispersal process to a plant fire adaptive trait, and provides the context for stimulating subsequent life history evolution in the plant host.

  4. Line segment extraction for large scale unorganized point clouds

    NASA Astrophysics Data System (ADS)

    Lin, Yangbin; Wang, Cheng; Cheng, Jun; Chen, Bili; Jia, Fukai; Chen, Zhonggui; Li, Jonathan

    2015-04-01

    Line segment detection in images is already a well-investigated topic, although it has received considerably less attention in 3D point clouds. Benefiting from current LiDAR devices, large-scale point clouds are becoming increasingly common. Most human-made objects have flat surfaces. Line segments that occur where pairs of planes intersect give important information regarding the geometric content of point clouds, which is especially useful for automatic building reconstruction and segmentation. This paper proposes a novel method that is capable of accurately extracting plane intersection line segments from large-scale raw scan points. The 3D line-support region, namely, a point set near a straight linear structure, is extracted simultaneously. The 3D line-support region is fitted by our Line-Segment-Half-Planes (LSHP) structure, which provides a geometric constraint for a line segment, making the line segment more reliable and accurate. We demonstrate our method on the point clouds of large-scale, complex, real-world scenes acquired by LiDAR devices. We also demonstrate the application of 3D line-support regions and their LSHP structures on urban scene abstraction.

  5. [A large-scale accident in Alpine terrain].

    PubMed

    Wildner, M; Paal, P

    2015-02-01

    Due to the geographical conditions, large-scale accidents amounting to mass casualty incidents (MCI) in Alpine terrain regularly present rescue teams with huge challenges. Using an example incident, specific conditions and typical problems associated with such a situation are presented. The first rescue team members to arrive have the elementary tasks of qualified triage and communication to the control room, which is required to dispatch the necessary additional support. Only with a clear "concept", to which all have to adhere, can the subsequent chaos phase be limited. In this respect, a time factor confounded by adverse weather conditions or darkness represents enormous pressure. Additional hazards are frostbite and hypothermia. If priorities can be established in terms of urgency, then treatment and procedure algorithms have proven successful. For evacuation of causalities, a helicopter should be strived for. Due to the low density of hospitals in Alpine regions, it is often necessary to distribute the patients over a wide area. Rescue operations in Alpine terrain have to be performed according to the particular conditions and require rescue teams to have specific knowledge and expertise. The possibility of a large-scale accident should be considered when planning events. With respect to optimization of rescue measures, regular training and exercises are rational, as is the analysis of previous large-scale Alpine accidents.

  6. Large scale structure in universes dominated by cold dark matter

    NASA Technical Reports Server (NTRS)

    Bond, J. Richard

    1986-01-01

    The theory of Gaussian random density field peaks is applied to a numerical study of the large-scale structure developing from adiabatic fluctuations in models of biased galaxy formation in universes with Omega = 1, h = 0.5 dominated by cold dark matter (CDM). The angular anisotropy of the cross-correlation function demonstrates that the far-field regions of cluster-scale peaks are asymmetric, as recent observations indicate. These regions will generate pancakes or filaments upon collapse. One-dimensional singularities in the large-scale bulk flow should arise in these CDM models, appearing as pancakes in position space. They are too rare to explain the CfA bubble walls, but pancakes that are just turning around now are sufficiently abundant and would appear to be thin walls normal to the line of sight in redshift space. Large scale streaming velocities are significantly smaller than recent observations indicate. To explain the reported 700 km/s coherent motions, mass must be significantly more clustered than galaxies with a biasing factor of less than 0.4 and a nonlinear redshift at cluster scales greater than one for both massive neutrino and cold models.

  7. Learning Short Binary Codes for Large-scale Image Retrieval.

    PubMed

    Liu, Li; Yu, Mengyang; Shao, Ling

    2017-03-01

    Large-scale visual information retrieval has become an active research area in this big data era. Recently, hashing/binary coding algorithms prove to be effective for scalable retrieval applications. Most existing hashing methods require relatively long binary codes (i.e., over hundreds of bits, sometimes even thousands of bits) to achieve reasonable retrieval accuracies. However, for some realistic and unique applications, such as on wearable or mobile devices, only short binary codes can be used for efficient image retrieval due to the limitation of computational resources or bandwidth on these devices. In this paper, we propose a novel unsupervised hashing approach called min-cost ranking (MCR) specifically for learning powerful short binary codes (i.e., usually the code length shorter than 100 b) for scalable image retrieval tasks. By exploring the discriminative ability of each dimension of data, MCR can generate one bit binary code for each dimension and simultaneously rank the discriminative separability of each bit according to the proposed cost function. Only top-ranked bits with minimum cost-values are then selected and grouped together to compose the final salient binary codes. Extensive experimental results on large-scale retrieval demonstrate that MCR can achieve comparative performance as the state-of-the-art hashing algorithms but with significantly shorter codes, leading to much faster large-scale retrieval.

  8. Robust regression for large-scale neuroimaging studies.

    PubMed

    Fritsch, Virgile; Da Mota, Benoit; Loth, Eva; Varoquaux, Gaël; Banaschewski, Tobias; Barker, Gareth J; Bokde, Arun L W; Brühl, Rüdiger; Butzek, Brigitte; Conrod, Patricia; Flor, Herta; Garavan, Hugh; Lemaitre, Hervé; Mann, Karl; Nees, Frauke; Paus, Tomas; Schad, Daniel J; Schümann, Gunter; Frouin, Vincent; Poline, Jean-Baptiste; Thirion, Bertrand

    2015-05-01

    Multi-subject datasets used in neuroimaging group studies have a complex structure, as they exhibit non-stationary statistical properties across regions and display various artifacts. While studies with small sample sizes can rarely be shown to deviate from standard hypotheses (such as the normality of the residuals) due to the poor sensitivity of normality tests with low degrees of freedom, large-scale studies (e.g. >100 subjects) exhibit more obvious deviations from these hypotheses and call for more refined models for statistical inference. Here, we demonstrate the benefits of robust regression as a tool for analyzing large neuroimaging cohorts. First, we use an analytic test based on robust parameter estimates; based on simulations, this procedure is shown to provide an accurate statistical control without resorting to permutations. Second, we show that robust regression yields more detections than standard algorithms using as an example an imaging genetics study with 392 subjects. Third, we show that robust regression can avoid false positives in a large-scale analysis of brain-behavior relationships with over 1500 subjects. Finally we embed robust regression in the Randomized Parcellation Based Inference (RPBI) method and demonstrate that this combination further improves the sensitivity of tests carried out across the whole brain. Altogether, our results show that robust procedures provide important advantages in large-scale neuroimaging group studies. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Reliability assessment for components of large scale photovoltaic systems

    NASA Astrophysics Data System (ADS)

    Ahadi, Amir; Ghadimi, Noradin; Mirabbasi, Davar

    2014-10-01

    Photovoltaic (PV) systems have significantly shifted from independent power generation systems to a large-scale grid-connected generation systems in recent years. The power output of PV systems is affected by the reliability of various components in the system. This study proposes an analytical approach to evaluate the reliability of large-scale, grid-connected PV systems. The fault tree method with an exponential probability distribution function is used to analyze the components of large-scale PV systems. The system is considered in the various sequential and parallel fault combinations in order to find all realistic ways in which the top or undesired events can occur. Additionally, it can identify areas that the planned maintenance should focus on. By monitoring the critical components of a PV system, it is possible not only to improve the reliability of the system, but also to optimize the maintenance costs. The latter is achieved by informing the operators about the system component's status. This approach can be used to ensure secure operation of the system by its flexibility in monitoring system applications. The implementation demonstrates that the proposed method is effective and efficient and can conveniently incorporate more system maintenance plans and diagnostic strategies.

  10. Impact of Large-scale Geological Architectures On Recharge

    NASA Astrophysics Data System (ADS)

    Troldborg, L.; Refsgaard, J. C.; Engesgaard, P.; Jensen, K. H.

    Geological and hydrogeological data constitutes the basis for assessment of ground- water flow pattern and recharge zones. The accessibility and applicability of hard ge- ological data is often a major obstacle in deriving plausible conceptual models. Nev- ertheless focus is often on parameter uncertainty caused by the effect of geological heterogeneity due to lack of hard geological data, thus neglecting the possibility of alternative conceptualizations of the large-scale geological architecture. For a catchment in the eastern part of Denmark we have constructed different geologi- cal models based on different conceptualization of the major geological trends and fa- cies architecture. The geological models are equally plausible in a conceptually sense and they are all calibrated to well head and river flow measurements. Comparison of differences in recharge zones and subsequently well protection zones emphasize the importance of assessing large-scale geological architecture in hydrological modeling on regional scale in a non-deterministic way. Geostatistical modeling carried out in a transitional probability framework shows the possibility of assessing multiple re- alizations of large-scale geological architecture from a combination of soft and hard geological information.

  11. Alteration of Large-Scale Chromatin Structure by Estrogen Receptor

    PubMed Central

    Nye, Anne C.; Rajendran, Ramji R.; Stenoien, David L.; Mancini, Michael A.; Katzenellenbogen, Benita S.; Belmont, Andrew S.

    2002-01-01

    The estrogen receptor (ER), a member of the nuclear hormone receptor superfamily important in human physiology and disease, recruits coactivators which modify local chromatin structure. Here we describe effects of ER on large-scale chromatin structure as visualized in live cells. We targeted ER to gene-amplified chromosome arms containing large numbers of lac operator sites either directly, through a lac repressor-ER fusion protein (lac rep-ER), or indirectly, by fusing lac repressor with the ER interaction domain of the coactivator steroid receptor coactivator 1. Significant decondensation of large-scale chromatin structure, comparable to that produced by the ∼150-fold-stronger viral protein 16 (VP16) transcriptional activator, was produced by ER in the absence of estradiol using both approaches. Addition of estradiol induced a partial reversal of this unfolding by green fluorescent protein-lac rep-ER but not by wild-type ER recruited by a lac repressor-SRC570-780 fusion protein. The chromatin decondensation activity did not require transcriptional activation by ER nor did it require ligand-induced coactivator interactions, and unfolding did not correlate with histone hyperacetylation. Ligand-induced coactivator interactions with helix 12 of ER were necessary for the partial refolding of chromatin in response to estradiol using the lac rep-ER tethering system. This work demonstrates that when tethered or recruited to DNA, ER possesses a novel large-scale chromatin unfolding activity. PMID:11971975

  12. Multiresolution comparison of precipitation datasets for large-scale models

    NASA Astrophysics Data System (ADS)

    Chun, K. P.; Sapriza Azuri, G.; Davison, B.; DeBeer, C. M.; Wheater, H. S.

    2014-12-01

    Gridded precipitation datasets are crucial for driving large-scale models which are related to weather forecast and climate research. However, the quality of precipitation products is usually validated individually. Comparisons between gridded precipitation products along with ground observations provide another avenue for investigating how the precipitation uncertainty would affect the performance of large-scale models. In this study, using data from a set of precipitation gauges over British Columbia and Alberta, we evaluate several widely used North America gridded products including the Canadian Gridded Precipitation Anomalies (CANGRD), the National Center for Environmental Prediction (NCEP) reanalysis, the Water and Global Change (WATCH) project, the thin plate spline smoothing algorithms (ANUSPLIN) and Canadian Precipitation Analysis (CaPA). Based on verification criteria for various temporal and spatial scales, results provide an assessment of possible applications for various precipitation datasets. For long-term climate variation studies (~100 years), CANGRD, NCEP, WATCH and ANUSPLIN have different comparative advantages in terms of their resolution and accuracy. For synoptic and mesoscale precipitation patterns, CaPA provides appealing performance of spatial coherence. In addition to the products comparison, various downscaling methods are also surveyed to explore new verification and bias-reduction methods for improving gridded precipitation outputs for large-scale models.

  13. Equivalent common path method in large-scale laser comparator

    NASA Astrophysics Data System (ADS)

    He, Mingzhao; Li, Jianshuang; Miao, Dongjing

    2015-02-01

    Large-scale laser comparator is main standard device that providing accurate, reliable and traceable measurements for high precision large-scale line and 3D measurement instruments. It mainly composed of guide rail, motion control system, environmental parameters monitoring system and displacement measurement system. In the laser comparator, the main error sources are temperature distribution, straightness of guide rail and pitch and yaw of measuring carriage. To minimize the measurement uncertainty, an equivalent common optical path scheme is proposed and implemented. Three laser interferometers are adjusted to parallel with the guide rail. The displacement in an arbitrary virtual optical path is calculated using three displacements without the knowledge of carriage orientations at start and end positions. The orientation of air floating carriage is calculated with displacements of three optical path and position of three retroreflectors which are precisely measured by Laser Tracker. A 4th laser interferometer is used in the virtual optical path as reference to verify this compensation method. This paper analyzes the effect of rail straightness on the displacement measurement. The proposed method, through experimental verification, can improve the measurement uncertainty of large-scale laser comparator.

  14. Dispersal Mutualism Incorporated into Large-Scale, Infrequent Disturbances

    PubMed Central

    Parker, V. Thomas

    2015-01-01

    Because of their influence on succession and other community interactions, large-scale, infrequent natural disturbances also should play a major role in mutualistic interactions. Using field data and experiments, I test whether mutualisms have been incorporated into large-scale wildfire by whether the outcomes of a mutualism depend on disturbance. In this study a seed dispersal mutualism is shown to depend on infrequent, large-scale disturbances. A dominant shrubland plant (Arctostaphylos species) produces seeds that make up a persistent soil seed bank and requires fire to germinate. In post-fire stands, I show that seedlings emerging from rodent caches dominate sites experiencing higher fire intensity. Field experiments show that rodents (Perimyscus californicus, P. boylii) do cache Arctostaphylos fruit and bury most seed caches to a sufficient depth to survive a killing heat pulse that a fire might drive into the soil. While the rodent dispersal and caching behavior itself has not changed compared to other habitats, the environmental transformation caused by wildfire converts the caching burial of seed from a dispersal process to a plant fire adaptive trait, and provides the context for stimulating subsequent life history evolution in the plant host. PMID:26151560

  15. Large-scale flow generation by inhomogeneous helicity.

    PubMed

    Yokoi, N; Brandenburg, A

    2016-03-01

    The effect of kinetic helicity (velocity-vorticity correlation) on turbulent momentum transport is investigated. The turbulent kinetic helicity (pseudoscalar) enters the Reynolds stress (mirror-symmetric tensor) expression in the form of a helicity gradient as the coupling coefficient for the mean vorticity and/or the angular velocity (axial vector), which suggests the possibility of mean-flow generation in the presence of inhomogeneous helicity. This inhomogeneous helicity effect, which was previously confirmed at the level of a turbulence- or closure-model simulation, is examined with the aid of direct numerical simulations of rotating turbulence with nonuniform helicity sustained by an external forcing. The numerical simulations show that the spatial distribution of the Reynolds stress is in agreement with the helicity-related term coupled with the angular velocity, and that a large-scale flow is generated in the direction of angular velocity. Such a large-scale flow is not induced in the case of homogeneous turbulent helicity. This result confirms the validity of the inhomogeneous helicity effect in large-scale flow generation and suggests that a vortex dynamo is possible even in incompressible turbulence where there is no baroclinicity effect.

  16. Large-scale flow experiments for managing river systems

    USGS Publications Warehouse

    Konrad, Christopher P.; Olden, Julian D.; Lytle, David A.; Melis, Theodore S.; Schmidt, John C.; Bray, Erin N.; Freeman, Mary C.; Gido, Keith B.; Hemphill, Nina P.; Kennard, Mark J.; McMullen, Laura E.; Mims, Meryl C.; Pyron, Mark; Robinson, Christopher T.; Williams, John G.

    2011-01-01

    Experimental manipulations of streamflow have been used globally in recent decades to mitigate the impacts of dam operations on river systems. Rivers are challenging subjects for experimentation, because they are open systems that cannot be isolated from their social context. We identify principles to address the challenges of conducting effective large-scale flow experiments. Flow experiments have both scientific and social value when they help to resolve specific questions about the ecological action of flow with a clear nexus to water policies and decisions. Water managers must integrate new information into operating policies for large-scale experiments to be effective. Modeling and monitoring can be integrated with experiments to analyze long-term ecological responses. Experimental design should include spatially extensive observations and well-defined, repeated treatments. Large-scale flow manipulations are only a part of dam operations that affect river systems. Scientists can ensure that experimental manipulations continue to be a valuable approach for the scientifically based management of river systems.

  17. Foundational perspectives on causality in large-scale brain networks.

    PubMed

    Mannino, Michael; Bressler, Steven L

    2015-12-01

    A profusion of recent work in cognitive neuroscience has been concerned with the endeavor to uncover causal influences in large-scale brain networks. However, despite the fact that many papers give a nod to the important theoretical challenges posed by the concept of causality, this explosion of research has generally not been accompanied by a rigorous conceptual analysis of the nature of causality in the brain. This review provides both a descriptive and prescriptive account of the nature of causality as found within and between large-scale brain networks. In short, it seeks to clarify the concept of causality in large-scale brain networks both philosophically and scientifically. This is accomplished by briefly reviewing the rich philosophical history of work on causality, especially focusing on contributions by David Hume, Immanuel Kant, Bertrand Russell, and Christopher Hitchcock. We go on to discuss the impact that various interpretations of modern physics have had on our understanding of causality. Throughout all this, a central focus is the distinction between theories of deterministic causality (DC), whereby causes uniquely determine their effects, and probabilistic causality (PC), whereby causes change the probability of occurrence of their effects. We argue that, given the topological complexity of its large-scale connectivity, the brain should be considered as a complex system and its causal influences treated as probabilistic in nature. We conclude that PC is well suited for explaining causality in the brain for three reasons: (1) brain causality is often mutual; (2) connectional convergence dictates that only rarely is the activity of one neuronal population uniquely determined by another one; and (3) the causal influences exerted between neuronal populations may not have observable effects. A number of different techniques are currently available to characterize causal influence in the brain. Typically, these techniques quantify the statistical

  18. Robust large-scale parallel nonlinear solvers for simulations.

    SciTech Connect

    Bader, Brett William; Pawlowski, Roger Patrick; Kolda, Tamara Gibson

    2005-11-01

    This report documents research to develop robust and efficient solution techniques for solving large-scale systems of nonlinear equations. The most widely used method for solving systems of nonlinear equations is Newton's method. While much research has been devoted to augmenting Newton-based solvers (usually with globalization techniques), little has been devoted to exploring the application of different models. Our research has been directed at evaluating techniques using different models than Newton's method: a lower order model, Broyden's method, and a higher order model, the tensor method. We have developed large-scale versions of each of these models and have demonstrated their use in important applications at Sandia. Broyden's method replaces the Jacobian with an approximation, allowing codes that cannot evaluate a Jacobian or have an inaccurate Jacobian to converge to a solution. Limited-memory methods, which have been successful in optimization, allow us to extend this approach to large-scale problems. We compare the robustness and efficiency of Newton's method, modified Newton's method, Jacobian-free Newton-Krylov method, and our limited-memory Broyden method. Comparisons are carried out for large-scale applications of fluid flow simulations and electronic circuit simulations. Results show that, in cases where the Jacobian was inaccurate or could not be computed, Broyden's method converged in some cases where Newton's method failed to converge. We identify conditions where Broyden's method can be more efficient than Newton's method. We also present modifications to a large-scale tensor method, originally proposed by Bouaricha, for greater efficiency, better robustness, and wider applicability. Tensor methods are an alternative to Newton-based methods and are based on computing a step based on a local quadratic model rather than a linear model. The advantage of Bouaricha's method is that it can use any existing linear solver, which makes it simple to write

  19. New probes of Cosmic Microwave Background large-scale anomalies

    NASA Astrophysics Data System (ADS)

    Aiola, Simone

    Fifty years of Cosmic Microwave Background (CMB) data played a crucial role in constraining the parameters of the LambdaCDM model, where Dark Energy, Dark Matter, and Inflation are the three most important pillars not yet understood. Inflation prescribes an isotropic universe on large scales, and it generates spatially-correlated density fluctuations over the whole Hubble volume. CMB temperature fluctuations on scales bigger than a degree in the sky, affected by modes on super-horizon scale at the time of recombination, are a clean snapshot of the universe after inflation. In addition, the accelerated expansion of the universe, driven by Dark Energy, leaves a hardly detectable imprint in the large-scale temperature sky at late times. Such fundamental predictions have been tested with current CMB data and found to be in tension with what we expect from our simple LambdaCDM model. Is this tension just a random fluke or a fundamental issue with the present model? In this thesis, we present a new framework to probe the lack of large-scale correlations in the temperature sky using CMB polarization data. Our analysis shows that if a suppression in the CMB polarization correlations is detected, it will provide compelling evidence for new physics on super-horizon scale. To further analyze the statistical properties of the CMB temperature sky, we constrain the degree of statistical anisotropy of the CMB in the context of the observed large-scale dipole power asymmetry. We find evidence for a scale-dependent dipolar modulation at 2.5sigma. To isolate late-time signals from the primordial ones, we test the anomalously high Integrated Sachs-Wolfe effect signal generated by superstructures in the universe. We find that the detected signal is in tension with the expectations from LambdaCDM at the 2.5sigma level, which is somewhat smaller than what has been previously argued. To conclude, we describe the current status of CMB observations on small scales, highlighting the

  20. Foundational perspectives on causality in large-scale brain networks

    NASA Astrophysics Data System (ADS)

    Mannino, Michael; Bressler, Steven L.

    2015-12-01

    A profusion of recent work in cognitive neuroscience has been concerned with the endeavor to uncover causal influences in large-scale brain networks. However, despite the fact that many papers give a nod to the important theoretical challenges posed by the concept of causality, this explosion of research has generally not been accompanied by a rigorous conceptual analysis of the nature of causality in the brain. This review provides both a descriptive and prescriptive account of the nature of causality as found within and between large-scale brain networks. In short, it seeks to clarify the concept of causality in large-scale brain networks both philosophically and scientifically. This is accomplished by briefly reviewing the rich philosophical history of work on causality, especially focusing on contributions by David Hume, Immanuel Kant, Bertrand Russell, and Christopher Hitchcock. We go on to discuss the impact that various interpretations of modern physics have had on our understanding of causality. Throughout all this, a central focus is the distinction between theories of deterministic causality (DC), whereby causes uniquely determine their effects, and probabilistic causality (PC), whereby causes change the probability of occurrence of their effects. We argue that, given the topological complexity of its large-scale connectivity, the brain should be considered as a complex system and its causal influences treated as probabilistic in nature. We conclude that PC is well suited for explaining causality in the brain for three reasons: (1) brain causality is often mutual; (2) connectional convergence dictates that only rarely is the activity of one neuronal population uniquely determined by another one; and (3) the causal influences exerted between neuronal populations may not have observable effects. A number of different techniques are currently available to characterize causal influence in the brain. Typically, these techniques quantify the statistical

  1. Large-Scale Hybrid Motor Testing. Chapter 10

    NASA Technical Reports Server (NTRS)

    Story, George

    2006-01-01

    Hybrid rocket motors can be successfully demonstrated at a small scale virtually anywhere. There have been many suitcase sized portable test stands assembled for demonstration of hybrids. They show the safety of hybrid rockets to the audiences. These small show motors and small laboratory scale motors can give comparative burn rate data for development of different fuel/oxidizer combinations, however questions that are always asked when hybrids are mentioned for large scale applications are - how do they scale and has it been shown in a large motor? To answer those questions, large scale motor testing is required to verify the hybrid motor at its true size. The necessity to conduct large-scale hybrid rocket motor tests to validate the burn rate from the small motors to application size has been documented in several place^'^^.^. Comparison of small scale hybrid data to that of larger scale data indicates that the fuel burn rate goes down with increasing port size, even with the same oxidizer flux. This trend holds for conventional hybrid motors with forward oxidizer injection and HTPB based fuels. While the reason this is occurring would make a great paper or study or thesis, it is not thoroughly understood at this time. Potential causes include the fact that since hybrid combustion is boundary layer driven, the larger port sizes reduce the interaction (radiation, mixing and heat transfer) from the core region of the port. This chapter focuses on some of the large, prototype sized testing of hybrid motors. The largest motors tested have been AMROC s 250K-lbf thrust motor at Edwards Air Force Base and the Hybrid Propulsion Demonstration Program s 250K-lbf thrust motor at Stennis Space Center. Numerous smaller tests were performed to support the burn rate, stability and scaling concepts that went into the development of those large motors.

  2. The Large-Scale Current System During Auroral Substorms

    NASA Astrophysics Data System (ADS)

    Gjerloev, Jesper

    2015-04-01

    The substorm process has been discussed for more than four decades and new empirical large-scale models continue to be published. The continued activity implies both the importance and the complexity of the problem. We recently published a new model of the large-scale substorm current system (Gjerloev and Hoffman, JGR, 2014). Based on data from >100 ground magnetometers (obtained from SuperMAG), 116 isolated substorms, global auroral images (obtained by the Polar VIS Earth Camera) and a careful normalization technique we derived an empirical model of the ionospheric equivalent current system. Our model yield some unexpected features that appear inconsistent with the classical single current wedge current system. One of these features is a distinct latitudinal shift of the westward electrojet (WEJ) current between the pre- and post-midnight region and we find evidence that these two WEJ regions are quasi disconnected. This, and other observational facts, led us to propose a modified 3D current system configuration that consists of 2 wedge type systems: a current wedge in the pre-midnight region (bulge current wedge), and another current wedge system in the post-midnight region (oval current wedge). The two wedge systems are shifted in latitude but overlap in local time in the midnight region. Our model is at considerable variance with previous global models and conceptual schematics of the large-scale substorm current system. We speculate that the data coverage, the methodologies and the techniques used in these previous global studies are the cause of the differences in solutions. In this presentation we present our model, compare with other published models and discuss possible causes for the differences.

  3. Improving Design Efficiency for Large-Scale Heterogeneous Circuits

    NASA Astrophysics Data System (ADS)

    Gregerson, Anthony

    Despite increases in logic density, many Big Data applications must still be partitioned across multiple computing devices in order to meet their strict performance requirements. Among the most demanding of these applications is high-energy physics (HEP), which uses complex computing systems consisting of thousands of FPGAs and ASICs to process the sensor data created by experiments at particles accelerators such as the Large Hadron Collider (LHC). Designing such computing systems is challenging due to the scale of the systems, the exceptionally high-throughput and low-latency performance constraints that necessitate application-specific hardware implementations, the requirement that algorithms are efficiently partitioned across many devices, and the possible need to update the implemented algorithms during the lifetime of the system. In this work, we describe our research to develop flexible architectures for implementing such large-scale circuits on FPGAs. In particular, this work is motivated by (but not limited in scope to) high-energy physics algorithms for the Compact Muon Solenoid (CMS) experiment at the LHC. To make efficient use of logic resources in multi-FPGA systems, we introduce Multi-Personality Partitioning, a novel form of the graph partitioning problem, and present partitioning algorithms that can significantly improve resource utilization on heterogeneous devices while also reducing inter-chip connections. To reduce the high communication costs of Big Data applications, we also introduce Information-Aware Partitioning, a partitioning method that analyzes the data content of application-specific circuits, characterizes their entropy, and selects circuit partitions that enable efficient compression of data between chips. We employ our information-aware partitioning method to improve the performance of the hardware validation platform for evaluating new algorithms for the CMS experiment. Together, these research efforts help to improve the efficiency

  4. Solving large scale structure in ten easy steps with COLA

    NASA Astrophysics Data System (ADS)

    Tassev, Svetlin; Zaldarriaga, Matias; Eisenstein, Daniel J.

    2013-06-01

    We present the COmoving Lagrangian Acceleration (COLA) method: an N-body method for solving for Large Scale Structure (LSS) in a frame that is comoving with observers following trajectories calculated in Lagrangian Perturbation Theory (LPT). Unlike standard N-body methods, the COLA method can straightforwardly trade accuracy at small-scales in order to gain computational speed without sacrificing accuracy at large scales. This is especially useful for cheaply generating large ensembles of accurate mock halo catalogs required to study galaxy clustering and weak lensing, as those catalogs are essential for performing detailed error analysis for ongoing and future surveys of LSS. As an illustration, we ran a COLA-based N-body code on a box of size 100 Mpc/h with particles of mass ≈ 5 × 109Msolar/h. Running the code with only 10 timesteps was sufficient to obtain an accurate description of halo statistics down to halo masses of at least 1011Msolar/h. This is only at a modest speed penalty when compared to mocks obtained with LPT. A standard detailed N-body run is orders of magnitude slower than our COLA-based code. The speed-up we obtain with COLA is due to the fact that we calculate the large-scale dynamics exactly using LPT, while letting the N-body code solve for the small scales, without requiring it to capture exactly the internal dynamics of halos. Achieving a similar level of accuracy in halo statistics without the COLA method requires at least 3 times more timesteps than when COLA is employed.

  5. Large-scale smart passive system for civil engineering applications

    NASA Astrophysics Data System (ADS)

    Jung, Hyung-Jo; Jang, Dong-Doo; Lee, Heon-Jae; Cho, Sang-Won

    2008-03-01

    The smart passive system consisting of a magnetorheological (MR) damper and an electromagnetic induction (EMI) part has been recently proposed. An EMI part can generate the input current for an MR damper from vibration of a structure according to Faraday's law of electromagnetic induction. The control performance of the smart passive system has been demonstrated mainly by numerical simulations. It was verified from the numerical results that the system could be effective to reduce the structural responses in the cases of civil engineering structures such as buildings and bridges. On the other hand, the experimental validation of the system is not sufficiently conducted yet. In this paper, the feasibility of the smart passive system to real-scale structures is investigated. To do this, the large-scale smart passive system is designed, manufactured, and tested. The system consists of the large-capacity MR damper, which has a maximum force level of approximately +/-10,000N, a maximum stroke level of +/-35mm and the maximum current level of 3 A, and the large-scale EMI part, which is designed to generate sufficient induced current for the damper. The applicability of the smart passive system to large real-scale structures is examined through a series of shaking table tests. The magnitudes of the induced current of the EMI part with various sinusoidal excitation inputs are measured. According to the test results, the large-scale EMI part shows the possibility that it could generate the sufficient current or power for changing the damping characteristics of the large-capacity MR damper.

  6. Infectious diseases in large-scale cat hoarding investigations.

    PubMed

    Polak, K C; Levy, J K; Crawford, P C; Leutenegger, C M; Moriello, K A

    2014-08-01

    Animal hoarders accumulate animals in over-crowded conditions without adequate nutrition, sanitation, and veterinary care. As a result, animals rescued from hoarding frequently have a variety of medical conditions including respiratory infections, gastrointestinal disease, parasitism, malnutrition, and other evidence of neglect. The purpose of this study was to characterize the infectious diseases carried by clinically affected cats and to determine the prevalence of retroviral infections among cats in large-scale cat hoarding investigations. Records were reviewed retrospectively from four large-scale seizures of cats from failed sanctuaries from November 2009 through March 2012. The number of cats seized in each case ranged from 387 to 697. Cats were screened for feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) in all four cases and for dermatophytosis in one case. A subset of cats exhibiting signs of upper respiratory disease or diarrhea had been tested for infections by PCR and fecal flotation for treatment planning. Mycoplasma felis (78%), calicivirus (78%), and Streptococcus equi subspecies zooepidemicus (55%) were the most common respiratory infections. Feline enteric coronavirus (88%), Giardia (56%), Clostridium perfringens (49%), and Tritrichomonas foetus (39%) were most common in cats with diarrhea. The seroprevalence of FeLV and FIV were 8% and 8%, respectively. In the one case in which cats with lesions suspicious for dermatophytosis were cultured for Microsporum canis, 69/76 lesional cats were culture-positive; of these, half were believed to be truly infected and half were believed to be fomite carriers. Cats from large-scale hoarding cases had high risk for enteric and respiratory infections, retroviruses, and dermatophytosis. Case responders should be prepared for mass treatment of infectious diseases and should implement protocols to prevent transmission of feline or zoonotic infections during the emergency response and when

  7. Solving large scale structure in ten easy steps with COLA

    SciTech Connect

    Tassev, Svetlin; Zaldarriaga, Matias; Eisenstein, Daniel J. E-mail: matiasz@ias.edu

    2013-06-01

    We present the COmoving Lagrangian Acceleration (COLA) method: an N-body method for solving for Large Scale Structure (LSS) in a frame that is comoving with observers following trajectories calculated in Lagrangian Perturbation Theory (LPT). Unlike standard N-body methods, the COLA method can straightforwardly trade accuracy at small-scales in order to gain computational speed without sacrificing accuracy at large scales. This is especially useful for cheaply generating large ensembles of accurate mock halo catalogs required to study galaxy clustering and weak lensing, as those catalogs are essential for performing detailed error analysis for ongoing and future surveys of LSS. As an illustration, we ran a COLA-based N-body code on a box of size 100 Mpc/h with particles of mass ≈ 5 × 10{sup 9}M{sub s}un/h. Running the code with only 10 timesteps was sufficient to obtain an accurate description of halo statistics down to halo masses of at least 10{sup 11}M{sub s}un/h. This is only at a modest speed penalty when compared to mocks obtained with LPT. A standard detailed N-body run is orders of magnitude slower than our COLA-based code. The speed-up we obtain with COLA is due to the fact that we calculate the large-scale dynamics exactly using LPT, while letting the N-body code solve for the small scales, without requiring it to capture exactly the internal dynamics of halos. Achieving a similar level of accuracy in halo statistics without the COLA method requires at least 3 times more timesteps than when COLA is employed.

  8. Statistical analysis of large-scale neuronal recording data

    PubMed Central

    Reed, Jamie L.; Kaas, Jon H.

    2010-01-01

    Relating stimulus properties to the response properties of individual neurons and neuronal networks is a major goal of sensory research. Many investigators implant electrode arrays in multiple brain areas and record from chronically implanted electrodes over time to answer a variety of questions. Technical challenges related to analyzing large-scale neuronal recording data are not trivial. Several analysis methods traditionally used by neurophysiologists do not account for dependencies in the data that are inherent in multi-electrode recordings. In addition, when neurophysiological data are not best modeled by the normal distribution and when the variables of interest may not be linearly related, extensions of the linear modeling techniques are recommended. A variety of methods exist to analyze correlated data, even when data are not normally distributed and the relationships are nonlinear. Here we review expansions of the Generalized Linear Model designed to address these data properties. Such methods are used in other research fields, and the application to large-scale neuronal recording data will enable investigators to determine the variable properties that convincingly contribute to the variances in the observed neuronal measures. Standard measures of neuron properties such as response magnitudes can be analyzed using these methods, and measures of neuronal network activity such as spike timing correlations can be analyzed as well. We have done just that in recordings from 100-electrode arrays implanted in the primary somatosensory cortex of owl monkeys. Here we illustrate how one example method, Generalized Estimating Equations analysis, is a useful method to apply to large-scale neuronal recordings. PMID:20472395

  9. LARGE-SCALE CO2 TRANSPORTATION AND DEEP OCEAN SEQUESTRATION

    SciTech Connect

    Hamid Sarv

    1999-03-01

    Technical and economical feasibility of large-scale CO{sub 2} transportation and ocean sequestration at depths of 3000 meters or grater was investigated. Two options were examined for transporting and disposing the captured CO{sub 2}. In one case, CO{sub 2} was pumped from a land-based collection center through long pipelines laid on the ocean floor. Another case considered oceanic tanker transport of liquid carbon dioxide to an offshore floating structure for vertical injection to the ocean floor. In the latter case, a novel concept based on subsurface towing of a 3000-meter pipe, and attaching it to the offshore structure was considered. Budgetary cost estimates indicate that for distances greater than 400 km, tanker transportation and offshore injection through a 3000-meter vertical pipe provides the best method for delivering liquid CO{sub 2} to deep ocean floor depressions. For shorter distances, CO{sub 2} delivery by parallel-laid, subsea pipelines is more cost-effective. Estimated costs for 500-km transport and storage at a depth of 3000 meters by subsea pipelines and tankers were 1.5 and 1.4 dollars per ton of stored CO{sub 2}, respectively. At these prices, economics of ocean disposal are highly favorable. Future work should focus on addressing technical issues that are critical to the deployment of a large-scale CO{sub 2} transportation and disposal system. Pipe corrosion, structural design of the transport pipe, and dispersion characteristics of sinking CO{sub 2} effluent plumes have been identified as areas that require further attention. Our planned activities in the next Phase include laboratory-scale corrosion testing, structural analysis of the pipeline, analytical and experimental simulations of CO{sub 2} discharge and dispersion, and the conceptual economic and engineering evaluation of large-scale implementation.

  10. Solving Large-scale Eigenvalue Problems in SciDACApplications

    SciTech Connect

    Yang, Chao

    2005-06-29

    Large-scale eigenvalue problems arise in a number of DOE applications. This paper provides an overview of the recent development of eigenvalue computation in the context of two SciDAC applications. We emphasize the importance of Krylov subspace methods, and point out its limitations. We discuss the value of alternative approaches that are more amenable to the use of preconditioners, and report the progression using the multi-level algebraic sub-structuring techniques to speed up eigenvalue calculation. In addition to methods for linear eigenvalue problems, we also examine new approaches to solving two types of non-linear eigenvalue problems arising from SciDAC applications.

  11. Analysis Plan for 1985 Large-Scale Tests.

    DTIC Science & Technology

    1983-01-01

    KEY WORDS (Continue on reverse side it necessary mnd Identify by block number) Large-Scale Blasting Agents Multiburst ANFO S:,ock Waves 20. ABSTRACT...CONSIDERATIONS 6 1.5 MULTIBURST TECHNIQUES 6 1.6 TEST SITE CONSIDERATIONS 6 2 CANDIDATE EXPLOSIVES 8 2.1 INTRODUCTION 82.2 ANFO 8 2.2.1 Bulk (Loose) ANFO 11...2.2.2 Bagged ANFO 13 2.3 APEX 1360 15 2.4 NITRIC ACID AND NITROPROPANE 17 2.5 NITROPROPANENITRATE (NPN) 19 2.6 DBA - 22M 21 2.7 HARDENING EMULSION 22 2.8

  12. Large-Scale Patterns of Filament Channels and Filaments

    NASA Astrophysics Data System (ADS)

    Mackay, Duncan

    2016-07-01

    In this review the properties and large-scale patterns of filament channels and filaments will be considered. Initially, the global formation locations of filament channels and filaments are discussed, along with their hemispheric pattern. Next, observations of the formation of filament channels and filaments are described where two opposing views are considered. Finally, the wide range of models that have been constructed to consider the formation of filament channels and filaments over long time-scales are described, along with the origin of the hemispheric pattern of filaments.

  13. Design of a large-scale CFB boiler

    SciTech Connect

    Darling, S.; Li, S.

    1997-12-31

    Many CFB boilers sized 100--150 MWe are in operation, and several others sized 150--250 MWe are in operation or under construction. The next step for CFB technology is the 300--400 MWe size range. This paper will describe Foster Wheeler`s large-scale CFB boiler experience and the design for a 300 MWe CFB boiler. The authors will show how the design incorporates Foster Wheeler`s unique combination of extensive utility experience and CFB boiler experience. All the benefits of CFB technology which include low emissions, fuel flexibility, low maintenance and competitive cost are now available in the 300--400 MWe size range.

  14. An iterative decoupling solution method for large scale Lyapunov equations

    NASA Technical Reports Server (NTRS)

    Athay, T. M.; Sandell, N. R., Jr.

    1976-01-01

    A great deal of attention has been given to the numerical solution of the Lyapunov equation. A useful classification of the variety of solution techniques are the groupings of direct, transformation, and iterative methods. The paper summarizes those methods that are at least partly favorable numerically, giving special attention to two criteria: exploitation of a general sparse system matrix structure and efficiency in resolving the governing linear matrix equation for different matrices. An iterative decoupling solution method is proposed as a promising approach for solving large-scale Lyapunov equation when the system matrix exhibits a general sparse structure. A Fortran computer program that realizes the iterative decoupling algorithm is also discussed.

  15. Large-scale normal fluid circulation in helium superflows

    NASA Astrophysics Data System (ADS)

    Galantucci, Luca; Sciacca, Michele; Barenghi, Carlo F.

    2017-01-01

    We perform fully coupled numerical simulations of helium II pure superflows in a channel, with vortex-line density typical of experiments. Peculiar to our model is the computation of the back-reaction of the superfluid vortex motion on the normal fluid and the presence of solid boundaries. We recover the uniform vortex-line density experimentally measured employing second sound resonators and we show that pure superflow in helium II is associated with a large-scale circulation of the normal fluid which can be detected using existing particle-tracking visualization techniques.

  16. On decentralized control of large-scale systems

    NASA Technical Reports Server (NTRS)

    Siljak, D. D.

    1978-01-01

    A scheme is presented for decentralized control of large-scale linear systems which are composed of a number of interconnected subsystems. By ignoring the interconnections, local feedback controls are chosen to optimize each decoupled subsystem. Conditions are provided to establish compatibility of the individual local controllers and achieve stability of the overall system. Besides computational simplifications, the scheme is attractive because of its structural features and the fact that it produces a robust decentralized regulator for large dynamic systems, which can tolerate a wide range of nonlinearities and perturbations among the subsystems.

  17. Large-Scale periodic solar velocities: An observational study

    NASA Technical Reports Server (NTRS)

    Dittmer, P. H.

    1977-01-01

    Observations of large-scale solar velocities were made using the mean field telescope and Babcock magnetograph of the Stanford Solar Observatory. Observations were made in the magnetically insensitive ion line at 5124 A, with light from the center (limb) of the disk right (left) circularly polarized, so that the magnetograph measures the difference in wavelength between center and limb. Computer calculations are made of the wavelength difference produced by global pulsations for spherical harmonics up to second order and of the signal produced by displacing the solar image relative to polarizing optics or diffraction grating.

  18. Large-Scale Compton Imaging for Wide-Area Surveillance

    SciTech Connect

    Lange, D J; Manini, H A; Wright, D M

    2006-03-01

    We study the performance of a large-scale Compton imaging detector placed in a low-flying aircraft, used to search wide areas for rad/nuc threat sources. In this paper we investigate the performance potential of equipping aerial platforms with gamma-ray detectors that have photon sensitivity up to a few MeV. We simulate the detector performance, and present receiver operating characteristics (ROC) curves for a benchmark scenario using a {sup 137}Cs source. The analysis uses a realistic environmental background energy spectrum and includes air attenuation.

  19. Large-Scale Measurement of Absolute Protein Glycosylation Stoichiometry.

    PubMed

    Sun, Shisheng; Zhang, Hui

    2015-07-07

    Protein glycosylation is one of the most important protein modifications. Glycosylation site occupancy alteration has been implicated in human diseases and cancers. However, current glycoproteomic methods focus on the identification and quantification of glycosylated peptides and glycosylation sites but not glycosylation occupancy or glycoform stoichiometry. Here we describe a method for large-scale determination of the absolute glycosylation stoichiometry using three independent relative ratios. Using this method, we determined 117 absolute N-glycosylation occupancies in OVCAR-3 cells. Finally, we investigated the possible functions and the determinants for partial glycosylation.

  20. Enabling Large-Scale Biomedical Analysis in the Cloud

    PubMed Central

    Lin, Ying-Chih; Yu, Chin-Sheng; Lin, Yen-Jen

    2013-01-01

    Recent progress in high-throughput instrumentations has led to an astonishing growth in both volume and complexity of biomedical data collected from various sources. The planet-size data brings serious challenges to the storage and computing technologies. Cloud computing is an alternative to crack the nut because it gives concurrent consideration to enable storage and high-performance computing on large-scale data. This work briefly introduces the data intensive computing system and summarizes existing cloud-based resources in bioinformatics. These developments and applications would facilitate biomedical research to make the vast amount of diversification data meaningful and usable. PMID:24288665

  1. Large-scale intermittency in the atmospheric boundary layer.

    PubMed

    Kholmyansky, M; Moriconi, L; Tsinober, A

    2007-08-01

    We find actual evidence, relying upon vorticity time series taken in a high-Reynolds-number atmospheric experiment, that to a very good approximation the surface boundary layer flow may be described, in a statistical sense and under certain regimes, as an advected ensemble of homogeneous turbulent systems, characterized by a log-normal distribution of fluctuating intensities. Our analysis suggests that the usual direct numerical simulations of homogeneous and isotropic turbulence, performed at moderate Reynolds numbers, may play an important role in the study of turbulent boundary layer flows, if supplemented with appropriate statistical information concerned with the structure of large-scale fluctuations.

  2. Frequency domain multiplexing for large-scale bolometer arrays

    SciTech Connect

    Spieler, Helmuth

    2002-05-31

    The development of planar fabrication techniques for superconducting transition-edge sensors has brought large-scale arrays of 1000 pixels or more to the realm of practicality. This raises the problem of reading out a large number of sensors with a tractable number of connections. A possible solution is frequency-domain multiplexing. I summarize basic principles, present various circuit topologies, and discuss design trade-offs, noise performance, cross-talk and dynamic range. The design of a practical device and its readout system is described with a discussion of fabrication issues, practical limits and future prospects.

  3. A Modular Ring Architecture for Large Scale Neural Network Implementations

    NASA Astrophysics Data System (ADS)

    Jump, Lance B.; Ligomenides, Panos A.

    1989-11-01

    Constructing fully parallel, large scale, neural networks is complicated by the problems of providing for massive interconnectivity and of overcoming fan in/out limitations in area-efficient VLSI/WSI realizations. A modular, bus switched, neural ring architecture employing primitive ring (pRing) processors is proposed, which solves the fan in/out and connectivity problems by a dynamically reconfigurable communication ring that synchronously serves identical, radially connected, processing elements. It also allows cost versus performance trade-offs by the assignment of variable numbers of logical neurons to each physical processing element.

  4. Simplified DGS procedure for large-scale genome structural study.

    PubMed

    Jung, Yong-Chul; Xu, Jia; Chen, Jun; Kim, Yeong; Winchester, David; Wang, San Ming

    2009-11-01

    Ditag genome scanning (DGS) uses next-generation DNA sequencing to sequence the ends of ditag fragments produced by restriction enzymes. These sequences are compared to known genome sequences to determine their structure. In order to use DGS for large-scale genome structural studies, we have substantially revised the original protocol by replacing the in vivo genomic DNA cloning with in vitro adaptor ligation, eliminating the ditag concatemerization steps, and replacing the 454 sequencer with Solexa or SOLiD sequencers for ditag sequence collection. This revised protocol further increases genome coverage and resolution and allows DGS to be used to analyze multiple genomes simultaneously.

  5. UAV Data Processing for Large Scale Topographical Mapping

    NASA Astrophysics Data System (ADS)

    Tampubolon, W.; Reinhardt, W.

    2014-06-01

    Large scale topographical mapping in the third world countries is really a prominent challenge in geospatial industries nowadays. On one side the demand is significantly increasing while on the other hand it is constrained by limited budgets available for mapping projects. Since the advent of Act Nr.4/yr.2011 about Geospatial Information in Indonesia, large scale topographical mapping has been on high priority for supporting the nationwide development e.g. detail spatial planning. Usually large scale topographical mapping relies on conventional aerial survey campaigns in order to provide high resolution 3D geospatial data sources. Widely growing on a leisure hobby, aero models in form of the so-called Unmanned Aerial Vehicle (UAV) bring up alternative semi photogrammetric aerial data acquisition possibilities suitable for relatively small Area of Interest (AOI) i.e. <5,000 hectares. For detail spatial planning purposes in Indonesia this area size can be used as a mapping unit since it usually concentrates on the basis of sub district area (kecamatan) level. In this paper different camera and processing software systems will be further analyzed for identifying the best optimum UAV data acquisition campaign components in combination with the data processing scheme. The selected AOI is covering the cultural heritage of Borobudur Temple as one of the Seven Wonders of the World. A detailed accuracy assessment will be concentrated within the object feature of the temple at the first place. Feature compilation involving planimetric objects (2D) and digital terrain models (3D) will be integrated in order to provide Digital Elevation Models (DEM) as the main interest of the topographic mapping activity. By doing this research, incorporating the optimum amount of GCPs in the UAV photo data processing will increase the accuracy along with its high resolution in 5 cm Ground Sampling Distance (GSD). Finally this result will be used as the benchmark for alternative geospatial

  6. Large Scale Composite Manufacturing for Heavy Lift Launch Vehicles

    NASA Technical Reports Server (NTRS)

    Stavana, Jacob; Cohen, Leslie J.; Houseal, Keth; Pelham, Larry; Lort, Richard; Zimmerman, Thomas; Sutter, James; Western, Mike; Harper, Robert; Stuart, Michael

    2012-01-01

    Risk reduction for the large scale composite manufacturing is an important goal to produce light weight components for heavy lift launch vehicles. NASA and an industry team successfully employed a building block approach using low-cost Automated Tape Layup (ATL) of autoclave and Out-of-Autoclave (OoA) prepregs. Several large, curved sandwich panels were fabricated at HITCO Carbon Composites. The aluminum honeycomb core sandwich panels are segments of a 1/16th arc from a 10 meter cylindrical barrel. Lessons learned highlight the manufacturing challenges required to produce light weight composite structures such as fairings for heavy lift launch vehicles.

  7. Clusters as cornerstones of large-scale structure.

    NASA Astrophysics Data System (ADS)

    Gottlöber, S.; Retzlaff, J.; Turchaninov, V.

    1997-04-01

    Galaxy clusters are one of the best tracers of large-scale structure in the Universe on scales well above 100 Mpc. The authors investigate here the clustering properties of a redshift sample of Abell/ACO clusters and compare the observational sample with mock samples constructed from N-body simulations on the basis of four different cosmological models. The authors discuss the power spectrum, the Minkowski functionals and the void statistics of these samples and conclude, that the SCDM and TCDM models are ruled out whereas the ACDM and BSI models are in agreement with the observational data.

  8. Artificial intelligence and large scale computation: A physics perspective

    NASA Astrophysics Data System (ADS)

    Hogg, Tad; Huberman, B. A.

    1987-12-01

    We study the macroscopic behavior of computation and examine both emergent collective phenomena and dynamical aspects with an emphasis on software issues, which are at the core of large scale distributed computation and artificial intelligence systems. By considering large systems, we exhibit novel phenomena which cannot be foreseen from examination of their smaller counterparts. We review both the symbolic and connectionist views of artificial intelligence, provide a number of examples which display these phenomena, and resort to statistical mechanics, dynamical systems theory and the theory of random graphs to elicit the range of possible behaviors.

  9. Potential for geophysical experiments in large scale tests

    SciTech Connect

    Dieterich, J.H.

    1981-07-01

    Potential research applications for large-specimen geophysical experiments include measurements of scale dependence of physical parameters and examination of interactions with heterogeneities, especially flaws such as cracks. In addition, increased specimen size provides opportunities for improved recording resolution and greater control of experimental variables. Large-scale experiments using a special purpose low stress (<40 MPa) bi-axial apparatus demonstrate that a minimum fault length is required to generate confined shear instabilities along pre-existing faults. Experimental analysis of source interactions for simulated earthquakes consisting of confined shear instabilities on a fault with gouge appears to require large specimens (approx.1m) and high confining pressures (>100 MPa).

  10. Quantum computation for large-scale image classification

    NASA Astrophysics Data System (ADS)

    Ruan, Yue; Chen, Hanwu; Tan, Jianing; Li, Xi

    2016-10-01

    Due to the lack of an effective quantum feature extraction method, there is currently no effective way to perform quantum image classification or recognition. In this paper, for the first time, a global quantum feature extraction method based on Schmidt decomposition is proposed. A revised quantum learning algorithm is also proposed that will classify images by computing the Hamming distance of these features. From the experimental results derived from the benchmark database Caltech 101, and an analysis of the algorithm, an effective approach to large-scale image classification is derived and proposed against the background of big data.

  11. Large-scale genotoxicity assessments in the marine environment.

    PubMed

    Hose, J E

    1994-12-01

    There are a number of techniques for detecting genotoxicity in the marine environment, and many are applicable to large-scale field assessments. Certain tests can be used to evaluate responses in target organisms in situ while others utilize surrogate organisms exposed to field samples in short-term laboratory bioassays. Genotoxicity endpoints appear distinct from traditional toxicity endpoints, but some have chemical or ecotoxicologic correlates. One versatile end point, the frequency of anaphase aberrations, has been used in several large marine assessments to evaluate genotoxicity in the New York Bight, in sediment from San Francisco Bay, and following the Exxon Valdez oil spill.

  12. Large-scale sodium spray fire code validation (SOFICOV) test

    SciTech Connect

    Jeppson, D.W.; Muhlestein, L.D.

    1985-01-01

    A large-scale, sodium, spray fire code validation test was performed in the HEDL 850-m/sup 3/ Containment System Test Facility (CSTF) as part of the Sodium Spray Fire Code Validation (SOFICOV) program. Six hundred fifty eight kilograms of sodium spray was sprayed in an air atmosphere for a period of 2400 s. The sodium spray droplet sizes and spray pattern distribution were estimated. The containment atmosphere temperature and pressure response, containment wall temperature response and sodium reaction rate with oxygen were measured. These results are compared to post-test predictions using SPRAY and NACOM computer codes.

  13. Water-based scintillators for large-scale liquid calorimetry

    SciTech Connect

    Winn, D.R.; Raftery, D.

    1985-02-01

    We have investigated primary and secondary solvent intermediates in search of a recipe to create a bulk liquid scintillator with water as the bulk solvent and common fluors as the solutes. As we are not concerned with energy resolution below 1 MeV in large-scale experiments, light-output at the 10% level of high-quality organic solvent based scintillators is acceptable. We have found encouraging performance from industrial surfactants as primary solvents for PPO and POPOP. This technique may allow economical and environmentally safe bulk scintillator for kiloton-sized high energy calorimetry.

  14. Large scale mortality of nestling ardeids caused by nematode infection.

    PubMed

    Wiese, J H; Davidson, W R; Nettles, V F

    1977-10-01

    During the summer of 1976, an epornitic of verminous peritonitis caused by Eustrongylides ignotus resulted in large scale mortality of young herons and egrets on Pea Patch Island, Delaware. Mortality was highest (84%) in snowy egret nestlings ( Egretta thula ) and less severe in great egrets ( Casmerodius albus ), Louisiana herons ( Hydranassa tricolor ), little blue herons ( Florida caerulea ), and black crowned night herons ( Nycticorax nycticorax ). Most deaths occured within the first 4 weeks after hatching. Migration of E. ignotus resulted in multiple perforations of the visceral organs, escape of intestinal contents into the body cavity and subsequent bacterial peritonitis. Killifish ( Fundulus heteroclitus ) served as the source of infective larvae.

  15. The large-scale structure of the solar wind

    NASA Technical Reports Server (NTRS)

    Wolfe, J. H.

    1972-01-01

    The large-scale structure of the solar wind is reviewed on the basis of experimental space measurements acquired over approximately the last decade. The observations cover the fading portion of the last solar cycle up through the maximum of the present cycle. The character of the interplanetary medium is considered from the viewpoint of the temporal behavior of the solar wind over increasingly longer time intervals, the average properties of the various solar wind parameters and their interrelationships. Interplanetary-terrestrial relationships and the expected effects of heliographic lattitude and radial distance are briefly discussed.

  16. Structure and function of large-scale brain systems.

    PubMed

    Koziol, Leonard F; Barker, Lauren A; Joyce, Arthur W; Hrin, Skip

    2014-01-01

    This article introduces the functional neuroanatomy of large-scale brain systems. Both the structure and functions of these brain networks are presented. All human behavior is the result of interactions within and between these brain systems. This system of brain function completely changes our understanding of how cognition and behavior are organized within the brain, replacing the traditional lesion model. Understanding behavior within the context of brain network interactions has profound implications for modifying abstract constructs such as attention, learning, and memory. These constructs also must be understood within the framework of a paradigm shift, which emphasizes ongoing interactions within a dynamically changing environment.

  17. Large scale obscuration and related climate effects open literature bibliography

    SciTech Connect

    Russell, N.A.; Geitgey, J.; Behl, Y.K.; Zak, B.D.

    1994-05-01

    Large scale obscuration and related climate effects of nuclear detonations first became a matter of concern in connection with the so-called ``Nuclear Winter Controversy`` in the early 1980`s. Since then, the world has changed. Nevertheless, concern remains about the atmospheric effects of nuclear detonations, but the source of concern has shifted. Now it focuses less on global, and more on regional effects and their resulting impacts on the performance of electro-optical and other defense-related systems. This bibliography reflects the modified interest.

  18. Decentrally stabilizable linear and bilinear large-scale systems

    NASA Technical Reports Server (NTRS)

    Siljak, D. D.; Vukcevic, M. B.

    1977-01-01

    Two classes of large-scale systems are identified, which can always be stabilized by decentralized feedback control. For the class of systems composed of interconnected linear subsystems, we can choose local controllers for the subsystems to achieve stability of the overall system. The same linear feedback scheme can be used to stabilize a class of linear systems with bilinear interconnections. In this case, however, the scheme is used to establish a finite region of stability for the overall system. The stabilization algorithm is applied to the design of a control system for the Large-Space Telescope.

  19. Large-scale structure from wiggly cosmic strings

    NASA Astrophysics Data System (ADS)

    Vachaspati, Tanmay; Vilenkin, Alexander

    1991-08-01

    Recent simulations of the evolution of cosmic strings indicate the presence of small-scale structure on the strings. It is shown that wakes produced by such 'wiggly' cosmic strings can result in the efficient formation of large-scale structure and large streaming velocities in the universe without significantly affecting the microwave-background isotropy. It is also argued that the motion of strings will lead to the generation of a primordial magnetic field. The most promising version of this scenario appears to be the one in which the universe is dominated by light neutrinos.

  20. Large-scale genotoxicity assessments in the marine environment.

    PubMed Central

    Hose, J E

    1994-01-01

    There are a number of techniques for detecting genotoxicity in the marine environment, and many are applicable to large-scale field assessments. Certain tests can be used to evaluate responses in target organisms in situ while others utilize surrogate organisms exposed to field samples in short-term laboratory bioassays. Genotoxicity endpoints appear distinct from traditional toxicity endpoints, but some have chemical or ecotoxicologic correlates. One versatile end point, the frequency of anaphase aberrations, has been used in several large marine assessments to evaluate genotoxicity in the New York Bight, in sediment from San Francisco Bay, and following the Exxon Valdez oil spill. PMID:7713029

  1. Towards large scale production and separation of carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Alvarez, Noe T.

    Since their discovery, carbon nanotubes (CNTs) have boosted the research and applications of nanotechnology; however, many applications of CNTs are inaccessible because they depend upon large-scale CNT production and separations. Type, chirality and diameter control of CNTs determine many of their physical properties, and such control is still not accesible. This thesis studies the fundamentals for scalable selective reactions of HiPCo CNTs as well as the early phase of routes to an inexpensive approach for large-scale CNT production. In the growth part, this thesis covers a complete wet-chemistry process of catalyst and catalyst support deposition for growth of vertically aligned (VA) CNTs. A wet-chemistry preparation process has significant importance for CNT synthesis through chemical vapor deposition (CVD). CVD is by far, the most suitable and inexpensive process for large-scale CNT production when compared to other common processes such as laser ablation and arc discharge. However, its potential has been limited by low-yielding and difficult preparation processes of catalyst and its support, therefore its competitiveness has been reduced. The wet-chemistry process takes advantage of current nanoparticle technology to deposit the catalyst and the catalyst support as a thin film of nanoparticles, making the protocol simple compared to electron beam evaporation and sputtering processes. In the CNT selective reactions part, this thesis studies UV irradiation of individually dispersed HiPCo CNTs that generates auto-selective reactions in the liquid phase with good control over their diameter and chirality. This technique is ideal for large-scale and continuous-process of separations of CNTs by diameter and type. Additionally, an innovative simple catalyst deposition through abrasion is demonstrated. Simple friction between the catalyst and the substrates deposit a high enough density of metal catalyst particles for successful CNT growth. This simple approach has

  2. Large-scale genotoxicity assessments in the marine environment

    SciTech Connect

    Hose, J.E.

    1994-12-01

    There are a number of techniques for detecting genotoxicity in the marine environment, and many are applicable to large-scale field assessments. Certain tests can be used to evaluate responses in target organisms in situ while others utilize surrogate organisms exposed to field samples in short-term laboratory bioassays. Genotoxicity endpoints appear distinct from traditional toxicity endpoints, but some have chemical or ecotoxicologic correlates. One versatile end point, the frequency of anaphase aberrations, has been used in several large marine assessments to evaluate genotoxicity in the New York Bight, in sediment from San Francisco Bay, and following the Exxon Valdez oil spill. 31 refs., 2 tabs.

  3. Large Scale Observatories for Changing Cold Regions - Recent Progress and Future Vision

    NASA Astrophysics Data System (ADS)

    Wheater, H. S.; Pomeroy, J. W.; Carey, S. K.; DeBeer, C. M.

    2016-12-01

    Observatories are at the core of hydrological science and a critical resource for the detection and analysis of environmental change. The combination of multiple pressures on the water environment and new scientific opportunities provides a context where a broader vision is urgently needed. Human activities are increasingly affecting land and water management at multiple scales, so our observatories now need to more fully include the human dimensions of water, including their integration across jurisdictional boundaries and at large basin scales. And large scales are also needed to diagnose and predict impacts of climate change at regional and continental scales, and to address land-water-atmosphere interactions and feedbacks. We argue the need to build on the notable past successes of the World Climate Research Programme and move forward to a new era of globally-distributed large scale observatories. This paper introduces 2 such observatories in rapidly warming western Canada - the 405,000 km2 Saskatchewan and the 1.8 million km2 Mackenzie river basins. We review progress in these multi-scale observatories, including the use of point and small basin-scale observatory sites to observe and diagnose complex regional patterns of hydrological change. And building on new opportunities for observational systems and data assimilation, we present a vision for a pan-Canadian observing system to support the science needed for the management of future societal risk from extreme events and environmental change.

  4. Fully-automated roller bottle handling system for large scale culture of mammalian cells.

    PubMed

    Kunitake, R; Suzuki, A; Ichihashi, H; Matsuda, S; Hirai, O; Morimoto, K

    1997-01-20

    A fully automatic and continuous cell culture system based on roller bottles is described in this paper. The system includes a culture rack storage station for storing a large number of roller bottles filled with culture medium and inoculated with mammalian cells, mass-handling facility for extracting completed cultures from the roller bottles, and replacing the culture medium. The various component units of the system were controlled either by a general-purpose programmable logic controller or a dedicated controller. The system provided four subsequent operation modes: cell inoculation, medium change, harvesting, and medium change. The operator could easily select and change the appropriate mode from outside of the aseptic area. The development of the system made large-scale production of mammalian cells, and manufacturing and stabilization of high quality products such as erythropoietin possible under total aseptic control, and opened up the door for industrial production of physiologically active substances as pharmaceutical drugs by mammalian cell culture.

  5. Ecohydrological modeling for large-scale environmental impact assessment.

    PubMed

    Woznicki, Sean A; Nejadhashemi, A Pouyan; Abouali, Mohammad; Herman, Matthew R; Esfahanian, Elaheh; Hamaamin, Yaseen A; Zhang, Zhen

    2016-02-01

    Ecohydrological models are frequently used to assess the biological integrity of unsampled streams. These models vary in complexity and scale, and their utility depends on their final application. Tradeoffs are usually made in model scale, where large-scale models are useful for determining broad impacts of human activities on biological conditions, and regional-scale (e.g. watershed or ecoregion) models provide stakeholders greater detail at the individual stream reach level. Given these tradeoffs, the objective of this study was to develop large-scale stream health models with reach level accuracy similar to regional-scale models thereby allowing for impacts assessments and improved decision-making capabilities. To accomplish this, four measures of biological integrity (Ephemeroptera, Plecoptera, and Trichoptera taxa (EPT), Family Index of Biotic Integrity (FIBI), Hilsenhoff Biotic Index (HBI), and fish Index of Biotic Integrity (IBI)) were modeled based on four thermal classes (cold, cold-transitional, cool, and warm) of streams that broadly dictate the distribution of aquatic biota in Michigan. The Soil and Water Assessment Tool (SWAT) was used to simulate streamflow and water quality in seven watersheds and the Hydrologic Index Tool was used to calculate 171 ecologically relevant flow regime variables. Unique variables were selected for each thermal class using a Bayesian variable selection method. The variables were then used in development of adaptive neuro-fuzzy inference systems (ANFIS) models of EPT, FIBI, HBI, and IBI. ANFIS model accuracy improved when accounting for stream thermal class rather than developing a global model.

  6. Brief Mental Training Reorganizes Large-Scale Brain Networks

    PubMed Central

    Tang, Yi-Yuan; Tang, Yan; Tang, Rongxiang; Lewis-Peacock, Jarrod A.

    2017-01-01

    Emerging evidences have shown that one form of mental training—mindfulness meditation, can improve attention, emotion regulation and cognitive performance through changing brain activity and structural connectivity. However, whether and how the short-term mindfulness meditation alters large-scale brain networks are not well understood. Here, we applied a novel data-driven technique, the multivariate pattern analysis (MVPA) to resting-state fMRI (rsfMRI) data to identify changes in brain activity patterns and assess the neural mechanisms induced by a brief mindfulness training—integrative body–mind training (IBMT), which was previously reported in our series of randomized studies. Whole brain rsfMRI was performed on an undergraduate group who received 2 weeks of IBMT with 30 min per session (5 h training in total). Classifiers were trained on measures of functional connectivity in this fMRI data, and they were able to reliably differentiate (with 72% accuracy) patterns of connectivity from before vs. after the IBMT training. After training, an increase in positive functional connections (60 connections) were detected, primarily involving bilateral superior/middle occipital gyrus, bilateral frontale operculum, bilateral superior temporal gyrus, right superior temporal pole, bilateral insula, caudate and cerebellum. These results suggest that brief mental training alters the functional connectivity of large-scale brain networks at rest that may involve a portion of the neural circuitry supporting attention, cognitive and affective processing, awareness and sensory integration and reward processing. PMID:28293180

  7. Topographically Engineered Large Scale Nanostructures for Plasmonic Biosensing

    PubMed Central

    Xiao, Bo; Pradhan, Sangram K.; Santiago, Kevin C.; Rutherford, Gugu N.; Pradhan, Aswini K.

    2016-01-01

    We demonstrate that a nanostructured metal thin film can achieve enhanced transmission efficiency and sharp resonances and use a large-scale and high-throughput nanofabrication technique for the plasmonic structures. The fabrication technique combines the features of nanoimprint and soft lithography to topographically construct metal thin films with nanoscale patterns. Metal nanogratings developed using this method show significantly enhanced optical transmission (up to a one-order-of-magnitude enhancement) and sharp resonances with full width at half maximum (FWHM) of ~15nm in the zero-order transmission using an incoherent white light source. These nanostructures are sensitive to the surrounding environment, and the resonance can shift as the refractive index changes. We derive an analytical method using a spatial Fourier transformation to understand the enhancement phenomenon and the sensing mechanism. The use of real-time monitoring of protein-protein interactions in microfluidic cells integrated with these nanostructures is demonstrated to be effective for biosensing. The perpendicular transmission configuration and large-scale structures provide a feasible platform without sophisticated optical instrumentation to realize label-free surface plasmon resonance (SPR) sensing. PMID:27072067

  8. Development of Large-Scale Functional Brain Networks in Children

    PubMed Central

    Supekar, Kaustubh; Musen, Mark; Menon, Vinod

    2009-01-01

    The ontogeny of large-scale functional organization of the human brain is not well understood. Here we use network analysis of intrinsic functional connectivity to characterize the organization of brain networks in 23 children (ages 7–9 y) and 22 young-adults (ages 19–22 y). Comparison of network properties, including path-length, clustering-coefficient, hierarchy, and regional connectivity, revealed that although children and young-adults' brains have similar “small-world” organization at the global level, they differ significantly in hierarchical organization and interregional connectivity. We found that subcortical areas were more strongly connected with primary sensory, association, and paralimbic areas in children, whereas young-adults showed stronger cortico-cortical connectivity between paralimbic, limbic, and association areas. Further, combined analysis of functional connectivity with wiring distance measures derived from white-matter fiber tracking revealed that the development of large-scale brain networks is characterized by weakening of short-range functional connectivity and strengthening of long-range functional connectivity. Importantly, our findings show that the dynamic process of over-connectivity followed by pruning, which rewires connectivity at the neuronal level, also operates at the systems level, helping to reconfigure and rebalance subcortical and paralimbic connectivity in the developing brain. Our study demonstrates the usefulness of network analysis of brain connectivity to elucidate key principles underlying functional brain maturation, paving the way for novel studies of disrupted brain connectivity in neurodevelopmental disorders such as autism. PMID:19621066

  9. The effective field theory of cosmological large scale structures

    SciTech Connect

    Carrasco, John Joseph M.; Hertzberg, Mark P.; Senatore, Leonardo

    2012-09-20

    Large scale structure surveys will likely become the next leading cosmological probe. In our universe, matter perturbations are large on short distances and small at long scales, i.e. strongly coupled in the UV and weakly coupled in the IR. To make precise analytical predictions on large scales, we develop an effective field theory formulated in terms of an IR effective fluid characterized by several parameters, such as speed of sound and viscosity. These parameters, determined by the UV physics described by the Boltzmann equation, are measured from N-body simulations. We find that the speed of sound of the effective fluid is c2s ≈ 10–6c2 and that the viscosity contributions are of the same order. The fluid describes all the relevant physics at long scales k and permits a manifestly convergent perturbative expansion in the size of the matter perturbations δ(k) for all the observables. As an example, we calculate the correction to the power spectrum at order δ(k)4. As a result, the predictions of the effective field theory are found to be in much better agreement with observation than standard cosmological perturbation theory, already reaching percent precision at this order up to a relatively short scale k ≃ 0.24h Mpc–1.

  10. Maestro: an orchestration framework for large-scale WSN simulations.

    PubMed

    Riliskis, Laurynas; Osipov, Evgeny

    2014-03-18

    Contemporary wireless sensor networks (WSNs) have evolved into large and complex systems and are one of the main technologies used in cyber-physical systems and the Internet of Things. Extensive research on WSNs has led to the development of diverse solutions at all levels of software architecture, including protocol stacks for communications. This multitude of solutions is due to the limited computational power and restrictions on energy consumption that must be accounted for when designing typical WSN systems. It is therefore challenging to develop, test and validate even small WSN applications, and this process can easily consume significant resources. Simulations are inexpensive tools for testing, verifying and generally experimenting with new technologies in a repeatable fashion. Consequently, as the size of the systems to be tested increases, so does the need for large-scale simulations. This article describes a tool called Maestro for the automation of large-scale simulation and investigates the feasibility of using cloud computing facilities for such task. Using tools that are built into Maestro, we demonstrate a feasible approach for benchmarking cloud infrastructure in order to identify cloud Virtual Machine (VM)instances that provide an optimal balance of performance and cost for a given simulation.

  11. High Speed Networking and Large-scale Simulation in Geodynamics

    NASA Technical Reports Server (NTRS)

    Kuang, Weijia; Gary, Patrick; Seablom, Michael; Truszkowski, Walt; Odubiyi, Jide; Jiang, Weiyuan; Liu, Dong

    2004-01-01

    Large-scale numerical simulation has been one of the most important approaches for understanding global geodynamical processes. In this approach, peta-scale floating point operations (pflops) are often required to carry out a single physically-meaningful numerical experiment. For example, to model convective flow in the Earth's core and generation of the geomagnetic field (geodynamo), simulation for one magnetic free-decay time (approximately 15000 years) with a modest resolution of 150 in three spatial dimensions would require approximately 0.2 pflops. If such a numerical model is used to predict geomagnetic secular variation over decades and longer, with e.g. an ensemble Kalman filter assimilation approach, approximately 30 (and perhaps more) independent simulations of similar scales would be needed for one data assimilation analysis. Obviously, such a simulation would require an enormous computing resource that exceeds the capacity of a single facility currently available at our disposal. One solution is to utilize a very fast network (e.g. 10Gb optical networks) and available middleware (e.g. Globus Toolkit) to allocate available but often heterogeneous resources for such large-scale computing efforts. At NASA GSFC, we are experimenting with such an approach by networking several clusters for geomagnetic data assimilation research. We shall present our initial testing results in the meeting.

  12. Online education in a large scale rehabilitation institution.

    PubMed

    Mazzoleni, M Cristina; Rognoni, Carla; Pagani, Marco; Imbriani, Marcello

    2012-01-01

    Large scale multiple venue institutions face problems when delivering educations to their healthcare staff. The present study is aimed at evaluating the feasibility of relying on e-learning for at least part of the training of the Salvatore Maugeri Foundation healthcare staff. The paper reports the results of the delivery of e-learning courses to the personnel during a span of time of 7 months in order to assess the attitude to online courses attendance, the proportion between administered online education and administered traditional education, the economic sustainability of the online education delivery process. 37% of the total healthcare staff have attended online courses and 46% of nurses have proved to be the very active. The ratio between total number of credits and total number of courses for online and traditional education are respectively 18268/5 and 20354/96. These results point out that eLearning is not at all a niche tool used (or usable) by a limited number of people. Economic sustainability, assessed via personnel work hour saving, has been demonstrated. When distance learning is appropriate, online education is an effective, sustainable, well accepted mean to support and promote healthcare staff's education in a large scale institution.

  13. Large-scale anisotropy in stably stratified rotating flows

    DOE PAGES

    Marino, R.; Mininni, P. D.; Rosenberg, D. L.; ...

    2014-08-28

    We present results from direct numerical simulations of the Boussinesq equations in the presence of rotation and/or stratification, both in the vertical direction. The runs are forced isotropically and randomly at small scales and have spatial resolutions of up tomore » $1024^3$ grid points and Reynolds numbers of $$\\approx 1000$$. We first show that solutions with negative energy flux and inverse cascades develop in rotating turbulence, whether or not stratification is present. However, the purely stratified case is characterized instead by an early-time, highly anisotropic transfer to large scales with almost zero net isotropic energy flux. This is consistent with previous studies that observed the development of vertically sheared horizontal winds, although only at substantially later times. However, and unlike previous works, when sufficient scale separation is allowed between the forcing scale and the domain size, the total energy displays a perpendicular (horizontal) spectrum with power law behavior compatible with $$\\sim k_\\perp^{-5/3}$$, including in the absence of rotation. In this latter purely stratified case, such a spectrum is the result of a direct cascade of the energy contained in the large-scale horizontal wind, as is evidenced by a strong positive flux of energy in the parallel direction at all scales including the largest resolved scales.« less

  14. Large-scale anisotropy in stably stratified rotating flows

    SciTech Connect

    Marino, R.; Mininni, P. D.; Rosenberg, D. L.; Pouquet, A.

    2014-08-28

    We present results from direct numerical simulations of the Boussinesq equations in the presence of rotation and/or stratification, both in the vertical direction. The runs are forced isotropically and randomly at small scales and have spatial resolutions of up to $1024^3$ grid points and Reynolds numbers of $\\approx 1000$. We first show that solutions with negative energy flux and inverse cascades develop in rotating turbulence, whether or not stratification is present. However, the purely stratified case is characterized instead by an early-time, highly anisotropic transfer to large scales with almost zero net isotropic energy flux. This is consistent with previous studies that observed the development of vertically sheared horizontal winds, although only at substantially later times. However, and unlike previous works, when sufficient scale separation is allowed between the forcing scale and the domain size, the total energy displays a perpendicular (horizontal) spectrum with power law behavior compatible with $\\sim k_\\perp^{-5/3}$, including in the absence of rotation. In this latter purely stratified case, such a spectrum is the result of a direct cascade of the energy contained in the large-scale horizontal wind, as is evidenced by a strong positive flux of energy in the parallel direction at all scales including the largest resolved scales.

  15. Practical considerations for large-scale gut microbiome studies.

    PubMed

    Vandeputte, Doris; Tito, Raul Y; Vanleeuwen, Rianne; Falony, Gwen; Raes, Jeroen

    2017-08-01

    First insights on the human gut microbiome have been gained from medium-sized, cross-sectional studies. However, given the modest portion of explained variance of currently identified covariates and the small effect size of gut microbiota modulation strategies, upscaling seems essential for further discovery and characterisation of the multiple influencing factors and their relative contribution. In order to guide future research projects and standardisation efforts, we here review currently applied collection and preservation methods for gut microbiome research. We discuss aspects such as sample quality, applicable omics techniques, user experience and time and cost efficiency. In addition, we evaluate the protocols of a large-scale microbiome cohort initiative, the Flemish Gut Flora Project, to give an idea of perspectives, and pitfalls of large-scale faecal sampling studies. Although cryopreservation can be regarded as the gold standard, freezing protocols generally require more resources due to cold chain management. However, here we show that much can be gained from an optimised transport chain and sample aliquoting before freezing. Other protocols can be useful as long as they preserve the microbial signature of a sample such that relevant conclusions can be drawn regarding the research question, and the obtained data are stable and reproducible over time. © FEMS 2017.

  16. Large scale CMB anomalies from thawing cosmic strings

    SciTech Connect

    Ringeval, Christophe; Yamauchi, Daisuke; Yokoyama, Jun'ichi; Bouchet, François R. E-mail: yamauchi@resceu.s.u-tokyo.ac.jp E-mail: bouchet@iap.fr

    2016-02-01

    Cosmic strings formed during inflation are expected to be either diluted over super-Hubble distances, i.e., invisible today, or to have crossed our past light cone very recently. We discuss the latter situation in which a few strings imprint their signature in the Cosmic Microwave Background (CMB) Anisotropies after recombination. Being almost frozen in the Hubble flow, these strings are quasi static and evade almost all of the previously derived constraints on their tension while being able to source large scale anisotropies in the CMB sky. Using a local variance estimator on thousand of numerically simulated Nambu-Goto all sky maps, we compute the expected signal and show that it can mimic a dipole modulation at large angular scales while being negligible at small angles. Interestingly, such a scenario generically produces one cold spot from the thawing of a cosmic string loop. Mixed with anisotropies of inflationary origin, we find that a few strings of tension GU = O(1) × 10{sup −6} match the amplitude of the dipole modulation reported in the Planck satellite measurements and could be at the origin of other large scale anomalies.

  17. The Impact of Large Scale Environments on Cluster Entropy Profiles

    NASA Astrophysics Data System (ADS)

    Trierweiler, Isabella; Su, Yuanyuan

    2017-01-01

    We perform a systematic analysis of 21 clusters imaged by the Suzaku satellite to determine the relation between the richness of cluster environments and entropy at large radii. Entropy profiles for clusters are expected to follow a power-law, but Suzaku observations show that the entropy profiles of many clusters are significantly flattened beyond 0.3 Rvir. While the entropy at the outskirts of clusters is thought to be highly dependent on the large scale cluster environment, the exact nature of the environment/entropy relation is unclear. Using the Sloan Digital Sky Survey and 6dF Galaxy Survey, we study the 20 Mpc large scale environment for all clusters in our sample. We find no strong relation between the entropy deviations at the virial radius and the total luminosity of the cluster surroundings, indicating that accretion and mergers have a more complex and indirect influence on the properties of the gas at large radii. We see a possible anti-correlation between virial temperature and richness of the cluster environment and find that density excess appears to play a larger role in the entropy flattening than temperature, suggesting that clumps of gas can lower entropy.

  18. The combustion behavior of large scale lithium titanate battery

    PubMed Central

    Huang, Peifeng; Wang, Qingsong; Li, Ke; Ping, Ping; Sun, Jinhua

    2015-01-01

    Safety problem is always a big obstacle for lithium battery marching to large scale application. However, the knowledge on the battery combustion behavior is limited. To investigate the combustion behavior of large scale lithium battery, three 50 Ah Li(NixCoyMnz)O2/Li4Ti5O12 batteries under different state of charge (SOC) were heated to fire. The flame size variation is depicted to analyze the combustion behavior directly. The mass loss rate, temperature and heat release rate are used to analyze the combustion behavior in reaction way deeply. Based on the phenomenon, the combustion process is divided into three basic stages, even more complicated at higher SOC with sudden smoke flow ejected. The reason is that a phase change occurs in Li(NixCoyMnz)O2 material from layer structure to spinel structure. The critical temperatures of ignition are at 112–121°C on anode tab and 139 to 147°C on upper surface for all cells. But the heating time and combustion time become shorter with the ascending of SOC. The results indicate that the battery fire hazard increases with the SOC. It is analyzed that the internal short and the Li+ distribution are the main causes that lead to the difference. PMID:25586064

  19. The effect of large scale inhomogeneities on the luminosity distance

    NASA Astrophysics Data System (ADS)

    Brouzakis, Nikolaos; Tetradis, Nikolaos; Tzavara, Eleftheria

    2007-02-01

    We study the form of the luminosity distance as a function of redshift in the presence of large scale inhomogeneities, with sizes of order 10 Mpc or larger. We approximate the Universe through the Swiss-cheese model, with each spherical region described by the Lemaitre Tolman Bondi metric. We study the propagation of light beams in this background, assuming that the locations of the source and the observer are random. We derive the optical equations for the evolution of the beam area and shear. Through their integration we determine the configurations that can lead to an increase of the luminosity distance relative to the homogeneous cosmology. We find that this can be achieved if the Universe is composed of spherical void-like regions, with matter concentrated near their surface. For inhomogeneities consistent with the observed large scale structure, the relative increase of the luminosity distance is of the order of a few per cent at redshifts near 1, and falls short of explaining the substantial increase required by the supernova data. On the other hand, the effect we describe is important for the correct determination of the energy content of the Universe from observations.

  20. Brief Mental Training Reorganizes Large-Scale Brain Networks.

    PubMed

    Tang, Yi-Yuan; Tang, Yan; Tang, Rongxiang; Lewis-Peacock, Jarrod A

    2017-01-01

    Emerging evidences have shown that one form of mental training-mindfulness meditation, can improve attention, emotion regulation and cognitive performance through changing brain activity and structural connectivity. However, whether and how the short-term mindfulness meditation alters large-scale brain networks are not well understood. Here, we applied a novel data-driven technique, the multivariate pattern analysis (MVPA) to resting-state fMRI (rsfMRI) data to identify changes in brain activity patterns and assess the neural mechanisms induced by a brief mindfulness training-integrative body-mind training (IBMT), which was previously reported in our series of randomized studies. Whole brain rsfMRI was performed on an undergraduate group who received 2 weeks of IBMT with 30 min per session (5 h training in total). Classifiers were trained on measures of functional connectivity in this fMRI data, and they were able to reliably differentiate (with 72% accuracy) patterns of connectivity from before vs. after the IBMT training. After training, an increase in positive functional connections (60 connections) were detected, primarily involving bilateral superior/middle occipital gyrus, bilateral frontale operculum, bilateral superior temporal gyrus, right superior temporal pole, bilateral insula, caudate and cerebellum. These results suggest that brief mental training alters the functional connectivity of large-scale brain networks at rest that may involve a portion of the neural circuitry supporting attention, cognitive and affective processing, awareness and sensory integration and reward processing.

  1. Measuring Cosmic Expansion and Large Scale Structure with Destiny

    NASA Technical Reports Server (NTRS)

    Benford, Dominic J.; Lauer, Tod R.

    2007-01-01

    Destiny is a simple, direct, low cost mission to determine the properties of dark energy by obtaining a cosmologically deep supernova (SN) type Ia Hubble diagram and by measuring the large-scale mass power spectrum over time. Its science instrument is a 1.65m space telescope, featuring a near-infrared survey camera/spectrometer with a large field of view. During its first two years, Destiny will detect, observe, and characterize 23000 SN Ia events over the redshift interval 0.4lo00 square degrees to measure the large-scale mass power spectrum. The combination of surveys is much more powerful than either technique on its own, and will have over an order of magnitude greater sensitivity than will be provided by ongoing ground-based projects.

  2. Power suppression at large scales in string inflation

    SciTech Connect

    Cicoli, Michele; Downes, Sean; Dutta, Bhaskar E-mail: sddownes@physics.tamu.edu

    2013-12-01

    We study a possible origin of the anomalous suppression of the power spectrum at large angular scales in the cosmic microwave background within the framework of explicit string inflationary models where inflation is driven by a closed string modulus parameterizing the size of the extra dimensions. In this class of models the apparent power loss at large scales is caused by the background dynamics which involves a sharp transition from a fast-roll power law phase to a period of Starobinsky-like slow-roll inflation. An interesting feature of this class of string inflationary models is that the number of e-foldings of inflation is inversely proportional to the string coupling to a positive power. Therefore once the string coupling is tuned to small values in order to trust string perturbation theory, enough e-foldings of inflation are automatically obtained without the need of extra tuning. Moreover, in the less tuned cases the sharp transition responsible for the power loss takes place just before the last 50-60 e-foldings of inflation. We illustrate these general claims in the case of Fibre Inflation where we study the strength of this transition in terms of the attractor dynamics, finding that it induces a pivot from a blue to a redshifted power spectrum which can explain the apparent large scale power loss. We compute the effects of this pivot for example cases and demonstrate how magnitude and duration of this effect depend on model parameters.

  3. Large-scale columnar vortices in rotating turbulence

    NASA Astrophysics Data System (ADS)

    Yokoyama, Naoto; Takaoka, Masanori

    2016-11-01

    In the rotating turbulence, flow structures are affected by the angular velocity of the system's rotation. When the angular velocity is small, three-dimensional statistically-isotropic flow, which has the Kolmogorov spectrum all over the inertial subrange, is formed. When the angular velocity increases, the flow becomes two-dimensional anisotropic, and the energy spectrum has a power law k-2 in the small wavenumbers in addition to the Kolmogorov spectrum in the large wavenumbers. When the angular velocity decreases, the flow returns to the isotropic one. It is numerically found that the transition between the isotropic and anisotropic flows is hysteretic; the critical angular velocity at which the flow transitions from the anisotropic one to the isotropic one, and that of the reverse transition are different. It is also observed that the large-scale columnar structures in the anisotropic flow depends on the external force which maintains a statistically-steady state. In some cases, small-scale anticyclonic structures are aligned in a columnar structure apart from the cyclonic Taylor column. The formation mechanism of the large-scale columnar structures will be discussed. This work was partially supported by JSPS KAKENHI.

  4. Knocking down highly-ordered large-scale nanowire arrays.

    PubMed

    Pevzner, Alexander; Engel, Yoni; Elnathan, Roey; Ducobni, Tamir; Ben-Ishai, Moshit; Reddy, Koteeswara; Shpaisman, Nava; Tsukernik, Alexander; Oksman, Mark; Patolsky, Fernando

    2010-04-14

    The large-scale assembly of nanowire elements with controlled and uniform orientation and density at spatially well-defined locations on solid substrates presents one of the most significant challenges facing their integration in real-world electronic applications. Here, we present the universal "knocking-down" approach, based on the controlled in-place planarization of nanowire elements, for the formation of large-scale ordered nanowire arrays. The controlled planarization of the nanowires is achieved by the use of an appropriate elastomer-covered rigid-roller device. After being knocked down, each nanowire in the array can be easily addressed electrically, by a simple single photolithographic step, to yield a large number of nanoelectrical devices with an unprecedented high-fidelity rate. The approach allows controlling, in only two simple steps, all possible array parameters, that is, nanowire dimensions, chemical composition, orientation, and density. The resulting knocked-down arrays can be further used for the creation of massive nanoelectronic-device arrays. More than million devices were already fabricated with yields over 98% on substrate areas of up, but not limited to, to 10 cm(2).

  5. Large-scale forcing on lightning in Portugal

    NASA Astrophysics Data System (ADS)

    Santos, J. A.; Sousa, J.; Reis, M. A.; Leite, S. M.; Correia, S.; Fraga, H.; Fragoso, M.

    2012-04-01

    An overview of the large-scale atmospheric forcing on the occurrence of cloud-to-ground lightning activity over Portugal is presented here. A dataset generated by a network of nine sensors, maintained by the Portuguese Meteorological Institute (four sensors) and by Spanish Meteorological Agency (five sensors), with available data over the 2003-2009 time period (7 years) is used for this purpose. For the same time period, a state-of-the-art high-resolution reanalysis dataset in a 1.0° latitude × 1.0° longitude grid (Modern Era Retrospective - Analysis for Research and Applications; MERRA300) is also considered in order to assess the atmospheric large-scale features over the target region. Three lightning regimes of the atmospheric general circulation within the Euro-Atlantic sector can be clearly detected. These regimes are characterized according to their underlying dynamical conditions (sea surface pressure, 500 hPa geopotential height and air temperature, streamlines of the 10 m wind vectors, and best 4-layer lifted index at 500 hPa). The spatial distribution of lighting activity in Portugal (patterns of the density of the atmospheric electrical discharges) is also analyzed for each regime separately. Considerations regarding seasonality, flash polarity and daily cycles in the lighting activity are also given for each lightning regime.

  6. Halo detection via large-scale Bayesian inference

    NASA Astrophysics Data System (ADS)

    Merson, Alexander I.; Jasche, Jens; Abdalla, Filipe B.; Lahav, Ofer; Wandelt, Benjamin; Jones, D. Heath; Colless, Matthew

    2016-08-01

    We present a proof-of-concept of a novel and fully Bayesian methodology designed to detect haloes of different masses in cosmological observations subject to noise and systematic uncertainties. Our methodology combines the previously published Bayesian large-scale structure inference algorithm, HAmiltonian Density Estimation and Sampling algorithm (HADES), and a Bayesian chain rule (the Blackwell-Rao estimator), which we use to connect the inferred density field to the properties of dark matter haloes. To demonstrate the capability of our approach, we construct a realistic galaxy mock catalogue emulating the wide-area 6-degree Field Galaxy Survey, which has a median redshift of approximately 0.05. Application of HADES to the catalogue provides us with accurately inferred three-dimensional density fields and corresponding quantification of uncertainties inherent to any cosmological observation. We then use a cosmological simulation to relate the amplitude of the density field to the probability of detecting a halo with mass above a specified threshold. With this information, we can sum over the HADES density field realisations to construct maps of detection probabilities and demonstrate the validity of this approach within our mock scenario. We find that the probability of successful detection of haloes in the mock catalogue increases as a function of the signal to noise of the local galaxy observations. Our proposed methodology can easily be extended to account for more complex scientific questions and is a promising novel tool to analyse the cosmic large-scale structure in observations.

  7. A visual backchannel for large-scale events.

    PubMed

    Dörk, Marian; Gruen, Daniel; Williamson, Carey; Carpendale, Sheelagh

    2010-01-01

    We introduce the concept of a Visual Backchannel as a novel way of following and exploring online conversations about large-scale events. Microblogging communities, such as Twitter, are increasingly used as digital backchannels for timely exchange of brief comments and impressions during political speeches, sport competitions, natural disasters, and other large events. Currently, shared updates are typically displayed in the form of a simple list, making it difficult to get an overview of the fast-paced discussions as it happens in the moment and how it evolves over time. In contrast, our Visual Backchannel design provides an evolving, interactive, and multi-faceted visual overview of large-scale ongoing conversations on Twitter. To visualize a continuously updating information stream, we include visual saliency for what is happening now and what has just happened, set in the context of the evolving conversation. As part of a fully web-based coordinated-view system we introduce Topic Streams, a temporally adjustable stacked graph visualizing topics over time, a People Spiral representing participants and their activity, and an Image Cloud encoding the popularity of event photos by size. Together with a post listing, these mutually linked views support cross-filtering along topics, participants, and time ranges. We discuss our design considerations, in particular with respect to evolving visualizations of dynamically changing data. Initial feedback indicates significant interest and suggests several unanticipated uses.

  8. Very large-scale motions in a turbulent pipe flow

    NASA Astrophysics Data System (ADS)

    Lee, Jae Hwa; Jang, Seong Jae; Sung, Hyung Jin

    2011-11-01

    Direct numerical simulation of a turbulent pipe flow with ReD=35000 was performed to investigate the spatially coherent structures associated with very large-scale motions. The corresponding friction Reynolds number, based on pipe radius R, is R+=934, and the computational domain length is 30 R. The computed mean flow statistics agree well with previous DNS data at ReD=44000 and 24000. Inspection of the instantaneous fields and two-point correlation of the streamwise velocity fluctuations showed that the very long meandering motions exceeding 25R exist in logarithmic and wake regions, and the streamwise length scale is almost linearly increased up to y/R ~0.3, while the structures in the turbulent boundary layer only reach up to the edge of the log-layer. Time-resolved instantaneous fields revealed that the hairpin packet-like structures grow with continuous stretching along the streamwise direction and create the very large-scale structures with meandering in the spanwise direction, consistent with the previous conceptual model of Kim & Adrian (1999). This work was supported by the Creative Research Initiatives of NRF/MEST of Korea (No. 2011-0000423).

  9. Semantic overlay network for large-scale spatial information indexing

    NASA Astrophysics Data System (ADS)

    Zou, Zhiqiang; Wang, Yue; Cao, Kai; Qu, Tianshan; Wang, Zhongmin

    2013-08-01

    The increased demand for online services of spatial information poses new challenges to the combined filed of Computer Science and Geographic Information Science. Amongst others, these include fast indexing of spatial data in distributed networks. In this paper we propose a novel semantic overlay network for large-scale multi-dimensional spatial information indexing, called SON_LSII, which has a hybrid structure integrating a semantic quad-tree and Chord ring. The SON_LSII is a small world overlay network that achieves a very competitive trade-off between indexing efficiency and maintenance overhead. To create SON_LSII, we use an effective semantic clustering strategy that considers two aspects, i.e., the semantic of spatial information that peer holds in overlay network and physical network performances. Based on SON_LSII, a mapping method is used to reduce the multi-dimensional features into a single dimension and an efficient indexing algorithm is presented to support complex range queries of the spatial information with a massive number of concurrent users. The results from extensive experiments demonstrate that SON_LSII is superior to existing overlay networks in various respects, including scalability, maintenance, rate of indexing hits, indexing logical hops, and adaptability. Thus, the proposed SON_LSII can be used for large-scale spatial information indexing.

  10. High Speed Networking and Large-scale Simulation in Geodynamics

    NASA Technical Reports Server (NTRS)

    Kuang, Weijia; Gary, Patrick; Seablom, Michael; Truszkowski, Walt; Odubiyi, Jide; Jiang, Weiyuan; Liu, Dong

    2004-01-01

    Large-scale numerical simulation has been one of the most important approaches for understanding global geodynamical processes. In this approach, peta-scale floating point operations (pflops) are often required to carry out a single physically-meaningful numerical experiment. For example, to model convective flow in the Earth's core and generation of the geomagnetic field (geodynamo), simulation for one magnetic free-decay time (approximately 15000 years) with a modest resolution of 150 in three spatial dimensions would require approximately 0.2 pflops. If such a numerical model is used to predict geomagnetic secular variation over decades and longer, with e.g. an ensemble Kalman filter assimilation approach, approximately 30 (and perhaps more) independent simulations of similar scales would be needed for one data assimilation analysis. Obviously, such a simulation would require an enormous computing resource that exceeds the capacity of a single facility currently available at our disposal. One solution is to utilize a very fast network (e.g. 10Gb optical networks) and available middleware (e.g. Globus Toolkit) to allocate available but often heterogeneous resources for such large-scale computing efforts. At NASA GSFC, we are experimenting with such an approach by networking several clusters for geomagnetic data assimilation research. We shall present our initial testing results in the meeting.

  11. Simulator for Large-scale Planetary and Terrestrial Radar Sounding

    NASA Astrophysics Data System (ADS)

    Haynes, M.; Schroeder, D. M.; Duan, X.; Arumugam, D.; McMichael, J. G.; Hensley, S.; Cwik, T. A.

    2016-12-01

    We are developing a radar sounding simulation tool that can simulate radar scattering from large-scale, heterogeneous sub-surfaces for all existing, proposed, and future potential planetary and terrestrial sounder missions for Mars, Venus, Earth (e.g., atmosphere, ice sheets), Europa, Ganymede, Enceladus or other icy planetary bodies. This tool will be the first of its kind in planetary and terrestrial radar sounding simulation to support system engineering and to test scientific observables. No extant radar simulator is capable of producing echoes with realistic phase histories, heterogeneous media propagation effects, and processing gains at the spatial scales of planetary or terrestrial radar sounding (e.g., computational subsurface volumes of 10,000s of wavelengths in three dimensions at sounding frequencies of 5-100 MHz). Today's radar point target simulators are fast, but do not model transmission and propagation through heterogeneous dielectric media. We present progress on two simulation modules aimed at addressing different regimes of the sounding scattering problem: the Pseudo-Spectral Time-Domain (PSTD) for scattering from shallow subsurface dielectric heterogeneities, and the Multi-layer Fast Multipole Method for scattering from deep, large-scale dielectric interfaces. We will show simulated radargrams and compare computation times for realistic radar sounding scenes, in addition we solicit community input for this tool and outline the development path.

  12. Some ecological guidelines for large-scale biomass plantations

    SciTech Connect

    Hoffman, W.; Cook, J.H.; Beyea, J.

    1993-12-31

    The National Audubon Society sees biomass as an appropriate and necessary source of energy to help replace fossil fuels in the near future, but is concerned that large-scale biomass plantations could displace significant natural vegetation and wildlife habitat, and reduce national and global biodiversity. We support the development of an industry large enough to provide significant portions of our energy budget, but we see a critical need to ensure that plantations are designed and sited in ways that minimize ecological disruption, or even provide environmental benefits. We have been studying the habitat value of intensively managed short-rotation tree plantations. Our results show that these plantations support large populations of some birds, but not all of the species using the surrounding landscape, and indicate that their value as habitat can be increased greatly by including small areas of mature trees within them. We believe short-rotation plantations can benefit regional biodiversity if they can be deployed as buffers for natural forests, or as corridors connecting forest tracts. To realize these benefits, and to avoid habitat degradation, regional biomass plantation complexes (e.g., the plantations supplying all the fuel for a powerplant) need to be planned, sited, and developed as large-scale units in the context of the regional landscape mosaic.

  13. Modulation of energetic coherent motions by large-scale topography

    NASA Astrophysics Data System (ADS)

    Lai, Wing; Hamed, Ali M.; Troolin, Dan; Chamorro, Leonardo P.

    2016-11-01

    The distinctive characteristics and dynamics of the large-scale coherent motions induced over 2D and 3D large-scale wavy walls were explored experimentally with time-resolved volumetric PIV, and selected wall-normal high-resolution stereo PIV in a refractive-index-matching channel. The 2D wall consists of a sinusoidal wave in the streamwise direction with amplitude to wavelength ratio a/ λx = 0.05, while the 3D wall has an additional wave in the spanwise direction with a/ λy = 0.1. The ?ow was characterized at Re 8000, based on the bulk velocity and the channel half height. The walls are such that the amplitude to boundary layer thickness ratio is a/ δ99 0.1, which resemble geophysical-like topography. Insight on the dynamics of the coherent motions, Reynolds stress and spatial interaction of sweep and ejection events will be discussed in terms of the wall topography modulation.

  14. Very-large-scale coherent motions in open channel flows

    NASA Astrophysics Data System (ADS)

    Zhong, Qiang; Hussain, Fazle; Li, Dan-Xun

    2016-11-01

    Very-large-scale coherent structures (VLSSs) - whose characteristic length is of the order of 10 h (h is the water depth) - are found to exist in the log and outer layers near the bed of open channel flows. For decades researchers have speculated that large coherent structures may exist in open channel flows. However, conclusive evidence is still lacking. The present study employed pre-multiplied velocity power spectral and co-spectral analyses of time-resolved PIV data obtained in open channel flows. In all cases, two modes - large-scale structures (of the order of h) and VLSSs - dominate the log and outer layers of the turbulent boundary layer. More than half of TKE and 40% of the Reynolds shear stress in the log and outer layers are contributed by VLSSs. The strength difference of VLSSs between open and closed channel flows leads to pronounced redistribution of TKE near the free surface of open channel flows, which is a unique phenomenon that sets the open channel flows apart from other wall-bounded turbulent flows. Funded by China Postdoctoral Science Foundation (No.2015M580105), National Natural Science Foundation of China (No.51127006).

  15. Large-scale Direct Targeting for Drug Repositioning and Discovery

    PubMed Central

    Zheng, Chunli; Guo, Zihu; Huang, Chao; Wu, Ziyin; Li, Yan; Chen, Xuetong; Fu, Yingxue; Ru, Jinlong; Ali Shar, Piar; Wang, Yuan; Wang, Yonghua

    2015-01-01

    A system-level identification of drug-target direct interactions is vital to drug repositioning and discovery. However, the biological means on a large scale remains challenging and expensive even nowadays. The available computational models mainly focus on predicting indirect interactions or direct interactions on a small scale. To address these problems, in this work, a novel algorithm termed weighted ensemble similarity (WES) has been developed to identify drug direct targets based on a large-scale of 98,327 drug-target relationships. WES includes: (1) identifying the key ligand structural features that are highly-related to the pharmacological properties in a framework of ensemble; (2) determining a drug’s affiliation of a target by evaluation of the overall similarity (ensemble) rather than a single ligand judgment; and (3) integrating the standardized ensemble similarities (Z score) by Bayesian network and multi-variate kernel approach to make predictions. All these lead WES to predict drug direct targets with external and experimental test accuracies of 70% and 71%, respectively. This shows that the WES method provides a potential in silico model for drug repositioning and discovery. PMID:26155766

  16. Resonant plankton patchiness induced by large-scale turbulent flow

    NASA Astrophysics Data System (ADS)

    McKiver, William J.; Neufeld, Zoltán

    2011-01-01

    Here we study how large-scale variability of oceanic plankton is affected by mesoscale turbulence in a spatially heterogeneous environment. We consider a phytoplankton-zooplankton (PZ) ecosystem model, with different types of zooplankton grazing functions, coupled to a turbulent flow described by the two-dimensional Navier-Stokes equations, representing large-scale horizontal transport in the ocean. We characterize the system using a dimensionless parameter, γ=TB/TF, which is the ratio of the ecosystem biological time scale TB and the flow time scale TF. Through numerical simulations, we examine how the PZ system depends on the time-scale ratio γ and find that the variance of both species changes significantly, with maximum phytoplankton variability at intermediate mixing rates. Through an analysis of the linearized population dynamics, we find an analytical solution based on the forced harmonic oscillator, which explains the behavior of the ecosystem, where there is resonance between the advection and the ecosystem predator-prey dynamics when the forcing time scales match the ecosystem time scales. We also examine the dependence of the power spectra on γ and find that the resonance behavior leads to different spectral slopes for phytoplankton and zooplankton, in agreement with observations.

  17. Resonant plankton patchiness induced by large-scale turbulent flow.

    PubMed

    McKiver, William J; Neufeld, Zoltán

    2011-01-01

    Here we study how large-scale variability of oceanic plankton is affected by mesoscale turbulence in a spatially heterogeneous environment. We consider a phytoplankton-zooplankton (PZ) ecosystem model, with different types of zooplankton grazing functions, coupled to a turbulent flow described by the two-dimensional Navier-Stokes equations, representing large-scale horizontal transport in the ocean. We characterize the system using a dimensionless parameter, γ=T(B)/T(F), which is the ratio of the ecosystem biological time scale T(B) and the flow time scale T(F). Through numerical simulations, we examine how the PZ system depends on the time-scale ratio γ and find that the variance of both species changes significantly, with maximum phytoplankton variability at intermediate mixing rates. Through an analysis of the linearized population dynamics, we find an analytical solution based on the forced harmonic oscillator, which explains the behavior of the ecosystem, where there is resonance between the advection and the ecosystem predator-prey dynamics when the forcing time scales match the ecosystem time scales. We also examine the dependence of the power spectra on γ and find that the resonance behavior leads to different spectral slopes for phytoplankton and zooplankton, in agreement with observations.

  18. Exact-Differential Large-Scale Traffic Simulation

    SciTech Connect

    Hanai, Masatoshi; Suzumura, Toyotaro; Theodoropoulos, Georgios; Perumalla, Kalyan S

    2015-01-01

    Analyzing large-scale traffics by simulation needs repeating execution many times with various patterns of scenarios or parameters. Such repeating execution brings about big redundancy because the change from a prior scenario to a later scenario is very minor in most cases, for example, blocking only one of roads or changing the speed limit of several roads. In this paper, we propose a new redundancy reduction technique, called exact-differential simulation, which enables to simulate only changing scenarios in later execution while keeping exactly same results as in the case of whole simulation. The paper consists of two main efforts: (i) a key idea and algorithm of the exact-differential simulation, (ii) a method to build large-scale traffic simulation on the top of the exact-differential simulation. In experiments of Tokyo traffic simulation, the exact-differential simulation shows 7.26 times as much elapsed time improvement in average and 2.26 times improvement even in the worst case as the whole simulation.

  19. Evaluating Unmanned Aerial Platforms for Cultural Heritage Large Scale Mapping

    NASA Astrophysics Data System (ADS)

    Georgopoulos, A.; Oikonomou, C.; Adamopoulos, E.; Stathopoulou, E. K.

    2016-06-01

    When it comes to large scale mapping of limited areas especially for cultural heritage sites, things become critical. Optical and non-optical sensors are developed to such sizes and weights that can be lifted by such platforms, like e.g. LiDAR units. At the same time there is an increase in emphasis on solutions that enable users to get access to 3D information faster and cheaper. Considering the multitude of platforms, cameras and the advancement of algorithms in conjunction with the increase of available computing power this challenge should and indeed is further investigated. In this paper a short review of the UAS technologies today is attempted. A discussion follows as to their applicability and advantages, depending on their specifications, which vary immensely. The on-board cameras available are also compared and evaluated for large scale mapping. Furthermore a thorough analysis, review and experimentation with different software implementations of Structure from Motion and Multiple View Stereo algorithms, able to process such dense and mostly unordered sequence of digital images is also conducted and presented. As test data set, we use a rich optical and thermal data set from both fixed wing and multi-rotor platforms over an archaeological excavation with adverse height variations and using different cameras. Dense 3D point clouds, digital terrain models and orthophotos have been produced and evaluated for their radiometric as well as metric qualities.

  20. Large-scale impact cratering on the terrestrial planets

    SciTech Connect

    Grieve, R.A.F.

    1982-01-01

    The crater densities on the earth and moon form the basis for a standard flux-time curve that can be used in dating unsampled planetary surfaces and constraining the temporal history of endogenic geologic processes. Abundant evidence is seen not only that impact cratering was an important surface process in planetary history but also that large imapact events produced effects that were crucial in scale. By way of example, it is noted that the formation of multiring basins on the early moon was as important in defining the planetary tectonic framework as plate tectonics is on the earth. Evidence from several planets suggests that the effects of very-large-scale impacts go beyond the simple formation of an impact structure and serve to localize increased endogenic activity over an extended period of geologic time. Even though no longer occurring with the frequency and magnitude of early solar system history, it is noted that large scale impact events continue to affect the local geology of the planets. 92 references.

  1. The combustion behavior of large scale lithium titanate battery.

    PubMed

    Huang, Peifeng; Wang, Qingsong; Li, Ke; Ping, Ping; Sun, Jinhua

    2015-01-14

    Safety problem is always a big obstacle for lithium battery marching to large scale application. However, the knowledge on the battery combustion behavior is limited. To investigate the combustion behavior of large scale lithium battery, three 50 Ah Li(Ni(x)Co(y)Mn(z))O2/Li(4)Ti(5)O(12) batteries under different state of charge (SOC) were heated to fire. The flame size variation is depicted to analyze the combustion behavior directly. The mass loss rate, temperature and heat release rate are used to analyze the combustion behavior in reaction way deeply. Based on the phenomenon, the combustion process is divided into three basic stages, even more complicated at higher SOC with sudden smoke flow ejected. The reason is that a phase change occurs in Li(Ni(x)Co(y)Mn(z))O2 material from layer structure to spinel structure. The critical temperatures of ignition are at 112-121 °C on anode tab and 139 to 147 °C on upper surface for all cells. But the heating time and combustion time become shorter with the ascending of SOC. The results indicate that the battery fire hazard increases with the SOC. It is analyzed that the internal short and the Li(+) distribution are the main causes that lead to the difference.

  2. Large Scale Organization of a Near Wall Turbulent Boundary Layer

    NASA Astrophysics Data System (ADS)

    Stanislas, Michel; Dekou Tiomajou, Raoul Florent; Foucaut, Jean Marc

    2016-11-01

    This study lies in the context of large scale coherent structures investigation in a near wall turbulent boundary layer. An experimental database at high Reynolds numbers (Re θ = 9830 and Re θ = 19660) was obtained in the LML wind tunnel with stereo-PIV at 4 Hz and hot wire anemometry at 30 kHz. A Linear Stochastic Estimation procedure, is used to reconstruct a 3 component field resolved in space and time. Algorithms were developed to extract coherent structures from the reconstructed field. A sample of 3D view of the structures is depicted in Figure 1. Uniform momentum regions are characterized with their mean hydraulic diameter in the YZ plane, their life time and their contribution to Reynolds stresses. The vortical motions are characterized by their position, radius, circulation and vorticity in addition to their life time and their number computed at a fixed position from the wall. The spatial organization of the structures was investigated through a correlation of their respective indicative functions in the spanwise direction. The simplified large scale model that arise is compared to the ones available in the literature. Streamwise low (green) and high (yellow) uniform momentum regions with positive (red) and negative (blue) vortical motions. This work was supported by Campus International pour la Sécurité et l'Intermodalité des Transports.

  3. Large Scale Land Acquisition as a driver of slope instability

    NASA Astrophysics Data System (ADS)

    Danilo Chiarelli, Davide; Rulli, Maria Cristina; Davis, Kyle F.; D'Odorico, Paolo

    2017-04-01

    Forests play a key role in preventing shallow landslides and deforestation has been analyzed as one of the main causes of increased mass wasting in hillsplopes undergoing land cover change. In the last few years vast tracts of lands have been acquired by foreign investors to satisfy an increasing demand for agricultural products. Large Scale Land Acquisitions (LSLA) often entail the conversion of forested landscapes into agricultural fields. Mozambique has been a major target of LSLAs and there is evidence that many of the acquired land have recently undergone forest clearing. The Zambezia Province in Mozambique has lost more than 500000ha of forest from 2000 to 2014; 25.4% of them were in areas acquired by large scale land investors. According to Land Matrix, an open-source database of reported land deals, there are currently 123 intended and confirmed deals in Mozambique; collectively, they account for 2.34million ha, the majority of which are located in forested areas. This study analyses the relationship between deforestation taking place inside LSLA areas(usually for agricultural purpose) and the likelihood of landslides occurrence in the Zambezia province in Mozambique. To this aim we use a spatially distributed and physically based model that couples slope stability analysis with a hillslope scale hydrological model and we compare the change in slope stability associated the forest loss documented by satellite imagery.

  4. Literature Review: Herbal Medicine Treatment after Large-Scale Disasters.

    PubMed

    Takayama, Shin; Kaneko, Soichiro; Numata, Takehiro; Kamiya, Tetsuharu; Arita, Ryutaro; Saito, Natsumi; Kikuchi, Akiko; Ohsawa, Minoru; Kohayagawa, Yoshitaka; Ishii, Tadashi

    2017-09-27

    Large-scale natural disasters, such as earthquakes, tsunamis, volcanic eruptions, and typhoons, occur worldwide. After the Great East Japan earthquake and tsunami, our medical support operation's experiences suggested that traditional medicine might be useful for treating the various symptoms of the survivors. However, little information is available regarding herbal medicine treatment in such situations. Considering that further disasters will occur, we performed a literature review and summarized the traditional medicine approaches for treatment after large-scale disasters. We searched PubMed and Cochrane Library for articles written in English, and Ichushi for those written in Japanese. Articles published before 31 March 2016 were included. Keywords "disaster" and "herbal medicine" were used in our search. Among studies involving herbal medicine after a disaster, we found two randomized controlled trials investigating post-traumatic stress disorder (PTSD), three retrospective investigations of trauma or common diseases, and seven case series or case reports of dizziness, pain, and psychosomatic symptoms. In conclusion, herbal medicine has been used to treat trauma, PTSD, and other symptoms after disasters. However, few articles have been published, likely due to the difficulty in designing high quality studies in such situations. Further study will be needed to clarify the usefulness of herbal medicine after disasters.

  5. IP over optical multicasting for large-scale video delivery

    NASA Astrophysics Data System (ADS)

    Jin, Yaohui; Hu, Weisheng; Sun, Weiqiang; Guo, Wei

    2007-11-01

    In the IPTV systems, multicasting will play a crucial role in the delivery of high-quality video services, which can significantly improve bandwidth efficiency. However, the scalability and the signal quality of current IPTV can barely compete with the existing broadcast digital TV systems since it is difficult to implement large-scale multicasting with end-to-end guaranteed quality of service (QoS) in packet-switched IP network. China 3TNet project aimed to build a high performance broadband trial network to support large-scale concurrent streaming media and interactive multimedia services. The innovative idea of 3TNet is that an automatic switched optical networks (ASON) with the capability of dynamic point-to-multipoint (P2MP) connections replaces the conventional IP multicasting network in the transport core, while the edge remains an IP multicasting network. In this paper, we will introduce the network architecture and discuss challenges in such IP over Optical multicasting for video delivery.

  6. Detecting differential protein expression in large-scale population proteomics

    SciTech Connect

    Ryu, Soyoung; Qian, Weijun; Camp, David G.; Smith, Richard D.; Tompkins, Ronald G.; Davis, Ronald W.; Xiao, Wenzhong

    2014-06-17

    Mass spectrometry-based high-throughput quantitative proteomics shows great potential in clinical biomarker studies, identifying and quantifying thousands of proteins in biological samples. However, methods are needed to appropriately handle issues/challenges unique to mass spectrometry data in order to detect as many biomarker proteins as possible. One issue is that different mass spectrometry experiments generate quite different total numbers of quantified peptides, which can result in more missing peptide abundances in an experiment with a smaller total number of quantified peptides. Another issue is that the quantification of peptides is sometimes absent, especially for less abundant peptides and such missing values contain the information about the peptide abundance. Here, we propose a Significance Analysis for Large-scale Proteomics Studies (SALPS) that handles missing peptide intensity values caused by the two mechanisms mentioned above. Our model has a robust performance in both simulated data and proteomics data from a large clinical study. Because varying patients’ sample qualities and deviating instrument performances are not avoidable for clinical studies performed over the course of several years, we believe that our approach will be useful to analyze large-scale clinical proteomics data.

  7. Maestro: An Orchestration Framework for Large-Scale WSN Simulations

    PubMed Central

    Riliskis, Laurynas; Osipov, Evgeny

    2014-01-01

    Contemporary wireless sensor networks (WSNs) have evolved into large and complex systems and are one of the main technologies used in cyber-physical systems and the Internet of Things. Extensive research on WSNs has led to the development of diverse solutions at all levels of software architecture, including protocol stacks for communications. This multitude of solutions is due to the limited computational power and restrictions on energy consumption that must be accounted for when designing typical WSN systems. It is therefore challenging to develop, test and validate even small WSN applications, and this process can easily consume significant resources. Simulations are inexpensive tools for testing, verifying and generally experimenting with new technologies in a repeatable fashion. Consequently, as the size of the systems to be tested increases, so does the need for large-scale simulations. This article describes a tool called Maestro for the automation of large-scale simulation and investigates the feasibility of using cloud computing facilities for such task. Using tools that are built into Maestro, we demonstrate a feasible approach for benchmarking cloud infrastructure in order to identify cloud Virtual Machine (VM)instances that provide an optimal balance of performance and cost for a given simulation. PMID:24647123

  8. Large-scale network-level processes during entrainment.

    PubMed

    Lithari, Chrysa; Sánchez-García, Carolina; Ruhnau, Philipp; Weisz, Nathan

    2016-03-15

    Visual rhythmic stimulation evokes a robust power increase exactly at the stimulation frequency, the so-called steady-state response (SSR). Localization of visual SSRs normally shows a very focal modulation of power in visual cortex and led to the treatment and interpretation of SSRs as a local phenomenon. Given the brain network dynamics, we hypothesized that SSRs have additional large-scale effects on the brain functional network that can be revealed by means of graph theory. We used rhythmic visual stimulation at a range of frequencies (4-30 Hz), recorded MEG and investigated source level connectivity across the whole brain. Using graph theoretical measures we observed a frequency-unspecific reduction of global density in the alpha band "disconnecting" visual cortex from the rest of the network. Also, a frequency-specific increase of connectivity between occipital cortex and precuneus was found at the stimulation frequency that exhibited the highest resonance (30 Hz). In conclusion, we showed that SSRs dynamically re-organized the brain functional network. These large-scale effects should be taken into account not only when attempting to explain the nature of SSRs, but also when used in various experimental designs. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  9. Large-scale structure of randomly jammed spheres

    NASA Astrophysics Data System (ADS)

    Ikeda, Atsushi; Berthier, Ludovic; Parisi, Giorgio

    2017-05-01

    We numerically analyze the density field of three-dimensional randomly jammed packings of monodisperse soft frictionless spherical particles, paying special attention to fluctuations occurring at large length scales. We study in detail the two-point static structure factor at low wave vectors in Fourier space. We also analyze the nature of the density field in real space by studying the large-distance behavior of the two-point pair correlation function, of density fluctuations in subsystems of increasing sizes, and of the direct correlation function. We show that such real space analysis can be greatly improved by introducing a coarse-grained density field to disentangle genuine large-scale correlations from purely local effects. Our results confirm that both Fourier and real space signatures of vanishing density fluctuations at large scale are absent, indicating that randomly jammed packings are not hyperuniform. In addition, we establish that the pair correlation function displays a surprisingly complex structure at large distances, which is however not compatible with the long-range negative correlation of hyperuniform systems but fully compatible with an analytic form for the structure factor. This implies that the direct correlation function is short ranged, as we also demonstrate directly. Our results reveal that density fluctuations in jammed packings do not follow the behavior expected for random hyperuniform materials, but display instead a more complex behavior.

  10. Systematic renormalization of the effective theory of Large Scale Structure

    SciTech Connect

    Abolhasani, Ali Akbar; Mirbabayi, Mehrdad; Pajer, Enrico

    2016-05-31

    A perturbative description of Large Scale Structure is a cornerstone of our understanding of the observed distribution of matter in the universe. Renormalization is an essential and defining step to make this description physical and predictive. Here we introduce a systematic renormalization procedure, which neatly associates counterterms to the UV-sensitive diagrams order by order, as it is commonly done in quantum field theory. As a concrete example, we renormalize the one-loop power spectrum and bispectrum of both density and velocity. In addition, we present a series of results that are valid to all orders in perturbation theory. First, we show that while systematic renormalization requires temporally non-local counterterms, in practice one can use an equivalent basis made of local operators. We give an explicit prescription to generate all counterterms allowed by the symmetries. Second, we present a formal proof of the well-known general argument that the contribution of short distance perturbations to large scale density contrast δ and momentum density π(k) scale as k{sup 2} and k, respectively. Third, we demonstrate that the common practice of introducing counterterms only in the Euler equation when one is interested in correlators of δ is indeed valid to all orders.

  11. Scalable WIM: effective exploration in large-scale astrophysical environments.

    PubMed

    Li, Yinggang; Fu, Chi-Wing; Hanson, Andrew J

    2006-01-01

    Navigating through large-scale virtual environments such as simulations of the astrophysical Universe is difficult. The huge spatial range of astronomical models and the dominance of empty space make it hard for users to travel across cosmological scales effectively, and the problem of wayfinding further impedes the user's ability to acquire reliable spatial knowledge of astronomical contexts. We introduce a new technique called the scalable world-in-miniature (WIM) map as a unifying interface to facilitate travel and wayfinding in a virtual environment spanning gigantic spatial scales: Power-law spatial scaling enables rapid and accurate transitions among widely separated regions; logarithmically mapped miniature spaces offer a global overview mode when the full context is too large; 3D landmarks represented in the WIM are enhanced by scale, positional, and directional cues to augment spatial context awareness; a series of navigation models are incorporated into the scalable WIM to improve the performance of travel tasks posed by the unique characteristics of virtual cosmic exploration. The scalable WIM user interface supports an improved physical navigation experience and assists pragmatic cognitive understanding of a visualization context that incorporates the features of large-scale astronomy.

  12. Extending SME to Handle Large-Scale Cognitive Modeling.

    PubMed

    Forbus, Kenneth D; Ferguson, Ronald W; Lovett, Andrew; Gentner, Dedre

    2016-06-20

    Analogy and similarity are central phenomena in human cognition, involved in processes ranging from visual perception to conceptual change. To capture this centrality requires that a model of comparison must be able to integrate with other processes and handle the size and complexity of the representations required by the tasks being modeled. This paper describes extensions to Structure-Mapping Engine (SME) since its inception in 1986 that have increased its scope of operation. We first review the basic SME algorithm, describe psychological evidence for SME as a process model, and summarize its role in simulating similarity-based retrieval and generalization. Then we describe five techniques now incorporated into the SME that have enabled it to tackle large-scale modeling tasks: (a) Greedy merging rapidly constructs one or more best interpretations of a match in polynomial time: O(n(2) log(n)); (b) Incremental operation enables mappings to be extended as new information is retrieved or derived about the base or target, to model situations where information in a task is updated over time; (c) Ubiquitous predicates model the varying degrees to which items may suggest alignment; (d) Structural evaluation of analogical inferences models aspects of plausibility judgments; (e) Match filters enable large-scale task models to communicate constraints to SME to influence the mapping process. We illustrate via examples from published studies how these enable it to capture a broader range of psychological phenomena than before.

  13. Dark energy from large-scale structure lensing information

    SciTech Connect

    Lu Tingting; Pen Ueli; Dore, Oliver

    2010-06-15

    Wide area large-scale structure (LSS) surveys are planning to map a substantial fraction of the visible Universe to quantify dark energy through baryon acoustic oscillations. At increasing redshift, for example, that probed by proposed 21-cm intensity mapping surveys, gravitational lensing potentially limits the fidelity (Hui et al., 2007) because it distorts the apparent matter distribution. In this paper we show that these distortions can be reconstructed, and actually used to map the distribution of intervening dark matter. The lensing information for sources at z=1-3 allows accurate reconstruction of the gravitational potential on large scales, l < or approx. 100, which is well matched for integrated Sachs-Wolfe effect measurements of dark energy and its sound speed, and a strong constraint for modified gravity models of dark energy. We built an optimal quadratic lensing estimator for non-Gaussian sources, which is necessary for LSS. The phenomenon of 'information saturation' (Rimes and Hamilton, 2005) saturates reconstruction at mildly nonlinear scales, where the linear source power spectrum {Delta}{sup 2{approx}}0.2-0.5, depending on power spectrum slope. Naive Gaussian estimators with nonlinear cutoff can be tuned to reproduce the optimal non-Gaussian errors within a factor of 2. We compute the effective number densities of independent lensing sources for LSS lensing, and find that they increase rapidly with redshifts. For LSS/21-cm sources at z{approx}2-4, the lensing reconstruction is limited by cosmic variance at l < or approx. 100.

  14. Large-Scale Low-Boom Inlet Test Overview

    NASA Technical Reports Server (NTRS)

    Hirt, Stefanie

    2011-01-01

    This presentation provides a high level overview of the Large-Scale Low-Boom Inlet Test and was presented at the Fundamental Aeronautics 2011 Technical Conference. In October 2010 a low-boom supersonic inlet concept with flow control was tested in the 8'x6' supersonic wind tunnel at NASA Glenn Research Center (GRC). The primary objectives of the test were to evaluate the inlet stability and operability of a large-scale low-boom supersonic inlet concept by acquiring performance and flowfield validation data, as well as evaluate simple, passive, bleedless inlet boundary layer control options. During this effort two models were tested: a dual stream inlet intended to model potential flight hardware and a single stream design to study a zero-degree external cowl angle and to permit surface flow visualization of the vortex generator flow control on the internal centerbody surface. The tests were conducted by a team of researchers from NASA GRC, Gulfstream Aerospace Corporation, University of Illinois at Urbana-Champaign, and the University of Virginia

  15. A study of synthetic large scales in turbulent boundary layers

    NASA Astrophysics Data System (ADS)

    Duvvuri, Subrahmanyam; Luhar, Mitul; Barnard, Casey; Sheplak, Mark; McKeon, Beverley

    2013-11-01

    Synthetic spanwise-constant spatio-temporal disturbances are excited in a turbulent boundary layer through a spatially impulsive patch of dynamic wall-roughness. The downstream flow response is studied through hot wire anemometry, pressure measurements at the wall and direct measurements of wall-shear-stress made using a novel micro-machined capacitive floating element sensor. These measurements are phase-locked to the input perturbation to recover the synthetic large-scale motion and characterize its structure and wall signature. The phase relationship between the synthetic large scale and small scale activity provides further insights into the apparent amplitude modulation effect between them, and the dynamics of wall-bounded turbulent flows in general. Results from these experiments will be discussed in the context of the critical-layer behavior revealed by the resolvent analysis of McKeon & Sharma (J Fluid Mech, 2010), and compared with similar earlier work by Jacobi & McKeon (J Fluid Mech, 2011). Model predictions are shown to be in broad agreement with experiments. The support of AFOSR grant #FA 9550-12-1-0469, Resnick Institute Graduate Research Fellowship (S.D.) and Sandia Graduate Fellowship (C.B.) are gratefully acknowledged.

  16. Nearly incompressible fluids: hydrodynamics and large scale inhomogeneity.

    PubMed

    Hunana, P; Zank, G P; Shaikh, D

    2006-08-01

    A system of hydrodynamic equations in the presence of large-scale inhomogeneities for a high plasma beta solar wind is derived. The theory is derived under the assumption of low turbulent Mach number and is developed for the flows where the usual incompressible description is not satisfactory and a full compressible treatment is too complex for any analytical studies. When the effects of compressibility are incorporated only weakly, a new description, referred to as "nearly incompressible hydrodynamics," is obtained. The nearly incompressible theory, was originally applied to homogeneous flows. However, large-scale gradients in density, pressure, temperature, etc., are typical in the solar wind and it was unclear how inhomogeneities would affect the usual incompressible and nearly incompressible descriptions. In the homogeneous case, the lowest order expansion of the fully compressible equations leads to the usual incompressible equations, followed at higher orders by the nearly incompressible equations, as introduced by Zank and Matthaeus. With this work we show that the inclusion of large-scale inhomogeneities (in this case time-independent and radially symmetric background solar wind) modifies the leading-order incompressible description of solar wind flow. We find, for example, that the divergence of velocity fluctuations is nonsolenoidal and that density fluctuations can be described to leading order as a passive scalar. Locally (for small lengthscales), this system of equations converges to the usual incompressible equations and we therefore use the term "locally incompressible" to describe the equations. This term should be distinguished from the term "nearly incompressible," which is reserved for higher-order corrections. Furthermore, we find that density fluctuations scale with Mach number linearly, in contrast to the original homogeneous nearly incompressible theory, in which density fluctuations scale with the square of Mach number. Inhomogeneous nearly

  17. Autonomic Computing Paradigm For Large Scale Scientific And Engineering Applications

    NASA Astrophysics Data System (ADS)

    Hariri, S.; Yang, J.; Zhang, Y.

    2005-12-01

    Large-scale distributed scientific applications are highly adaptive and heterogeneous in terms of their computational requirements. The computational complexity associated with each computational region or domain varies continuously and dramatically both in space and time throughout the whole life cycle of the application execution. Furthermore, the underlying distributed computing environment is similarly complex and dynamic in the availabilities and capacities of the computing resources. These challenges combined together make the current paradigms, which are based on passive components and static compositions, ineffectual. Autonomic Computing paradigm is an approach that efficiently addresses the complexity and dynamism of large scale scientific and engineering applications and realizes the self-management of these applications. In this presentation, we present an Autonomic Runtime Manager (ARM) that supports the development of autonomic applications. The ARM includes two modules: online monitoring and analysis module and autonomic planning and scheduling module. The ARM behaves as a closed-loop control system that dynamically controls and manages the execution of the applications at runtime. It regularly senses the state changes of both the applications and the underlying computing resources. It then uses these runtime information and prior knowledge about the application behavior and its physics to identify the appropriate solution methods as well as the required computing and storage resources. Consequently this approach enables us to develop autonomic applications, which are capable of self-management and self-optimization. We have developed and implemented the autonomic computing paradigms for several large scale applications such as wild fire simulations, simulations of flow through variably saturated geologic formations, and life sciences. The distributed wildfire simulation models the wildfire spread behavior by considering such factors as fuel

  18. Climatological context for large-scale coral bleaching

    NASA Astrophysics Data System (ADS)

    Barton, A. D.; Casey, K. S.

    2005-12-01

    Large-scale coral bleaching was first observed in 1979 and has occurred throughout virtually all of the tropics since that time. Severe bleaching may result in the loss of live coral and in a decline of the integrity of the impacted coral reef ecosystem. Despite the extensive scientific research and increased public awareness of coral bleaching, uncertainties remain about the past and future of large-scale coral bleaching. In order to reduce these uncertainties and place large-scale coral bleaching in the longer-term climatological context, specific criteria and methods for using historical sea surface temperature (SST) data to examine coral bleaching-related thermal conditions are proposed by analyzing three, 132 year SST reconstructions: ERSST, HadISST1, and GISST2.3b. These methodologies are applied to case studies at Discovery Bay, Jamaica (77.27°W, 18.45°N), Sombrero Reef, Florida, USA (81.11°W, 24.63°N), Academy Bay, Galápagos, Ecuador (90.31°W, 0.74°S), Pearl and Hermes Reef, Northwest Hawaiian Islands, USA (175.83°W, 27.83°N), Midway Island, Northwest Hawaiian Islands, USA (177.37°W, 28.25°N), Davies Reef, Australia (147.68°E, 18.83°S), and North Male Atoll, Maldives (73.35°E, 4.70°N). The results of this study show that (1) The historical SST data provide a useful long-term record of thermal conditions in reef ecosystems, giving important insight into the thermal history of coral reefs and (2) While coral bleaching and anomalously warm SSTs have occurred over much of the world in recent decades, case studies in the Caribbean, Northwest Hawaiian Islands, and parts of other regions such as the Great Barrier Reef exhibited SST conditions and cumulative thermal stress prior to 1979 that were comparable to those conditions observed during the strong, frequent coral bleaching events since 1979. This climatological context and knowledge of past environmental conditions in reef ecosystems may foster a better understanding of how coral reefs will

  19. Large-Scale Graphene Film Deposition for Monolithic Device Fabrication

    NASA Astrophysics Data System (ADS)

    Al-shurman, Khaled

    Since 1958, the concept of integrated circuit (IC) has achieved great technological developments and helped in shrinking electronic devices. Nowadays, an IC consists of more than a million of compacted transistors. The majority of current ICs use silicon as a semiconductor material. According to Moore's law, the number of transistors built-in on a microchip can be double every two years. However, silicon device manufacturing reaches its physical limits. To explain, there is a new trend to shrinking circuitry to seven nanometers where a lot of unknown quantum effects such as tunneling effect can not be controlled. Hence, there is an urgent need for a new platform material to replace Si. Graphene is considered a promising material with enormous potential applications in many electronic and optoelectronics devices due to its superior properties. There are several techniques to produce graphene films. Among these techniques, chemical vapor deposition (CVD) offers a very convenient method to fabricate films for large-scale graphene films. Though CVD method is suitable for large area growth of graphene, the need for transferring a graphene film to silicon-based substrates is required. Furthermore, the graphene films thus achieved are, in fact, not single crystalline. Also, graphene fabrication utilizing Cu and Ni at high growth temperature contaminates the substrate that holds Si CMOS circuitry and CVD chamber as well. So, lowering the deposition temperature is another technological milestone for the successful adoption of graphene in integrated circuits fabrication. In this research, direct large-scale graphene film fabrication on silicon based platform (i.e. SiO2 and Si3N4) at low temperature was achieved. With a focus on low-temperature graphene growth, hot-filament chemical vapor deposition (HF-CVD) was utilized to synthesize graphene film using 200 nm thick nickel film. Raman spectroscopy was utilized to examine graphene formation on the bottom side of the Ni film

  20. Modelling large-scale halo bias using the bispectrum

    NASA Astrophysics Data System (ADS)

    Pollack, Jennifer E.; Smith, Robert E.; Porciani, Cristiano

    2012-03-01

    We study the relation between the density distribution of tracers for large-scale structure and the underlying matter distribution - commonly termed bias - in the Λ cold dark matter framework. In particular, we examine the validity of the local model of biasing at quadratic order in the matter density. This model is characterized by parameters b1 and b2. Using an ensemble of N-body simulations, we apply several statistical methods to estimate the parameters. We measure halo and matter fluctuations smoothed on various scales. We find that, whilst the fits are reasonably good, the parameters vary with smoothing scale. We argue that, for real-space measurements, owing to the mixing of wavemodes, no smoothing scale can be found for which the parameters are independent of smoothing. However, this is not the case in Fourier space. We measure halo and halo-mass power spectra and from these construct estimates of the effective large-scale bias as a guide for b1. We measure the configuration dependence of the halo bispectra Bhhh and reduced bispectra Qhhh for very large-scale k-space triangles. From these data, we constrain b1 and b2, taking into account the full bispectrum covariance matrix. Using the lowest order perturbation theory, we find that for Bhhh the best-fitting parameters are in reasonable agreement with one another as the triangle scale is varied, although the fits become poor as smaller scales are included. The same is true for Qhhh. The best-fitting values were found to depend on the discreteness correction. This led us to consider halo-mass cross-bispectra. The results from these statistics supported our earlier findings. We then developed a test to explore whether the inconsistency in the recovered bias parameters could be attributed to missing higher order corrections in the models. We prove that low-order expansions are not sufficiently accurate to model the data, even on scales k1˜ 0.04 h Mpc-1. If robust inferences concerning bias are to be drawn

  1. Probing large-scale structure with radio observations

    NASA Astrophysics Data System (ADS)

    Brown, Shea D.

    This thesis focuses on detecting magnetized relativistic plasma in the intergalactic medium (IGM) of filamentary large-scale structure (LSS) by observing synchrotron emission emitted by structure formation shocks. Little is known about the IGM beyond the largest clusters of galaxies, and synchrotron emission holds enormous promise as a means of probing magnetic fields and relativistic particle populations in these low density regions. I'll first report on observations taken at the Very Large Array and the Westerbork Synthesis Radio Telescope of the diffuse radio source 0809+39. I use these observations to demonstrate that 0809+39 is likely the first "radio relic" discovered that is not associated with a rich |"X-ray emitting cluster of galaxies. I then demonstrate that an unconventional reprocessing of the NVSS polarization survey can reveal structures on scales from 15' to hundreds of degrees, far larger than the nominal shortest-baseline scale. This yields hundreds of new diffuse sources as well as the identification of a new nearby galactic loop . These observations also highlight the major obstacle that diffuse galactic foreground emission poses for any search for large-scale, low surface- brightness extragalactic emission. I therefore explore the cross-correlation of diffuse radio emission with optical tracers of LSS as a means of statistically detecting the presence of magnetic fields in the low-density regions of the cosmic web. This initial study with the Bonn 1.4 GHz radio survey yields an upper limit of 0.2 mG for large-scale filament magnetic fields. Finally, I report on new Green Bank Telescope and Westerbork Synthesis Radio Telescope observations of the famous Coma cluster of galaxies. Major findings include an extension to the Coma cluster radio relic source 1253+275 which makes its total extent ~2 Mpc, as well as a sharp edge, or "front", on the Western side of the radio halo which shows a strong correlation with merger activity associated with an

  2. Large-scale dimension densities for heart rate variability analysis

    NASA Astrophysics Data System (ADS)

    Raab, Corinna; Wessel, Niels; Schirdewan, Alexander; Kurths, Jürgen

    2006-04-01

    In this work, we reanalyze the heart rate variability (HRV) data from the 2002 Computers in Cardiology (CiC) Challenge using the concept of large-scale dimension densities and additionally apply this technique to data of healthy persons and of patients with cardiac diseases. The large-scale dimension density (LASDID) is estimated from the time series using a normalized Grassberger-Procaccia algorithm, which leads to a suitable correction of systematic errors produced by boundary effects in the rather large scales of a system. This way, it is possible to analyze rather short, nonstationary, and unfiltered data, such as HRV. Moreover, this method allows us to analyze short parts of the data and to look for differences between day and night. The circadian changes in the dimension density enable us to distinguish almost completely between real data and computer-generated data from the CiC 2002 challenge using only one parameter. In the second part we analyzed the data of 15 patients with atrial fibrillation (AF), 15 patients with congestive heart failure (CHF), 15 elderly healthy subjects (EH), as well as 18 young and healthy persons (YH). With our method we are able to separate completely the AF (ρlsμ=0.97±0.02) group from the others and, especially during daytime, the CHF patients show significant differences from the young and elderly healthy volunteers (CHF, 0.65±0.13 ; EH, 0.54±0.05 ; YH, 0.57±0.05 ; p<0.05 for both comparisons). Moreover, for the CHF patients we find no circadian changes in ρlsμ (day, 0.65±0.13 ; night, 0.66±0.12 ; n.s.) in contrast to healthy controls (day, 0.54±0.05 ; night, 0.61±0.05 ; p=0.002 ). Correlation analysis showed no statistical significant relation between standard HRV and circadian LASDID, demonstrating a possibly independent application of our method for clinical risk stratification.

  3. Standard Errors for National Trends in International Large-Scale Assessments in the Case of Cross-National Differential Item Functioning

    ERIC Educational Resources Information Center

    Sachse, Karoline A.; Haag, Nicole

    2017-01-01

    Standard errors computed according to the operational practices of international large-scale assessment studies such as the Programme for International Student Assessment's (PISA) or the Trends in International Mathematics and Science Study (TIMSS) may be biased when cross-national differential item functioning (DIF) and item parameter drift are…

  4. Crowdsourcing for large-scale mosquito (Diptera: Culicidae) sampling

    USDA-ARS?s Scientific Manuscript database

    Sampling a cosmopolitan mosquito (Diptera: Culicidae) species throughout its range is logistically challenging and extremely resource intensive. Mosquito control programmes and regional networks operate at the local level and often conduct sampling activities across much of North America. A method f...

  5. Scalable Parallel Distance Field Construction for Large-Scale Applications.

    PubMed

    Yu, Hongfeng; Xie, Jinrong; Ma, Kwan-Liu; Kolla, Hemanth; Chen, Jacqueline H

    2015-10-01

    Computing distance fields is fundamental to many scientific and engineering applications. Distance fields can be used to direct analysis and reduce data. In this paper, we present a highly scalable method for computing 3D distance fields on massively parallel distributed-memory machines. A new distributed spatial data structure, named parallel distance tree, is introduced to manage the level sets of data and facilitate surface tracking over time, resulting in significantly reduced computation and communication costs for calculating the distance to the surface of interest from any spatial locations. Our method supports several data types and distance metrics from real-world applications. We demonstrate its efficiency and scalability on state-of-the-art supercomputers using both large-scale volume datasets and surface models. We also demonstrate in-situ distance field computation on dynamic turbulent flame surfaces for a petascale combustion simulation. Our work greatly extends the usability of distance fields for demanding applications.

  6. A large-scale evaluation of computational protein function prediction.

    PubMed

    Radivojac, Predrag; Clark, Wyatt T; Oron, Tal Ronnen; Schnoes, Alexandra M; Wittkop, Tobias; Sokolov, Artem; Graim, Kiley; Funk, Christopher; Verspoor, Karin; Ben-Hur, Asa; Pandey, Gaurav; Yunes, Jeffrey M; Talwalkar, Ameet S; Repo, Susanna; Souza, Michael L; Piovesan, Damiano; Casadio, Rita; Wang, Zheng; Cheng, Jianlin; Fang, Hai; Gough, Julian; Koskinen, Patrik; Törönen, Petri; Nokso-Koivisto, Jussi; Holm, Liisa; Cozzetto, Domenico; Buchan, Daniel W A; Bryson, Kevin; Jones, David T; Limaye, Bhakti; Inamdar, Harshal; Datta, Avik; Manjari, Sunitha K; Joshi, Rajendra; Chitale, Meghana; Kihara, Daisuke; Lisewski, Andreas M; Erdin, Serkan; Venner, Eric; Lichtarge, Olivier; Rentzsch, Robert; Yang, Haixuan; Romero, Alfonso E; Bhat, Prajwal; Paccanaro, Alberto; Hamp, Tobias; Kaßner, Rebecca; Seemayer, Stefan; Vicedo, Esmeralda; Schaefer, Christian; Achten, Dominik; Auer, Florian; Boehm, Ariane; Braun, Tatjana; Hecht, Maximilian; Heron, Mark; Hönigschmid, Peter; Hopf, Thomas A; Kaufmann, Stefanie; Kiening, Michael; Krompass, Denis; Landerer, Cedric; Mahlich, Yannick; Roos, Manfred; Björne, Jari; Salakoski, Tapio; Wong, Andrew; Shatkay, Hagit; Gatzmann, Fanny; Sommer, Ingolf; Wass, Mark N; Sternberg, Michael J E; Škunca, Nives; Supek, Fran; Bošnjak, Matko; Panov, Panče; Džeroski, Sašo; Šmuc, Tomislav; Kourmpetis, Yiannis A I; van Dijk, Aalt D J; ter Braak, Cajo J F; Zhou, Yuanpeng; Gong, Qingtian; Dong, Xinran; Tian, Weidong; Falda, Marco; Fontana, Paolo; Lavezzo, Enrico; Di Camillo, Barbara; Toppo, Stefano; Lan, Liang; Djuric, Nemanja; Guo, Yuhong; Vucetic, Slobodan; Bairoch, Amos; Linial, Michal; Babbitt, Patricia C; Brenner, Steven E; Orengo, Christine; Rost, Burkhard; Mooney, Sean D; Friedberg, Iddo

    2013-03-01

    Automated annotation of protein function is challenging. As the number of sequenced genomes rapidly grows, the overwhelming majority of protein products can only be annotated computationally. If computational predictions are to be relied upon, it is crucial that the accuracy of these methods be high. Here we report the results from the first large-scale community-based critical assessment of protein function annotation (CAFA) experiment. Fifty-four methods representing the state of the art for protein function prediction were evaluated on a target set of 866 proteins from 11 organisms. Two findings stand out: (i) today's best protein function prediction algorithms substantially outperform widely used first-generation methods, with large gains on all types of targets; and (ii) although the top methods perform well enough to guide experiments, there is considerable need for improvement of currently available tools.

  7. Solving large scale traveling salesman problems by chaotic neurodynamics.

    PubMed

    Hasegawa, Mikio; Ikeguch, Tohru; Aihara, Kazuyuki

    2002-03-01

    We propose a novel approach for solving large scale traveling salesman problems (TSPs) by chaotic dynamics. First, we realize the tabu search on a neural network, by utilizing the refractory effects as the tabu effects. Then, we extend it to a chaotic neural network version. We propose two types of chaotic searching methods, which are based on two different tabu searches. While the first one requires neurons of the order of n2 for an n-city TSP, the second one requires only n neurons. Moreover, an automatic parameter tuning method of our chaotic neural network is presented for easy application to various problems. Last, we show that our method with n neurons is applicable to large TSPs such as an 85,900-city problem and exhibits better performance than the conventional stochastic searches and the tabu searches.

  8. Stability of large scale chromomagnetic fields in the early universe

    NASA Astrophysics Data System (ADS)

    Elmfors, Per; Persson, David

    1999-01-01

    It is well known that Yang-Mills theory in vacuum has a perturbative instability to spontaneously form a large scale magnetic field (the Savvidy mechanism) and that a constant field is unstable so that a possible ground state has to be inhomogenous over the non-perturbative scale Λ (the Copenhagen vacuum). We argue that this spontaneous instability does not occur at high temperature when the induced field strength gB~Λ2 is much weaker than the magnetic mass squared (g2T)2. At high temperature, oscillations of gauge fields acquire a thermal mass M~gT and we show that this mass stabilizes a magnetic field which is constant over length scales shorter than the magnetic screening length (g2T)-1. We therefore conclude that there is no indication for any spontaneous generation of weak non-abelian magnetic fields in the early universe.

  9. Large-scale transport across narrow gaps in rod bundles

    SciTech Connect

    Guellouz, M.S.; Tavoularis, S.

    1995-09-01

    Flow visualization and how-wire anemometry were used to investigate the velocity field in a rectangular channel containing a single cylindrical rod, which could be traversed on the centreplane to form gaps of different widths with the plane wall. The presence of large-scale, quasi-periodic structures in the vicinity of the gap has been demonstrated through flow visualization, spectral analysis and space-time correlation measurements. These structures are seen to exist even for relatively large gaps, at least up to W/D=1.350 (W is the sum of the rod diameter, D, and the gap width). The above measurements appear to compatible with the field of a street of three-dimensional, counter-rotating vortices, whose detailed structure, however, remains to be determined. The convection speed and the streamwise spacing of these vortices have been determined as functions of the gap size.

  10. Rapid large-scale oligonucleotide selection for microarrays.

    PubMed

    Rahmann, Sven

    2002-01-01

    We present the first algorithm that selects oligonucleotide probes (e.g. 25-mers) for microarray experiments on a large scale. For example, oligos for human genes can be found within 50 hours. This becomes possible by using the longest common substring as a specificity measure for candidate oligos. We present an algorithm based on a suffix array with additional information that is efficient both in terms of memory usage and running time to rank all candidate oligos according to their specificity. We also introduce the concept of master sequences to describe the sequences from which oligos are to be selected. Constraints such as oligo length, melting temperature, and self-complementarity are incorporated in the master sequence at a preprocessing stage and thus kept separate from the main selection problem. As a result, custom oligos can now be designed for any sequenced genome, just as the technology for on-site chip synthesis is becoming increasingly mature.

  11. Optimal Wind Energy Integration in Large-Scale Electric Grids

    NASA Astrophysics Data System (ADS)

    Albaijat, Mohammad H.

    The major concern in electric grid operation is operating under the most economical and reliable fashion to ensure affordability and continuity of electricity supply. This dissertation investigates the effects of such challenges, which affect electric grid reliability and economic operations. These challenges are: 1. Congestion of transmission lines, 2. Transmission lines expansion, 3. Large-scale wind energy integration, and 4. Phaser Measurement Units (PMUs) optimal placement for highest electric grid observability. Performing congestion analysis aids in evaluating the required increase of transmission line capacity in electric grids. However, it is necessary to evaluate expansion of transmission line capacity on methods to ensure optimal electric grid operation. Therefore, the expansion of transmission line capacity must enable grid operators to provide low-cost electricity while maintaining reliable operation of the electric grid. Because congestion affects the reliability of delivering power and increases its cost, the congestion analysis in electric grid networks is an important subject. Consequently, next-generation electric grids require novel methodologies for studying and managing congestion in electric grids. We suggest a novel method of long-term congestion management in large-scale electric grids. Owing to the complication and size of transmission line systems and the competitive nature of current grid operation, it is important for electric grid operators to determine how many transmission lines capacity to add. Traditional questions requiring answers are "Where" to add, "How much of transmission line capacity" to add, and "Which voltage level". Because of electric grid deregulation, transmission lines expansion is more complicated as it is now open to investors, whose main interest is to generate revenue, to build new transmission lines. Adding a new transmission capacity will help the system to relieve the transmission system congestion, create

  12. Large scale anisotropic bias from primordial non-Gaussianity

    SciTech Connect

    Baghram, Shant; Firouzjahi, Hassan; Namjoo, Mohammad Hossein E-mail: mh.namjoo@ipm.ir

    2013-08-01

    In this work we study the large scale structure bias in models of anisotropic inflation. We use the Peak Background Splitting method in Excursion Set Theory to find the scale-dependent bias. We show that the amplitude of the bias is modified by a direction-dependent factor. In the specific anisotropic inflation model which we study, the scale-dependent bias vanishes at leading order when the long wavelength mode in squeezed limit is aligned with the anisotropic direction in the sky. We also extend the scale-dependent bias formulation to the general situations with primordial anisotropy. We find some selection rules indicating that some specific parts of a generic anisotropic bispectrum is picked up by the bias parameter. We argue that the anisotropic bias is mainly sourced by the angle between the anisotropic direction and the long wavelength mode in the squeezed limit.

  13. Large-scale velocity fields. [of solar rotation

    NASA Technical Reports Server (NTRS)

    Howard, Robert F.; Kichatinov, L. L.; Bogart, Richard S.; Ribes, Elizabeth

    1991-01-01

    The present evaluation of recent observational results bearing on the nature and characteristics of solar rotation gives attention to the status of current understanding on such large-scale velocity-field-associated phenomena as solar supergranulation, mesogranulation, and giant-scale convection. Also noted are theoretical suggestions reconciling theory and observations of giant-scale solar convection. The photosphere's global meridional circulation is suggested by solar rotation models requiring pole-to-equator flows of a few m/sec, as well as by the observed migration of magnetic activity over the solar cycle. The solar rotation exhibits a latitude and cycle dependence which can be understood in terms of a time-dependent convective toroidal roll pattern.

  14. Modeling Failure Propagation in Large-Scale Engineering Networks

    NASA Astrophysics Data System (ADS)

    Schläpfer, Markus; Shapiro, Jonathan L.

    The simultaneous unavailability of several technical components within large-scale engineering systems can lead to high stress, rendering them prone to cascading events. In order to gain qualitative insights into the failure propagation mechanisms resulting from independent outages, we adopt a minimalistic model representing the components and their interdependencies by an undirected, unweighted network. The failure dynamics are modeled by an anticipated accelerated “wearout” process being dependent on the initial degree of a node and on the number of failed nearest neighbors. The results of the stochastic simulations imply that the influence of the network topology on the speed of the cascade highly depends on how the number of failed nearest neighbors shortens the life expectancy of a node. As a formal description of the decaying networks we propose a continuous-time mean field approximation, estimating the average failure rate of the nearest neighbors of a node based on the degree-degree distribution.

  15. Large-Scale Quantitative Analysis of Painting Arts

    NASA Astrophysics Data System (ADS)

    Kim, Daniel; Son, Seung-Woo; Jeong, Hawoong

    2014-12-01

    Scientists have made efforts to understand the beauty of painting art in their own languages. As digital image acquisition of painting arts has made rapid progress, researchers have come to a point where it is possible to perform statistical analysis of a large-scale database of artistic paints to make a bridge between art and science. Using digital image processing techniques, we investigate three quantitative measures of images - the usage of individual colors, the variety of colors, and the roughness of the brightness. We found a difference in color usage between classical paintings and photographs, and a significantly low color variety of the medieval period. Interestingly, moreover, the increment of roughness exponent as painting techniques such as chiaroscuro and sfumato have advanced is consistent with historical circumstances.

  16. Honeycomb: Visual Analysis of Large Scale Social Networks

    NASA Astrophysics Data System (ADS)

    van Ham, Frank; Schulz, Hans-Jörg; Dimicco, Joan M.

    The rise in the use of social network sites allows us to collect large amounts of user reported data on social structures and analysis of this data could provide useful insights for many of the social sciences. This analysis is typically the domain of Social Network Analysis, and visualization of these structures often proves invaluable in understanding them. However, currently available visual analysis tools are not very well suited to handle the massive scale of this network data, and often resolve to displaying small ego networks or heavily abstracted networks. In this paper, we present Honeycomb, a visualization tool that is able to deal with much larger scale data (with millions of connections), which we illustrate by using a large scale corporate social networking site as an example. Additionally, we introduce a new probability based network metric to guide users to potentially interesting or anomalous patterns and discuss lessons learned during design and implementation.

  17. Applications of large-scale density functional theory in biology

    NASA Astrophysics Data System (ADS)

    Cole, Daniel J.; Hine, Nicholas D. M.

    2016-10-01

    Density functional theory (DFT) has become a routine tool for the computation of electronic structure in the physics, materials and chemistry fields. Yet the application of traditional DFT to problems in the biological sciences is hindered, to a large extent, by the unfavourable scaling of the computational effort with system size. Here, we review some of the major software and functionality advances that enable insightful electronic structure calculations to be performed on systems comprising many thousands of atoms. We describe some of the early applications of large-scale DFT to the computation of the electronic properties and structure of biomolecules, as well as to paradigmatic problems in enzymology, metalloproteins, photosynthesis and computer-aided drug design. With this review, we hope to demonstrate that first principles modelling of biological structure-function relationships are approaching a reality.

  18. Exploiting large-scale correlations to detect continuous gravitational waves.

    PubMed

    Pletsch, Holger J; Allen, Bruce

    2009-10-30

    Fully coherent searches (over realistic ranges of parameter space and year-long observation times) for unknown sources of continuous gravitational waves are computationally prohibitive. Less expensive hierarchical searches divide the data into shorter segments which are analyzed coherently, then detection statistics from different segments are combined incoherently. The novel method presented here solves the long-standing problem of how best to do the incoherent combination. The optimal solution exploits large-scale parameter-space correlations in the coherent detection statistic. Application to simulated data shows dramatic sensitivity improvements compared with previously available (ad hoc) methods, increasing the spatial volume probed by more than 2 orders of magnitude at lower computational cost.

  19. Large-scale testing of structural clay tile infilled frames

    SciTech Connect

    Flanagan, R.D.; Bennett, R.M.

    1993-03-18

    A summary of large-scale cyclic static tests of structural clay tile infilled frames is given. In-plane racking tests examined the effects of varying frame stiffness, varying infill size, infill offset from frame centerline, and single and double wythe infill construction. Out-of-plane tests examined infilled frame response to inertial loadings and inter-story drift loadings. Sequential in-plane and out-of-plane loadings were performed to determine the effects of orthogonal damage and degradation on both strength and stiffness. A combined out-of-plane inertial and in-plane racking test was conducted to investigate the interaction of multi-directional loading. To determine constitutive properties of the infills, prism compression, mortar compression and various unit tile tests were performed.

  20. Engineering large-scale agent-based systems with consensus

    NASA Technical Reports Server (NTRS)

    Bokma, A.; Slade, A.; Kerridge, S.; Johnson, K.

    1994-01-01

    The paper presents the consensus method for the development of large-scale agent-based systems. Systems can be developed as networks of knowledge based agents (KBA) which engage in a collaborative problem solving effort. The method provides a comprehensive and integrated approach to the development of this type of system. This includes a systematic analysis of user requirements as well as a structured approach to generating a system design which exhibits the desired functionality. There is a direct correspondence between system requirements and design components. The benefits of this approach are that requirements are traceable into design components and code thus facilitating verification. The use of the consensus method with two major test applications showed it to be successful and also provided valuable insight into problems typically associated with the development of large systems.

  1. Large-Scale All-Dielectric Metamaterial Perfect Reflectors

    DOE PAGES

    Moitra, Parikshit; Slovick, Brian A.; li, Wei; ...

    2015-05-08

    All-dielectric metamaterials offer a potential low-loss alternative to plasmonic metamaterials at optical frequencies. In this paper, we take advantage of the low absorption loss as well as the simple unit cell geometry to demonstrate large-scale (centimeter-sized) all-dielectric metamaterial perfect reflectors made from silicon cylinder resonators. These perfect reflectors, operating in the telecommunications band, were fabricated using self-assembly based nanosphere lithography. In spite of the disorder originating from the self-assembly process, the average reflectance of the metamaterial perfect reflectors is 99.7% at 1530 nm, surpassing the reflectance of metallic mirrors. Moreover, the spectral separation of the electric and magnetic resonances canmore » be chosen to achieve the required reflection bandwidth while maintaining a high tolerance to disorder. Finally, the scalability of this design could lead to new avenues of manipulating light for low-loss and large-area photonic applications.« less

  2. Large-Scale All-Dielectric Metamaterial Perfect Reflectors

    SciTech Connect

    Moitra, Parikshit; Slovick, Brian A.; li, Wei; Kravchencko, Ivan I.; Briggs, Dayrl P.; Krishnamurthy, S.; Valentine, Jason

    2015-05-08

    All-dielectric metamaterials offer a potential low-loss alternative to plasmonic metamaterials at optical frequencies. In this paper, we take advantage of the low absorption loss as well as the simple unit cell geometry to demonstrate large-scale (centimeter-sized) all-dielectric metamaterial perfect reflectors made from silicon cylinder resonators. These perfect reflectors, operating in the telecommunications band, were fabricated using self-assembly based nanosphere lithography. In spite of the disorder originating from the self-assembly process, the average reflectance of the metamaterial perfect reflectors is 99.7% at 1530 nm, surpassing the reflectance of metallic mirrors. Moreover, the spectral separation of the electric and magnetic resonances can be chosen to achieve the required reflection bandwidth while maintaining a high tolerance to disorder. Finally, the scalability of this design could lead to new avenues of manipulating light for low-loss and large-area photonic applications.

  3. Biohazards Assessment in Large-Scale Zonal Centrifugation

    PubMed Central

    Baldwin, C. L.; Lemp, J. F.; Barbeito, M. S.

    1975-01-01

    A study was conducted to determine the biohazards associated with use of the large-scale zonal centrifuge for purification of moderate risk oncogenic viruses. To safely and conveniently assess the hazard, coliphage T3 was substituted for the virus in a typical processing procedure performed in a National Cancer Institute contract laboratory. Risk of personnel exposure was found to be minimal during optimal operation but definite potential for virus release from a number of centrifuge components during mechanical malfunction was shown by assay of surface, liquid, and air samples collected during the processing. High concentration of phage was detected in the turbine air exhaust and the seal coolant system when faulty seals were employed. The simulant virus was also found on both centrifuge chamber interior and rotor surfaces. Images PMID:1124921

  4. Biohazards assessment in large-scale zonal centrifugation.

    PubMed

    Baldwin, C L; Lemp, J F; Barbeito, M S

    1975-04-01

    A study was conducted to determine the biohazards associated with use of the large-scale zonal centrifuge for purification of moderate risk oncogenic viruses. To safely and conveniently assess the hazard, coliphage T3 was substituted for the virus in a typical processing procedure performed in a National Cancer Institute contract laboratory. Risk of personnel exposure was found to be minimal during optimal operation but definite potential for virus release from a number of centrifuge components during mechanical malfunction was shown by assay of surface, liquid, and air samples collected during the processing. High concentration of phage was detected in the turbine air exhaust and the seal coolant system when faulty seals were employed. The simulant virus was also found on both the centrifuge chamber interior and rotor surfaces.

  5. Lightweight computational steering of very large scale molecular dynamics simulations

    SciTech Connect

    Beazley, D.M.; Lomdahl, P.S.

    1996-09-01

    We present a computational steering approach for controlling, analyzing, and visualizing very large scale molecular dynamics simulations involving tens to hundreds of millions of atoms. Our approach relies on extensible scripting languages and an easy to use tool for building extensions and modules. The system is extremely easy to modify, works with existing C code, is memory efficient, and can be used from inexpensive workstations and networks. We demonstrate how we have used this system to manipulate data from production MD simulations involving as many as 104 million atoms running on the CM-5 and Cray T3D. We also show how this approach can be used to build systems that integrate common scripting languages (including Tcl/Tk, Perl, and Python), simulation code, user extensions, and commercial data analysis packages.

  6. Retention of memory for large-scale spaces.

    PubMed

    Ishikawa, Toru

    2013-01-01

    This study empirically examined the retention of large-scale spatial memory, taking different types of spatial knowledge and levels of sense of direction into consideration. A total of 38 participants learned a route from a video and conducted spatial tasks immediately after learning the route and after 2 weeks or 3 months had passed. Results showed that spatial memory decayed over time, at a faster rate for the first 2-week period than for the subsequent period of up to 3 months, although it was not completely forgotten even after 3 months. The rate of forgetting differed depending on the type of knowledge, with landmark and route knowledge deteriorating at a much faster rate than survey knowledge. Sense of direction affected both the acquisition and the retention of survey knowledge. Survey knowledge by people with a good sense of direction was more accurate and decayed much less than that by people with a poor sense of direction.

  7. Large scale rigidity-based flexibility analysis of biomolecules

    PubMed Central

    Streinu, Ileana

    2016-01-01

    KINematics And RIgidity (KINARI) is an on-going project for in silico flexibility analysis of proteins. The new version of the software, Kinari-2, extends the functionality of our free web server KinariWeb, incorporates advanced web technologies, emphasizes the reproducibility of its experiments, and makes substantially improved tools available to the user. It is designed specifically for large scale experiments, in particular, for (a) very large molecules, including bioassemblies with high degree of symmetry such as viruses and crystals, (b) large collections of related biomolecules, such as those obtained through simulated dilutions, mutations, or conformational changes from various types of dynamics simulations, and (c) is intended to work as seemlessly as possible on the large, idiosyncratic, publicly available repository of biomolecules, the Protein Data Bank. We describe the system design, along with the main data processing, computational, mathematical, and validation challenges underlying this phase of the KINARI project. PMID:26958583

  8. Large Scale Bacterial Colony Screening of Diversified FRET Biosensors

    PubMed Central

    Litzlbauer, Julia; Schifferer, Martina; Ng, David; Fabritius, Arne; Thestrup, Thomas; Griesbeck, Oliver

    2015-01-01

    Biosensors based on Förster Resonance Energy Transfer (FRET) between fluorescent protein mutants have started to revolutionize physiology and biochemistry. However, many types of FRET biosensors show relatively small FRET changes, making measurements with these probes challenging when used under sub-optimal experimental conditions. Thus, a major effort in the field currently lies in designing new optimization strategies for these types of sensors. Here we describe procedures for optimizing FRET changes by large scale screening of mutant biosensor libraries in bacterial colonies. We describe optimization of biosensor expression, permeabilization of bacteria, software tools for analysis, and screening conditions. The procedures reported here may help in improving FRET changes in multiple suitable classes of biosensors. PMID:26061878

  9. Measuring Large-Scale Social Networks with High Resolution

    PubMed Central

    Stopczynski, Arkadiusz; Sekara, Vedran; Sapiezynski, Piotr; Cuttone, Andrea; Madsen, Mette My; Larsen, Jakob Eg; Lehmann, Sune

    2014-01-01

    This paper describes the deployment of a large-scale study designed to measure human interactions across a variety of communication channels, with high temporal resolution and spanning multiple years—the Copenhagen Networks Study. Specifically, we collect data on face-to-face interactions, telecommunication, social networks, location, and background information (personality, demographics, health, politics) for a densely connected population of 1 000 individuals, using state-of-the-art smartphones as social sensors. Here we provide an overview of the related work and describe the motivation and research agenda driving the study. Additionally, the paper details the data-types measured, and the technical infrastructure in terms of both backend and phone software, as well as an outline of the deployment procedures. We document the participant privacy procedures and their underlying principles. The paper is concluded with early results from data analysis, illustrating the importance of multi-channel high-resolution approach to data collection. PMID:24770359

  10. Performance Health Monitoring of Large-Scale Systems

    SciTech Connect

    Rajamony, Ram

    2014-11-20

    This report details the progress made on the ASCR funded project Performance Health Monitoring for Large Scale Systems. A large-­scale application may not achieve its full performance potential due to degraded performance of even a single subsystem. Detecting performance faults, isolating them, and taking remedial action is critical for the scale of systems on the horizon. PHM aims to develop techniques and tools that can be used to identify and mitigate such performance problems. We accomplish this through two main aspects. The PHM framework encompasses diagnostics, system monitoring, fault isolation, and performance evaluation capabilities that indicates when a performance fault has been detected, either due to an anomaly present in the system itself or due to contention for shared resources between concurrently executing jobs. Software components called the PHM Control system then build upon the capabilities provided by the PHM framework to mitigate degradation caused by performance problems.

  11. Computational Issues in Damping Identification for Large Scale Problems

    NASA Technical Reports Server (NTRS)

    Pilkey, Deborah L.; Roe, Kevin P.; Inman, Daniel J.

    1997-01-01

    Two damping identification methods are tested for efficiency in large-scale applications. One is an iterative routine, and the other a least squares method. Numerical simulations have been performed on multiple degree-of-freedom models to test the effectiveness of the algorithm and the usefulness of parallel computation for the problems. High Performance Fortran is used to parallelize the algorithm. Tests were performed using the IBM-SP2 at NASA Ames Research Center. The least squares method tested incurs high communication costs, which reduces the benefit of high performance computing. This method's memory requirement grows at a very rapid rate meaning that larger problems can quickly exceed available computer memory. The iterative method's memory requirement grows at a much slower pace and is able to handle problems with 500+ degrees of freedom on a single processor. This method benefits from parallelization, and significant speedup can he seen for problems of 100+ degrees-of-freedom.

  12. Large-scale and global features of complex genomic signals

    NASA Astrophysics Data System (ADS)

    Cristea, Paul D.

    2003-10-01

    The paper briefly reviews the methodology of the symbolic nucleic sequence conversion into genomic signals and presents large scale and global features of the resulting genomic signals. Whole chromosomes or whole genomes are converted into complex signals and phase analysis is performed. The phase, cumulated phase and unwrapped phase of genomic signals are studied as tools for revealing important features of to the first and second order statistics of nucleotide distribution along DNA strands. It is shown that the unwrapped phase displays an almost linear variation along whole chromosomes. The property holds for all the investigated genomes, being shared by both prokaryotes and eukaryotes, while the magnitude and sign of the unwrapped phase slope is specific for each taxon and chromosome. The comparison between the behavior of the cumulated phase and of the unwrapped phase across the putative origins and termini of the replichores suggests a model of the 'patchy' structure of the chromosomes.

  13. Star formation associated with a large-scale infrared bubble

    NASA Astrophysics Data System (ADS)

    Xu, Jin-Long; Ju, Bing-Gang

    2014-09-01

    Aims: To investigate how a large-scale infrared bubble centered at l = 53.9° and b = 0.2° forms, and to study if star formation is taking place at the periphery of the bubble, we performed a multiwavelength study. Methods: Using the data from the Galactic Ring Survey (GRS) and Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE), we performed a study of a large-scale infrared bubble with a size of about 16 pc at a distance of 2.0 kpc. We present the 12CO J = 1-0, 13CO J = 1-0, and C18O J = 1-0 observations of HII region G53.54-0.01 (Sh2-82) obtained at the Purple Mountain Observation (PMO) 13.7 m radio telescope to investigate the detailed distribution of associated molecular material. In addition, we also used radiorecombination line and VLA data. To select young stellar objects (YSOs) consistent with this region, we used the GLIMPSE I catalog. Results: The large-scale infrared bubble shows a half-shell morphology at 8 μm. The H II regions of G53.54-0.01, G53.64+0.24, and G54.09-0.06 are situated on the bubble. Comparing the radio recombination line velocities and associated 13CO J = 1-0 components of the three H II regions, we found that the 8 μm emission associated with H II region G53.54-0.01 should belong to the foreground emission, and only overlap with the large-scale infrared bubble in the line of sight. Three extended green objects (EGOs, the candidate massive young stellar objects), as well as three H II regions and two small-scale bubbles are found located in the G54.09-0.06 complex, indicating an active massive star-forming region. Emission from C18O at J = 1-0 presents four cloud clumps on the northeastern border of H II region G53.54-0.01. By comparing the spectral profiles of 12CO J = 1-0, 13CO J = 1-0, and C18O J = 1-0 at the peak position of each clump, we found the collected gas in the three clumps, except for the clump coinciding with a massive YSO (IRAS 19282+1814). Using the evolutive model of the H II region, we derived that

  14. Galaxies and large scale structure at high redshifts

    PubMed Central

    Steidel, Charles C.

    1998-01-01

    It is now straightforward to assemble large samples of very high redshift (z ∼ 3) field galaxies selected by their pronounced spectral discontinuity at the rest frame Lyman limit of hydrogen (at 912 Å). This makes possible both statistical analyses of the properties of the galaxies and the first direct glimpse of the progression of the growth of their large-scale distribution at such an early epoch. Here I present a summary of the progress made in these areas to date and some preliminary results of and future plans for a targeted redshift survey at z = 2.7–3.4. Also discussed is how the same discovery method may be used to obtain a “census” of star formation in the high redshift Universe, and the current implications for the history of galaxy formation as a function of cosmic epoch. PMID:9419319

  15. The dynamics of large-scale arrays of coupled resonators

    NASA Astrophysics Data System (ADS)

    Borra, Chaitanya; Pyles, Conor S.; Wetherton, Blake A.; Quinn, D. Dane; Rhoads, Jeffrey F.

    2017-03-01

    This work describes an analytical framework suitable for the analysis of large-scale arrays of coupled resonators, including those which feature amplitude and phase dynamics, inherent element-level parameter variation, nonlinearity, and/or noise. In particular, this analysis allows for the consideration of coupled systems in which the number of individual resonators is large, extending as far as the continuum limit corresponding to an infinite number of resonators. Moreover, this framework permits analytical predictions for the amplitude and phase dynamics of such systems. The utility of this analytical methodology is explored through the analysis of a system of N non-identical resonators with global coupling, including both reactive and dissipative components, physically motivated by an electromagnetically-transduced microresonator array. In addition to the amplitude and phase dynamics, the behavior of the system as the number of resonators varies is investigated and the convergence of the discrete system to the infinite-N limit is characterized.

  16. Large scale ocean circulation from the GRACE GGM01 Geoid

    NASA Astrophysics Data System (ADS)

    Tapley, B. D.; Chambers, D. P.; Bettadpur, S.; Ries, J. C.

    2003-11-01

    The GRACE Gravity Model 01 (GGM01), computed from 111 days of GRACE K-band ranging (KBR) data, is differenced from a global mean sea surface (MSS) computed from a decade of satellite altimetry to determine a mean dynamic ocean topography (DOT). As a test of the GGM01 gravity model, large-scale zonal and meridional surface geostrophic currents are computed from the topography and are compared with those derived from a mean hydrographic surface. Reduction in residual RMS between the two by 30-60% (and increased correlation) indicates that the GGM01 geoid represents a dramatic improvement over older geoid models, which were developed from multiple satellite tracking data, altimetry, and surface gravity measurements. For the first time, all major current systems are clearly observed in the DOT from space-based measurements.

  17. Efficient Distributed Test Architectures for Large-Scale Systems

    NASA Astrophysics Data System (ADS)

    de Almeida, Eduardo Cunha; Marynowski, Jõao Eugenio; Sunyé, Gerson; Le Traon, Yves; Valduriez, Patrick

    Typical testing architectures for distributed software rely on a centralized test controller, which decomposes test cases in steps and deploy them across distributed testers. The controller also guarantees the correct execution of test steps through synchronization messages. These architectures are not scalable while testing large-scale distributed systems due to the cost of synchronization management, which may increase the cost of a test and even prevent its execution. This paper presents a distributed architecture to synchronize the test execution sequence. This approach organizes the testers in a tree, where messages are exchanged among parents and children. The experimental evaluation shows that the synchronization management overhead can be reduced by several orders of magnitude. We conclude that testing architectures should scale up along with the distributed system under test.

  18. Large-Scale Quantitative Analysis of Painting Arts

    PubMed Central

    Kim, Daniel; Son, Seung-Woo; Jeong, Hawoong

    2014-01-01

    Scientists have made efforts to understand the beauty of painting art in their own languages. As digital image acquisition of painting arts has made rapid progress, researchers have come to a point where it is possible to perform statistical analysis of a large-scale database of artistic paints to make a bridge between art and science. Using digital image processing techniques, we investigate three quantitative measures of images – the usage of individual colors, the variety of colors, and the roughness of the brightness. We found a difference in color usage between classical paintings and photographs, and a significantly low color variety of the medieval period. Interestingly, moreover, the increment of roughness exponent as painting techniques such as chiaroscuro and sfumato have advanced is consistent with historical circumstances. PMID:25501877

  19. U-shaped Vortex Structures in Large Scale Cloud Cavitation

    NASA Astrophysics Data System (ADS)

    Cao, Yantao; Peng, Xiaoxing; Xu, Lianghao; Hong, Fangwen

    2015-12-01

    The control of cloud cavitation, especially large scale cloud cavitation(LSCC), is always a hot issue in the field of cavitation research. However, there has been little knowledge on the evolution of cloud cavitation since it is associated with turbulence and vortex flow. In this article, the structure of cloud cavitation shed by sheet cavitation around different hydrofoils and a wedge were observed in detail with high speed camera (HSC). It was found that the U-shaped vortex structures always existed in the development process of LSCC. The results indicated that LSCC evolution was related to this kind of vortex structures, and it may be a universal character for LSCC. Then vortex strength of U-shaped vortex structures in a cycle was analyzed with numerical results.

  20. A large-scale crop protection bioassay data set

    PubMed Central

    Gaulton, Anna; Kale, Namrata; van Westen, Gerard J. P.; Bellis, Louisa J.; Bento, A. Patrícia; Davies, Mark; Hersey, Anne; Papadatos, George; Forster, Mark; Wege, Philip; Overington, John P.

    2015-01-01

    ChEMBL is a large-scale drug discovery database containing bioactivity information primarily extracted from scientific literature. Due to the medicinal chemistry focus of the journals from which data are extracted, the data are currently of most direct value in the field of human health research. However, many of the scientific use-cases for the current data set are equally applicable in other fields, such as crop protection research: for example, identification of chemical scaffolds active against a particular target or endpoint, the de-convolution of the potential targets of a phenotypic assay, or the potential targets/pathways for safety liabilities. In order to broaden the applicability of the ChEMBL database and allow more widespread use in crop protection research, an extensive data set of bioactivity data of insecticidal, fungicidal and herbicidal compounds and assays was collated and added to the database. PMID:26175909