WorldWideScience

Sample records for bandwidth sharing policy

  1. Fluid limits for bandwidth-sharing networks with rate constraints

    NARCIS (Netherlands)

    M. Frolkova (Masha); J. Reed (Josh); A.P. Zwart (Bert)

    2013-01-01

    htmlabstractBandwidth-sharing networks as introduced by Massouli\\'e~\\& Roberts (1998) model the dynamic interaction among an evolving population of elastic flows competing for several links. With policies based on optimization procedures, such models are of interest both from a~Queueing Theory and

  2. Fluid limits for Bandwidth-Sharing Networks with Impatience.

    NARCIS (Netherlands)

    Remerova, M.; Reed, J.; Zwart, A.P.

    2014-01-01

    Bandwidth-sharing networks as introduced by Roberts and Massoulié [Roberts JW, Massoulié L (1998) Bandwidth sharing and admission control for elastic traffic. Proc. ITC Specialist Seminar, Yokohama, Japan], Massoulié and Roberts [Massoulié L, Roberts JW (1999) Bandwidth sharing: Objectives and

  3. Fluid Limits for Bandwidth-Sharing Networks in Overload.

    NARCIS (Netherlands)

    Borst, S.; Egorova, R.; Zwart, A.P.

    2014-01-01

    Bandwidth-sharing networks as considered by Roberts and Massoulié [28] (Roberts JW, Massoulié L (1998) Bandwidth sharing and admission control for elastic traffic. Proc. ITC Specialist Seminar, Yokohama, Japan) provide a natural modeling framework for describing the dynamic flow-level interaction

  4. Fluid limits for bandwidth-sharing networks in overload

    NARCIS (Netherlands)

    Borst, S.C.; Egorova, R.R.; Zwart, B.

    2014-01-01

    Bandwidth-sharing networks as considered by Roberts and Massoulié [28] (Roberts JW, Massoulié L (1998) Bandwidth sharing and admission control for elastic traffic. Proc. ITC Specialist Seminar, Yokohama, Japan) provide a natural modeling framework for describing the dynamic flow-level interaction

  5. Bandwidth-sharing in LHCONE, an analysis of the problem

    Science.gov (United States)

    Wildish, T.

    2015-12-01

    to inefficient use of the network. If one user cannot use their quota for some reason, that bandwidth is lost. Likewise, there is no incentive for the user to be efficient within their quota, they have nothing to gain by using less than their allocation. As with CPU farms, some sort of dynamic allocation is more likely to be useful. A promising approach for sharing bandwidth at LHCONE is the ’Progressive Second-Price auction’, where users are given a budget and are required to bid from that budget for the specific resources they want to reserve. The auction allows users to effectively determine among themselves the degree of sharing they are willing to accept based on the priorities of their traffic and their global share, as represented by their total budget. The network then implements those allocations using whatever mix of technologies is appropriate or available. This paper describes how the Progressive Second-Price auction works and how it can be applied to LHCONE. Practical questions are addressed, such as how are budgets set, what strategy should users use to manage their budget, how and how often should the auction be run, and how do we ensure that the goals of fairness and efficiency are met.

  6. BBSRC Data Sharing Policy

    OpenAIRE

    Amanda Collis; David McAllister; Michael Ball

    2011-01-01

    BBSRC recognizes the importance of contributing to the growing international efforts in data sharing. BBSRC is committed to getting the best value for the funds we invest and believes that making research data more readily available will reinforce open scientific inquiry and stimulate new investigations and analyses. BBSRC supports the view that data sharing should be led by the scientific community and driven by scientific need. It should also be cost effective and the data shared should be ...

  7. Fixed-Point Approximations of Bandwidth-Sharing Networks with Rate Constraints

    NARCIS (Netherlands)

    M. Frolkova (Masha); J. Reed (Josh); A.P. Zwart (Bert)

    2011-01-01

    htmlabstractBandwidth-sharing networks are important flow level models of communication networks. We focus on the fact that it takes a signicant number of users to saturate a link, necessitating the inclusion of individual rate constraints. In particular we extend work of Reed & Zwart on fluid

  8. Data Sharing For Precision Medicine: Policy Lessons And Future Directions.

    Science.gov (United States)

    Blasimme, Alessandro; Fadda, Marta; Schneider, Manuel; Vayena, Effy

    2018-05-01

    Data sharing is a precondition of precision medicine. Numerous organizations have produced abundant guidance on data sharing. Despite such efforts, data are not being shared to a degree that can trigger the expected data-driven revolution in precision medicine. We set out to explore why. Here we report the results of a comprehensive analysis of data-sharing guidelines issued over the past two decades by multiple organizations. We found that the guidelines overlap on a restricted set of policy themes. However, we observed substantial fragmentation in the policy landscape across specific organizations and data types. This may have contributed to the current stalemate in data sharing. To move toward a more efficient data-sharing ecosystem for precision medicine, policy makers should explore innovative ways to cope with central policy themes such as privacy, consent, and data quality; focus guidance on interoperability, attribution, and public engagement; and promote data-sharing policies that can be adapted to multiple data types.

  9. Journal Data Sharing Policies and Statistical Reporting Inconsistencies in Psychology

    Directory of Open Access Journals (Sweden)

    Michèle B. Nuijten

    2017-12-01

    Full Text Available In this paper, we present three retrospective observational studies that investigate the relation between data sharing and statistical reporting inconsistencies. Previous research found that reluctance to share data was related to a higher prevalence of statistical errors, often in the direction of statistical significance (Wicherts, Bakker, & Molenaar, 2011. We therefore hypothesized that journal policies about data sharing and data sharing itself would reduce these inconsistencies. In Study 1, we compared the prevalence of reporting inconsistencies in two similar journals on decision making with different data sharing policies. In Study 2, we compared reporting inconsistencies in psychology articles published in PLOS journals (with a data sharing policy and Frontiers in Psychology (without a stipulated data sharing policy. In Study 3, we looked at papers published in the journal Psychological Science to check whether papers with or without an Open Practice Badge differed in the prevalence of reporting errors. Overall, we found no relationship between data sharing and reporting inconsistencies. We did find that journal policies on data sharing seem extremely effective in promoting data sharing. We argue that open data is essential in improving the quality of psychological science, and we discuss ways to detect and reduce reporting inconsistencies in the literature.

  10. Data sharing policy design for consortia: challenges for sustainability.

    Science.gov (United States)

    Kaye, Jane; Hawkins, Naomi

    2014-01-01

    The field of human genomics has led advances in the sharing of data with a view to facilitating translation of research into innovations for human health. This change in scientific practice has been implemented through new policy developed by many principal investigators, project managers and funders, which has ultimately led to new forms of practice and innovative governance models for data sharing. Here, we examine the development of the governance of data sharing in genomics, and explore some of the key challenges associated with the design and implementation of these policies. We examine how the incremental nature of policy design, the perennial problem of consent, the gridlock caused by multiple and overlapping access systems, the administrative burden and the problems with incentives and acknowledgment all have an impact on the potential for data sharing to be maximized. We conclude by proposing ways in which the scientific community can address these problems, to improve the sustainability of data sharing into the future.

  11. On Sharing and Quasi-Sharing : The Tension between Sharing-Economy Practices, Public Policy, and Regulation

    NARCIS (Netherlands)

    Ranchordás, Sofia; Albinsson, Pia A.; Perera, B. Yasanthi

    2018-01-01

    This paper offers a critical and comparative overview of the main regulatory and policy challenges faced by regulators in the context of the sharing economy. The regulation of the sharing economy has been particularly challenging as regulators are being asked to balance the interests protected by

  12. Job-Sharing Couples in Academia: Administrative Policies and Practices.

    Science.gov (United States)

    Mikitka, Kathleen Faith

    1984-01-01

    Examined existing administrative policies and procedures for academic job sharing for married couples in a survey of 12 institutions and 16 administrators. Results suggested growing consideration of job sharing by academic employers and pointed out advantages such as attracting high-quality faculty and extending faculty resources. (JAC)

  13. Sharing the 620-790 MHz band allocated to terrestrial television with an audio-bandwidth social service satellite system

    Science.gov (United States)

    Smith, E. K.; Reinhart, E. E.

    1977-01-01

    A study was carried out to identify the optimum uplink and downlink frequencies for audio-bandwidth channels for use by a satellite system distributing social services. The study considered functional-user-need models for five types of social services and identified a general baseline system that is appropriate for most of them. Technical aspects and costs of this system and of the frequency bands that it might use were reviewed, leading to the identification of the 620-790 MHz band as a perferred candidate for both uplink and downlink transmissions for nonmobile applications. The study also led to some ideas as to how to configure the satellite system.

  14. An Adaptive Insertion and Promotion Policy for Partitioned Shared Caches

    Science.gov (United States)

    Mahrom, Norfadila; Liebelt, Michael; Raof, Rafikha Aliana A.; Daud, Shuhaizar; Hafizah Ghazali, Nur

    2018-03-01

    Cache replacement policies in chip multiprocessors (CMP) have been investigated extensively and proven able to enhance shared cache management. However, competition among multiple processors executing different threads that require simultaneous access to a shared memory may cause cache contention and memory coherence problems on the chip. These issues also exist due to some drawbacks of the commonly used Least Recently Used (LRU) policy employed in multiprocessor systems, which are because of the cache lines residing in the cache longer than required. In image processing analysis of for example extra pulmonary tuberculosis (TB), an accurate diagnosis for tissue specimen is required. Therefore, a fast and reliable shared memory management system to execute algorithms for processing vast amount of specimen image is needed. In this paper, the effects of the cache replacement policy in a partitioned shared cache are investigated. The goal is to quantify whether better performance can be achieved by using less complex replacement strategies. This paper proposes a Middle Insertion 2 Positions Promotion (MI2PP) policy to eliminate cache misses that could adversely affect the access patterns and the throughput of the processors in the system. The policy employs a static predefined insertion point, near distance promotion, and the concept of ownership in the eviction policy to effectively improve cache thrashing and to avoid resource stealing among the processors.

  15. Threshold policy for global games with noisy information sharing

    KAUST Repository

    Mahdavifar, Hessam

    2015-12-15

    It is known that global games with noisy sharing of information do not admit a certain type of threshold policies [1]. Motivated by this result, we investigate the existence of threshold-type policies on global games with noisy sharing of information and show that such equilibrium strategies exist and are unique if the sharing of information happens over a sufficiently noisy environment. To show this result, we establish that if a threshold function is an equilibrium strategy, then it will be a solution to a fixed point equation. Then, we show that for a sufficiently noisy environment, the functional fixed point equation leads to a contraction mapping, and hence, its iterations converge to a unique continuous threshold policy.

  16. Link Before You Share: Managing Privacy Policies through Blockchain

    OpenAIRE

    Banerjee, Agniva; Joshi, Karuna Pande

    2017-01-01

    With the advent of numerous online content providers, utilities and applications, each with their own specific version of privacy policies and its associated overhead, it is becoming increasingly difficult for concerned users to manage and track the confidential information that they share with the providers. Users consent to providers to gather and share their Personally Identifiable Information (PII). We have developed a novel framework to automatically track details about how a users' PII ...

  17. Dividend policy and share price volatility: UK evidence

    OpenAIRE

    Hussainey, Khaled; Mgbame, Chijoke Oscar; Chijoke Mgbame, Aruoriwo M.

    2011-01-01

    Purpose – The purpose of this paper is to examine the relation between dividend policy and share price changes in the UK stock market. Design/methodology/approach – Multiple regression analyses are used to explore the association between share price changes and both dividend yield and dividend payout ratio. Findings – A positive relation is found between dividend yield and stock price changes, and a negative relation between dividend payout ratio and stock price changes. In a...

  18. International production sharing: A case for a coherent policy framework

    OpenAIRE

    Nordås, Hildegunn Kyvik

    2007-01-01

    This study seeks to clarify what vertical specialization/fragmented production/production sharing is, how widespread it is, how it is organized, its driving forces, and what the policy implications are. It presents six country case studies ( USA, Japan, Germany, Brazil, China and South Africa ) where the importance and nature of production sharing or vertical specialization in the automotive and electronics sectors are studied for each country. The automotive industry has always been a leadin...

  19. Market Share, R&D Cooperation, and EU Competition Policy

    OpenAIRE

    Richard Rubble; Bruno Versaevel

    2009-01-01

    Working Paper GATE 2009-10; Current EU policy exempts horizontal R&D agreements from antitrust con- cerns when the combined market shares of participants are low enough. This paper argues that existing theory does not support limiting the exemption to low market shares. This is done by introducing a set of non-innovating outside firms to the standard framework to assess what link might exist between the market share of innovating firms and the product market benefits of cooperation. With R&D out...

  20. The Dividend and Share Repurchase Policies of Canadian Firms

    NARCIS (Netherlands)

    A. de Jong (Abe); R. van Dijk (Ronald); C.H. Veld

    2001-01-01

    textabstractWe empirically investigate dividend and share repurchase policies of Canadian firms. We have sent a questionnaire to the 500 largest non-financial Canadian companies listed on the Toronto Stock Exchange, of which 191 usable responses were returned. These data are used to measure

  1. Revenue Sharing: An Assessment of Current Policies at UK Universities

    Science.gov (United States)

    Gazzard, James; Brown, Sarah A.

    2012-01-01

    The transfer of academic technologies to industry is an important process underpinning innovation and economic development. Various approaches have been adopted by universities to encourage academics to participate in commercial activities. Many have implemented revenue sharing policies, through which the revenues generated from university-owned…

  2. Risk sharing, public policy and the contribution of Islamic finance

    Directory of Open Access Journals (Sweden)

    Hossein Askari

    2014-12-01

    Full Text Available A major reason for the recurrent episodes of financial instability is the predominance of interest-based debt and leveraging. Financial stability is achievable through risk sharing finance instead of risk shifting that characterizes contemporary finance. A risk sharing system serves the true function of finance as facilitator of real sector activities and avoids the emergence of a “paper economy” where there is gradual decoupling of finance from the real sector. Islamic finance was initially proposed as a profit-loss sharing system, but its core principle is risk sharing. In prohibiting interest-based debt instruments, Islam grounds finance on a strong risk sharing footing. Although still a young industry that has come a long way, it has not managed to develop truly risk-sharing instruments that would allow individuals, households, and firms as well as whole economies to mitigate systematic and un-systematic risks. It is suggested that governments should intervene and issue macro-market instruments to provide their treasuries with a significant source of non-interest rate based financing while promoting risk sharing. Moreover, given that evidence across the world suggests that monetary policy’s transmission mechanism may be impaired, it is suggested that these government issued securities could also impart added potency to monetary policy.

  3. Impact of Dividend Policy on Share Price Volatility: UK Evidence

    OpenAIRE

    ZHANG, YIDING

    2012-01-01

    This research attempts to shed light on the linkage between dividend policy and share price volatility in the context of UK. As a rework and extension of pervious research, the study is expected to reveal the potential impact of dividend change on the fluctuation of stock price, taking existing theoretical and empirical framework as basis. A snapshot of UK economy is provided after the preceding introductory section. The third chapter consists of a review of theories and empirical studies. Wi...

  4. Economic impact and policy implications from urban shared transportation: The case of Pittsburgh's shared bike system.

    Science.gov (United States)

    Pelechrinis, Konstantinos; Zacharias, Christos; Kokkodis, Marios; Lappas, Theodoros

    2017-01-01

    During the last years the number of cities that have installed and started operating shared bike systems has significantly increased. These systems provide an alternative and sustainable mean of transportation to the city dwellers. Apart from the energy sustainability benefits, shared bike systems can have a positive effect on residents' health, air quality and the overall condition of the currently crumbling road network infrastructure. Anecdotal stories and survey studies have also identified that bike lanes have a positive impact on local businesses. In this study, driven by the rapid adoption of shared bike systems by city governments and their potential positive effects on a number of urban life facets we opt to study and quantify the value of these systems. We focus on a specific aspect of this value and use evidence from the real estate market in the city of Pittsburgh to analyze the effect on dwellers' properties of the shared bike system installed in the city in June 2015. We use quasi-experimental techniques and find that the shared bike system led to an increase in the housing prices (both sales and rental prices) in the zip codes where shared bike stations were installed. We further bring into the light potential negative consequences of this impact (i.e., gentrification) and discuss/propose two public policies that can exploit the impact of the system for the benefit of both the local government as well as the city dwellers.

  5. Economic impact and policy implications from urban shared transportation: The case of Pittsburgh's shared bike system.

    Directory of Open Access Journals (Sweden)

    Konstantinos Pelechrinis

    Full Text Available During the last years the number of cities that have installed and started operating shared bike systems has significantly increased. These systems provide an alternative and sustainable mean of transportation to the city dwellers. Apart from the energy sustainability benefits, shared bike systems can have a positive effect on residents' health, air quality and the overall condition of the currently crumbling road network infrastructure. Anecdotal stories and survey studies have also identified that bike lanes have a positive impact on local businesses. In this study, driven by the rapid adoption of shared bike systems by city governments and their potential positive effects on a number of urban life facets we opt to study and quantify the value of these systems. We focus on a specific aspect of this value and use evidence from the real estate market in the city of Pittsburgh to analyze the effect on dwellers' properties of the shared bike system installed in the city in June 2015. We use quasi-experimental techniques and find that the shared bike system led to an increase in the housing prices (both sales and rental prices in the zip codes where shared bike stations were installed. We further bring into the light potential negative consequences of this impact (i.e., gentrification and discuss/propose two public policies that can exploit the impact of the system for the benefit of both the local government as well as the city dwellers.

  6. The Wireless Craze, The Unlimited Bandwidth Myth, The Spectrum Auction Faux Pas, and the Punchline to Ronald Coase's 'Big Joke': An Essay on Airwave Allocation Policy

    OpenAIRE

    Hazlett, Thomas W.

    2001-01-01

    In 1959 the Federal Communications Commission invited economist Ronald Coase to testify about his proposal for market allocation of radio spectrum rights. The FCC's first question: 'Is this all a big joke'' Today, however, leading policy makers, including the current FCC Chair, decry the 'spectrum drought' produced by administrative allocation and call for the creation of private bandwidth markets. This essay examines marketplace trends driving regulators' change of humor, and considers the p...

  7. Tourism revenue sharing policy at Bwindi Impenetrable National Park, Uganda: a policy arrangements approach

    NARCIS (Netherlands)

    Ahebwa, W.M.; Duim, van der V.R.; Sandbrook, C.

    2012-01-01

    Debates on how to deliver conservation benefits to communities living close to protected high-biodiversity areas have preoccupied conservationists for over 20 years. Tourism revenue sharing (TRS) has become a widespread policy intervention in Africa and elsewhere where charismatic populations of

  8. Guide to Policies and Contracts on Job Sharing in the Schools.

    Science.gov (United States)

    Moorman, Barbara; And Others

    Job Sharing--two persons sharing one full-time position--is becoming increasingly popular in the nation's schools. This guide provides information on policies and contracts and collective bargaining implications, based on practices in California, where the job sharing is allowed in 27 percent of the school districts. Provisions of policies and…

  9. Codifying collegiality: recent developments in data sharing policy in the life sciences.

    Directory of Open Access Journals (Sweden)

    Genevieve Pham-Kanter

    Full Text Available Over the last decade, there have been significant changes in data sharing policies and in the data sharing environment faced by life science researchers. Using data from a 2013 survey of over 1600 life science researchers, we analyze the effects of sharing policies of funding agencies and journals. We also examine the effects of new sharing infrastructure and tools (i.e., third party repositories and online supplements. We find that recently enacted data sharing policies and new sharing infrastructure and tools have had a sizable effect on encouraging data sharing. In particular, third party repositories and online supplements as well as data sharing requirements of funding agencies, particularly the NIH and the National Human Genome Research Institute, were perceived by scientists to have had a large effect on facilitating data sharing. In addition, we found a high degree of compliance with these new policies, although noncompliance resulted in few formal or informal sanctions. Despite the overall effectiveness of data sharing policies, some significant gaps remain: about one third of grant reviewers placed no weight on data sharing plans in their reviews, and a similar percentage ignored the requirements of material transfer agreements. These patterns suggest that although most of these new policies have been effective, there is still room for policy improvement.

  10. Journal data sharing policies and statistical reporting inconsistencies in psychology.

    NARCIS (Netherlands)

    Nuijten, M.B.; Borghuis, J.; Veldkamp, C.L.S.; Dominguez Alvarez, L.; van Assen, M.A.L.M.; Wicherts, J.M.

    2018-01-01

    In this paper, we present three retrospective observational studies that investigate the relation between data sharing and statistical reporting inconsistencies. Previous research found that reluctance to share data was related to a higher prevalence of statistical errors, often in the direction of

  11. Processes for consensus building and role sharing. Lessons learned from HLW policies in European countries

    International Nuclear Information System (INIS)

    Nagano, Koji

    2003-01-01

    This report attempts to obtain lessons in implementation of HLW management policies for Japan by reviewing past experiences and present status of policy formulation and implementation as well as reflection of public opinions and consensus building of selected European countries, such as Finland, Sweden and others. After examining the situations of those countries, the author derives four key aspects that need to be addressed; separation of nuclear energy policies and HLW policies, fundamental support shared among national public, sense of controllability, and proper scheme of responsibility sharing. (author)

  12. Threshold policy for global games with noisy information sharing

    KAUST Repository

    Mahdavifar, Hessam; Beirami, Ahmad; Touri, Behrouz; Shamma, Jeff S.

    2015-01-01

    of information and show that such equilibrium strategies exist and are unique if the sharing of information happens over a sufficiently noisy environment. To show this result, we establish that if a threshold function is an equilibrium strategy, then it will be a

  13. Land Sparing and Land Sharing Policies in Developing Countries - Drivers and Linkages to Scientific Debates

    DEFF Research Database (Denmark)

    Mertz, Ole; Mertens, Charlotte Filt

    2017-01-01

    The need for developing land sparing or land sharing policies for protecting the environment has been a polarized debate in the scientific literature. Some studies show that "spared" landscapes with clearly separated intensive agriculture and pristine forest are better for biodiversity and other...... ecosystem services, whereas others demonstrate the benefits of "shared" mosaic landscapes composed of a mix of forest types, agricultural fields, grassland, and plantations. Increasingly, these scientific views have been depolarized, recognizing that both shared and spared landscapes have a role to play......, depending on the context. However, it is less clear from the literature what drives actual policy-making related to land sparing and land sharing in developing countries and what the outcomes of these policies are. We therefore reviewed the international peer-reviewed literature for evidence of policies...

  14. Network Bandwidth Utilization Forecast Model on High Bandwidth Network

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Wucherl; Sim, Alex

    2014-07-07

    With the increasing number of geographically distributed scientific collaborations and the scale of the data size growth, it has become more challenging for users to achieve the best possible network performance on a shared network. We have developed a forecast model to predict expected bandwidth utilization for high-bandwidth wide area network. The forecast model can improve the efficiency of resource utilization and scheduling data movements on high-bandwidth network to accommodate ever increasing data volume for large-scale scientific data applications. Univariate model is developed with STL and ARIMA on SNMP path utilization data. Compared with traditional approach such as Box-Jenkins methodology, our forecast model reduces computation time by 83.2percent. It also shows resilience against abrupt network usage change. The accuracy of the forecast model is within the standard deviation of the monitored measurements.

  15. Network bandwidth utilization forecast model on high bandwidth networks

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Wuchert (William) [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sim, Alex [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2015-03-30

    With the increasing number of geographically distributed scientific collaborations and the scale of the data size growth, it has become more challenging for users to achieve the best possible network performance on a shared network. We have developed a forecast model to predict expected bandwidth utilization for high-bandwidth wide area network. The forecast model can improve the efficiency of resource utilization and scheduling data movements on high-bandwidth network to accommodate ever increasing data volume for large-scale scientific data applications. Univariate model is developed with STL and ARIMA on SNMP path utilization data. Compared with traditional approach such as Box-Jenkins methodology, our forecast model reduces computation time by 83.2%. It also shows resilience against abrupt network usage change. The accuracy of the forecast model is within the standard deviation of the monitored measurements.

  16. Economic impact and policy implications from urban shared transportation: The case of Pittsburgh’s shared bike system

    Science.gov (United States)

    Zacharias, Christos; Kokkodis, Marios; Lappas, Theodoros

    2017-01-01

    During the last years the number of cities that have installed and started operating shared bike systems has significantly increased. These systems provide an alternative and sustainable mean of transportation to the city dwellers. Apart from the energy sustainability benefits, shared bike systems can have a positive effect on residents’ health, air quality and the overall condition of the currently crumbling road network infrastructure. Anecdotal stories and survey studies have also identified that bike lanes have a positive impact on local businesses. In this study, driven by the rapid adoption of shared bike systems by city governments and their potential positive effects on a number of urban life facets we opt to study and quantify the value of these systems. We focus on a specific aspect of this value and use evidence from the real estate market in the city of Pittsburgh to analyze the effect on dwellers’ properties of the shared bike system installed in the city in June 2015. We use quasi-experimental techniques and find that the shared bike system led to an increase in the housing prices (both sales and rental prices) in the zip codes where shared bike stations were installed. We further bring into the light potential negative consequences of this impact (i.e., gentrification) and discuss/propose two public policies that can exploit the impact of the system for the benefit of both the local government as well as the city dwellers. PMID:28859121

  17. The correlation between dividend policy measures and share price volatility on OMX Helsinki

    OpenAIRE

    Lindeman, Tuomas

    2016-01-01

    Dividend policy refers to the decision whether a firm decides to distribute some of its earnings as dividends to shareholders or not. Two significant variables are related to it: dividend yield and payout ratio. The former indicates how much a firm pays out in dividends each year relative to its share price, whereas the latter refers to the percentage of earnings paid to shareholders in dividends. Dividend policy is seen as one indicator of share price volatility, which measures the dispersio...

  18. Secure, Policy-Based, Multi-Recipient Data Sharing

    Science.gov (United States)

    2009-01-01

    directed by: Professor Virgil D. Gligor Department of Electrical and Computer Engineering In distributed systems users often need to share sensitive data...organizational role with short-term responsibilities result in useful compound attributes; e.g., ‘Faculty’ in ‘College of Engineering ’ serving as...KDC then contacts the Attribute Database that manages user attributes and privileges and enviromental attributes (i.e., context). The KDC uses these

  19. Efficient Attribute-Based Secure Data Sharing with Hidden Policies and Traceability in Mobile Health Networks

    Directory of Open Access Journals (Sweden)

    Changhee Hahn

    2016-01-01

    Full Text Available Mobile health (also written as mHealth provisions the practice of public health supported by mobile devices. mHealth systems let patients and healthcare providers collect and share sensitive information, such as electronic and personal health records (EHRs at any time, allowing more rapid convergence to optimal treatment. Key to achieving this is securely sharing data by providing enhanced access control and reliability. Typically, such sharing follows policies that depend on patient and physician preferences defined by a set of attributes. In mHealth systems, not only the data but also the policies for sharing it may be sensitive since they directly contain sensitive information which can reveal the underlying data protected by the policy. Also, since the policies usually incur linearly increasing communication costs, mHealth is inapplicable to resource-constrained environments. Lastly, access privileges may be publicly known to users, so a malicious user could illegally share his access privileges without the risk of being traced. In this paper, we propose an efficient attribute-based secure data sharing scheme in mHealth. The proposed scheme guarantees a hidden policy, constant-sized ciphertexts, and traces, with security analyses. The computation cost to the user is reduced by delegating approximately 50% of the decryption operations to the more powerful storage systems.

  20. An Improved Droop Control Method for DC Microgrids Based on Low Bandwidth Communication with DC Bus Voltage Restoration and Enhanced Current Sharing Accuracy

    DEFF Research Database (Denmark)

    Lu, Xiaonan; Guerrero, Josep M.; Sun, Kai

    2014-01-01

    Droop control is the basic control method for load current sharing in dc microgrid applications. The conventional dc droop control method is realized by linearly reducing the dc output voltage as the output current increases. This method has two limitations. First, with the consideration of line...... resistance in a droop-controlled dc microgrid, since the output voltage of each converter cannot be exactly the same, the output current sharing accuracy is degraded. Second, the DC bus voltage deviation increases with the load due to the droop action. In this paper, in order to improve the performance......, and the LBC system is only used for changing the values of the dc voltage and current. Hence, a decentralized control scheme is accomplished. The simulation test based on Matlab/Simulink and the experimental validation based on a 2×2.2 kW prototype were implemented to demonstrate the proposed approach....

  1. Ethics policies and ethics work in cross-national genetic research and data sharing

    DEFF Research Database (Denmark)

    Hoeyer, Klaus; Tupasela, Aaro; Rasmussen, Malene B.

    2017-01-01

    of scientific work. This paper takes its point of departure in the practices of a Danish laboratory with great experience in international collaboration regarding genetic research. We focus on a simple query, what makes genetic material and health data flow, and which hopes and concerns travel along with them......In recent years, cross-national collaboration in medical research has gained increased policy attention. Policies are developed to enhance data sharing, ensure open-access, and harmonize international standards and ethics rules in order to promote access to existing resources and increase...... scientific output. In tandem with this promotion of data sharing, numerous ethics policies are developed to control data flows and protect privacy and confidentiality. Both sets of policy making, however, pay limited attention to the moral decisions and social ties enacted in the everyday routines...

  2. Technical and policy approaches to balancing patient privacy and data sharing in clinical and translational research.

    Science.gov (United States)

    Malin, Bradley; Karp, David; Scheuermann, Richard H

    2010-01-01

    Clinical researchers need to share data to support scientific validation and information reuse and to comply with a host of regulations and directives from funders. Various organizations are constructing informatics resources in the form of centralized databases to ensure reuse of data derived from sponsored research. The widespread use of such open databases is contingent on the protection of patient privacy. We review privacy-related problems associated with data sharing for clinical research from technical and policy perspectives. We investigate existing policies for secondary data sharing and privacy requirements in the context of data derived from research and clinical settings. In particular, we focus on policies specified by the US National Institutes of Health and the Health Insurance Portability and Accountability Act and touch on how these policies are related to current and future use of data stored in public database archives. We address aspects of data privacy and identifiability from a technical, although approachable, perspective and summarize how biomedical databanks can be exploited and seemingly anonymous records can be reidentified using various resources without hacking into secure computer systems. We highlight which clinical and translational data features, specified in emerging research models, are potentially vulnerable or exploitable. In the process, we recount a recent privacy-related concern associated with the publication of aggregate statistics from pooled genome-wide association studies that have had a significant impact on the data sharing policies of National Institutes of Health-sponsored databanks. Based on our analysis and observations we provide a list of recommendations that cover various technical, legal, and policy mechanisms that open clinical databases can adopt to strengthen data privacy protection as they move toward wider deployment and adoption.

  3. Digital Distributed Control System Design: Control Policy for Shared Objects in HTR-PM

    International Nuclear Information System (INIS)

    Zhou Shuqiao; Huang Xiaojin

    2014-01-01

    HTR-PM is an HTR demonstration plant with a structure of two modules feeding one steam turbine. Compared with the structure of one single reactor feeding one turbine, there are more devices shared between these two modules. When they are operated, the shared components are prone to introduce collisions or even logical deadlocks for different technical processes. The future commercial HTR-PM plants are supposed to comprise more modules for a larger turbine, thus the collision problem introduced by the shared components may become severer. Therefore, how to design suitable policies in the distributed control system (DCS) to relieve the collisions during using these shared devices is a new and also a very important problem. In this paper, the classifications of the shared devices are first addressed, and then how to identify the shared objects of an NPP is proposed. Furthermore, a general model for the control logic design is proposed, taking into consideration the collision avoidance, time delay and fairness. The example of how to apply the schemes to relieve the conflicts and deadlocks in the processes of using the shared devices in fuel element cycling system is illustrated. (author)

  4. The knowledge game - motivating knowledge sharing and testing organization policies in this concern

    International Nuclear Information System (INIS)

    Barroso, Antonio C.O.; Seixas, Marcelo A.

    2011-01-01

    The ageing of nuclear experts and operating personnel and the lack of attractiveness of nuclear jobs to younger generation were emphasized as two of the most important factors that could jeopardize the preservation and sustainable development of the present body of nuclear knowledge worldwide. The willingness to share knowledge is at the inner core of any process involving transfer and dissemination of knowledge. This paper deals with the development of a tool to demonstrate the advantages of a culture inductive of knowledge sharing and cooperation from both the organization's and individual's viewpoints and coins the basics of reward policies that foster the development of desirable cultures. The Knowledge Game is a software tool to: (a) show the importance of sharing knowledge to both the individual and the organization; (b) demonstrate the fact that collaborative behaviors achieve higher payoffs in the long run; (c) test organizational rewards policies. It is an agent based modeling tool in which users may play with other humans and/or built in agents with fixed strategies. Payoff rules, simulation speed, number of players and their strategies and number of cycles are set before beginning the simulation. Plots display results in real time and output files can be generated for further analysis. Tests encompassing proof of concept and application confirm the game's great potential as a demonstration and policy testing tool. To test policies more effectively future implementations of intelligent agents coupled with fitness selection of players should be a very key lever. (author)

  5. Align, share responsibility and collaborate: potential considerations to aid in e-health policy development.

    Science.gov (United States)

    Ragaban, Nouran; Day, Karen; Orr, Martin

    2012-01-01

    Policies that support strategic development and implementation are related to health ICT implementation successes. This research aimed to explore the question, 'Why have we not seen more successful ICT implementation in healthcare, and what does policy have to do with success?' Healthcare systems are faced with rising costs, increased prevalence of chronic diseases and diminishing resources. E-health initiatives have gained acceptance in addressing these crucial health sector issues. National governments and healthcare organisations are finding it necessary to have health Information and Communications Technology (ICT) systems in place. However, poorly developed health information policies, lack of a clear business plan and ineffective leadership contribute to failure of ICT implementation in healthcare. This study uses a Grounded Theory approach, in which a series of data gathering activities will be completed. The first author attended the Health Information Management & Systems Society (HIMSS) Policy Summit in the USA in 2011. Five Summit participants were approached individually and informally discussed the 'meaningful use' policy and how it influences ICT implementation in healthcare. Field notes were made and analysed for themes relating to the research question. There were three overlapping concepts that all of the participants indicated as primary considerations for policymakers. The alignment aspect stresses the need to align e-health initiatives with overall health policy, ensuring that e-health is incorporated with other healthcare investments. The shared responsibility theme involves the need for e-health initiatives to be recognised as a priority along all levels of government, i.e. local, state, federal, and national. This stresses the importance of health ICT development and implementation in a joint government direction. The last theme is collaboration with stakeholders, including clear division of tasks and clarity about technical and non

  6. Health Data Sharing Preferences of Consumers: Public Policy and Legal Implications of Consumer-Mediated Data Management

    Science.gov (United States)

    Moon, Lisa A.

    2017-01-01

    An individual's choice to share or have control of the sharing or withholding of their personal health information is one of the most significant public policy challenges associated with electronic information exchange. There were four aims of this study. First, to describe predictors of health data sharing preferences of consumers. Second, to…

  7. Involving Research Stakeholders in Developing Policy on Sharing Public Health Research Data in Kenya

    Science.gov (United States)

    Jao, Irene; Kombe, Francis; Mwalukore, Salim; Bull, Susan; Parker, Michael; Kamuya, Dorcas; Molyneux, Sassy

    2015-01-01

    Increased global sharing of public health research data has potential to advance scientific progress but may present challenges to the interests of research stakeholders, particularly in low-to-middle income countries. Policies for data sharing should be responsive to public views, but there is little evidence of the systematic study of these from low-income countries. This qualitative study explored views on fair data-sharing processes among 60 stakeholders in Kenya with varying research experience, using a deliberative approach. Stakeholders’ attitudes were informed by perceptions of benefit and concerns for research data sharing, including risks of stigmatization, loss of privacy, and undermining scientific careers and validity, reported in detail elsewhere. In this article, we discuss institutional trust-building processes seen as central to perceptions of fairness in sharing research data in this setting, including forms of community involvement, individual prior awareness and agreement to data sharing, independence and accountability of governance mechanisms, and operating under a national framework. PMID:26297748

  8. Chemical Industry Bandwidth Study

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2006-12-01

    The Chemical Bandwidth Study provides a snapshot of potentially recoverable energy losses during chemical manufacturing. The advantage of this study is the use of "exergy" analysis as a tool for pinpointing inefficiencies.

  9. Bandwidth efficient coding

    CERN Document Server

    Anderson, John B

    2017-01-01

    Bandwidth Efficient Coding addresses the major challenge in communication engineering today: how to communicate more bits of information in the same radio spectrum. Energy and bandwidth are needed to transmit bits, and bandwidth affects capacity the most. Methods have been developed that are ten times as energy efficient at a given bandwidth consumption as simple methods. These employ signals with very complex patterns and are called "coding" solutions. The book begins with classical theory before introducing new techniques that combine older methods of error correction coding and radio transmission in order to create narrowband methods that are as efficient in both spectrum and energy as nature allows. Other topics covered include modulation techniques such as CPM, coded QAM and pulse design.

  10. Glass Industry Bandwidth Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Rue, David M. [Gas Technology Inst., Des Plaines, IL (United States)

    2006-07-01

    This is a study on energy use and potential savings, or "bandwidth" study, for several glassmaking processes. Intended to provide a realistic estimate of the potential amount of energy that can be saved in an industrial process, the "bandwidth" refers to the difference between the amount of energy that would be consumed in a process using commercially available technology versus the minimum amount of energy needed to achieve those same results.

  11. Industrial Glass Bandwidth Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Rue, David M. [Gas Technology Inst., Des Plaines, IL (United States); Servaites, James [Gas Technology Inst., Des Plaines, IL (United States); Wolf, Warren [Gas Technology Inst., Des Plaines, IL (United States)

    2007-08-01

    This is a study on energy use and potential savings, or "bandwidth" study, for several glassmaking processes. Intended to provide a realistic estimate of the potential amount of energy that can be saved in an industrial process, the "bandwidth" refers to the difference between the amount of energy that would be consumed in a process using commercially available technology versus the minimum amount of energy needed to achieve those same results.

  12. CORPORATE DIVIDEND POLICY AND SHARE PRICE VOLATILITY:A STUDY OF THE BOMBAY STOCK EXCHANGE

    OpenAIRE

    Vijayakumar, Arvind

    2012-01-01

    Purpose: The research paper aims to identify the empirical relationship between Corporate Dividend policy in India and share price volatility. Design/Methodology/Approach: A sample of 197 dividend paying companies listed on the Bombay stock exchange (BSE 500) was examined from 2006 to 2010.A panel data approach was applied to identify the relationship between price volatility against dividend yield and dividend payout ratio. Findings: The findings observe a significant relationship be...

  13. Paper Fish and Policy Conflict: Catch Shares and Ecosystem-Based Management in Maine's Groundfishery

    Directory of Open Access Journals (Sweden)

    Jennifer F. Brewer

    2011-03-01

    Full Text Available The National Oceanic and Atmospheric Administration professes support for ecosystem-based fisheries management, as mandated by Congress in the Fishery Conservation and Management Act, and as endorsed by the Obama Administration's national ocean policy. Nonetheless, driving agency policies, including catch shares and fishing quotas, focus principally on individual species, diverting attention from ecosystem considerations such as habitat, migratory patterns, trophic relationships, fishing gear, and firm-level decision making. Environmental non-governmental organization (ENGO agendas manifest similar inconsistencies. A case study of Maine's groundfishery demonstrates implications of this policy conflict at the local level. There, multigenerational fishing villages have historically pursued diversified and adaptive livelihood strategies, supported by local ecological knowledge. This tradition is increasingly eroded by regulatory constraints, including catch shares. Field observation, interviews, survey data, and archival review reveal that industry-supported, ecosystem-focused proposals have been rejected by the New England Fishery Management Council, despite the apparent failure of single-species approaches to sustain fish populations, fished ecosystems, and fishing-dependent communities. The creation of groundfishery catch share sectors is likely to perpetuate industry consolidation and political entrenchment under more mobile capital, following precedent set by days-at-sea, and making area protections and gear restrictions less likely. Pending marine spatial planning efforts could enhance social-ecological resilience by creating new opportunities for transdisciplinary decision support, and broader public participation and accountability.

  14. The knowledge game - motivating knowledge sharing and testing organization policies in this concern

    Energy Technology Data Exchange (ETDEWEB)

    Barroso, Antonio C.O.; Seixas, Marcelo A., E-mail: barroso@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    The ageing of nuclear experts and operating personnel and the lack of attractiveness of nuclear jobs to younger generation were emphasized as two of the most important factors that could jeopardize the preservation and sustainable development of the present body of nuclear knowledge worldwide. The willingness to share knowledge is at the inner core of any process involving transfer and dissemination of knowledge. This paper deals with the development of a tool to demonstrate the advantages of a culture inductive of knowledge sharing and cooperation from both the organization's and individual's viewpoints and coins the basics of reward policies that foster the development of desirable cultures. The Knowledge Game is a software tool to: (a) show the importance of sharing knowledge to both the individual and the organization; (b) demonstrate the fact that collaborative behaviors achieve higher payoffs in the long run; (c) test organizational rewards policies. It is an agent based modeling tool in which users may play with other humans and/or built in agents with fixed strategies. Payoff rules, simulation speed, number of players and their strategies and number of cycles are set before beginning the simulation. Plots display results in real time and output files can be generated for further analysis. Tests encompassing proof of concept and application confirm the game's great potential as a demonstration and policy testing tool. To test policies more effectively future implementations of intelligent agents coupled with fitness selection of players should be a very key lever. (author)

  15. Practicing what we preach: developing a data sharing policy for the Journal of the Medical Library Association.

    Science.gov (United States)

    Read, Kevin B; Amos, Liz; Federer, Lisa M; Logan, Ayaba; Plutchak, T Scott; Akers, Katherine G

    2018-04-01

    Providing access to the data underlying research results in published literature allows others to reproduce those results or analyze the data in new ways. Health sciences librarians and information professionals have long been advocates of data sharing. It is time for us to practice what we preach and share the data associated with our published research. This editorial describes the activity of a working group charged with developing a research data sharing policy for the Journal of the Medical Library Association.

  16. Data sharing and reanalysis of randomized controlled trials in leading biomedical journals with a full data sharing policy: survey of studies published in The BMJ and PLOS Medicine

    Science.gov (United States)

    Naudet, Florian; Sakarovitch, Charlotte; Janiaud, Perrine; Cristea, Ioana; Fanelli, Daniele; Moher, David

    2018-01-01

    Abstract Objectives To explore the effectiveness of data sharing by randomized controlled trials (RCTs) in journals with a full data sharing policy and to describe potential difficulties encountered in the process of performing reanalyses of the primary outcomes. Design Survey of published RCTs. Setting PubMed/Medline. Eligibility criteria RCTs that had been submitted and published by The BMJ and PLOS Medicine subsequent to the adoption of data sharing policies by these journals. Main outcome measure The primary outcome was data availability, defined as the eventual receipt of complete data with clear labelling. Primary outcomes were reanalyzed to assess to what extent studies were reproduced. Difficulties encountered were described. Results 37 RCTs (21 from The BMJ and 16 from PLOS Medicine) published between 2013 and 2016 met the eligibility criteria. 17/37 (46%, 95% confidence interval 30% to 62%) satisfied the definition of data availability and 14 of the 17 (82%, 59% to 94%) were fully reproduced on all their primary outcomes. Of the remaining RCTs, errors were identified in two but reached similar conclusions and one paper did not provide enough information in the Methods section to reproduce the analyses. Difficulties identified included problems in contacting corresponding authors and lack of resources on their behalf in preparing the datasets. In addition, there was a range of different data sharing practices across study groups. Conclusions Data availability was not optimal in two journals with a strong policy for data sharing. When investigators shared data, most reanalyses largely reproduced the original results. Data sharing practices need to become more widespread and streamlined to allow meaningful reanalyses and reuse of data. Trial registration Open Science Framework osf.io/c4zke. PMID:29440066

  17. Policy Framework for Covering Preventive Services Without Cost Sharing: Saving Lives and Saving Money?

    Science.gov (United States)

    Chen, Stephanie C; Pearson, Steven D

    2016-08-01

    The US Affordable Care Act mandates that private insurers cover a list of preventive services without cost sharing. The list is determined by 4 expert committees that evaluate the overall health effect of preventive services. We analyzed the process by which the expert committees develop their recommendations. Each committee uses different criteria to evaluate preventive services and none of the committees consider cost systematically. We propose that the existing committees adopt consistent evidence review methodologies and expand the scope of preventive services reviewed and that a separate advisory committee be established to integrate economic considerations into the final selection of free preventive services. The comprehensive framework and associated criteria are intended to help policy makers in the future develop a more evidence-based, consistent, and ethically sound approach.

  18. On the evolving portfolio of community-standards and data sharing policies: turning challenges into new opportunities

    Directory of Open Access Journals (Sweden)

    Sansone Susanna-Assunta

    2012-07-01

    Full Text Available Abstract There are thousands of biology databases with hundreds of terminologies, reporting guidelines, representations models, and exchange formats to help annotate, report, and share bioscience investigations. It is evident, however, that researchers and bioinformaticians struggle to navigate the various standards and to find the appropriate database to collect, manage, and share data. Further, policy makers, funders, and publishers lack sufficient information to formulate their guidelines. In this paper, we highlight a number of key issues that can be used to turn these challenges into new opportunities. It is time for all stakeholders to work together to reconcile cause and effect and make the data-sharing culture functional and efficient.

  19. Ultrahigh bandwidth signal processing

    DEFF Research Database (Denmark)

    Oxenløwe, Leif Katsuo

    2016-01-01

    Optical time lenses have proven to be very versatile for advanced optical signal processing. Based on a controlled interplay between dispersion and phase-modulation by e.g. four-wave mixing, the processing is phase-preserving, an hence useful for all types of data signals including coherent multi......-level modulation founats. This has enabled processing of phase-modulated spectrally efficient data signals, such as orthogonal frequency division multiplexed (OFDM) signa In that case, a spectral telescope system was used, using two time lenses with different focal lengths (chirp rates), yielding a spectral...... regeneratio These operations require a broad bandwidth nonlinear platform, and novel photonic integrated nonlinear platform like aluminum gallium arsenide nano-waveguides used for 1.28 Tbaud optical signal processing will be described....

  20. Cutter Connectivity Bandwidth Study

    Science.gov (United States)

    2002-10-01

    The goal of this study was to determine how much bandwidth is required for cutters to meet emerging data transfer requirements. The Cutter Connectivity Business Solutions Team with guidance front the Commandant's 5 Innovation Council sponsored this study. Today, many Coast Guard administrative and business functions are being conducted via electronic means. Although our larger cutters can establish part-time connectivity using commercial satellite communications (SATCOM) while underway, there are numerous complaints regarding poor application performance. Additionally, smaller cutters do not have any standard means of underway connectivity. The R&D study shows the most important factor affecting web performance and enterprise applications onboard cutters was latency. Latency describes the time it takes the signal to reach the satellite and come back down through space. The latency due to use of higher orbit satellites is causing poor application performance and inefficient use of expensive SATCOM links. To improve performance, the CC must, (1) reduce latency by using alternate communications links such as low-earth orbit satellites, (2) tailor applications to the SATCOM link and/or (3) optimize protocols used for data communication to minimize time required by present applications to establish communications between the user and the host systems.

  1. submitter BioSharing: curated and crowd-sourced metadata standards, databases and data policies in the life sciences

    CERN Document Server

    McQuilton, Peter; Rocca-Serra, Philippe; Thurston, Milo; Lister, Allyson; Maguire, Eamonn; Sansone, Susanna-Assunta

    2016-01-01

    BioSharing (http://www.biosharing.org) is a manually curated, searchable portal of three linked registries. These resources cover standards (terminologies, formats and models, and reporting guidelines), databases, and data policies in the life sciences, broadly encompassing the biological, environmental and biomedical sciences. Launched in 2011 and built by the same core team as the successful MIBBI portal, BioSharing harnesses community curation to collate and cross-reference resources across the life sciences from around the world. BioSharing makes these resources findable and accessible (the core of the FAIR principle). Every record is designed to be interlinked, providing a detailed description not only on the resource itself, but also on its relations with other life science infrastructures. Serving a variety of stakeholders, BioSharing cultivates a growing community, to which it offers diverse benefits. It is a resource for funding bodies and journal publishers to navigate the metadata landscape of the ...

  2. Promoting physical activity through the shared use of school recreational spaces: a policy statement from the American Heart Association.

    Science.gov (United States)

    Young, Deborah R; Spengler, John O; Frost, Natasha; Evenson, Kelly R; Vincent, Jeffrey M; Whitsel, Laurie

    2014-09-01

    Most Americans are not sufficiently physically active, even though regular physical activity improves health and reduces the risk of many chronic diseases. Those living in rural, non-White, and lower-income communities often have insufficient access to places to be active, which can contribute to their lower level of physical activity. The shared use of school recreational facilities can provide safe and affordable places for communities. Studies suggest that challenges to shared use include additional cost, liability protection, communication among constituencies interested in sharing space, and decision-making about scheduling and space allocation. This American Heart Association policy statement has provided recommendations for federal, state, and local decision-makers to support and expand opportunities for physical activity in communities through the shared use of school spaces.

  3. Improved-Bandwidth Transimpedance Amplifier

    Science.gov (United States)

    Chapsky, Jacob

    2009-01-01

    The widest available operational amplifier, with the best voltage and current noise characteristics, is considered for transimpedance amplifier (TIA) applications where wide bandwidth is required to handle fast rising input signals (as for time-of-flight measurement cases). The added amplifier inside the TIA feedback loop can be configured to have slightly lower voltage gain than the bandwidth reduction factor.

  4. How do high cost-sharing policies for physician care affect total care costs among people with chronic disease?

    Science.gov (United States)

    Xin, Haichang; Harman, Jeffrey S; Yang, Zhou

    2014-01-01

    This study examines whether high cost-sharing in physician care is associated with a differential impact on total care costs by health status. Total care includes physician care, emergency room (ER) visits and inpatient care. Since high cost-sharing policies can reduce needed care as well as unneeded care use, it raises the concern whether these policies are a good strategy for controlling costs among chronically ill patients. This study used the 2007 Medical Expenditure Panel Survey data with a cross-sectional study design. Difference in difference (DID), instrumental variable technique, two-part model, and bootstrap technique were employed to analyze cost data. Chronically ill individuals' probability of reducing any overall care costs was significantly less than healthier individuals (beta = 2.18, p = 0.04), while the integrated DID estimator from split results indicated that going from low cost-sharing to high cost-sharing significantly reduced costs by $12,853.23 more for sick people than for healthy people (95% CI: -$17,582.86, -$8,123.60). This greater cost reduction in total care among sick people likely resulted from greater cost reduction in physician care, and may have come at the expense of jeopardizing health outcomes by depriving patients of needed care. Thus, these policies would be inappropriate in the short run, and unlikely in the long run to control health plans costs among chronically ill individuals. A generous benefit design with low cost-sharing policies in physician care or primary care is recommended for both health plans and chronically ill individuals, to save costs and protect these enrollees' health status.

  5. “Don't affect the share price”: social media policy in higher education as reputation management

    Directory of Open Access Journals (Sweden)

    Tony McNeill

    2012-08-01

    Full Text Available The last 5 years have seen a growing number of universities use social media services such as Twitter, Facebook and YouTube to engage with past, present and prospective students. More recently still, a number of universities have published policy or guidance documents on the use of social media for a range of university-related purposes including learning, teaching and assessment. This study considers the social media policies of 14 universities in the United Kingdom (UK that are currently in the public domain. It addresses some of the ways in which Higher Education Institutions (HEIs are responding to both the positive potential of social media as well as its perceived threats. Drawing inspiration, if not actual method, from critical discourse analysis, this study argues that marketisation has been the main policy driver with many social media policies being developed to promote university “brands” as well as protect institutional reputation. The creation and implementation of social media policies are therefore playing a role in helping universities manage both the risks and the benefits of social media in the context of an increasingly marketised Higher Education (HE environment in which protecting institutional reputation has become a priority. However, in the defence of the metaphorical institutional “share price”, some policies constrain both academic autonomy and the possibilities for innovation and risk-taking.

  6. Iraq: Oil and Gas Legislation, Revenue Sharing, and U.S. Policy

    National Research Council Canada - National Science Library

    Blanchard, Christopher M

    2007-01-01

    Iraqi leaders continue to debate a package of hydrocarbon sector and revenue sharing legislation that will define the terms for the future management and development of the country's significant oil...

  7. Iraq: Oil and Gas Legislation, Revenue Sharing, and U.S. Policy

    National Research Council Canada - National Science Library

    Blanchard, Christopher M

    2008-01-01

    Iraqi leaders continue to debate a package of hydrocarbon sector and revenue sharing legislation that would define the terms for the future management and development of the country's significant oil...

  8. Iraq: Oil and Gas Legislation, Revenue Sharing, and U.S. Policy

    National Research Council Canada - National Science Library

    Blanchard, Christoper M

    2007-01-01

    Iraqi leaders continue to debate a package of hydrocarbon sector and revenue sharing legislation that would define the terms for the future management and development of the country's significant oil...

  9. Iraq: Oil and Gas Legislation, Revenue Sharing, and U.S. Policy

    National Research Council Canada - National Science Library

    Blanchard, Christopher M

    2007-01-01

    Iraqis continue to debate a package of hydrocarbon sector and revenue sharing legislation that will define the terms for the future management and development of the country's significant oil and natural gas resources...

  10. Sharing the burden of adaptation financing. Translating ethical principles into practical policy

    International Nuclear Information System (INIS)

    Dellink, R.; Dekker, T.; Aiking, H.; Peters, J.; Gupta, J.; Bergsma, E.; Berkhout, F.; Den Elzen, M.

    2008-12-01

    Burden-sharing of adaptation costs to climate change has received limited attention in the scientific literature. This study identifies a set of principles that can serve as a basis for choices about how to share the burden of the costs of adaptation to climate change, i.e. historical responsibility and capacity to pay. The numerical analysis shows that the developed countries need to contribute the greatest burden

  11. Defensive Changes in Corporate Payout Policy: Share Repurchases and Special Dividends.

    OpenAIRE

    Denis, David J

    1990-01-01

    This paper examines defensive payouts announced in response to hostile corporate control activity. The evidence indicates that the announcement of defensive share repurchases is associated with an average negative impact on the share price of the target firm. In contrast, special dividend payments generally increase the wealth of target-firm shareholders. Regardless of payout type, those firms remaining independent after the outcome of the corporate control contest experience an abnormal shar...

  12. Science, Policy, and Practice: Three Cultures in Search of a Shared Mission.

    Science.gov (United States)

    Shonkoff, Jack P.

    2000-01-01

    Discusses how child development research, social policy design, and human service delivery for children and families reflect three separate yet related cultures. Argues that transmitting knowledge from the academy to social policy and practice could be facilitated by a simple taxonomy differentiating established knowledge from both reasonable…

  13. Impact of public transportation market share and other transportation and environmental policy variables on sustainable transportation.

    Science.gov (United States)

    2015-01-01

    Policies that encourage reduced travel, such as traveling shorter distances, and increased use of more efficient transportation modes, such as public transportation and high-occupancy private automobiles, are often considered one of several possible ...

  14. State mental health policy: Maryland's shared leadership approach to mental health transformation: partnerships that work.

    Science.gov (United States)

    Semansky, Rafael M

    2012-07-01

    In 2005, Maryland received a mental health transformation grant from the Substance Abuse and Mental Health Services Administration. Maryland's transformation efforts have differed from those in other grantee states and have evolved into a shared leadership approach that harnesses the power of leaders from all sectors of the community. This column describes Maryland's reform efforts, focusing in particular on the development of the position of a peer employment specialist to improve placement of consumers in employment. This shared leadership approach has the potential to enhance long-term sustainability of reform initiatives and uses fewer state resources.

  15. An Expressive, Lightweight and Secure Construction of Key Policy Attribute-Based Cloud Data Sharing Access Control

    Science.gov (United States)

    Lin, Guofen; Hong, Hanshu; Xia, Yunhao; Sun, Zhixin

    2017-10-01

    Attribute-based encryption (ABE) is an interesting cryptographic technique for flexible cloud data sharing access control. However, some open challenges hinder its practical application. In previous schemes, all attributes are considered as in the same status while they are not in most of practical scenarios. Meanwhile, the size of access policy increases dramatically with the raise of its expressiveness complexity. In addition, current research hardly notices that mobile front-end devices, such as smartphones, are poor in computational performance while too much bilinear pairing computation is needed for ABE. In this paper, we propose a key-policy weighted attribute-based encryption without bilinear pairing computation (KP-WABE-WB) for secure cloud data sharing access control. A simple weighted mechanism is presented to describe different importance of each attribute. We introduce a novel construction of ABE without executing any bilinear pairing computation. Compared to previous schemes, our scheme has a better performance in expressiveness of access policy and computational efficiency.

  16. Iraq: Oil and Gas Sector, Revenue Sharing, and U.S. Policy

    Science.gov (United States)

    2010-03-03

    Statoil (Norway) 1,800,000* Majnoon Shell, Petronas (Malaysia) 1,800,000* Halfaya CNPC, Total (France), Petronas 535,000 Gharraf Japex (Japan... Petronas 230,000 Badra Gazprom (Russia), Petronas , TPAO (Turkey) 170,000 Qayara/Najmah Sonangol (Angola) 230,000* Select KRG Production Sharing

  17. A summary of design, policies and operational characteristics for shared bicycle/bus lanes.

    Science.gov (United States)

    2012-07-01

    This report contains the results of an investigation of the design and operation of shared bicycle/bus lanes in municipalities in the United States and other countries. These lanes are designated for use by public transit buses, bicycles, and usually...

  18. Online Cooperative Promotion and Cost Sharing Policy under Supply Chain Competition

    Directory of Open Access Journals (Sweden)

    Erjiang E

    2016-01-01

    Full Text Available This paper studies online cooperative promotion and cost sharing decisions in competing supply chains. We consider a model of one B2C e-commerce platform and two supply chains each consisting of a supplier and an online retailer. The problem is studied using a multistage game. Firstly, the e-commerce platform carries out the cooperative promotion and sets the magnitude of markdown (the value of e-coupon. Secondly, each retailer and his supplier determine the fraction of promotional cost sharing when they have different bargaining power. Lastly, the retailers decide whether to participate in the cooperative promotion campaign. We show that the retailers are likely to participate in the promotion if consumers become more price-sensitive. However, it does not imply that the retailers can benefit from the price promotion; the promotion decision game resembles the classical prisoner’s dilemma game. The retailers and suppliers can benefit from the cooperative promotion by designing an appropriate cost sharing contract. For a supply chain, the bargaining power between supplier and retailer, consumer price sensitivity, and competition intensity affect the fraction of the promotional cost sharing. We also find that equilibrium value of e-coupon set by the e-commerce platform is not optimal for all the parties.

  19. Spare parts sharing with joint optimization of maintenance and inventory policies

    DEFF Research Database (Denmark)

    Larsen, Christian; Wong, Hartanto Wijaya; Nielsen, Lars Relund

    We consider a collaborative arrangement where a number of companies are willing to share expensive spare parts, required for both failure replacement and preventive maintenance purposes. We develop a discrete-time Markov decision model for the joint optimization of maintenance and spare parts...

  20. High-bandwidth memory interface

    CERN Document Server

    Kim, Chulwoo; Song, Junyoung

    2014-01-01

    This book provides an overview of recent advances in memory interface design at both the architecture and circuit levels. Coverage includes signal integrity and testing, TSV interface, high-speed serial interface including equalization, ODT, pre-emphasis, wide I/O interface including crosstalk, skew cancellation, and clock generation and distribution. Trends for further bandwidth enhancement are also covered.   • Enables readers with minimal background in memory design to understand the basics of high-bandwidth memory interface design; • Presents state-of-the-art techniques for memory interface design; • Covers memory interface design at both the circuit level and system architecture level.

  1. Building a Culture of Data Sharing: Policy Design and Implementation for Research Data Management in Development Research

    Directory of Open Access Journals (Sweden)

    Cameron Neylon

    2017-10-01

    Full Text Available A pilot project worked with seven existing projects funded by the International Development Research Center of Canada (IDRC to investigate the implementation of data management and sharing requirements within development research projects. The seven projects, which were selected to achieve a diversity of project types, locations, host institutions and subject areas, demonstrated a broad range of existing capacities to work with data and access to technical expertise and infrastructures. The pilot project provided an introduction to data management and sharing concepts, helped projects develop a Data Management Plan, and then observed the implementation of that plan. In examining the uptake of Data Management and Sharing practice amongst these seven groups the project came to question the underlying goals of funders in introducing data management and sharing requirements. It was established that the ultimate goal was a change in culture amongst grantees. The project therefore looked for evidence of how funder interventions might promote or hinder such cultural change. The project had two core findings. First that the shift from an aim of changing behaviour, to changing culture, has both subtle and profound implications for policy design and implementation. A particular finding is that the single point of contact that many data management and sharing policies create where a Data Management Plan is required at grant submission but then not further utilised is at best neutral and likely counter productive in supporting change in researcher culture. As expected, there are significant bottlenecks within research institutions and for grantees in effectively sharing data including a lack of resources and expertise. However, a core finding is that many of the bottlenecks for change relate to structural issues at the funder level. Specifically, the expectation that policy initiatives are implemented, monitored, and evaluated by Program Officers who are

  2. A study on relationship between market share and cash flow policy

    OpenAIRE

    Somayeh Sadeghi Moghaddam; Fateme Zabihi

    2014-01-01

    This paper presents an empirical investigation to study the relationship between cash flow and market share on selected firms from Tehran Stock Exchange over the period 2007-2011. Using regression analysis, the study has detected a positive and meaningful relationship between cash flow on one side and three other investment opportunities, firm size and operating cash flow. In addition, there is a negative and meaningful relationship between leverage and cash flow. However, the study does not ...

  3. Implementing a Public Bicycle Share Program: Impact on Perceptions and Support for Public Policies for Active Transportation.

    Science.gov (United States)

    Bélanger-Gravel, Ariane; Gauvin, Lise; Fuller, Daniel; Drouin, Louis

    2015-04-01

    Favorable public opinion and support for policies are essential to favor the sustainability of environmental interventions. This study examined public perceptions and support for active living policies associated with implementing a public bicycle share program (PBSP). Two cross-sectional population-based telephone surveys were conducted in 2009 and 2010 among 5011 adults in Montréal, Canada. Difference-in-differences analyses tested the impact of the PBSP on negative perceptions of the impact of the PBSP on the image of the city, road safety, ease of traveling, active transportation, health, and resistance to policies. People living closer to docking stations were less likely to have negative perceptions of the effect of the PBSP on the image of the city (OR = 0.5; 95% CI, 0.4-0.8) and to be resistant to policies (OR = 0.8; 95% CI, 0.6-1.0). The likelihood of perceiving negative effects on road safety increased across time (OR = 1.4; 95% CI, 1.2-1.8). Significant interactions were observed for perceptions of ease of traveling (OR = 0.5; 95% CI, 0.4-0.8), active transportation (OR = 0.6; 95% CI, 0.4-1.0), and health (OR = 0.6; 95% CI, 0.4-0.8): likelihood of negative perceptions decreased across time among people exposed. Findings indicate that negative perceptions were more likely to abate among those living closer to the PBSP.

  4. "Don't Affect the Share Price": Social Media Policy in Higher Education as Reputation Management

    Science.gov (United States)

    McNeill, Tony

    2012-01-01

    The last 5 years have seen a growing number of universities use social media services such as Twitter, Facebook and YouTube to engage with past, present and prospective students. More recently still, a number of universities have published policy or guidance documents on the use of social media for a range of university-related purposes including…

  5. The Development of Shared Understandings of Assessment Policy: Travelling between Global and Local Contexts

    Science.gov (United States)

    Adie, Lenore

    2014-01-01

    In this paper, teachers' enactment of assessment policy within demands for accountability and consistency of teacher judgements is considered. Evidence is drawn from a qualitative study involving 50 middle school teachers from Queensland, Australia, who participated in online social moderation meetings with teachers located in dispersed areas…

  6. Sharing the caring : State, family and gender equality in parental leave policy

    NARCIS (Netherlands)

    Widener, Anmarie J.

    2006-01-01

    Parental leave policies give parents a temporary leave from employment in order to care for a child. Secondary aims are to increase women’s attachment to the labour force as well as supporting gender equal roles in paid and unpaid work. This study researched parent satisfaction of parental leave

  7. TPROXY dan FILTERING SEBAGAI METODE OPTIMASI PEMAKAIAN BANDWIDTH INTERNET

    Directory of Open Access Journals (Sweden)

    Sutiyo Sutiyo

    2015-04-01

    Full Text Available Until now the use of the internet disuatu agencies viewed from the initial planning, use and care, even long-term planning is still not optimal. The main factor lies in the existing human resources, especially in IT personnel and policy makers who do not understand or do not even know at all how your use of the Internet well, optimal, efficient, particularly associated with the consumption of Internet bandwidth. Internet bandwidth capacity greatly affect the speed of web access or other Internet applications. So we need a plan and maintance necessary to obtain good Internet bandwidth consumption efficiency and guaranteed QoS, such as by utilizing Tproxy and filtering methods. TProxy is a development of which has been patched Squid, a proxy to be able to pass traffic without NAT (Network Access Translation. Fitering a firewall system which is used for filtering data packets that do not want filtered dikendaki or akhirmya able to minimize traffic on bandwidth usage. Tproxy and filtering runs on the Linux platform. Linux distributions are often used to Tproxy is a variant Debian, Centos and then to use Mikrotik Filtering. At the end of each request or query from the client or the response of the proxy server does not have meaningful constraints, the bandwidth between the client and the proxy server does not happen limitation, bandwidth capable of running close to capacity including 10 Mbps Ethernet, 100 Mbps, and even a GPS (full speed.

  8. A Fluid Model for a Relay Node in an Ad Hoc Network: Evaluation of Resource Sharing Policies

    Directory of Open Access Journals (Sweden)

    Michel Mandjes

    2008-01-01

    Full Text Available Fluid queues offer a natural framework for analyzing waiting times in a relay node of an ad hoc network. Because of the resource sharing policy applied, the input and output of these queues are coupled. More specifically, when there are users who wish to transmit data through a specific node, each of them obtains a share 1/(+ of the service capacity to feed traffic into the queue of the node, whereas the remaining fraction /(+ is used to serve the queue; here >0 is a free design parameter. Assume now that jobs arrive at the relay node according to a Poisson process, and that they bring along exponentially distributed amounts of data. The case =1 has been addressed before; the present paper focuses on the intrinsically harder case >1, that is, policies that give more weight to serving the queue. Four performance metrics are considered: (i the stationary workload of the queue, (ii the queueing delay, that is, the delay of a “packet” (a fluid particle that arrives at an arbitrary point in time, (iii the flow transfer delay, (iv the sojourn time, that is, the flow transfer time increased by the time it takes before the last fluid particle of the flow is served. We explicitly compute the Laplace transforms of these random variables.

  9. Sharing more widely: data at the heart of evidence, policy and transformation at Defra

    OpenAIRE

    Cameron, Kath; Janusz, Stefan; Pilley, Vanessa; Amin, Farhana; Wilkinson, Steve; Hicks, Jonathan; Gauntlett, Francesca; Kass, Gary; Rose, Mike; Oliver, Sophia; Miles, Emily; Boyd, Ian

    2017-01-01

    Defra (the Department for the Environment, Food and Rural Affairs) and its network of arm’s length bodies – the Environment Agency, Natural England, the Marine Management Organisation, Kew Gardens, the Centre for Environment, Fisheries and Aquatic Science and the Animal and Plant Health Agency – produce large amounts of data. This has been instrumental in providing evidence to support the development and delivery of key policies. Historically, expertise has been embedded in subjectsp...

  10. The renewable energy industry in Massachussetts as a complex system: Developing a shared understanding for policy making

    Science.gov (United States)

    Jones, Charles A.

    A model-based field study was conducted to understand the mental models of participants in the photovoltaic industry in Massachusetts, with the purpose of understanding of how that industry works as a complex system. Mental models of industry participants are important, both as the holders of the best system information and as the critical actors in any policy solution. Experts from manufacturing, installation, development, policy, and advocacy sectors were interviewed. The knowledge they conveyed was expressed as a set system dynamics models; these models were characterized, compared, and combined in order to answer the following research questions: What are the mental models of participants? How widely are mental models shared among participants? What is the combined model of the system? How accurate are these models? Given these models, what policies would lead to success? The system described by informants is revealed as one of distributed and embedded agency---actors have the ability to take meaningful action, but that action and its effects are limited by the complexity of the system and by the actions of other actors. Both the growth of the industry and constraints on the growth occur through dynamic processes, many however outside local control. Mental models are shared in clusters of informants, with some differences between these groupings. Informants vary on the level of aggregation needed to express their descriptions and on the most important dynamic force. However, many processes are commonly perceived across informants, they perceive the same system trajectories, and the behavior of the simulation models constructed from their mental models was similar. A combined model was constructed which included a full range of potential feedback loops within an abstracted version of the described system. Testing for policy using the combined model reveals that the structures necessary for growth are present, as expected. Under several reasonable conditions

  11. Compensation and benefit sharing: Why resettlement policies and practices must be reformed

    Institute of Scientific and Technical Information of China (English)

    Michael M. Cernea

    2008-01-01

    Many public and private sector projects, such as hydropower dams or mines, trigger forced population displacement but fail to resettle people sustainably and instead cause their impoverishment. Social science research has found that one root cause of such failures and of impoverishment is asset dispossession and the insufficient financing of resettlement. Most governments, however, state that (1) compensation alone is sufficient for restoring the income and livelihood of those displaced, and (2) resources to supplement compensation with additional financing are not available. The author critiques and rejects these positions. He offers a theoretical analysis of the limits and flaws of compensation payments for expropriated assets, and argues that resources are available for supplementing compensation with financial investments for resettlers' development. The sources for supplementary financing are the economic rent (windfall profits) generated by natural resource projects such as hydropower or mining and the regular stream of benefits generated by all projects that require resettlement. Further, the author argues that financial investments in resettlers' welfare are indispensable and that benefit sharing is feasible. Therefore, both should become basic principles of resettlement legislation and practice. In addition to theoretical analysis, the author documents with empirical evidence that some countries (China, Brazil, Canada, Columbia and Japan) already make investments additional to compensation for post-displacement reconstruction. The author sums up his argument in these key points:(1) Compensation alone cannot prevent the impoverishment of resettlers and cannot in itself restore and improve their livelihoods;(2) Additional financing is needed for direct investments in resettlement with development;(3) Compensation levels must be increased;(4) Financing resources are available in most cases for investing in resettlers' development, but allocation of

  12. Compensation and benefit sharing: Why resettlement policies and practices must be reformed

    Directory of Open Access Journals (Sweden)

    Michael M. Cernea

    2008-03-01

    Full Text Available Many public and private sector projects, such as hydropower dams or mines, trigger forced population displacement but fail to resettle people sustainably and instead cause their impoverishment. Social science research has found that one root cause of such failures and of impoverishment is asset dispossession and the insufficient financing of resettlement. Most governments, however, state that (1 compensation alone is sufficient for restoring the income and livelihood of those displaced, and (2 resources to supplement compensation with additional financing are not available. The author critiques and rejects these positions. He offers a theoretical analysis of the limits and flaws of compensation payments for expropriated assets, and argues that resources are available for supplementing compensation with financial investments for resettlers’ development. The sources for supplementary financing are the economic rent (windfall profits generated by natural resource projects such as hydropower or mining and the regular stream of benefits generated by all projects that require resettlement. Further, the author argues that financial investments in resettlers’ welfare are indispensable and that benefit sharing is feasible. Therefore, both should become basic principles of resettlement legislation and practice. In addition to theoretical analysis, the author documents with empirical evidence that some countries (China, Brazil, Canada, Columbia and Japan already make investments additional to compensation for post-displacement reconstruction. The author sums up his argument in these key points: (1Compensation alone cannot prevent the impoverishment of resettlers and cannot in itself restore and improve their livelihoods; (2Additional financing is needed for direct investments in resettlement with development; (3Compensation levels must be increased; (4Financing resources are available in most cases for investing in resettlers’ development, but

  13. THE EAP: A FAILURE OF THE EUROPEAN NEIGHBOURHOOD POLICY OR SHARING A POWER BALANCE IN THE NEIGHBOURHOOD?

    Directory of Open Access Journals (Sweden)

    Nona TATIASHVILI

    2016-10-01

    Full Text Available The present paper analyses achievements and challenges of the EaP in the prism of EU-Russia asymmetric energy interdependence, as the major factor affecting the successful implementation of the Eastern partnership. To identify whether energy interdependence is the main sphere of interest in the EaP neighbourhood, where EU-Russia common interests intersect in one point or is it a sharing a power balance in “common neighbourhood”?. The research paper reviews major policy documents of the ENP/EaP, in order to analyze to what extent is policy coherent/incoherent towards partner countries. Moreover, the paper evaluates the European neighbourhood external policy instruments (the ENP/EaP from the perspective of three prioritised countries of the Eastern partnership: Moldova, Georgia and Ukraine, including the analysis of the effectiveness of proposed incentives under the ENP/EaP, as sufficient instruments for successful implementation of the Eastern partnership, in the presence of unpredictable external veto player.

  14. File sharing

    NARCIS (Netherlands)

    van Eijk, N.

    2011-01-01

    ‘File sharing’ has become generally accepted on the Internet. Users share files for downloading music, films, games, software etc. In this note, we have a closer look at the definition of file sharing, the legal and policy-based context as well as enforcement issues. The economic and cultural

  15. Policy gaps and technological deficiencies in social networking environments: Implications for information sharing

    Directory of Open Access Journals (Sweden)

    Stephen M. Mutula

    2013-06-01

    Objectives: The study sought to investigate the following research objectives to: (1 describe the types of social networks, (2 examine global penetration of the social networks, (3 outline the users’ legitimate rights that must be protected in the social networking sites (SNS, (4 determine the methods employed by SNS to protect the users’ legitimate rights and (5 identify the policy gaps and technological deficiencies in the protection of the users’ legitimate rights in the SNS. Method: A literature survey and content analysis of the SNS user policies were used to address objective four and objective five respectively. Results: The most actively used sites were Facebook and Twitter. Asian markets were leading in participation and in creating content than any other region. Business, education, politics and governance sectors were actively using social networking sites. Social networking sites relied upon user trust and internet security features which however, were inefficient and inadequate. Conclusion: Whilst SNS were impacting people of varying ages and of various professional persuasions, there were increased concerns about the violation and infringement of the users’ legitimate rights. Reliance on user trust and technological security features SNS to protect the users’ legitimate rights seemed ineffectual and inadequate.

  16. Policy gaps and technological deficiencies in social networking environments: Implications for information sharing

    Directory of Open Access Journals (Sweden)

    Stephen M. Mutula

    2013-06-01

    Full Text Available Background: With the growing adoption and acceptance of social networking, there are increased concerns about the violation of the users’ legitimate rights such as privacy, confidentiality, trust, security, safety, content ownership, content accuracy, integrity, access and accessibility to computer and digital networks amongst others.Objectives: The study sought to investigate the following research objectives to: (1 describe the types of social networks, (2 examine global penetration of the social networks, (3 outline the users’ legitimate rights that must be protected in the social networking sites (SNS, (4 determine the methods employed by SNS to protect the users’ legitimate rights and (5 identify the policy gaps and technological deficiencies in the protection of the users’ legitimate rights in the SNS.Method: A literature survey and content analysis of the SNS user policies were used to address objective four and objective five respectively.Results: The most actively used sites were Facebook and Twitter. Asian markets were leading in participation and in creating content than any other region. Business, education, politics and governance sectors were actively using social networking sites. Social networking sites relied upon user trust and internet security features which however, were inefficient and inadequate.Conclusion: Whilst SNS were impacting people of varying ages and of various professional persuasions, there were increased concerns about the violation and infringement of the users’ legitimate rights. Reliance on user trust and technological security features SNS to protect the users’ legitimate rights seemed ineffectual and inadequate.

  17. Security policy speculation of user uploaded images on content sharing sites

    Science.gov (United States)

    Iyapparaja, M.; Tiwari, Maneesh

    2017-11-01

    Innovation is developing step by step tremendously. As there are numerous social locales where information likes pictures, sound, video and so forth are shared by the client to each other. In concentrate to all exercises on social locales, there is need of protection to pictures. Because of this reason, I utilized Adaptive protection strategy forecast instrument to give security to the pictures. Issue identified with pictures is the huge issue in social locales like Facebook, twitter and so on. So here the part of a social thought, security to pictures, metadata and so on is produced. To conquer this issue we produced an answer which is 2 systems which understanding to a background marked by the pictures gives appropriated answer for them. Here we give an arrangement to the specific sort of pictures by characterizing them and in addition giving protection to pictures which are transferred agreement to a calculation that we utilized. Consequently as indicated by this arrangement expectation pictures take after a similar approach on up and coming pictures and give successful security to them.

  18. Improving the Bandwidth Selection in Kernel Equating

    Science.gov (United States)

    Andersson, Björn; von Davier, Alina A.

    2014-01-01

    We investigate the current bandwidth selection methods in kernel equating and propose a method based on Silverman's rule of thumb for selecting the bandwidth parameters. In kernel equating, the bandwidth parameters have previously been obtained by minimizing a penalty function. This minimization process has been criticized by practitioners…

  19. Insensitivity of proportional fairness in critically loaded bandwidth sharing networks

    NARCIS (Netherlands)

    Vlasiou, M.; Zhang, J.; Zwart, B.

    2014-01-01

    Proportional fairness is a popular service allocation mechanism to describe and analyze the performance of data networks at flow level. Recently, several authors have shown that the invariant distribution of such networks admits a product form distribution under critical loading. Assuming

  20. Resource sharing under global scheduling with partial processor bandwidth

    NARCIS (Netherlands)

    Afshar, Sara; Behnam, Moris; Bril, Reinder J.; Nolte, Thomas

    2015-01-01

    Resource efficient approaches are of great importance for resource constrained embedded systems. In this paper, we present an approach targeting systems where tasks of a critical application are partitioned on a multi-core platform and by using resource reservation techniques, the remaining

  1. Applying ethical and legal principles to new technology: the University of Auckland Faculty of Medical and Health Sciences' policy 'Taking and Sharing Images of Patients.'

    Science.gov (United States)

    Jonas, Monique; Malpas, Phillipa; Kersey, Kate; Merry, Alan; Bagg, Warwick

    2017-01-27

    To develop a policy governing the taking and sharing of photographic and radiological images by medical students. The Rules of the Health Information Privacy Code 1994 and the Code of Health and Disability Services Consumers' Rights were applied to the taking, storing and sharing of photographic and radiological images by medical students. Stakeholders, including clinicians, medical students, lawyers at district health boards in the Auckland region, the Office of the Privacy Commissioner and the Health and Disability Commissioner were consulted and their recommendations incorporated. The policy 'Taking and Sharing Images of Patients' sets expectations of students in relation to: photographs taken for the purpose of providing care; photographs taken for educational or professional practice purposes and photographic or radiological images used for educational or professional practice purposes. In addition, it prohibits students from uploading images of patients onto image-sharing apps such as Figure 1. The policy has since been extended to apply to all students at the Faculty of Medical and Health Sciences at the University of Auckland. Technology-driven evolutions in practice necessitate regular review to ensure compliance with existing legal regulations and ethical frameworks. This policy offers a starting point for healthcare providers to review their own policies and practice, with a view to ensuring that patients' trust in the treatment that their health information receives is upheld.

  2. Very broad bandwidth klystron amplifiers

    Science.gov (United States)

    Faillon, G.; Egloff, G.; Farvet, C.

    Large surveillance radars use transmitters at peak power levels of around one MW and average levels of a few kW, and possibly several tens of kW, in S band, or even C band. In general, the amplification stage of these transmitters is a microwave power tube, frequently a klystron. Although designers often turn to klystrons because of their good peak and average power capabilities, they still see them as narrow band amplifiers, undoubtedly because of their resonant cavities which, at first sight, would seem highly selective. But, with the progress of recent years, it has now become quite feasible to use these tubes in installations requiring bandwidths in excess of 10 - 12 percent, and even 15 percent, at 1 MW peak for example, in S-band.

  3. Controlling Laser Plasma Instabilities Using Temporal Bandwidth

    Science.gov (United States)

    Tsung, Frank; Weaver, J.; Lehmberg, R.

    2016-10-01

    We are performing particle-in-cell simulations using the code OSIRIS to study the effects of laser plasma interactions in the presence of temporal bandwidth under conditions relevant to current and future experiments on the NIKE laser. Our simulations show that, for sufficiently large bandwidth (where the inverse bandwidth is comparable with the linear growth time), the saturation level, and the distribution of hot electrons, can be effected by the addition of temporal bandwidths (which can be accomplished in experiments using beam smoothing techniques such as ISI). We will quantify these effects and investigate higher dimensional effects such as laser speckles. This work is supported by DOE and NRL.

  4. Development of a National Aboriginal and Torres Strait Islander Cancer Framework: A Shared Process to Guide Effective Policy and Practice

    Directory of Open Access Journals (Sweden)

    Jenny Brands

    2018-05-01

    -ranging stakeholder consultation described in this paper offers a model for other areas of national and international Indigenous priority setting and policy and practice development that meets the needs of those most affected. The Framework, through the establishment of an agreed, shared and evidence-based agenda, provides guidance for jurisdictional cancer plans, optimal care pathways, and program and service planning for the multiple players across all levels of the health system.

  5. On semidefinite programming bounds for graph bandwidth

    NARCIS (Netherlands)

    de Klerk, E.; Nagy, M.; Sotirov, R.

    2013-01-01

    In this paper, we propose two new lower bounds on graph bandwidth and cyclic bandwidth based on semidefinite programming (SDP) relaxations of the quadratic assignment problem. We compare the new bounds with two other SDP bounds reported in [A. Blum, G. Konjevod, R. Ravi, and S. Vempala,

  6. Directing Traffic: Managing Internet Bandwidth Fairly

    Science.gov (United States)

    Paine, Thomas A.; Griggs, Tyler J.

    2008-01-01

    Educational institutions today face budgetary restraints and scarce resources, complicating the decision of how to allot bandwidth for campus network users. Additionally, campus concerns over peer-to-peer networking (specifically outbound Internet traffic) have increased because of bandwidth and copyright issues. In this article, the authors…

  7. 47 CFR 2.202 - Bandwidths.

    Science.gov (United States)

    2010-10-01

    ... three numerals and one letter. The letter occupies the position of the decimal point and represents the... quality desired Speech and music, M=4000, Bandwidth: 8000 Hz= 8 kHz 8K00A3E Sound broadcasting, single... desired Speech and music, M=4000, Bandwidth: 4000 Hz= 4 kHz 4K00R3E Sound broadcasting, single-sideband...

  8. Bandwidth-on-demand motion control

    NARCIS (Netherlands)

    Van Loon, S.J.L.M.; Hunnekens, B.G.B.; Simon, A.S.; van de Wouw, N.; Heemels, W.P.M.H.

    2018-01-01

    In this brief, we introduce a 'bandwidth-on-demand' variable-gain control (VGC) strategy that allows for a varying bandwidth of the feedback controller. The proposed VGC can achieve improved performance given time-varying, reference-dependent performance requirements compared with linear

  9. Perbandingan Metode Simple Queues Dan Queues Tree Untuk Optimasi Manajemen Bandwidth Jaringan Komputer Di STMIK PPKIA Pradnya Paramita Malang

    OpenAIRE

    Syaifuddin, Aris; Yunus, Mahmud; Sundari, Retno

    2013-01-01

    This research resulted in a comparison between the Simple Queues method and Queues Tree using Mikrotik router that takes a case study in STMIK PPKIA PRADNYA PARAMITA MALANG has been tested to determine which method is the most optimal deal of bandwidth sharing on computer networks. After finding out where the most optimal method will be applied in STMIK PPKIA PRADNYA PARAMITA MALANG to maximize network performance and bandwidth sharing in place, the results of the study lead to the conclusion...

  10. In-house or outsourced public services? A social and economic analysis of the impact of spending policy on the private wage share in OECD countries.

    Science.gov (United States)

    Pensiero, Nicola

    2017-08-01

    This article analyses the relationship between government spending and the distribution of private income between capital and labour. While most previous research assumes that government spending redistributes in favour of the less wealthy, I distinguish between types of expenditures that enhance the bargaining position of labour - that is, unemployment benefits, public sector employment and investment in new capital - and labour-saving and pro-business types of expenditures - that is, outsourcing to private firms. The results are derived from various panel regression techniques on a panel of 19 Organisation for Economic Co-operation and Development (OECD) countries in the period 1985-2010 and show that expenditures on public sector employment and, to a lesser extent, on new capital prevented the private wage share from declining further, even after controlling for labour market institutions, globalisation and technological change. Conversely, expenditures on outsourcing substantially contributed to reducing the private wage share. Unemployment benefits had a non-significant and negative effect on the private wage share because their increase was the consequence of higher levels of unemployment rather than policy. Implications for theory and policy are drawn, including the support for a public employment-led spending policy.

  11. In-house or outsourced public services? A social and economic analysis of the impact of spending policy on the private wage share in OECD countries

    Science.gov (United States)

    Pensiero, Nicola

    2017-01-01

    This article analyses the relationship between government spending and the distribution of private income between capital and labour. While most previous research assumes that government spending redistributes in favour of the less wealthy, I distinguish between types of expenditures that enhance the bargaining position of labour – that is, unemployment benefits, public sector employment and investment in new capital – and labour-saving and pro-business types of expenditures – that is, outsourcing to private firms. The results are derived from various panel regression techniques on a panel of 19 Organisation for Economic Co-operation and Development (OECD) countries in the period 1985–2010 and show that expenditures on public sector employment and, to a lesser extent, on new capital prevented the private wage share from declining further, even after controlling for labour market institutions, globalisation and technological change. Conversely, expenditures on outsourcing substantially contributed to reducing the private wage share. Unemployment benefits had a non-significant and negative effect on the private wage share because their increase was the consequence of higher levels of unemployment rather than policy. Implications for theory and policy are drawn, including the support for a public employment-led spending policy. PMID:28919641

  12. College curriculum-sharing via CTS. [Communications Technology Satellite

    Science.gov (United States)

    Hudson, H. E.; Guild, P. D.; Coll, D. C.; Lumb, D. R.

    1975-01-01

    Domestic communication satellites and video compression techniques will increase communication channel capacity and reduce cost of video transmission. NASA Ames Research Center, Stanford University and Carleton University are participants in an experiment to develop, demonstrate, and evaluate college course sharing techniques via satellite using video compression. The universities will exchange televised seminar and lecture courses via CTS. The experiment features real-time video compression with channel coding and quadra-phase modulation for reducing transmission bandwidth and power requirements. Evaluation plans and preliminary results of Carleton surveys on student attitudes to televised teaching are presented. Policy implications for the U.S. and Canada are outlined.

  13. Average Bandwidth Allocation Model of WFQ

    Directory of Open Access Journals (Sweden)

    Tomáš Balogh

    2012-01-01

    Full Text Available We present a new iterative method for the calculation of average bandwidth assignment to traffic flows using a WFQ scheduler in IP based NGN networks. The bandwidth assignment calculation is based on the link speed, assigned weights, arrival rate, and average packet length or input rate of the traffic flows. We prove the model outcome with examples and simulation results using NS2 simulator.

  14. A system to build distributed multivariate models and manage disparate data sharing policies: implementation in the scalable national network for effectiveness research.

    Science.gov (United States)

    Meeker, Daniella; Jiang, Xiaoqian; Matheny, Michael E; Farcas, Claudiu; D'Arcy, Michel; Pearlman, Laura; Nookala, Lavanya; Day, Michele E; Kim, Katherine K; Kim, Hyeoneui; Boxwala, Aziz; El-Kareh, Robert; Kuo, Grace M; Resnic, Frederic S; Kesselman, Carl; Ohno-Machado, Lucila

    2015-11-01

    Centralized and federated models for sharing data in research networks currently exist. To build multivariate data analysis for centralized networks, transfer of patient-level data to a central computation resource is necessary. The authors implemented distributed multivariate models for federated networks in which patient-level data is kept at each site and data exchange policies are managed in a study-centric manner. The objective was to implement infrastructure that supports the functionality of some existing research networks (e.g., cohort discovery, workflow management, and estimation of multivariate analytic models on centralized data) while adding additional important new features, such as algorithms for distributed iterative multivariate models, a graphical interface for multivariate model specification, synchronous and asynchronous response to network queries, investigator-initiated studies, and study-based control of staff, protocols, and data sharing policies. Based on the requirements gathered from statisticians, administrators, and investigators from multiple institutions, the authors developed infrastructure and tools to support multisite comparative effectiveness studies using web services for multivariate statistical estimation in the SCANNER federated network. The authors implemented massively parallel (map-reduce) computation methods and a new policy management system to enable each study initiated by network participants to define the ways in which data may be processed, managed, queried, and shared. The authors illustrated the use of these systems among institutions with highly different policies and operating under different state laws. Federated research networks need not limit distributed query functionality to count queries, cohort discovery, or independently estimated analytic models. Multivariate analyses can be efficiently and securely conducted without patient-level data transport, allowing institutions with strict local data storage

  15. Shared Decision Making in ICUs: An American College of Critical Care Medicine and American Thoracic Society Policy Statement.

    Science.gov (United States)

    Kon, Alexander A; Davidson, Judy E; Morrison, Wynne; Danis, Marion; White, Douglas B

    2016-01-01

    Shared decision making is endorsed by critical care organizations; however, there remains confusion about what shared decision making is, when it should be used, and approaches to promote partnerships in treatment decisions. The purpose of this statement is to define shared decision making, recommend when shared decision making should be used, identify the range of ethically acceptable decision-making models, and present important communication skills. The American College of Critical Care Medicine and American Thoracic Society Ethics Committees reviewed empirical research and normative analyses published in peer-reviewed journals to generate recommendations. Recommendations approved by consensus of the full Ethics Committees of American College of Critical Care Medicine and American Thoracic Society were included in the statement. Six recommendations were endorsed: 1) DEFINITION: Shared decision making is a collaborative process that allows patients, or their surrogates, and clinicians to make healthcare decisions together, taking into account the best scientific evidence available, as well as the patient's values, goals, and preferences. 2) Clinicians should engage in a shared decision making process to define overall goals of care (including decisions regarding limiting or withdrawing life-prolonging interventions) and when making major treatment decisions that may be affected by personal values, goals, and preferences. 3) Clinicians should use as their "default" approach a shared decision making process that includes three main elements: information exchange, deliberation, and making a treatment decision. 4) A wide range of decision-making approaches are ethically supportable, including patient- or surrogate-directed and clinician-directed models. Clinicians should tailor the decision-making process based on the preferences of the patient or surrogate. 5) Clinicians should be trained in communication skills. 6) Research is needed to evaluate decision

  16. Data sharing in stem cell translational science: policy statement by the International Stem Cell Forum Ethics Working Party.

    Science.gov (United States)

    Bredenoord, Annelien L; Mostert, Menno; Isasi, Rosario; Knoppers, Bartha M

    2015-01-01

    Data and sample sharing constitute a scientific and ethical imperative but need to be conducted in a responsible manner in order to protect individual interests as well as maintain public trust. In 2014, the Global Alliance for Genomics and Health (GA4GH) adopted a common Framework for Responsible Sharing of Genomic and Health-Related Data. The GA4GH Framework is applicable to data sharing in the stem cell field, however, interpretation is required so as to provide guidance for this specific context. In this paper, the International Stem Cell Forum Ethics Working Party discusses those principles that are specific to translational stem cell science, including engagement, data quality and safety, privacy, security and confidentiality, risk-benefit analysis and sustainability.

  17. Asymmetry in scientific method and limits to cross-disciplinary dialogue: toward a shared language and science policy in pharmacogenomics and human disease genetics.

    Science.gov (United States)

    Ozdemir, Vural; Williams-Jones, Bryn; Graham, Janice E; Preskorn, Sheldon H; Gripeos, Dimitrios; Glatt, Stephen J; Friis, Robert H; Reist, Christopher; Szabo, Sandor; Lohr, James B; Someya, Toshiyuki

    2007-04-01

    Pharmacogenomics is a hybrid field of experimental science at the intersection of human disease genetics and clinical pharmacology sharing applications of the new genomic technologies. But this hybrid field is not yet stable or fully integrated, nor is science policy in pharmacogenomics fully equipped to resolve the challenges of this emerging hybrid field. The disciplines of human disease genetics and clinical pharmacology contain significant differences in their scientific practices. Whereas clinical pharmacology originates as an experimental science, human disease genetics is primarily observational in nature. The result is a significant asymmetry in scientific method that can differentially impact the degree to which gene-environment interactions are discerned and, by extension, the study sample size required in each discipline. Because the number of subjects enrolled in observational genetic studies of diseases is characteristically viewed as an important criterion of scientific validity and reliability, failure to recognize discipline-specific requirements for sample size may lead to inappropriate dismissal or silencing of meritorious, although smaller-scale, craft-based pharmacogenomic investigations using an experimental study design. Importantly, the recognition that pharmacogenomics is an experimental science creates an avenue for systematic policy response to the ethical imperative to prospectively pursue genetically customized therapies before regulatory approval of pharmaceuticals. To this end, we discuss the critical role of interdisciplinary engagement between medical sciences, policy, and social science. We emphasize the need for development of shared standards across scientific, methodologic, and socioethical epistemologic divides in the hybrid field of pharmacogenomics to best serve the interests of public health.

  18. The impact of cost recovery and sharing system on water policy implementation and human right to water: a case of Ileje, Tanzania.

    Science.gov (United States)

    Kibassa, Deusdedit

    2011-01-01

    In Tanzania, the National Water Policy (NAWAPO) of 2002 clearly stipulates that access to water supply and sanitation is a right for every Tanzanian and that cost recovery is the foundation of sustainable service delivery. To meet these demands, water authorities have introduced cost recovery and a water sharing system. The overall objective of this study was to assess the impact of cost recovery and the sharing system on water policy implementation and human rights to water in four villages in the Ileje district. The specific objectives were: (1) to assess the impact of cost recovery and the sharing system on the availability of water to the poor, (2) to assess user willingness to pay for the services provided, (3) to assess community understanding on the issue of water as a human right, (4) to analyse the implications of the results in relation to policies on human rights to water and the effectiveness of the implementation of the national water policy at the grassroots, and (5) to establish the guidelines for water pricing in rural areas. Questionnaires at water demand, water supply, ability and willingness to pay and revenue collection were the basis for data collection. While 36.7% of the population in the district had water supply coverage, more than 73,077 people of the total population of 115,996 still lacked access to clean and safe water and sanitation services in the Ileje district. The country's rural water supply coverage is 49%. Seventy-nine percent of the interviewees in all four villages said that water availability in litres per household per day had decreased mainly due to high water pricing which did not consider the income of villagers. On the other hand, more than 85% of the villagers were not satisfied with the amount they were paying because the services were still poor. On the issue of human rights to water, more than 92% of the villagers know about their right to water and want it exercised by the government. In all four villages, more than

  19. The statistical bandwidth of Butterworth filters

    Science.gov (United States)

    Davy, J. L.; Dunn, I. P.

    1987-06-01

    The precision of standard architectural acoustic measurements is a function of the statistical bandwidth of the band pass filters used in the measurements. The International and United States Standards on octave and fractional octave-band filters which specify the band pass filters used in architectural acoustics measurements give the effective bandwidth, but unfortunately not the statistical bandwidth of the filters. Both these Standards are currently being revised and both revisions require the use of Butterworth filter characteristics. In this paper it is shown theoretically that the ratio of statistical bandwidth to effective bandwidth for an nth order Butterworth band pass filter is {2n}/{(2n-1)}. This is verified experimentally for third-octave third-order Butterworth band pass filters. It is also shown experimentally that this formula is approximately correct for some non-Butterworth third-octave third-order band pass filters. Because of the importance of Butterworth filters in the revised Standards, the theory of Butterworth filters is reviewed and the formulae for Butterworth filters given in both revised Standards are derived.

  20. Distributed Secondary Control in DC Microgrids with Low-Bandwidth Communication Link

    DEFF Research Database (Denmark)

    Loh, Poh Chiang; Blaabjerg, Frede; Peyghami, Saeed

    2016-01-01

    In this paper, a distributed secondary power sharing approach with low bandwidth communication network is proposed for low voltage direct current (LVDC) microgrids. Conventional droop control causes voltage drop in the grid and also a mismatch on the current of converters in the case of considera...

  1. Bandwidth extension of speech using perceptual criteria

    CERN Document Server

    Berisha, Visar; Liss, Julie

    2013-01-01

    Bandwidth extension of speech is used in the International Telecommunication Union G.729.1 standard in which the narrowband bitstream is combined with quantized high-band parameters. Although this system produces high-quality wideband speech, the additional bits used to represent the high band can be further reduced. In addition to the algorithm used in the G.729.1 standard, bandwidth extension methods based on spectrum prediction have also been proposed. Although these algorithms do not require additional bits, they perform poorly when the correlation between the low and the high band is weak. In this book, two wideband speech coding algorithms that rely on bandwidth extension are developed. The algorithms operate as wrappers around existing narrowband compression schemes. More specifically, in these algorithms, the low band is encoded using an existing toll-quality narrowband system, whereas the high band is generated using the proposed extension techniques. The first method relies only on transmitted high-...

  2. Bandwidth Assessment for MultiRotor UAVs

    Directory of Open Access Journals (Sweden)

    Ferrarese Gastone

    2017-06-01

    Full Text Available This paper is a technical note about the theoretical evaluation of the bandwidth of multirotor helicopters. Starting from a mathematical linear model of the dynamics of a multirotor aircraft, the transfer functions of the state variables that deeply affect the stability characteristics of the aircraft are obtained. From these transfer functions, the frequency response analysis of the system is effected. After this analysis, the bandwidth of the system is defined. This result is immediately utilized for the design of discrete PID controllers for hovering flight stabilization. Numeric simulations are shown to demonstrate that the knowledge of the bandwidth is a valid aid in the design of flight control systems of these machines.

  3. Teleoperation over low bandwidth communication links

    International Nuclear Information System (INIS)

    Fryer, R.J.; Mair, G.M.; Clark, N.; Heng, J.

    1996-01-01

    Teleoperation is well established for many areas of hazardous environment working. Where such environments are well structured and contained, such as within a working plant, communications bandwidths need not be a constraining factor. However where the worksite is remote, large, poorly structured or damaged communications rapidly become a critical factor in the efficient deployment and use of teleoperation equipment. The paper justifies and describes means which we are exploring to reduce the required communications bandwidth for teleoperation whist retaining full functionality. Techniques involved include incorporation of local intelligence at the worksite, with bandwidth devoted to high-level up-link control signals and down-link feedback, and the use of highly compressed video feeding 'virtual reality type' HMDs to provide maximum system transparency for the operator. The work is drawing on previous experience with an 'anthropomorphic robot heat' for telepresence work, and proprietary algorithms capable of compressing full colour video to standard telephone modem data rates. (Author)

  4. United Network for Organ Sharing

    Science.gov (United States)

    ... donor families & recipients Organ donation facts Policy Policy development Policy brochures Membership Data Transplant trends Data resources Technology Get Involved EDUCATE Become a UNOS Ambassador Promote organ donation Share through social media VISIT Attend a UNOS event Tour the National ...

  5. THE IMPROVEMENT OF COMPUTER NETWORK PERFORMANCE WITH BANDWIDTH MANAGEMENT IN KEMURNIAN II SENIOR HIGH SCHOOL

    Directory of Open Access Journals (Sweden)

    Bayu Kanigoro

    2012-05-01

    Full Text Available This research describes the improvement of computer network performance with bandwidth management in Kemurnian II Senior High School. The main issue of this research is the absence of bandwidth division on computer, which makes user who is downloading data, the provided bandwidth will be absorbed by the user. It leads other users do not get the bandwidth. Besides that, it has been done IP address division on each room, such as computer, teacher and administration room for supporting learning process in Kemurnian II Senior High School, so wireless network is needed. The method is location observation and interview with related parties in Kemurnian II Senior High School, the network analysis has run and designed a new topology network including the wireless network along with its configuration and separation bandwidth on microtic router and its limitation. The result is network traffic on Kemurnian II Senior High School can be shared evenly to each user; IX and IIX traffic are separated, which improve the speed on network access at school and the implementation of wireless network.Keywords: Bandwidth Management; Wireless Network

  6. International Organisations and the Shared Construction of Policy "Problems": Problematisation and Change in Education Governance in Europe

    Science.gov (United States)

    Grek, Sotiria

    2010-01-01

    Over recent years, research has shown the ways that national governments have seemingly ceded some of their autonomy in education policy development to international organisations (IOs) in the context of globalisation and one of its conduits, Europeanisation. This article develops the idea that IOs, and particularly the Organisation for Economic…

  7. Working at the nexus between public health policy, practice and research. Dynamics of knowledge sharing in the Netherlands

    Directory of Open Access Journals (Sweden)

    Jansen Maria W

    2012-10-01

    Full Text Available Abstract Background Joining the domains of practice, research and policy is an important aspect of boosting the quality performance required to tackle complex public health problems. “Joining domains” implies a departure from the linear and technocratic knowledge-translation approach. Integrating the practice, research and policy triangle means knowing its elements, appreciating the barriers, identifying possible cooperation strategies and studying strategy effectiveness under specified conditions. This article examines the dynamic process of developing an Academic Collaborative Centre for Public Health in the Netherlands, with the objective of achieving that the three domains of policy, practice and research become working partners on an equal footing. Method An interpretative hermeneutic approach was used to interpret the phenomenon of collaboration at the nexus between the three domains. The project was explicitly grounded in current organizational culture and routines, applied to nexus action. In the process of examination, we used both quantitative (e.g. records and qualitative data (e.g., interviews and observations. The data were interpreted using the Actor-Network, Institutional Re-Design and Blurring the Boundaries theories. Results Results show commitment at strategic level. At the tactical level, however, managers were inclined to prioritize daily routine, while the policy domain remained absent. At the operational level, practitioners learned to do PhD research in real-life practice and researchers became acquainted with problems of practice and policy, resulting in new research initiatives. Conclusion We conclude that working at the nexus is an ongoing process of formation and reformation. Strategies based on Institutional Re-Design theories in particular might help to more actively stimulate managers’ involvement to establish mutually supportive networks.

  8. Working at the nexus between public health policy, practice and research. Dynamics of knowledge sharing in The Netherlands.

    Science.gov (United States)

    Jansen, Maria W; De Leeuw, Evelyne; Hoeijmakers, Marjan; De Vries, Nanne K

    2012-10-17

    Joining the domains of practice, research and policy is an important aspect of boosting the quality performance required to tackle complex public health problems. "Joining domains" implies a departure from the linear and technocratic knowledge-translation approach. Integrating the practice, research and policy triangle means knowing its elements, appreciating the barriers, identifying possible cooperation strategies and studying strategy effectiveness under specified conditions.This article examines the dynamic process of developing an Academic Collaborative Centre for Public Health in the Netherlands, with the objective of achieving that the three domains of policy, practice and research become working partners on an equal footing. An interpretative hermeneutic approach was used to interpret the phenomenon of collaboration at the nexus between the three domains. The project was explicitly grounded in current organizational culture and routines, applied to nexus action. In the process of examination, we used both quantitative (e.g. records) and qualitative data (e.g., interviews and observations). The data were interpreted using the Actor-Network, Institutional Re-Design and Blurring the Boundaries theories. Results show commitment at strategic level. At the tactical level, however, managers were inclined to prioritize daily routine, while the policy domain remained absent. At the operational level, practitioners learned to do PhD research in real-life practice and researchers became acquainted with problems of practice and policy, resulting in new research initiatives. We conclude that working at the nexus is an ongoing process of formation and reformation. Strategies based on Institutional Re-Design theories in particular might help to more actively stimulate managers' involvement to establish mutually supportive networks.

  9. Digital demodulator for wide bandwidth SAR

    DEFF Research Database (Denmark)

    Jørgensen, Jørn Hjelm

    2000-01-01

    A novel approach to the design of efficient digital quadrature demodulators for wide bandwidth SAR systems is described. Efficiency is obtained by setting the intermediate frequency to 1/4 the ADC sampling frequency. One channel is made filter-free by synchronizing the local oscillator...

  10. Experiences in Traceroute and Bandwidth Change Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Logg, C

    2004-06-23

    SLAC has been studying end-to-end WAN bandwidth availability and achievability for 2.5 years via IEPM-BW [1]. IEPM-BW performs network intensive tests every 90 minutes. Based on that experience we have also developed a light weight available bandwidth (ABwE [2]) measurement tool that can make a measurement within a second. We are now extending this to a WAN measurement and detection system (IEPM-LITE) aimed at more quickly detecting and troubleshooting network performance problems and also to be more friendly on lower performance paths. IEPM-LITE uses ping, forward traceroutes, and ABwE sensors to monitor, in close to real-time, Round Trip Times (RTT), changes in available bandwidth and routes to and from target hosts. This paper discusses the experiences, techniques and algorithms used to detect and report on significant traceroute and bandwidth changes. The ultimate aim is to develop a lightweight WAN network performance monitoring system that can detect, in near real time, significant changes and generate alerts.

  11. Experiences in Traceroute and Bandwidth Change Analysis

    International Nuclear Information System (INIS)

    Logg, C

    2004-01-01

    SLAC has been studying end-to-end WAN bandwidth availability and achievability for 2.5 years via IEPM-BW [1]. IEPM-BW performs network intensive tests every 90 minutes. Based on that experience we have also developed a light weight available bandwidth (ABwE [2]) measurement tool that can make a measurement within a second. We are now extending this to a WAN measurement and detection system (IEPM-LITE) aimed at more quickly detecting and troubleshooting network performance problems and also to be more friendly on lower performance paths. IEPM-LITE uses ping, forward traceroutes, and ABwE sensors to monitor, in close to real-time, Round Trip Times (RTT), changes in available bandwidth and routes to and from target hosts. This paper discusses the experiences, techniques and algorithms used to detect and report on significant traceroute and bandwidth changes. The ultimate aim is to develop a lightweight WAN network performance monitoring system that can detect, in near real time, significant changes and generate alerts

  12. Improved space bandwidth product in image upconversion

    DEFF Research Database (Denmark)

    Dam, Jeppe Seidelin; Pedersen, Christian; Tidemand-Lichtenberg, Peter

    2012-01-01

    We present a technique increasing the space bandwidth product of a nonlinear image upconversion process used for spectral imaging. The technique exploits the strong dependency of the phase-matching condition in sum frequency generation (SFG) on the angle of propagation of the interacting fields...

  13. Fast Faraday Cup With High Bandwidth

    Science.gov (United States)

    Deibele, Craig E [Knoxville, TN

    2006-03-14

    A circuit card stripline Fast Faraday cup quantitatively measures the picosecond time structure of a charged particle beam. The stripline configuration maintains signal integrity, and stitching of the stripline increases the bandwidth. A calibration procedure ensures the measurement of the absolute charge and time structure of the charged particle beam.

  14. Vaccination benefits and cost-sharing policy for non-institutionalized adult Medicaid enrollees in the United States

    OpenAIRE

    Stewart, Alexandra M.; Lindley, Megan C.; Chang, Kristen H.M.; Cox, Marisa A.

    2013-01-01

    Medicaid is the largest funding source of health services for the poorest people in the United States. Medicaid enrollees have greater health care, needs, and higher health risks than other individuals in the country and, experience disproportionately low rates of preventive care. Without, Medicaid coverage, poor uninsured adults may not be vaccinated or would, rely on publicly-funded programs that provide vaccinations. We examined each programs’ policies related to benefit coverage and, copa...

  15. Why do generic drugs fail to achieve an adequate market share in Greece? Empirical findings and policy suggestions.

    Science.gov (United States)

    Balasopoulos, T; Charonis, A; Athanasakis, K; Kyriopoulos, J; Pavi, E

    2017-03-01

    Since 2010, the memoranda of understanding were implemented in Greece as a measure of fiscal adjustment. Public pharmaceutical expenditure was one of the main focuses of this implementation. Numerous policies, targeted on pharma spending, reduced the pharmaceutical budget by 60.5%. Yet, generics' penetration in Greece remained among the lowest among OECD countries. This study aims to highlight the factors that affect the perceptions of the population on generic drugs and to suggest effective policy measures. The empirical analysis is based on a national cross-sectional survey that was conducted through a sample of 2003 individuals, representative of the general population. Two ordinal logistic regression models were constructed in order to identify the determinants that affect the respondents' beliefs on the safety and the effectiveness of generic drugs. The empirical findings presented a positive and statistically significant correlation with income, bill payment difficulties, safety and effectiveness of drugs, prescription and dispensing preferences and the views toward pharmaceutical companies. Also, age and trust toward medical community have a positive and statistically significant correlation with the perception on the safety of generic drugs. Policy interventions are suggested on the bases of the empirical results on 3 major categories; (a) information campaigns, (b) incentives to doctors and pharmacists and (c) to strengthen the bioequivalence control framework and the dissemination of results. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Flexible power and bandwidth allocation in mobile satellites

    Science.gov (United States)

    Keyes, L. A.

    The introduction of L-band mobile communication services by spot beam satellites creates a payload design challenge due to uncertainty in the location and size of the new market to be served. A combination of payload technologies that allow a flexible allocation of power and bandwidth to any portion of the coverage area is described. Power flexibility is achieved by a novel combination of a low-level beam-forming network and a matrix power module which ensures equal sharing of power among individual amplifiers. This eliminates the loss of efficiency and increased mass when an amplifier associated with a beam must be over-designed to meet uncertainties in power distribution between beams. Flexibility in allocation of bandwidth to beams is achieved by intermediate frequency subdivision of the L-band service categories defined by ITU. These spectral subdivisions are assigned to beams by an IF interconnect matrix having beam ports and filter ports as inputs and outputs, respectively. Two such filter switch matrices are required, one for the inbound L-band to feeder link transponder, and one for the outbound feeder link to L-band transponder.

  17. Shared Decision Making in Intensive Care Units: An American College of Critical Care Medicine and American Thoracic Society Policy Statement

    Science.gov (United States)

    Kon, Alexander A.; Davidson, Judy E.; Morrison, Wynne; Danis, Marion; White, Douglas B.

    2015-01-01

    Objectives Shared decision-making (SDM) is endorsed by critical care organizations, however there remains confusion about what SDM is, when it should be used, and approaches to promote partnerships in treatment decisions. The purpose of this statement is to define SDM, recommend when SDM should be used, identify the range of ethically acceptable decision-making models, and present important communication skills. Methods The American College of Critical Care Medicine (ACCM) and American Thoracic Society (ATS) Ethics Committees reviewed empirical research and normative analyses published in peer-reviewed journals to generate recommendations. Recommendations approved by consensus of the full Ethics Committees of ACCM and ATS were included in the statement. Main Results Six recommendations were endorsed: 1) Definition: Shared decision-making is a collaborative process that allows patients, or their surrogates, and clinicians to make health care decisions together, taking into account the best scientific evidence available, as well as the patient’s values, goals, and preferences. 2) Clinicians should engage in a SDM process to define overall goals of care (including decisions regarding limiting or withdrawing life-prolonging interventions) and when making major treatment decisions that may be affected by personal values, goals, and preferences. 3) Clinicians should use as their “default” approach a SDM process that includes three main elements: information exchange, deliberation, and making a treatment decision. 4) A wide range of decision-making approaches are ethically supportable including patient- or surrogate-directed and clinician-directed models. Clinicians should tailor the decision-making process based on the preferences of the patient or surrogate. 5) Clinicians should be trained in communication skills. 6) Research is needed to evaluate decision-making strategies. Conclusions Patient and surrogate preferences for decision-making roles regarding value

  18. Reconstitution of Low Bandwidth Reaction History

    International Nuclear Information System (INIS)

    May, M.; Clancy, T.; Fittinghoff, D.; Gennaro, P.; Hagans, K.; Halvorson, G.; Lowry, M.; Perry, T.; Roberson, P.; Smith, D.; Teruya, A.; Blair, J.; Davis, B.; Hunt, E.; Emkeit, B.; Galbraith, J.; Kelly, B.; Montoya, R.; Nickel, G.; Ogle, J.; Wilson, K.; Wood, M.

    2004-01-01

    The goal of the Test Readiness Program is to transition to a 24 month test readiness posture and if approved move to an 18-month posture. One of the key components of the Test Readiness Program necessary to meet this goal is the reconstitution of the important diagnostics. Since the end of nuclear testing, the ability to field diagnostics on a nuclear test has deteriorated. Reconstitution of diagnostics before those who had experience in nuclear testing either retire or leave is essential to achieving a shorter test readiness posture. Also, the data recording systems have not been used since the end of testing. This report documents the reconstitution of one vital diagnostic: the low bandwidth reaction history diagnostic for FY04. Reaction history is one of the major diagnostics that has been used on all LLNL and LANL tests since the early days of nuclear testing. Reaction history refers to measuring the time history of the gamma and neutron output from a nuclear test. This gives direct information on the nuclear reactions taking place in the device. The reaction history measurements are one of the prime measurements the nuclear weapon scientists use to validate their models of device performance. All tests currently under consideration require the reaction history diagnostic. Thus moving to a shorter test readiness posture requires the reconstitution of the ability to make reaction history measurements. Reconstitution of reaction history was planned to be in two steps. Reaction history measurements that have been used in the past can be broadly placed into two categories. The most common type of reaction history and the one that has been performed on virtually all nuclear tests is termed low bandwidth reaction history. This measurement has a time response that is limited by the bandpass of kilometer length coaxial cables. When higher bandwidth has been required for specific measurements, fiber optic techniques have been used. This is referred to as high-bandwidth

  19. Large-bandwidth planar photonic crystal waveguides

    DEFF Research Database (Denmark)

    Søndergaard, Thomas; Lavrinenko, Andrei

    2002-01-01

    A general design principle is presented for making finite-height photonic crystal waveguides that support leakage-free guidance of light over large frequency intervals. The large bandwidth waveguides are designed by introducing line defects in photonic crystal slabs, where the material in the line...... defect has appropriate dispersion properties relative to the photonic crystal slab material surrounding the line defect. A three-dimensional theoretical analysis is given for large-bandwidth waveguide designs based on a silicon-air photonic crystal slab suspended in air. In one example, the leakage......-free single-mode guidance is found for a large frequency interval covering 60% of the photonic band-gap....

  20. Bandwidth tunable amplifier for recording biopotential signals.

    Science.gov (United States)

    Hwang, Sungkil; Aninakwa, Kofi; Sonkusale, Sameer

    2010-01-01

    This paper presents a low noise, low power, bandwidth tunable amplifier for bio-potential signal recording applications. By employing depletion-mode pMOS transistor in diode configuration as a tunable sub pA current source to adjust the resistivity of MOS-Bipolar pseudo-resistor, the bandwidth is adjusted without any need for a separate band-pass filter stage. For high CMRR, PSRR and dynamic range, a fully differential structure is used in the design of the amplifier. The amplifier achieves a midband gain of 39.8dB with a tunable high-pass cutoff frequency ranging from 0.1Hz to 300Hz. The amplifier is fabricated in 0.18εm CMOS process and occupies 0.14mm(2) of chip area. A three electrode ECG measurement is performed using the proposed amplifier to show its feasibility for low power, compact wearable ECG monitoring application.

  1. High bandwidth concurrent processing on commodity platforms

    CERN Document Server

    Boosten, M; Van der Stok, P D V

    1999-01-01

    The I/O bandwidth and real-time processing power required for high- energy physics experiments is increasing rapidly over time. The current requirements can only be met by using large-scale concurrent processing. We are investigating the use of a large PC cluster interconnected by Fast and Gigabit Ethernet to meet the performance requirements of the ATLAS second level trigger. This architecture is attractive because of its performance and competitive pricing. A major problem is obtaining frequent high-bandwidth I/O without sacrificing the CPU's processing power. We present a tight integration of a user-level scheduler and a zero-copy communication layer. This system closely approaches the performance of the underlying hardware in terms of both CPU power and I/O capacity. (0 refs).

  2. Time-optimal control with finite bandwidth

    Science.gov (United States)

    Hirose, M.; Cappellaro, P.

    2018-04-01

    Time-optimal control theory provides recipes to achieve quantum operations with high fidelity and speed, as required in quantum technologies such as quantum sensing and computation. While technical advances have achieved the ultrastrong driving regime in many physical systems, these capabilities have yet to be fully exploited for the precise control of quantum systems, as other limitations, such as the generation of higher harmonics or the finite response time of the control apparatus, prevent the implementation of theoretical time-optimal control. Here we present a method to achieve time-optimal control of qubit systems that can take advantage of fast driving beyond the rotating wave approximation. We exploit results from time-optimal control theory to design driving protocols that can be implemented with realistic, finite-bandwidth control fields, and we find a relationship between bandwidth limitations and achievable control fidelity.

  3. Probabilistic Bandwidth Assignment in Wireless Sensor Networks

    OpenAIRE

    Khan , Dawood; Nefzi , Bilel; Santinelli , Luca; Song , Ye-Qiong

    2012-01-01

    International audience; With this paper we offer an insight in designing and analyzing wireless sensor networks in a versatile manner. Our framework applies probabilistic and component-based design principles for the wireless sensor network modeling and consequently analysis; while maintaining flexibility and accuracy. In particular, we address the problem of allocating and reconfiguring the available bandwidth. The framework has been successfully implemented in IEEE 802.15.4 using an Admissi...

  4. Polybinary modulation for bandwidth limited optical links

    DEFF Research Database (Denmark)

    Vegas Olmos, Juan José; Jurado-Navas, Antonio

    2015-01-01

    form of partial response modulation, employs simple codification and filtering at the transmitter to drastically increase the spectral efficiency. At the receiver side, poly binary modulation requires low complexity direct detection and very little digital signal processing. This talk will review...... the recent results on poly binary modulation, comprising both binary and multilevel signals as seed signals. The results will show how poly binary modulation effectively reduces the bandwidth requirements on optical links while providing high spectral efficiency....

  5. Efficient Bandwidth Management for Ethernet Passive Optical Networks

    KAUST Repository

    Elrasad, Amr

    2016-01-01

    The increasing bandwidth demands in access networks motivates network operators, networking devices manufacturers, and standardization institutions to search for new approaches for access networks. These approaches should support higher bandwidth

  6. Low and Expensive Bandwidth Remains Key Bottleneck for ...

    African Journals Online (AJOL)

    These bottlenecks have dwarfed the expectations of the citizens to fully participate in the new world economic order galvanized by e-commerce and world trade. It is estimated that M.I.T in Boston USA has bandwidth allocation that surpasses all the bandwidth allocated to Nigeria put together. Low bandwidth has been found ...

  7. Sharing knowledge

    Energy Technology Data Exchange (ETDEWEB)

    2009-07-01

    The workshop on Climate Change Impacts and Adaptation Strategies for Arctic Indigenous Communities is one stage in developing positions and providing input from the perspectives of Arctic Peoples in preparation for the Indigenous Peoples' Global Summit on Climate Change that will take place in April, 2009, in Anchorage, Alaska. The Summit, organized by the Inuit Circumpolar Council with oversight of an International Steering Committee, will bring together hundreds of indigenous Peoples around the world. This Workshop intended to bring together Arctic Indigenous Peoples to deliver and to share information, academic research, case studies based on traditional knowledge and researchers knowledgeable in traditional knowledge and/or policy issues drawn from traditional knowledge. The following themes were discussed: 1) Traditional knowledge research and education; 2) Laws and lawmaking; 3) Food and health; 4) Organisation; 5) Communications and advocacy. (ln)

  8. Medicare Program; Revisions to Payment Policies Under the Physician Fee Schedule and Other Revisions to Part B for CY 2018; Medicare Shared Savings Program Requirements; and Medicare Diabetes Prevention Program. Final rule.

    Science.gov (United States)

    2017-11-15

    This major final rule addresses changes to the Medicare physician fee schedule (PFS) and other Medicare Part B payment policies such as changes to the Medicare Shared Savings Program, to ensure that our payment systems are updated to reflect changes in medical practice and the relative value of services, as well as changes in the statute. In addition, this final rule includes policies necessary to begin offering the expanded Medicare Diabetes Prevention Program model.

  9. Impacts of market liberalisation on the EU gas industry. The Shared Analysis project Energy Policy in Europe and Prospects to 2020. Volume No. 9

    International Nuclear Information System (INIS)

    Van Oostvoorn, F.; Boots, M.G.

    1999-10-01

    This final report presents the results of the analyses at relevant trends and features in the EU gas market enabling or limiting more competition. The study focuses in particular on the possible impacts of the implementation of the EU Gas Directive and subsequently of the expected effects of increasing competition and further integration of gas markets in Europe. The study is conducted in the framework of the Shared Analysis project entitled 'Economic Foundations for Energy Policy', coordinated by FhG-ISI and prepared for the European Commission Directorate General for Energy. The report contains an analysis of the recent changes in the structure of gas demand and the supply and its consequences for enhancement of competition in the EU gas market. lt discusses the role of growing gas demand, changing structure of the supply industry and access to the network. Next, the implementation of the EU Gas Directive is discussed. In order to deal with the uncertainty in the results of the implementation process, two extreme institutional scenarios for future development of the liberalisation process in the EU gas markets are formulated. Finally, the consequences of these two gas market liberalisation scenarios are analysed. Note that part of the conclusions of the expected effects of the Directive, i.e. the expected changes in gas prices and market structures, are based on a model analysis. However, it should be clear that at this stage our conclusions presented in this report are still of a tentative nature. Note also that the final report is based on an extensive collection of EU gas market data both on country and company level, which was described in the first interim report entitled 'The natural gas market in the European Union'. A second interim report was drafted with an energy policy interpretation of the analyses of data and developments over the past ten years. Furthermore, at this moment, facts, opinions and available data are rapidly changing in the beginning of

  10. Resource Distribution Approaches in Spectrum Sharing Systems

    Directory of Open Access Journals (Sweden)

    Friedrich K. Jondral

    2008-05-01

    Full Text Available It is increasingly difficult to satisfy growing demands for spectrum with the conventional policy of fixed spectrum allocation. To overcome this problem, flexible/dynamic spectrum sharing methods that can significantly improve spectrum utilization of the spectrum have gained increasing interest recently. This paper presents two dynamic spectrum sharing approaches, a centralized and a decentralized one. The centralized approach is based on hierarchical trading. Each level of hierarchy is composed of “markets” that are associated with a certain spatial area and trading occurrence frequency, whereas area size and trading occurrence frequency depend on the hierarchy level. The decentralized approach is based on game-theory. There, it is assumed that the operators are averse to unequal payoffs and act unselfishly, enabling a stable and sustainable community. Numerical results show that, in the observed scenario, both proposals outperform the reference case of fixed resource allocation significantly in terms of utilized bandwidth. Whereas, negotiation costs for spectrum brokerage appear in the centralized approach, nonnegligible amounts of spectrum are lost in the decentralized approach due to collisions. Thus, a hybrid of centralized and decentralized approach that exploits the benefits of both is also considered.

  11. Optimal Bandwidth Selection for Kernel Density Functionals Estimation

    Directory of Open Access Journals (Sweden)

    Su Chen

    2015-01-01

    Full Text Available The choice of bandwidth is crucial to the kernel density estimation (KDE and kernel based regression. Various bandwidth selection methods for KDE and local least square regression have been developed in the past decade. It has been known that scale and location parameters are proportional to density functionals ∫γ(xf2(xdx with appropriate choice of γ(x and furthermore equality of scale and location tests can be transformed to comparisons of the density functionals among populations. ∫γ(xf2(xdx can be estimated nonparametrically via kernel density functionals estimation (KDFE. However, the optimal bandwidth selection for KDFE of ∫γ(xf2(xdx has not been examined. We propose a method to select the optimal bandwidth for the KDFE. The idea underlying this method is to search for the optimal bandwidth by minimizing the mean square error (MSE of the KDFE. Two main practical bandwidth selection techniques for the KDFE of ∫γ(xf2(xdx are provided: Normal scale bandwidth selection (namely, “Rule of Thumb” and direct plug-in bandwidth selection. Simulation studies display that our proposed bandwidth selection methods are superior to existing density estimation bandwidth selection methods in estimating density functionals.

  12. Bandwidth Analysis of Smart Meter Network Infrastructure

    DEFF Research Database (Denmark)

    Balachandran, Kardi; Olsen, Rasmus Løvenstein; Pedersen, Jens Myrup

    2014-01-01

    Advanced Metering Infrastructure (AMI) is a net-work infrastructure in Smart Grid, which links the electricity customers to the utility company. This network enables smart services by making it possible for the utility company to get an overview of their customers power consumption and also control...... devices in their costumers household e.g. heat pumps. With these smart services, utility companies can do load balancing on the grid by shifting load using resources the customers have. The problem investigated in this paper is what bandwidth require-ments can be expected when implementing such network...... to utilize smart meters and which existing broadband network technologies can facilitate this smart meter service. Initially, scenarios for smart meter infrastructure are identified. The paper defines abstraction models which cover the AMI scenarios. When the scenario has been identified a general overview...

  13. RAID Disk Arrays for High Bandwidth Applications

    Science.gov (United States)

    Moren, Bill

    1996-01-01

    High bandwidth applications require large amounts of data transferred to/from storage devices at extremely high data rates. Further, these applications often are 'real time' in which access to the storage device must take place on the schedule of the data source, not the storage. A good example is a satellite downlink - the volume of data is quite large and the data rates quite high (dozens of MB/sec). Further, a telemetry downlink must take place while the satellite is overhead. A storage technology which is ideally suited to these types of applications is redundant arrays of independent discs (RAID). Raid storage technology, while offering differing methodologies for a variety of applications, supports the performance and redundancy required in real-time applications. Of the various RAID levels, RAID-3 is the only one which provides high data transfer rates under all operating conditions, including after a drive failure.

  14. Optimal filter bandwidth for pulse oximetry

    Science.gov (United States)

    Stuban, Norbert; Niwayama, Masatsugu

    2012-10-01

    Pulse oximeters contain one or more signal filtering stages between the photodiode and microcontroller. These filters are responsible for removing the noise while retaining the useful frequency components of the signal, thus improving the signal-to-noise ratio. The corner frequencies of these filters affect not only the noise level, but also the shape of the pulse signal. Narrow filter bandwidth effectively suppresses the noise; however, at the same time, it distorts the useful signal components by decreasing the harmonic content. In this paper, we investigated the influence of the filter bandwidth on the accuracy of pulse oximeters. We used a pulse oximeter tester device to produce stable, repetitive pulse waves with digitally adjustable R ratio and heart rate. We built a pulse oximeter and attached it to the tester device. The pulse oximeter digitized the current of its photodiode directly, without any analog signal conditioning. We varied the corner frequency of the low-pass filter in the pulse oximeter in the range of 0.66-15 Hz by software. For the tester device, the R ratio was set to R = 1.00, and the R ratio deviation measured by the pulse oximeter was monitored as a function of the corner frequency of the low-pass filter. The results revealed that lowering the corner frequency of the low-pass filter did not decrease the accuracy of the oxygen level measurements. The lowest possible value of the corner frequency of the low-pass filter is the fundamental frequency of the pulse signal. We concluded that the harmonics of the pulse signal do not contribute to the accuracy of pulse oximetry. The results achieved by the pulse oximeter tester were verified by human experiments, performed on five healthy subjects. The results of the human measurements confirmed that filtering out the harmonics of the pulse signal does not degrade the accuracy of pulse oximetry.

  15. Optical slotted circuit switched network: a bandwidth efficient alternative to wavelength-routed network

    Science.gov (United States)

    Li, Yan; Collier, Martin

    2007-11-01

    Wavelength-routed networks have received enormous attention due to the fact that they are relatively simple to implement and implicitly offer Quality of Service (QoS) guarantees. However, they suffer from a bandwidth inefficiency problem and require complex Routing and Wavelength Assignment (RWA). Most attempts to address the above issues exploit the joint use of WDM and TDM technologies. The resultant TDM-based wavelength-routed networks partition the wavelength bandwidth into fixed-length time slots organized as a fixed-length frame. Multiple connections can thus time-share a wavelength and the grooming of their traffic leads to better bandwidth utilization. The capability of switching in both wavelength and time domains in such networks also mitigates the RWA problem. However, TMD-based wavelength-routed networks work in synchronous mode and strict synchronization among all network nodes is required. Global synchronization for all-optical networks which operate at extremely high speed is technically challenging, and deploying an optical synchronizer for each wavelength involves considerable cost. An Optical Slotted Circuit Switching (OSCS) architecture is proposed in this paper. In an OSCS network, slotted circuits are created to better utilize the wavelength bandwidth than in classic wavelength-routed networks. The operation of the protocol is such as to avoid the need for global synchronization required by TDM-based wavelength-routed networks.

  16. PIC Simulation of Laser Plasma Interactions with Temporal Bandwidths

    Science.gov (United States)

    Tsung, Frank; Weaver, J.; Lehmberg, R.

    2015-11-01

    We are performing particle-in-cell simulations using the code OSIRIS to study the effects of laser plasma interactions in the presence of temperal bandwidths under conditions relevant to current and future shock ignition experiments on the NIKE laser. Our simulations show that, for sufficiently large bandwidth, the saturation level, and the distribution of hot electrons, can be effected by the addition of temporal bandwidths (which can be accomplished in experiments using smoothing techniques such as SSD or ISI). We will show that temporal bandwidth along play an important role in the control of LPI's in these lasers and discuss future directions. This work is conducted under the auspices of NRL.

  17. Extending the Peak Bandwidth of Parameters for Softmax Selection in Reinforcement Learning.

    Science.gov (United States)

    Iwata, Kazunori

    2016-05-11

    Softmax selection is one of the most popular methods for action selection in reinforcement learning. Although various recently proposed methods may be more effective with full parameter tuning, implementing a complicated method that requires the tuning of many parameters can be difficult. Thus, softmax selection is still worth revisiting, considering the cost savings of its implementation and tuning. In fact, this method works adequately in practice with only one parameter appropriately set for the environment. The aim of this paper is to improve the variable setting of this method to extend the bandwidth of good parameters, thereby reducing the cost of implementation and parameter tuning. To achieve this, we take advantage of the asymptotic equipartition property in a Markov decision process to extend the peak bandwidth of softmax selection. Using a variety of episodic tasks, we show that our setting is effective in extending the bandwidth and that it yields a better policy in terms of stability. The bandwidth is quantitatively assessed in a series of statistical tests.

  18. Reduced bandwidth video for remote vehicle operations

    Energy Technology Data Exchange (ETDEWEB)

    Noell, T.E.; DePiero, F.W.

    1993-08-01

    Oak Ridge National Laboratory staff have developed a video compression system for low-bandwidth remote operations. The objective is to provide real-time video at data rates comparable to available tactical radio links, typically 16 to 64 thousand bits per second (kbps), while maintaining sufficient quality to achieve mission objectives. The system supports both continuous lossy transmission of black and white (gray scale) video for remote driving and progressive lossless transmission of black and white images for remote automatic target acquisition. The average data rate of the resulting bit stream is 64 kbps. This system has been demonstrated to provide video of sufficient quality to allow remote driving of a High-Mobility Multipurpose Wheeled Vehicle at speeds up to 15 mph (24.1 kph) on a moguled dirt track. The nominal driving configuration provides a frame rate of 4 Hz, a compression per frame of 125:1, and a resulting latency of {approximately}1s. This paper reviews the system approach and implementation, and further describes some of our experiences when using the system to support remote driving.

  19. Bandwidth selection in smoothing functions | Kibua | East African ...

    African Journals Online (AJOL)

    ... inexpensive and, hence, worth adopting. We argue that the bandwidth parameter is determined by two factors: the kernel function and the length of the smoothing region. We give an illustrative example of its application using real data. Keywords: Kernel, Smoothing functions, Bandwidth > East African Journal of Statistics ...

  20. Variable Bandwidth Analog Channel Filters for Software Defined Radio

    NARCIS (Netherlands)

    Arkesteijn, V.J.; Klumperink, Eric A.M.; Nauta, Bram

    2001-01-01

    An important aspect of Software Defined Radio is the ability to define the bandwidth of the filter that selects the desired channel. This paper first explains the importance of channel filtering. Then the advantage of analog channel filtering with a variable bandwidth in a Software Defined Radio is

  1. Tactical Decision Aids High Bandwidth Links Using Autonomous Vehicles

    Science.gov (United States)

    2004-01-01

    1 Tactical Decision Aids (High Bandwidth Links Using Autonomous Vehicles ) A. J. Healey, D. P. Horner, Center for Autonomous Underwater Vehicle...SUBTITLE Tactical Decision Aids (High Bandwidth Links Using Autonomous Vehicles ) 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6

  2. 47 CFR 74.535 - Emission and bandwidth.

    Science.gov (United States)

    2010-10-01

    ... digital modulation in paragraph (a) of this section, the resolution bandwidth (BRES) of the measuring...), adjusted upward to the nearest greater resolution bandwidth available on the measuring equipment. In all... frequency energy outside the assigned channel. Upon notice by the FCC to the station licensee that...

  3. Optimal Bandwidth Selection in Observed-Score Kernel Equating

    Science.gov (United States)

    Häggström, Jenny; Wiberg, Marie

    2014-01-01

    The selection of bandwidth in kernel equating is important because it has a direct impact on the equated test scores. The aim of this article is to examine the use of double smoothing when selecting bandwidths in kernel equating and to compare double smoothing with the commonly used penalty method. This comparison was made using both an equivalent…

  4. Shared pledge shared vision

    International Nuclear Information System (INIS)

    Boussaha, Ali; Diatta, Christian Sina

    2005-01-01

    The New Partnership for Africa's Development (NEPAD) is a pledge by African leaders to eradicate poverty and to promote sustainable growth and development. NEPAD is a 'new framework of interaction with the rest of the world, including the industrialised countries and multilateral organizations.' The agenda is based on regional priorities and development plans and its implementation relies on African ownership and management. As a UN system organisation, the IAEA strongly supports the priorities identified in the Millennium Declaration and the New Partnership for Africa's Development. As a technical agency, the IAEA shares its recognized core competencies and technical expertise in support of NEPAD goals. Efforts aim at strengthening institutional capacity building in nuclear sciences and technology and promoting the sustainable application of nuclear techniques for social and economic development. The IAEA has a membership of 34 African countries. The Agency supports them under its technical cooperation programme through provision of expertise, training opportunities and equipment in priority areas identified by the countries themselves. For many African Member States, meeting basic human needs through the implementation of poverty alleviation strategies remains the top priority on the agenda for national development plans and international cooperation programmes. In the context of sustainable development, special attention is being paid to enlarging the contribution of isotopes and nuclear techniques in major areas of economic and social significance and to promoting regional cooperation in nuclear science and technology related fields. As a partner in development, the Agency has promoted and undertaken programmes to support African countries' efforts to address priority development issues particularly in the areas of health care, food and agriculture and water resources development. The IAEA technical cooperation mechanism includes support to the African Regional

  5. Physically Connected Stacked Patch Antenna Design with 100% Bandwidth

    KAUST Repository

    Klionovski, Kirill; Shamim, Atif

    2017-01-01

    Typically, stacked patch antennas are parasitically coupled and provide larger bandwidth than a single patch antenna. Here, we show a stacked patch antenna design where square patches with semi-circular cutouts are physically connected to each other. This arrangement provides 100% bandwidth from 23.9–72.2 GHz with consistent high gain (5 dBi or more) across the entire bandwidth. In another variation, a single patch loaded with a superstrate provides 83.5% bandwidth from 25.6–62.3 GHz. The mechanism of bandwidth enhancement is explained through electromagnetic simulations. Measured reflection coefficient, radiation patterns and gain results confirm the extremely wideband performance of the design.

  6. Physically Connected Stacked Patch Antenna Design with 100% Bandwidth

    KAUST Repository

    Klionovski, Kirill

    2017-11-01

    Typically, stacked patch antennas are parasitically coupled and provide larger bandwidth than a single patch antenna. Here, we show a stacked patch antenna design where square patches with semi-circular cutouts are physically connected to each other. This arrangement provides 100% bandwidth from 23.9–72.2 GHz with consistent high gain (5 dBi or more) across the entire bandwidth. In another variation, a single patch loaded with a superstrate provides 83.5% bandwidth from 25.6–62.3 GHz. The mechanism of bandwidth enhancement is explained through electromagnetic simulations. Measured reflection coefficient, radiation patterns and gain results confirm the extremely wideband performance of the design.

  7. Exploring the Sharing Economy

    DEFF Research Database (Denmark)

    Netter, Sarah

    Despite the growing interest on the part of proponents and opponents - ranging from business, civil society, media, to policy-makers alike - there is still limited knowledge about the working mechanisms of the sharing economy. The thesis is dedicated to explore this understudied phenomenon...... and to provide a more nuanced understanding of the micro- and macro-level tensions that characterize the sharing economy. This thesis consists of four research papers, each using different literature, methodology, and data sets. The first paper investigates how the sharing economy is diffused and is ‘talked......-level tensions experience by sharing platforms by looking at the case of mobile fashion reselling and swapping markets. The final paper combines the perspectives of different sharing economy stakeholders and outlines some of the micro and macro tensions arising in and influencing the organization of these multi...

  8. To share and be shared

    DEFF Research Database (Denmark)

    Winther, Ida Wentzel

    2018-01-01

    to another. To a certain degree, they share their everyday lives, things, places, memories, and past/future, but as the ones who move back and forth, they belong a little less in each place. This article is about children who are shared between their parent, households and siblings. They are shared...

  9. Bandwidth auction for SVC streaming in dynamic multi-overlay

    Science.gov (United States)

    Xiong, Yanting; Zou, Junni; Xiong, Hongkai

    2010-07-01

    In this paper, we study the optimal bandwidth allocation for scalable video coding (SVC) streaming in multiple overlays. We model the whole bandwidth request and distribution process as a set of decentralized auction games between the competing peers. For the upstream peer, a bandwidth allocation mechanism is introduced to maximize the aggregate revenue. For the downstream peer, a dynamic bidding strategy is proposed. It achieves maximum utility and efficient resource usage by collaborating with a content-aware layer dropping/adding strategy. Also, the convergence of the proposed auction games is theoretically proved. Experimental results show that the auction strategies can adapt to dynamic join of competing peers and video layers.

  10. 3600 digital phase detector with 100-kHz bandwidth

    International Nuclear Information System (INIS)

    Reid, D.W.; Riggin, D.; Fazio, M.V.; Biddle, R.S.; Patton, R.D.; Jackson, H.A.

    1981-01-01

    The general availability of digital circuit components with propagation delay times of a few nanoseconds makes a digital phase detector with good bandwidth feasible. Such a circuit has a distinct advantage over its analog counterpart because of its linearity over wide range of phase shift. A phase detector that is being built at Los Alamos National Laboratory for the Fusion Materials Irradiation Test (FMIT) project is described. The specifications are 100-kHz bandwidth, linearity of +- 1 0 over +- 180 0 of phase shift, and 0.66 0 resolution. To date, the circuit has achieved the bandwidth and resolution. The linearity is approximately +- 3 0 over +- 180 0 phase shift

  11. Large bandwidth RGC transimpedance preamplifier design in SCA

    International Nuclear Information System (INIS)

    Wang Ke; Wang Zheng; Liu Zhen'an; Wei Wei; Lu Weiguo; Gary Varner

    2009-01-01

    A Large Bandwidth RGC Transimpedance Preamplifier is designed for amplifying the high-fidelity timing signal in Switch Capacitance Array chip application. This amplifier have characteristics of low input impedance, large bandwidth, high transimpedance. It will be made under TSMC 0.25μm CMOS technology, and the supply voltage is single 2.5 V. Simulation results indicate: the transimpedance is 5000 ohm, -3dB BW is 953 MHz, and the detector output capacitance have litter effect on the bandwidth in some range. (authors)

  12. Energy efficiency in elastic-bandwidth optical networks

    DEFF Research Database (Denmark)

    Vizcaino, Jorge Lopez; Ye, Yabin; Tafur Monroy, Idelfonso

    2011-01-01

    of elastic bandwidth allocation, opens new horizons in the operation of optical networks. In this paper, we compare the network planning problem in an elastic bandwidth CO-OFDM-based network and a fixed-grid WDM network. We highlight the benefits that bandwidth elasticity and the selection of different......The forecasted growth in the Internet traffic has made the operators and industry to be concerned about the power consumption of the networks, and to become interested in alternatives to plan and operate the networks in a more energy efficient manner. The introduction of OFDM, and its property...

  13. Sharing City

    DEFF Research Database (Denmark)

    This magazine offers an insight into the growing commercial innovation, civic movements, and political narratives surrounding sharing economy services, solutions and organisational types. It presents a cross-section of the manifold sharing economy services and solutions that can be found in Denmark....... Moreover, 15 thought leading experts - professionals and academic - have been invited to give their perspective on sharing economy for cities. This magazine touches upon aspects of the sharing economy as mobility, communities, sustainability, business development, mobility, and urban-rural relation....

  14. One-way shared memory

    DEFF Research Database (Denmark)

    Schoeberl, Martin

    2018-01-01

    Standard multicore processors use the shared main memory via the on-chip caches for communication between cores. However, this form of communication has two limitations: (1) it is hardly time-predictable and therefore not a good solution for real-time systems and (2) this single shared memory...... is a bottleneck in the system. This paper presents a communication architecture for time-predictable multicore systems where core-local memories are distributed on the chip. A network-on-chip constantly copies data from a sender core-local memory to a receiver core-local memory. As this copying is performed...... in one direction we call this architecture a one-way shared memory. With the use of time-division multiplexing for the memory accesses and the network-on-chip routers we achieve a time-predictable solution where the communication latency and bandwidth can be bounded. An example architecture for a 3...

  15. Bandwidth Estimation in Wireless Lans for Multimedia Streaming Services

    Directory of Open Access Journals (Sweden)

    Heung Ki Lee

    2007-01-01

    Full Text Available The popularity of multimedia streaming services via wireless networks presents major challenges in the management of network bandwidth. One challenge is to quickly and precisely estimate the available bandwidth for the decision of streaming rates of layered and scalable multimedia services. Previous studies based on wired networks are too burdensome to be applied to multimedia applications in wireless networks. In this paper, a new method, IdleGap, is suggested to estimate the available bandwidth of a wireless LAN based on the information from a low layer in the protocol stack. We use a network simulation tool, NS-2, to evaluate our new method with various ranges of cross-traffic and observation times. Our simulation results show that IdleGap accurately estimates the available bandwidth for all ranges of cross-traffic (100 Kbps ∼ 1 Mbps with a very short observation time of 10 seconds.

  16. Composeable Chat over Low-Bandwidth Intermittent Communication Links

    National Research Council Canada - National Science Library

    Wilcox, D. R

    2007-01-01

    Intermittent low-bandwidth communication environments, such as those encountered in U.S. Navy tactical radio and satellite links, have special requirements that do not pertain to commercial applications...

  17. Bandwidth allocation and pricing problem for a duopoly market

    Directory of Open Access Journals (Sweden)

    You Peng-Sheng

    2011-01-01

    Full Text Available This research discusses the Internet service provider (ISP bandwidth allocation and pricing problems for a duopoly bandwidth market with two competitive ISPs. According to the contracts between Internet subscribers and ISPs, Internet subscribers can enjoy their services up to their contracted bandwidth limits. However, in reality, many subscribers may experience the facts that their on-line requests are denied or their connection speeds are far below their contracted speed limits. One of the reasons is that ISPs accept too many subscribers as their subscribers. To avoid this problem, ISPs can set limits for their subscribers to enhance their service qualities. This paper develops constrained nonlinear programming to deal with this problem for two competitive ISPs. The condition for reaching the equilibrium between the two competitive firms is derived. The market equilibrium price and bandwidth resource allocations are derived as closed form solutions.

  18. modeling the effect of bandwidth allocation on network performance

    African Journals Online (AJOL)

    Using MATLAB, simulations were then .... of the network resource. Network bandwidth design, simulation, and management ... encoder processes longer signal data blocks, which entails longer ... c is the modulated signal carrier. However, the ...

  19. Bandwidth-dependent transformation of noise data f

    OpenAIRE

    P. Bormann;  

    1998-01-01

    Additional keywords: bandwidth dependence amplitudes, Dynamikbereich, Frequenzband, relative Bandbreite, spektrale Leistungsdichte der Bodenunruhe, Darstellungen der Bodenunruhespektren in verschiedenen kinematischen Einheiten, Transformation kinematischer Einheiten, Transformation von Spektren in Amplituden der Bodenbewegung, Abhaengigkeit der Amplituden von der Bandbreite

  20. Shared leadership

    DEFF Research Database (Denmark)

    Ulhøi, John Parm; Müller, Sabine

    2012-01-01

    The aim of this paper is twofold. First, this paper comprehensively will review the conceptual and empirical literature to identify such critical underlying mechanisms which enable shared or collective leadership. Second, this article identifies the antecedents and outcomes of shared leadership...... according to the literature review to develop a re-conceptualised and synthesized framework for managing the organizational issues associated with shared leadership on various organizational levels. The paper rectifies this by identifying the critical factors and mechanisms which enable shared leadership...... and its antecedents and outcomes, and to develop a re-conceptualized and synthesized framework of shared leadership. The paper closes with a brief discussion of avenues for future research and implications for managers....

  1. Review of high bandwidth fiber optics radiation sensors

    International Nuclear Information System (INIS)

    Lyons, P.B.

    1985-01-01

    This paper summarizes the use of fiber optics or guided optical systems for radiation sensors. It is limited a passive systems wherein electrical is not required at the sensor location. However, electrically powered light sources, receivers and/or recorders may still be required for detection and data storage in sensor system operation. This paper emphasizes sensor technologies that permit high bandwidth measurements of transient radiation levels, and will also discuss several low bandwidth applications. 60 refs

  2. Utilising UDT to push the bandwidth envelope

    Science.gov (United States)

    Garrett, B.; Davies, B.

    eScience applications, in particular High Energy Physics, often involve large amounts of data and/or computing and often require secure resource sharing across organizational boundaries, and are thus not easily handled by today's networking infrastructures. By utilising the switched lightpath connections provided by the UKLight network it has been possible to research the use of alternate protocols for data transport. While the HEP projects make use of a number of middleware solutions for data storage and transport, they all rely on GridFTP for WAN transport. The GridFTP protocol runs over TCP as the layer 3 protocol by default, however with the latest released of the Globus toolkit it is possible to utilise alternate protocols at the layer 3 level. One of the alternatives is a reliable version of UDP called UDT. This report presents the results of the tests measuring the performance of single-threaded file transfers using GridFTP running over both TCP and the UDT protocol.

  3. Engineering the CernVM-Filesystem as a High Bandwidth Distributed Filesystem for Auxiliary Physics Data

    Science.gov (United States)

    Dykstra, D.; Bockelman, B.; Blomer, J.; Herner, K.; Levshina, T.; Slyz, M.

    2015-12-01

    A common use pattern in the computing models of particle physics experiments is running many distributed applications that read from a shared set of data files. We refer to this data is auxiliary data, to distinguish it from (a) event data from the detector (which tends to be different for every job), and (b) conditions data about the detector (which tends to be the same for each job in a batch of jobs). Relatively speaking, conditions data also tends to be relatively small per job where both event data and auxiliary data are larger per job. Unlike event data, auxiliary data comes from a limited working set of shared files. Since there is spatial locality of the auxiliary data access, the use case appears to be identical to that of the CernVM- Filesystem (CVMFS). However, we show that distributing auxiliary data through CVMFS causes the existing CVMFS infrastructure to perform poorly. We utilize a CVMFS client feature called "alien cache" to cache data on existing local high-bandwidth data servers that were engineered for storing event data. This cache is shared between the worker nodes at a site and replaces caching CVMFS files on both the worker node local disks and on the site's local squids. We have tested this alien cache with the dCache NFSv4.1 interface, Lustre, and the Hadoop Distributed File System (HDFS) FUSE interface, and measured performance. In addition, we use high-bandwidth data servers at central sites to perform the CVMFS Stratum 1 function instead of the low-bandwidth web servers deployed for the CVMFS software distribution function. We have tested this using the dCache HTTP interface. As a result, we have a design for an end-to-end high-bandwidth distributed caching read-only filesystem, using existing client software already widely deployed to grid worker nodes and existing file servers already widely installed at grid sites. Files are published in a central place and are soon available on demand throughout the grid and cached locally on the

  4. Engineering the CernVM-Filesystem as a High Bandwidth Distributed Filesystem for Auxiliary Physics Data

    Energy Technology Data Exchange (ETDEWEB)

    Dykstra, D. [Fermilab; Bockelman, B. [Nebraska U.; Blomer, J. [CERN; Herner, K. [Fermilab; Levshina, T. [Fermilab; Slyz, M. [Fermilab

    2015-12-23

    A common use pattern in the computing models of particle physics experiments is running many distributed applications that read from a shared set of data files. We refer to this data is auxiliary data, to distinguish it from (a) event data from the detector (which tends to be different for every job), and (b) conditions data about the detector (which tends to be the same for each job in a batch of jobs). Relatively speaking, conditions data also tends to be relatively small per job where both event data and auxiliary data are larger per job. Unlike event data, auxiliary data comes from a limited working set of shared files. Since there is spatial locality of the auxiliary data access, the use case appears to be identical to that of the CernVM- Filesystem (CVMFS). However, we show that distributing auxiliary data through CVMFS causes the existing CVMFS infrastructure to perform poorly. We utilize a CVMFS client feature called 'alien cache' to cache data on existing local high-bandwidth data servers that were engineered for storing event data. This cache is shared between the worker nodes at a site and replaces caching CVMFS files on both the worker node local disks and on the site's local squids. We have tested this alien cache with the dCache NFSv4.1 interface, Lustre, and the Hadoop Distributed File System (HDFS) FUSE interface, and measured performance. In addition, we use high-bandwidth data servers at central sites to perform the CVMFS Stratum 1 function instead of the low-bandwidth web servers deployed for the CVMFS software distribution function. We have tested this using the dCache HTTP interface. As a result, we have a design for an end-to-end high-bandwidth distributed caching read-only filesystem, using existing client software already widely deployed to grid worker nodes and existing file servers already widely installed at grid sites. Files are published in a central place and are soon available on demand throughout the grid and cached

  5. Reliable IoT Storage: Minimizing Bandwidth Use in Storage Without Newcomer Nodes

    DEFF Research Database (Denmark)

    Zhao, Xiaobo; Lucani Rötter, Daniel Enrique; Shen, Xiaohong

    2018-01-01

    This letter characterizes the optimal policies for bandwidth use and storage for the problem of distributed storage in Internet of Things (IoT) scenarios, where lost nodes cannot be replaced by new nodes as is typically assumed in Data Center and Cloud scenarios. We develop an information flow...... model that captures the overall process of data transmission between IoT devices, from the initial preparation stage (generating redundancy from the original data) to the different repair stages with fewer and fewer devices. Our numerical results show that in a system with 10 nodes, the proposed optimal...

  6. Knowledge Sharing

    DEFF Research Database (Denmark)

    Holdt Christensen, Peter

    The concept of knowledge management has, indeed, become a buzzword that every single organization is expected to practice and live by. Knowledge management is about managing the organization's knowledge for the common good of the organization -but practicing knowledge management is not as simple...... as that. This article focuses on knowledge sharing as the process seeking to reduce the resources spent on reinventing the wheel.The article introduces the concept of time sensitiveness; i.e. that knowledge is either urgently needed, or not that urgently needed. Furthermore, knowledge sharing...... is considered as either a push or pull system. Four strategies for sharing knowledge - help, post-it, manuals and meeting, and advice are introduced. Each strategy requires different channels for sharing knowledge. An empirical analysis in a production facility highlights how the strategies can be practiced....

  7. Staffing Alternatives: Use of Retired Persons, Flex-Time, Job Sharing and Other Suggestions. Suggested Personnel Policy Guidelines for School Districts. [Revised].

    Science.gov (United States)

    Oregon State Dept. of Education, Salem.

    This report addresses three alternatives in employing certified and classified staff in school districts: early retirement, flexible working hours, and (in the most detail) job sharing. It is noted that financial reductions make it difficult for schools to meet both their budgets and rising community/parental expectations, while declining…

  8. Open-Loop Wide-Bandwidth Phase Modulation Techniques

    Directory of Open Access Journals (Sweden)

    Nitin Nidhi

    2011-01-01

    Full Text Available The ever-increasing growth in the bandwidth of wireless communication channels requires the transmitter to be wide-bandwidth and power-efficient. Polar and outphasing transmitter topologies are two promising candidates for such applications, in future. Both these architectures require a wide-bandwidth phase modulator. Open-loop phase modulation presents a viable solution for achieving wide-bandwidth operation. An overview of prior art and recent approaches for phase modulation is presented in this paper. Phase quantization noise cancellation was recently introduced to lower the out-of-band noise in a digital phase modulator. A detailed analysis on the impact of timing and quantization of the cancellation signal is presented. Noise generated by the transmitter in the receive band frequency poses another challenge for wide-bandwidth transmitter design. Addition of a noise transfer function notch, in a digital phase modulator, to reduce the noise in the receive band during phase modulation is described in this paper.

  9. Local Control in Action: Learning from the CORE Districts' Focus on Measurement, Capacity Building, and Shared Accountability. Policy Brief 16-4

    Science.gov (United States)

    Marsh, Julie; Bush-Mecenas, Susan; Hough, Heather

    2016-01-01

    California and the nation are at the crossroads of a major shift in school accountability policy. At the state level, California's Local Control and Accountability Plan (LCAP) encourages the use of multiple measures of school performance used locally to support continuous improvement and strategic resource allocation. Similarly, the federal Every…

  10. Moiré volume Bragg grating filter with tunable bandwidth.

    Science.gov (United States)

    Mokhov, Sergiy; Ott, Daniel; Divliansky, Ivan; Zeldovich, Boris; Glebov, Leonid

    2014-08-25

    We propose a monolithic large-aperture narrowband optical filter based on a moiré volume Bragg grating formed by two sequentially recorded gratings with slightly different resonant wavelengths. Such recording creates a spatial modulation of refractive index with a slowly varying sinusoidal envelope. By cutting a specimen at a small angle, to a thickness of one-period of this envelope, the longitudinal envelope profile will shift from a sine profile to a cosine profile across the face of the device. The transmission peak of the filter has a tunable bandwidth while remaining at a fixed resonant wavelength by a transversal shift of incidence position. Analytical expressions for the tunable bandwidth of such a filter are calculated and experimental data from a filter operating at 1064 nm with bandwidth range 30-90 pm is demonstrated.

  11. Development of a bandwidth limiting neutron chopper for CSNS

    Science.gov (United States)

    Wang, P.; Yang, B.; Cai, W. L.

    2015-08-01

    Bandwidth limiting neutron choppers are indispensable key equipments for the time-of-flight neutron scattering spectrometers of China Spallation Neutron Source (CSNS). The main principle is to chop the neutron beam to limit the neutron wavelength bandwidth at the neutron detector. We have successfully developed a bandwidth limiting neutron chopper for CSNS in the CSNS advance research project II. The transmission rate of the neutron absorbing coating is less than 1×10-4 (for 1 angstrom neutron). The phase control accuracy is ±0.084° (±9.4 μs at 25 Hz). The dynamic balance grade is G1.0. Various experimental technical features have met the design requirements, and it also runs stably and reliably during the long-term tests.

  12. Development of a bandwidth limiting neutron chopper for CSNS

    International Nuclear Information System (INIS)

    Wang, P.; Yang, B.; Cai, W.L.

    2015-01-01

    Bandwidth limiting neutron choppers are indispensable key equipments for the time-of-flight neutron scattering spectrometers of China Spallation Neutron Source (CSNS). The main principle is to chop the neutron beam to limit the neutron wavelength bandwidth at the neutron detector. We have successfully developed a bandwidth limiting neutron chopper for CSNS in the CSNS advance research project II. The transmission rate of the neutron absorbing coating is less than 1×10 −4 (for 1 angstrom neutron). The phase control accuracy is ±0.084° (±9.4 μs at 25 Hz). The dynamic balance grade is G1.0. Various experimental technical features have met the design requirements, and it also runs stably and reliably during the long-term tests

  13. Path connectivity based spectral defragmentation in flexible bandwidth networks.

    Science.gov (United States)

    Wang, Ying; Zhang, Jie; Zhao, Yongli; Zhang, Jiawei; Zhao, Jie; Wang, Xinbo; Gu, Wanyi

    2013-01-28

    Optical networks with flexible bandwidth provisioning have become a very promising networking architecture. It enables efficient resource utilization and supports heterogeneous bandwidth demands. In this paper, two novel spectrum defragmentation approaches, i.e. Maximum Path Connectivity (MPC) algorithm and Path Connectivity Triggering (PCT) algorithm, are proposed based on the notion of Path Connectivity, which is defined to represent the maximum variation of node switching ability along the path in flexible bandwidth networks. A cost-performance-ratio based profitability model is given to denote the prons and cons of spectrum defragmentation. We compare these two proposed algorithms with non-defragmentation algorithm in terms of blocking probability. Then we analyze the differences of defragmentation profitability between MPC and PCT algorithms.

  14. Correlation and image compression for limited-bandwidth CCD.

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, Douglas G.

    2005-07-01

    As radars move to Unmanned Aerial Vehicles with limited-bandwidth data downlinks, the amount of data stored and transmitted with each image becomes more significant. This document gives the results of a study to determine the effect of lossy compression in the image magnitude and phase on Coherent Change Detection (CCD). We examine 44 lossy compression types, plus lossless zlib compression, and test each compression method with over 600 CCD image pairs. We also derive theoretical predictions for the correlation for most of these compression schemes, which compare favorably with the experimental results. We recommend image transmission formats for limited-bandwidth programs having various requirements for CCD, including programs which cannot allow performance degradation and those which have stricter bandwidth requirements at the expense of CCD performance.

  15. EMG-Torque Dynamics Change With Contraction Bandwidth.

    Science.gov (United States)

    Golkar, Mahsa A; Jalaleddini, Kian; Kearney, Robert E

    2018-04-01

    An accurate model for ElectroMyoGram (EMG)-torque dynamics has many uses. One of its applications which has gained high attention among researchers is its use, in estimating the muscle contraction level for the efficient control of prosthesis. In this paper, the dynamic relationship between the surface EMG and torque during isometric contractions at the human ankle was studied using system identification techniques. Subjects voluntarily modulated their ankle torque in dorsiflexion direction, by activating their tibialis anterior muscle, while tracking a pseudo-random binary sequence in a torque matching task. The effects of contraction bandwidth, described by torque spectrum, on EMG-torque dynamics were evaluated by varying the visual command switching time. Nonparametric impulse response functions (IRF) were estimated between the processed surface EMG and torque. It was demonstrated that: 1) at low contraction bandwidths, the identified IRFs had unphysiological anticipatory (i.e., non-causal) components, whose amplitude decreased as the contraction bandwidth increased. We hypothesized that this non-causal behavior arose, because the EMG input contained a component due to feedback from the output torque, i.e., it was recorded from within a closed-loop. Vision was not the feedback source since the non-causal behavior persisted when visual feedback was removed. Repeating the identification using a nonparametric closed-loop identification algorithm yielded causal IRFs at all bandwidths, supporting this hypothesis. 2) EMG-torque dynamics became faster and the bandwidth of system increased as contraction modulation rate increased. Thus, accurate prediction of torque from EMG signals must take into account the contraction bandwidth sensitivity of this system.

  16. Streamlining Policy Creation in Policy Frameworks

    NARCIS (Netherlands)

    M.A. Hills (Mark); N. Martí-Oliet; M. Palomino

    2012-01-01

    textabstract{\\it Policy frameworks} provide a technique for improving reuse in program analysis: the same language frontend, and a core analysis semantics, can be shared among multiple analysis policies for the same language, while analysis domains (such as units of measurement) can be shared among

  17. Bandwidth trading under misaligned objectives: decentralized measurement-based control

    NARCIS (Netherlands)

    M.R.H. Mandjes (Michel); M. Ramakrishnan

    2006-01-01

    htmlabstractThis paper studies the interplay between a profit-maximizing network and a number of users competing for the finite bandwidth on each link. In our setting, the objectives of the network and the users are ‘misaligned’, in that the prices that optimize the network’s profit do not maximize

  18. Bandwidth trading under misaligned objectives: decentralized measurement-based control

    NARCIS (Netherlands)

    Mandjes, M.R.H.; Ramakrishnan, M.

    2008-01-01

    This paper studies the interplay between a profit-maximizing network and a number of users competing for the finite bandwidth on each link. In our setting, the objectives of the network and the users are ‘misaligned’, in that the prices that optimize the network’s profit do not maximize the

  19. Iterative Available Bandwidth Estimation for Mobile Transport Networks

    DEFF Research Database (Denmark)

    Ubeda Castellanos, Carlos; López Villa, Dimas; Teyeb, Oumer Mohammed

    2007-01-01

    Available bandwidth estimation has lately been proposed to be used for end-to-end resource management in existing and emerging mobile communication systems, whose transport networks could end up being the bottleneck rather than the air interface. Algorithms for admission control, handover...

  20. Come together: African universities collaborate to improve bandwidth

    International Development Research Centre (IDRC) Digital Library (Canada)

    2011-02-02

    Feb 2, 2011 ... SEE ALSO... In Reports magazine: Viewpoint: Bandwidth can bring African universities up to speed. In Reports magazine: Brain Drain and Capacity Building in Africa · The AAU Web site. The Connectivity Africa Web site. The World Summit on the Information Society (WSIS) Web site. IDRC's ICT4D Web site ...

  1. Sensitivity-Bandwidth Limit in a Multimode Optoelectromechanical Transducer

    Science.gov (United States)

    Moaddel Haghighi, I.; Malossi, N.; Natali, R.; Di Giuseppe, G.; Vitali, D.

    2018-03-01

    An optoelectromechanical system formed by a nanomembrane capacitively coupled to an L C resonator and to an optical interferometer has recently been employed for the highly sensitive optical readout of rf signals [T. Bagci et al., Nature (London) 507, 81 (2013), 10.1038/nature13029]. We propose and experimentally demonstrate how the bandwidth of such a transducer can be increased by controlling the interference between two electromechanical interaction pathways of a two-mode mechanical system. With a proof-of-principle device operating at room temperature, we achieve a sensitivity of 300 nV /√{Hz } over a bandwidth of 15 kHz in the presence of radio-frequency noise, and an optimal shot-noise-limited sensitivity of 10 nV /√{Hz } over a bandwidth of 5 kHz. We discuss strategies for improving the performance of the device, showing that, for the same given sensitivity, a mechanical multimode transducer can achieve a bandwidth significantly larger than that for a single-mode one.

  2. Estimating auditory filter bandwidth using distortion product otoacoustic emissions

    DEFF Research Database (Denmark)

    Hauen, Sigurd van; Rukjær, Andreas Harbo; Ordoñez Pizarro, Rodrigo Eduardo

    2017-01-01

    The basic frequency selectivity in the listener’s hearing is often characterized by auditory filters. These filters are determined through listening tests, which determine the masking threshold as a function of frequency of the tone and the bandwidth of the masking sound. The auditory filters hav...

  3. Estimating Bandwidth Requirements using Flow-level Measurements

    NARCIS (Netherlands)

    Bruyère, P.; de Oliveira Schmidt, R.; Sperotto, Anna; Sadre, R.; Pras, Aiko

    Bandwidth provisioning is an important task of network management and it is done aiming to meet desired levels of quality of service. Current practices of provisioning are mostly based on rules-of-thumb and use coarse traffic measurements that may lead to problems of under and over dimensioning of

  4. Frequency Selective Surfaces for extended Bandwidth backing reflector functions

    NARCIS (Netherlands)

    Pasian, M.; Neto, A.; Monni, S.; Ettorre, M.; Gerini, G.

    2008-01-01

    This paper deals with the use of Frequency Selective Surfaces (FSS) to increase the Efficiency × Bandwidth product in Ultra-Wide Band (UWB) antenna arrays whose efficiency is limited by the front-to-back ratio. If the backing reflector is realized in one metal plane solution its location will be

  5. 47 CFR 15.35 - Measurement detector functions and bandwidths.

    Science.gov (United States)

    2010-10-01

    ... are based on the use of measurement instrumentation employing an average detector function. Unless... in terms of the average value of the emission, and pulsed operation is employed, the measurement... 47 Telecommunication 1 2010-10-01 2010-10-01 false Measurement detector functions and bandwidths...

  6. A Practical Approach For Excess Bandwidth Distribution for EPONs

    KAUST Repository

    Elrasad, Amr

    2014-03-09

    This paper introduces a novel approach called Delayed Excess Scheduling (DES), which practically reuse the excess bandwidth in EPONs system. DES is suitable for the industrial deployment as it requires no timing constraint and achieves better performance compared to the previously reported schemes.

  7. Come together: African universities collaborate to improve bandwidth

    International Development Research Centre (IDRC) Digital Library (Canada)

    2011-02-02

    Feb 2, 2011 ... However, a stumbling block to realizing this vision arose: the cost of access. As Bob Hawkins, a senior education specialist at the WBI, points out, “the average African university pays 50 times more than the amount a North American university pays for Internet access.” Moreover, the bandwidth available to ...

  8. Modeling the Effect of Bandwidth Allocation on Network Performance

    African Journals Online (AJOL)

    ... The proposed model showed improved performance for CDMA networks, but further increase in the bandwidth did not benefit the network; (iii) A reliability measure such as the spectral efficiency is therefore useful to redeem the limitation in (ii). Keywords: Coverage Capacity, CDMA, Mobile Network, Network Throughput ...

  9. BMCloud: Minimizing Repair Bandwidth and Maintenance Cost in Cloud Storage

    Directory of Open Access Journals (Sweden)

    Chao Yin

    2013-01-01

    Full Text Available To protect data in cloud storage, fault tolerance and efficient recovery become very important. Recent studies have developed numerous solutions based on erasure code techniques to solve this problem using functional repairs. However, there are two limitations to address. The first one is consistency since the Encoding Matrix (EM is different among clouds. The other one is repairing bandwidth, which is a concern for most of us. We addressed these two problems from both theoretical and practical perspectives. We developed BMCloud, a new low repair bandwidth, low maintenance cost cloud storage system, which aims to reduce repair bandwidth and maintenance cost. The system employs both functional repair and exact repair while it inherits advantages from the both. We propose the JUDGE_STYLE algorithm, which can judge whether the system should adopt exact repair or functional repair. We implemented a networked storage system prototype and demonstrated our findings. Compared with existing solutions, BMCloud can be used in engineering to save repair bandwidth and degrade maintenance significantly.

  10. Regional differences in recipient waitlist time and pre- and post-transplant mortality after the 2006 United Network for Organ Sharing policy changes in the donor heart allocation algorithm.

    Science.gov (United States)

    Schulze, P Christian; Kitada, Shuichi; Clerkin, Kevin; Jin, Zhezhen; Mancini, Donna M

    2014-04-01

    This study examined the impact of the United Network for Organ Sharing (UNOS) policy changes for regional differences in waitlist time and mortality before and after heart transplantation. The 2006 UNOS thoracic organ allocation policy change was implemented to allow for greater regional sharing of organs for heart transplantation. We analyzed 36,789 patients who were listed for heart transplantation from January 1999 through April 2012. These patients were separated into 2 eras centered on the July 12, 2006 UNOS policy change. Pre- and post-transplantation characteristics were compared by UNOS regions. Waitlist mortality decreased nationally (up to 180 days: 13.3% vs. 7.9% after the UNOS policy change, p < 0.001) and within each region. Similarly, 2-year post-transplant mortality decreased nationally (2-year mortality: 17.3% vs. 14.6%; p < 0.001) as well as regionally. Waitlist time for UNOS status 1A and 1B candidates increased nationally 17.8 days on average (p < 0.001) with variability between the regions. The greatest increases were in Region 9 (59.2-day increase, p < 0.001) and Region 4 (41.2-day increase, p < 0.001). Although the use of mechanical circulatory support increased nearly 2.3-fold nationally in Era 2, significant differences were present on a regional basis. In Regions 6, 7, and 10, nearly 40% of those transplanted required left ventricular assist device bridging, whereas only 19.6%, 22.3%, and 15.5% required a left ventricular assist device in regions 3, 4, and 5, respectively. The 2006 UNOS policy change has resulted in significant regional heterogeneity with respect to waitlist time and reliance on mechanical circulatory support as a bridge to transplantation, although overall both waitlist mortality and post-transplant survival are improved. Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  11. Efficient Bandwidth Management for Ethernet Passive Optical Networks

    KAUST Repository

    Elrasad, Amr Elsayed M.

    2016-05-15

    The increasing bandwidth demands in access networks motivates network operators, networking devices manufacturers, and standardization institutions to search for new approaches for access networks. These approaches should support higher bandwidth, longer distance between end user and network operator, and less energy consumption. Ethernet Passive Optical Network (EPON) is a favorable choice for broadband access networks. EPONs support transmission rates up to 10 Gbps. EPONs also support distance between end users and central office up to 20 Km. Moreover, optical networks have the least energy consumption among all types of networks. In this dissertation, we focus on reducing delay and saving energy in EPONs. Reducing delay is essential for delay-sensitive traffic, while minimizing energy consumption is an environmental necessity and also reduces the network operating costs. We identify five challenges, namely excess bandwidth allocation, frame delineation, congestion resolution, large round trip time delay in long-reach EPONs (LR-EPONs), and energy saving. We provide a Dynamic Bandwidth Allocation (DBA) approach for each challenge. We also propose a novel scheme that combines the features of the proposed approaches in one highly performing scheme. Our approach is to design novel DBA protocols that can further reduce the delay and be simultaneously simple and fair. We also present a dynamic bandwidth allocation scheme for Green EPONs taking into consideration maximizing energy saving under target delay constraints. Regarding excess bandwidth allocation, we develop an effective DBA scheme called Delayed Excess Scheduling (DES). DES achieves significant delay and jitter reduction and is more suitable for industrial deployment due to its simplicity. Utilizing DES in hybrid TDM/WDM EPONs (TWDM-EPONs) is also investigated. We also study eliminating the wasted bandwidth due to frame delineation. We develop an interactive DBA scheme, Efficient Grant Sizing Interleaved

  12. Display Sharing: An Alternative Paradigm

    Science.gov (United States)

    Brown, Michael A.

    2010-01-01

    The current Johnson Space Center (JSC) Mission Control Center (MCC) Video Transport System (VTS) provides flight controllers and management the ability to meld raw video from various sources with telemetry to improve situational awareness. However, maintaining a separate infrastructure for video delivery and integration of video content with data adds significant complexity and cost to the system. When considering alternative architectures for a VTS, the current system's ability to share specific computer displays in their entirety to other locations, such as large projector systems, flight control rooms, and back supporting rooms throughout the facilities and centers must be incorporated into any new architecture. Internet Protocol (IP)-based systems also support video delivery and integration. IP-based systems generally have an advantage in terms of cost and maintainability. Although IP-based systems are versatile, the task of sharing a computer display from one workstation to another can be time consuming for an end-user and inconvenient to administer at a system level. The objective of this paper is to present a prototype display sharing enterprise solution. Display sharing is a system which delivers image sharing across the LAN while simultaneously managing bandwidth, supporting encryption, enabling recovery and resynchronization following a loss of signal, and, minimizing latency. Additional critical elements will include image scaling support, multi -sharing, ease of initial integration and configuration, integration with desktop window managers, collaboration tools, host and recipient controls. This goal of this paper is to summarize the various elements of an IP-based display sharing system that can be used in today's control center environment.

  13. Pushing Memory Bandwidth Limitations Through Efficient Implementations of Block-Krylov Space Solvers on GPUs

    Energy Technology Data Exchange (ETDEWEB)

    Clark, M. A. [NVIDIA Corp., Santa Clara; Strelchenko, Alexei [Fermilab; Vaquero, Alejandro [Utah U.; Wagner, Mathias [NVIDIA Corp., Santa Clara; Weinberg, Evan [Boston U.

    2017-10-26

    Lattice quantum chromodynamics simulations in nuclear physics have benefited from a tremendous number of algorithmic advances such as multigrid and eigenvector deflation. These improve the time to solution but do not alleviate the intrinsic memory-bandwidth constraints of the matrix-vector operation dominating iterative solvers. Batching this operation for multiple vectors and exploiting cache and register blocking can yield a super-linear speed up. Block-Krylov solvers can naturally take advantage of such batched matrix-vector operations, further reducing the iterations to solution by sharing the Krylov space between solves. However, practical implementations typically suffer from the quadratic scaling in the number of vector-vector operations. Using the QUDA library, we present an implementation of a block-CG solver on NVIDIA GPUs which reduces the memory-bandwidth complexity of vector-vector operations from quadratic to linear. We present results for the HISQ discretization, showing a 5x speedup compared to highly-optimized independent Krylov solves on NVIDIA's SaturnV cluster.

  14. RTD and D to increase the share of renewables in emerging and developing countries with European technologies. Policy Assessment, Stakeholders opinions, Best-practices and Recommendations

    International Nuclear Information System (INIS)

    Hanekamp, E.

    2008-11-01

    The future energy demand worldwide will increase by 45% in 2030. To be able to meet this demand, respond to the threats of Climate Change and also improve access to energy for the very poor in emerging and developing countries (especially in rural areas) renewable energy technologies play a crucial role. The European Union envisions a thriving and sustainable future economy, with world leadership in a diverse portfolio of clean, efficient and low-carbon energy technologies as a motor for prosperity and a key contributor to growth and jobs. Strengthening of the international dimension in European Technology Platforms and in Joint Technology Initiatives is a priority in the EU. The demographic trends in Europe coupled with an ambitious strategy of growth based on the Lisbon agenda provide a new context for considering international co-operation in Science and Technology. No fortress Europe, but an open Europe - building open 'win-win' S and T relations with EDCs. The RTD4EDC project is focussed on the role of research, technological development and demonstration (RTD and D) in the implementation of renewable energy technologies in Emerging and Developing Countries (EDCs). The project is executed by a consortium of four partners based in Europe (Belgium/The Netherlands), and in Emerging and Developing Countries (Paraguay, South- Africa and India). The project consisted of desk research on relevant policies and developments, interviews with policymakers, representatives from EU RE industries and development cooperation agencies, a survey amongst EU RE industry representatives and analysis of 74 cases of RE implementations in EDCs. In this report the overall results are presented. Other deliverables are three reports with background material (policies, case studies and market potential for EU RE industry) and a website (www.developingrenewables.org) containing all information as reported and with a database containing the 74 cases of RE implementations in EDCs.

  15. Plasma density profiles and finite bandwidth effects on electron heating

    International Nuclear Information System (INIS)

    Spielman, R.B.; Mizuno, K.; DeGroot, J.S.; Bollen, W.M.; Woo, W.

    1980-01-01

    Intense, p-polarized microwaves are incident on an inhomogeneous plasma in a cylindrical waveguide. Microwaves are mainly absorbed by resonant absorption near the critical surface (where the plasma frequency, ω/sub pe/, equals the microwave frequency, ω/sub o/). The localized plasma waves strongly modify the plasma density. Step-plateau density profiles or a cavity are created depending on the plasma flow speed. Hot electron production is strongly affected by the microwave bandwidth. The hot electron temperature varies as T/sub H/ is proportional to (Δ ω/ω) -0 25 . As the hot electron temperature decreases with increasing driver bandwidth, the hot electron density increases. This increase is such that the heat flux into the overdense region (Q is proportional to eta/sub H/T/sub H/ 3 2 ) is nearly constant

  16. Optical interconnect technologies for high-bandwidth ICT systems

    Science.gov (United States)

    Chujo, Norio; Takai, Toshiaki; Mizushima, Akiko; Arimoto, Hideo; Matsuoka, Yasunobu; Yamashita, Hiroki; Matsushima, Naoki

    2016-03-01

    The bandwidth of information and communication technology (ICT) systems is increasing and is predicted to reach more than 10 Tb/s. However, an electrical interconnect cannot achieve such bandwidth because of its density limits. To solve this problem, we propose two types of high-density optical fiber wiring for backplanes and circuit boards such as interface boards and switch boards. One type uses routed ribbon fiber in a circuit board because it has the ability to be formed into complex shapes to avoid interfering with the LSI and electrical components on the board. The backplane is required to exhibit high density and flexibility, so the second type uses loose fiber. We developed a 9.6-Tb/s optical interconnect demonstration system using embedded optical modules, optical backplane, and optical connector in a network apparatus chassis. We achieved 25-Gb/s transmission between FPGAs via the optical backplane.

  17. Raman scheme for adjustable-bandwidth quantum memory

    International Nuclear Information System (INIS)

    Le Goueet, J.-L.; Berman, P. R.

    2009-01-01

    We propose a scenario of quantum memory for light based on Raman scattering. The storage medium is a vapor and the different spectral components of the input pulse are stored in different atomic velocity classes. One uses appropriate pulses to reverse the resulting Doppler phase shift and to regenerate the input pulse, without distortion, in the backward direction. The different stages of the protocol are detailed and the recovery efficiency is calculated in the semiclassical picture. Since the memory bandwidth is determined by the Raman transition Doppler width, it can be adjusted by changing the angle between the input pulse wave vector and the control beams. The optical depth also depends on the beam angle. As a consequence the available optical depth can be optimized depending on the needed bandwidth. The predicted recovery efficiency is close to 100% for large optical depth.

  18. Wide bandwidth transimpedance amplifier for extremely high sensitivity continuous measurements.

    Science.gov (United States)

    Ferrari, Giorgio; Sampietro, Marco

    2007-09-01

    This article presents a wide bandwidth transimpedance amplifier based on the series of an integrator and a differentiator stage, having an additional feedback loop to discharge the standing current from the device under test (DUT) to ensure an unlimited measuring time opportunity when compared to switched discharge configurations while maintaining a large signal amplification over the full bandwidth. The amplifier shows a flat response from 0.6 Hz to 1.4 MHz, the capability to operate with leakage currents from the DUT as high as tens of nanoamperes, and rail-to-rail dynamic range for sinusoidal current signals independent of the DUT leakage current. Also available is a monitor output of the stationary current to track experimental slow drifts. The circuit is ideal for noise spectral and impedance measurements of nanodevices and biomolecules when in the presence of a physiological medium and in all cases where high sensitivity current measurements are requested such as in scanning probe microscopy systems.

  19. The Bandwidths of a Matrix. A Survey of Algorithms

    Directory of Open Access Journals (Sweden)

    Mafteiu-Scai Liviu Octavian

    2014-12-01

    Full Text Available The bandwidth, average bandwidth, envelope, profile and antibandwidth of the matrices have been the subjects of study for at least 45 years. These problems have generated considerable interest over the years because of them practical relevance in areas like: solving the system of equations, finite element methods, circuit design, hypertext layout, chemical kinetics, numerical geophysics etc. In this paper a brief description of these problems are made in terms of their definitions, followed by a comparative study of them, using both approaches: matrix geometry and graph theory. Time evolution of the corresponding algorithms as well as a short description of them are made. The work also contains concrete real applications for which a large part of presented algorithms were developed.

  20. Gain-switched all-fiber laser with narrow bandwidth

    DEFF Research Database (Denmark)

    Larsen, Casper; Giesberts, M.; Nyga, S.

    2013-01-01

    pulse energy is 20 μJ in a duration of 135 ns at 7 kHz. The bandwidth increases for a higher pump pulse energy and repetition rate, and this sets the limit of the output pulse energy. A single power amplifier is added to raise the peak power to the kW-level and the pulse energy to 230 μJ while keeping......Gain-switching of a CW fiber laser is a simple and cost-effective approach to generate pulses using an all-fiber system. We report on the construction of a narrow bandwidth (below 0.1 nm) gain-switched fiber laser and optimize the pulse energy and pulse duration under this constraint. The extracted...

  1. Passive Mobile Bandwidth Classification Using Short Lived TCP Connections

    OpenAIRE

    Michelinakis, Foivos; Kreitz, Gunnar; Petrocco, Riccardo; Zhang, Boxun; Widmer, Joerg

    2015-01-01

    Consumption of multimedia content is moving from a residential environment to mobile phones. Optimizing Quality of Experience—smooth, quick, and high quality playback—is more difficult in this setting, due to the highly dynamic nature of wireless links. A key requirement for achieving this goal is estimating the available bandwidth of mobile devices. Ideally, this should be done quickly and with low overhead. One challenge is that the majority of connections on mobiles are short-lived TCP con...

  2. Bandwidth Allocation Considering Priorities among Multimedia Components in Mobile Networks

    OpenAIRE

    Shigeki, Shiokawa; Shuji, Tasaka

    2001-01-01

    This paper proposes a bandwidth allocation scheme which improves degradation of communication quality due to handoffs in mobile multimedia networks. In general, a multimedia call consists of several component calls. For example, a video phone call consists of a voice call and a video call. In realistic environments, each component call included in one multimedia call may have different requirements for quality-of-service (QoS) from each other, and priorities among these component calls often ...

  3. Power Versus Bandwidth Efficiency in Wireless Communication: The Economic Perspective

    OpenAIRE

    Akhtman, Jos; Hanzo, Lajos

    2009-01-01

    We carry out a comprehensive analysis of a range of wireless network efficiency considerations. Firstly, we explore the properties and the implications of the power- versus bandwidth-efficiency criteria. Secondly, we perform a detailed top-down analysis of a typical commercial wireless network, which emphasizes the inherent differences between the aforementioned two efficiency metrics, while demonstrating that the appropriate choice of the network optimization criterion can have a profound ef...

  4. Developing Reliable Telemedicine Platforms with Unreliable and Limited Communication Bandwidth

    Science.gov (United States)

    2017-10-01

    AFRL-SA-WP-TR-2017-0019 Developing Reliable Telemedicine Platforms with Unreliable and Limited Communication Bandwidth Peter F...Wright-Patterson AFB, OH 45433-7913 DISTRIBUTION STATEMENT A. Approved for public release. Distribution is unlimited. STINFO COPY NOTICE AND...invention that may relate to them. Qualified requestors may obtain copies of this report from the Defense Technical Information Center (DTIC) (http

  5. Bandwidth Management in Wireless Home Networks for IPTV Solutions

    Directory of Open Access Journals (Sweden)

    Tamás Jursonovics

    2013-01-01

    Full Text Available The optimal allocation of the retransmission bandwidth is essential for IPTV service providers to ensure maximal service quality. This paper highlights the relevance of the wireless transport in today’s IPTV solution and discusses how this new media affects the existing broadcast technologies. A new Markovian channel model is developed to address the optimization issues of the retransmission throughput, and a new method is presented which is evaluated by empirical measurements followed by mathematical analysis.

  6. Bandwidth Study of the Microwave Reflectors with Rectangular Corrugations

    Science.gov (United States)

    Zhang, Liang; He, Wenlong; Donaldson, Craig R.; Cross, Adrian W.

    2016-09-01

    The mode-selective microwave reflector with periodic rectangular corrugations in the inner surface of a circular metallic waveguide is studied in this paper. The relations between the bandwidth and reflection coefficient for different numbers of corrugation sections were studied through a global optimization method. Two types of reflectors were investigated. One does not consider the phase response and the other does. Both types of broadband reflectors operating at W-band were machined and measured to verify the numerical simulations.

  7. High bandwidth second-harmonic generation in partially deuterated KDP

    International Nuclear Information System (INIS)

    Webb, M.S.; Eimerl, D.; Velsko, S.P.

    1992-01-01

    We have experimentally determined the spectrally noncritical phasematching behavior of Type I frequency doubling in KDP and its dependence on deuteration level in partially deuterated KDP. The first order wavelength sensitivity parameter∂Δk/∂γ for Type I doubling of 1.053 μm light vanishes for a KD*P crystal with a deuteration level between 10 and 14%. Very high bandwidth frequency doubling of Nd:glass lasers is possible with such a crystal

  8. BMCloud: Minimizing Repair Bandwidth and Maintenance Cost in Cloud Storage

    OpenAIRE

    Yin, Chao; Xie, Changsheng; Wan, Jiguang; Hung, Chih-Cheng; Liu, Jinjiang; Lan, Yihua

    2013-01-01

    To protect data in cloud storage, fault tolerance and efficient recovery become very important. Recent studies have developed numerous solutions based on erasure code techniques to solve this problem using functional repairs. However, there are two limitations to address. The first one is consistency since the Encoding Matrix (EM) is different among clouds. The other one is repairing bandwidth, which is a concern for most of us. We addressed these two problems from both theoretical and practi...

  9. Information partnerships--shared data, shared scale.

    Science.gov (United States)

    Konsynski, B R; McFarlan, F W

    1990-01-01

    How can one company gain access to another's resources or customers without merging ownership, management, or plotting a takeover? The answer is found in new information partnerships, enabling diverse companies to develop strategic coalitions through the sharing of data. The key to cooperation is a quantum improvement in the hardware and software supporting relational databases: new computer speeds, cheaper mass-storage devices, the proliferation of fiber-optic networks, and networking architectures. Information partnerships mean that companies can distribute the technological and financial exposure that comes with huge investments. For the customer's part, partnerships inevitably lead to greater simplification on the desktop and more common standards around which vendors have to compete. The most common types of partnership are: joint marketing partnerships, such as American Airline's award of frequent flyer miles to customers who use Citibank's credit card; intraindustry partnerships, such as the insurance value-added network service (which links insurance and casualty companies to independent agents); customer-supplier partnerships, such as Baxter Healthcare's electronic channel to hospitals for medical and other equipment; and IT vendor-driven partnerships, exemplified by ESAB (a European welding supplies and equipment company), whose expansion strategy was premised on a technology platform offered by an IT vendor. Partnerships that succeed have shared vision at the top, reciprocal skills in information technology, concrete plans for an early success, persistence in the development of usable information for all partners, coordination on business policy, and a new and imaginative business architecture.

  10. Composite GPS Patch Antenna for the AR Bandwidth Enhancement

    Directory of Open Access Journals (Sweden)

    Minkil Park

    2016-01-01

    Full Text Available A composite Global Positioning System (GPS patch antenna with a quadrature 3 dB hybrid coupler was designed and implemented for working RHCP and had a broadband axial ratio (AR bandwidth. We designed two patches as a FR-4 patch and 1.5 mm thickness thin ceramic patch with a quadrature 3 dB hybrid coupler. A CP radiation pattern was achieved, and the AR bandwidth improved by incorporating a quadrature 3 dB hybrid coupler feed structure in a micro-strip patch antenna. SMD by chip elements was applied to the quadrature 3 dB hybrid coupler. For the composite FR-4 and ceramic patch antennas, the VSWR measurement showed a 2 : 1 ratio over the entire design band, and the 3 dB AR bandwidth was 295 and 580 MHz for the FR-4 patch and ceramic patch antennas, respectively. The antenna gains for the composite FR-4 and ceramic patch antennas were measured as 1.36–2.75 and 1.47–2.71 dBi with 15.11–25.3% and 19.25–28.45% efficiency, respectively.

  11. Ultra-high bandwidth quantum secured data transmission

    Science.gov (United States)

    Dynes, James F.; Tam, Winci W.-S.; Plews, Alan; Fröhlich, Bernd; Sharpe, Andrew W.; Lucamarini, Marco; Yuan, Zhiliang; Radig, Christian; Straw, Andrew; Edwards, Tim; Shields, Andrew J.

    2016-10-01

    Quantum key distribution (QKD) provides an attractive means for securing communications in optical fibre networks. However, deployment of the technology has been hampered by the frequent need for dedicated dark fibres to segregate the very weak quantum signals from conventional traffic. Up until now the coexistence of QKD with data has been limited to bandwidths that are orders of magnitude below those commonly employed in fibre optic communication networks. Using an optimised wavelength divisional multiplexing scheme, we transport QKD and the prevalent 100 Gb/s data format in the forward direction over the same fibre for the first time. We show a full quantum encryption system operating with a bandwidth of 200 Gb/s over a 100 km fibre. Exploring the ultimate limits of the technology by experimental measurements of the Raman noise, we demonstrate it is feasible to combine QKD with 10 Tb/s of data over a 50 km link. These results suggest it will be possible to integrate QKD and other quantum photonic technologies into high bandwidth data communication infrastructures, thereby allowing their widespread deployment.

  12. Managing high-bandwidth real-time data storage

    Energy Technology Data Exchange (ETDEWEB)

    Bigelow, David D. [Los Alamos National Laboratory; Brandt, Scott A [Los Alamos National Laboratory; Bent, John M [Los Alamos National Laboratory; Chen, Hsing-Bung [Los Alamos National Laboratory

    2009-09-23

    There exist certain systems which generate real-time data at high bandwidth, but do not necessarily require the long-term retention of that data in normal conditions. In some cases, the data may not actually be useful, and in others, there may be too much data to permanently retain in long-term storage whether it is useful or not. However, certain portions of the data may be identified as being vitally important from time to time, and must therefore be retained for further analysis or permanent storage without interrupting the ongoing collection of new data. We have developed a system, Mahanaxar, intended to address this problem. It provides quality of service guarantees for incoming real-time data streams and simultaneous access to already-recorded data on a best-effort basis utilizing any spare bandwidth. It has built in mechanisms for reliability and indexing, can scale upwards to meet increasing bandwidth requirements, and handles both small and large data elements equally well. We will show that a prototype version of this system provides better performance than a flat file (traditional filesystem) based version, particularly with regard to quality of service guarantees and hard real-time requirements.

  13. Shared decision-making.

    Science.gov (United States)

    Godolphin, William

    2009-01-01

    Shared decision-making has been called the crux of patient-centred care and identified as a key part of change for improved quality and safety in healthcare. However, it rarely happens, is hard to do and is not taught - for many reasons. Talking with patients about options is not embedded in the attitudes or communication skills training of most healthcare professionals. Information tools such as patient decision aids, personal health records and the Internet will help to shift this state, as will policy that drives patient and public involvement in healthcare delivery and training.

  14. End-to-end performance of cooperative relaying in spectrum-sharing systems with quality of service requirements

    KAUST Repository

    Asghari, Vahid Reza; Aissa, Sonia

    2011-01-01

    We propose adopting a cooperative relaying technique in spectrum-sharing cognitive radio (CR) systems to more effectively and efficiently utilize available transmission resources, such as power, rate, and bandwidth, while adhering to the quality

  15. Re-use of Low Bandwidth Equipment for High Bit Rate Transmission Using Signal Slicing Technique

    DEFF Research Database (Denmark)

    Wagner, Christoph; Spolitis, S.; Vegas Olmos, Juan José

    : Massive fiber-to-the-home network deployment requires never ending equipment upgrades operating at higher bandwidth. We show effective signal slicing method, which can reuse low bandwidth opto-electronical components for optical communications at higher bit rates.......: Massive fiber-to-the-home network deployment requires never ending equipment upgrades operating at higher bandwidth. We show effective signal slicing method, which can reuse low bandwidth opto-electronical components for optical communications at higher bit rates....

  16. Energy-efficient orthogonal frequency division multiplexing-based passive optical network based on adaptive sleep-mode control and dynamic bandwidth allocation

    Science.gov (United States)

    Zhang, Chongfu; Xiao, Nengwu; Chen, Chen; Yuan, Weicheng; Qiu, Kun

    2016-02-01

    We propose an energy-efficient orthogonal frequency division multiplexing-based passive optical network (OFDM-PON) using adaptive sleep-mode control and dynamic bandwidth allocation. In this scheme, a bidirectional-centralized algorithm named the receiver and transmitter accurate sleep control and dynamic bandwidth allocation (RTASC-DBA), which has an overall bandwidth scheduling policy, is employed to enhance the energy efficiency of the OFDM-PON. The RTASC-DBA algorithm is used in an optical line terminal (OLT) to control the sleep mode of an optical network unit (ONU) sleep and guarantee the quality of service of different services of the OFDM-PON. The obtained results show that, by using the proposed scheme, the average power consumption of the ONU is reduced by ˜40% when the normalized ONU load is less than 80%, compared with the average power consumption without using the proposed scheme.

  17. Information Sharing and International Taxation

    NARCIS (Netherlands)

    Keen, M.; Ligthart, J.E.

    2004-01-01

    The sharing between national tax authorities of taxpayer-specific information has emerged over the last few years as a-probably "the"-central issue in the formation of international tax policy.Yet this refocusing of the debate on international taxation-away from parametric tax coordination and

  18. A Statistical Approach for Gain Bandwidth Prediction of Phoenix-Cell Based Reflect arrays

    Directory of Open Access Journals (Sweden)

    Hassan Salti

    2018-01-01

    Full Text Available A new statistical approach to predict the gain bandwidth of Phoenix-cell based reflectarrays is proposed. It combines the effects of both main factors that limit the bandwidth of reflectarrays: spatial phase delays and intrinsic bandwidth of radiating cells. As an illustration, the proposed approach is successfully applied to two reflectarrays based on new Phoenix cells.

  19. Data analysis-based autonomic bandwidth adjustment in software defined multi-vendor optical transport networks.

    Science.gov (United States)

    Li, Yajie; Zhao, Yongli; Zhang, Jie; Yu, Xiaosong; Jing, Ruiquan

    2017-11-27

    Network operators generally provide dedicated lightpaths for customers to meet the demand for high-quality transmission. Considering the variation of traffic load, customers usually rent peak bandwidth that exceeds the practical average traffic requirement. In this case, bandwidth provisioning is unmetered and customers have to pay according to peak bandwidth. Supposing that network operators could keep track of traffic load and allocate bandwidth dynamically, bandwidth can be provided as a metered service and customers would pay for the bandwidth that they actually use. To achieve cost-effective bandwidth provisioning, this paper proposes an autonomic bandwidth adjustment scheme based on data analysis of traffic load. The scheme is implemented in a software defined networking (SDN) controller and is demonstrated in the field trial of multi-vendor optical transport networks. The field trial shows that the proposed scheme can track traffic load and realize autonomic bandwidth adjustment. In addition, a simulation experiment is conducted to evaluate the performance of the proposed scheme. We also investigate the impact of different parameters on autonomic bandwidth adjustment. Simulation results show that the step size and adjustment period have significant influences on bandwidth savings and packet loss. A small value of step size and adjustment period can bring more benefits by tracking traffic variation with high accuracy. For network operators, the scheme can serve as technical support of realizing bandwidth as metered service in the future.

  20. Bandwidth allocation for video under quality of service constraints

    CERN Document Server

    Anjum, Bushra

    2014-01-01

    We present queueing-based algorithms to calculate the bandwidth required for a video stream so that the three main Quality of Service constraints, i.e., end-to-end delay, jitter and packet loss, are ensured. Conversational and streaming video-based applications are becoming a major part of the everyday Internet usage. The quality of these applications (QoS), as experienced by the user, depends on three main metrics of the underlying network, namely, end-to-end delay, jitter and packet loss. These metrics are, in turn, directly related to the capacity of the links that the video traffic trave

  1. Adaptive slope compensation for high bandwidth digital current mode controller

    DEFF Research Database (Denmark)

    Taeed, Fazel; Nymand, Morten

    2015-01-01

    An adaptive slope compensation method for digital current mode control of dc-dc converters is proposed in this paper. The compensation slope is used for stabilizing the inner current loop in peak current mode control. In this method, the compensation slope is adapted with the variations...... in converter duty cycle. The adaptive slope compensation provides optimum controller operation in term of bandwidth over wide range of operating points. In this paper operation principle of the controller is discussed. The proposed controller is implemented in an FPGA to control a 100 W buck converter...

  2. OPTIM, Minimization of Band-Width of Finite Elements Problems

    International Nuclear Information System (INIS)

    Huart, M.

    1977-01-01

    1 - Nature of the physical problem solved: To minimize the band-width of finite element problems. 2 - Method of solution: A surface is constructed from the x-y-coordinates of each node using its node number as z-value. This surface consists of triangles. Nodes are renumbered in such a way as to minimize the surface area. 3 - Restrictions on the complexity of the problem: This program is applicable to 2-D problems. It is dimensioned for a maximum of 1000 elements

  3. Low Bandwidth Vocoding using EM Sensor and Acoustic Signal Processing

    International Nuclear Information System (INIS)

    Ng, L C; Holzrichter, J F; Larson, P E

    2001-01-01

    Low-power EM radar-like sensors have made it possible to measure properties of the human speech production system in real-time, without acoustic interference [1]. By combining these data with the corresponding acoustic signal, we've demonstrated an almost 10-fold bandwidth reduction in speech compression, compared to a standard 2.4 kbps LPC10 protocol used in the STU-III (Secure Terminal Unit, third generation) telephone. This paper describes a potential EM sensor/acoustic based vocoder implementation

  4. Modulator reliability and bandwidth improvement: replacing tetrodes with MOSFETs

    International Nuclear Information System (INIS)

    Donaldson, A.R.

    1982-01-01

    Three types of power MOS field effect transistors were studied with the intent of replacing a parallel pair of vacuum tube tetrodes in a linear modulator. The tetrodes have the shortest lifetimes of any other tubes in the system. The FETs offer definite performance advantages when compared to bipolar transistors and definite cost advantages when compared to vacuum tubes. Replacement of the tetrodes does however require careful consideration of voltage, current and to a lesser extent bandwidth capability in order to enhance overall modulator reliability without compromising present performance

  5. Implementasi Manajemen Bandwidth Dengan Disiplin Antrian Hierarchical Token Bucket (HTB Pada Sistem Operasi Linux

    Directory of Open Access Journals (Sweden)

    Muhammad Nugraha

    2016-09-01

    Full Text Available Important Problem on Internet networking is exhausted resource and bandwidth by some user while other user did not get service properly. To overcome that problem we need to implement traffic control and bandwidth management system in router. In this research author want to implement Hierarchical Token Bucket algorithm as queue discipline (qdisc to get bandwidth management accurately in order the user can get bandwidth properly. The result of this research is form the management bandwidth cheaply and efficiently by using Hierarchical Token Bucket qdisc on Linux operating system were able to manage the user as we want.

  6. IMPLEMENTASI MANAJEMEN BANDWIDTH DENGAN DISIPLIN ANTRIAN HIERARCHICAL TOKEN BUCKET (HTB PADA SISTEM OPERASI LINUX

    Directory of Open Access Journals (Sweden)

    Muhammad Nugraha

    2017-01-01

    Full Text Available Important Problem on Internet networking is exhausted resource and bandwidth by some user while other user did not get service properly. To overcome that problem we need to implement traffic control and bandwidth management system in router. In this research author want to implement Hierarchical Token Bucket algorithm as queue discipline (qdisc to get bandwidth management accurately in order the user can get bandwidth properly. The result of this research is form the management bandwidth cheaply and efficiently by using Hierarchical Token Bucket qdisc on Linux operating system were able to manage the user as we want.

  7. Shared decision making

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/patientinstructions/000877.htm Shared decision making To use the sharing features on this page, ... treatment you both support. When to use Shared Decision Making Shared decision making is often used when you ...

  8. BECSI: Bandwidth Efficient Certificate Status Information Distribution Mechanism for VANETs

    Directory of Open Access Journals (Sweden)

    Carlos Gañán

    2013-01-01

    Full Text Available Certificate revocation is a challenging task, especiallyin mobile network environments such as vehicular ad Hoc networks (VANETs.According to the IEEE 1609.2 security standard for VANETs, public keyinfrastructure (PKI will provide this functionality by means of certificate revocation lists (CRLs.When a certificate authority (CAneeds to revoke a certificate, itglobally distributes CRLs.Transmitting these lists pose a problem as they require high update frequencies and a lot of bandwidth. In this article, we propose BECSI, aBandwidth Efficient Certificate Status Informationmechanism to efficiently distributecertificate status information (CSI in VANETs.By means of Merkle hash trees (MHT, BECSI allowsto retrieve authenticated CSI not onlyfrom the infrastructure but also from vehicles actingas mobile repositories.Since these MHTs are significantly smaller than the CRLs, BECSIreduces the load on the CSI repositories and improves the response time for the vehicles.Additionally, BECSI improves the freshness of the CSIby combining the use of delta-CRLs with MHTs.Thus, vehicles that have cached the most current CRLcan download delta-CRLs to have a complete list of revoked certificates.Once a vehicle has the whole list of revoked certificates, it can act as mobile repository.

  9. Improving microwave antenna gain and bandwidth with phase compensation metasurface

    Directory of Open Access Journals (Sweden)

    Ke Chen

    2015-06-01

    Full Text Available Metasurface, as a planar version of artificial metamaterial, provide an effective way to manipulate electromagnetic wave propagation. Here, we present a transparent metasurface for compensating the out-of-phase radiation from a microstrip patch antenna to improve its radiation gain and bandwidth. Based on the equivalence principle of Huygens’ surface, we propose metasurface composed of both inductive and capacitive resonant elements which could produce high transmission with variable phase characteristics. Such metasurface mounted on a patch antenna can transform the spherical-like phase profile generated from the patch into an in-phase planar one. A prototype antenna has been fabricated and validated the squeezed radiation pattern with suppressed sidelobes as well as enhanced impedance bandwidth due to strong near-field coupling. As operating at around 5.7 GHz, the proposed antenna may have potential application in wireless communication systems especially for point-to-point data transmission. It is believed that the design methodology could also be scaled to other frequency bands such as millimeter or terahertz wave.

  10. Bandwidth Extension of Telephone Speech Aided by Data Embedding

    Directory of Open Access Journals (Sweden)

    Sagi Ariel

    2007-01-01

    Full Text Available A system for bandwidth extension of telephone speech, aided by data embedding, is presented. The proposed system uses the transmitted analog narrowband speech signal as a carrier of the side information needed to carry out the bandwidth extension. The upper band of the wideband speech is reconstructed at the receiving end from two components: a synthetic wideband excitation signal, generated from the narrowband telephone speech and a wideband spectral envelope, parametrically represented and transmitted as embedded data in the telephone speech. We propose a novel data embedding scheme, in which the scalar Costa scheme is combined with an auditory masking model allowing high rate transparent embedding, while maintaining a low bit error rate. The signal is transformed to the frequency domain via the discrete Hartley transform (DHT and is partitioned into subbands. Data is embedded in an adaptively chosen subset of subbands by modifying the DHT coefficients. In our simulations, high quality wideband speech was obtained from speech transmitted over a telephone line (characterized by spectral magnitude distortion, dispersion, and noise, in which side information data is transparently embedded at the rate of 600 information bits/second and with a bit error rate of approximately . In a listening test, the reconstructed wideband speech was preferred (at different degrees over conventional telephone speech in of the test utterances.

  11. Bandwidth Extension of Telephone Speech Aided by Data Embedding

    Directory of Open Access Journals (Sweden)

    David Malah

    2007-01-01

    Full Text Available A system for bandwidth extension of telephone speech, aided by data embedding, is presented. The proposed system uses the transmitted analog narrowband speech signal as a carrier of the side information needed to carry out the bandwidth extension. The upper band of the wideband speech is reconstructed at the receiving end from two components: a synthetic wideband excitation signal, generated from the narrowband telephone speech and a wideband spectral envelope, parametrically represented and transmitted as embedded data in the telephone speech. We propose a novel data embedding scheme, in which the scalar Costa scheme is combined with an auditory masking model allowing high rate transparent embedding, while maintaining a low bit error rate. The signal is transformed to the frequency domain via the discrete Hartley transform (DHT and is partitioned into subbands. Data is embedded in an adaptively chosen subset of subbands by modifying the DHT coefficients. In our simulations, high quality wideband speech was obtained from speech transmitted over a telephone line (characterized by spectral magnitude distortion, dispersion, and noise, in which side information data is transparently embedded at the rate of 600 information bits/second and with a bit error rate of approximately 3⋅10−4. In a listening test, the reconstructed wideband speech was preferred (at different degrees over conventional telephone speech in 92.5% of the test utterances.

  12. Bandwidth Optimization in Centralized WLANs for Different Traffic Types

    Directory of Open Access Journals (Sweden)

    Haines RJ

    2007-01-01

    Full Text Available Allocating bandwidth between different forms of coexisting traffic (such as web-browsing, streaming, and telephony within a wireless LAN is a challenging and interesting problem. Centralized coordination functions in wireless LANs offer several advantages over distributed approaches, having the benefit of a system overview at the controller, but obtaining a stable configuration of bandwidth allocation for the system is nontrivial. We present, review, and compare different mechanisms to achieve this end, and a number of different means of obtaining the configurations themselves. We describe an analytical model of the system under consideration and present two mathematical approaches to derive solutions for any system configuration and deployment, along with an adaptive feedback-based solution. We also describe a comprehensive simulation-based model for the problem, and a prototype that allows comparison of these approaches. Our investigations demonstrate that a self-adaptive dynamic approach far outperforms any static scheme, and that using a mathematical model to produce the configurations themselves confers several advantages.

  13. Ionospheric Coherence Bandwidth Measurements in the Lower VHF Frequency Range

    Science.gov (United States)

    Suszcynsky, D. M.; Light, M. E.; Pigue, M. J.

    2015-12-01

    The United States Department of Energy's Radio Frequency Propagation (RFProp) experiment consists of a satellite-based radio receiver suite to study various aspects of trans-ionospheric signal propagation and detection in four frequency bands, 2 - 55 MHz, 125 - 175 MHz, 365 - 415 MHz and 820 - 1100 MHz. In this paper, we present simultaneous ionospheric coherence bandwidth and S4 scintillation index measurements in the 32 - 44 MHz frequency range collected during the ESCINT equatorial scintillation experiment. 40-MHz continuous wave (CW) and 32 - 44 MHz swept frequency signals were transmitted simultaneously to the RFProp receiver suite from the Reagan Test Site at Kwajalein Atoll in the Marshall Islands (8.7° N, 167.7° E) in three separate campaigns during the 2014 and 2015 equinoxes. Results show coherence bandwidths as small as ~ 1 kHz for strong scintillation (S4 > 0.7) and indicate a high degree of ionospheric variability and irregularity on 10-m spatial scales. Spread-Doppler clutter effects arising from preferential ray paths to the satellite due to refraction off of isolated density irregularities are also observed and are dominant at low elevation angles. The results are compared to previous measurements and available scaling laws.

  14. A wide-bandwidth and high-sensitivity robust microgyroscope

    International Nuclear Information System (INIS)

    Sahin, Korhan; Sahin, Emre; Akin, Tayfun; Alper, Said Emre

    2009-01-01

    This paper reports a microgyroscope design concept with the help of a 2 degrees of freedom (DoF) sense mode to achieve a wide bandwidth without sacrificing mechanical and electronic sensitivity and to obtain robust operation against variations under ambient conditions. The design concept is demonstrated with a tuning fork microgyroscope fabricated with an in-house silicon-on-glass micromachining process. When the fabricated gyroscope is operated with a relatively wide bandwidth of 1 kHz, measurements show a relatively high raw mechanical sensitivity of 131 µV (° s −1 ) −1 . The variation in the amplified mechanical sensitivity (scale factor) of the gyroscope is measured to be less than 0.38% for large ambient pressure variations such as from 40 to 500 mTorr. The bias instability and angle random walk of the gyroscope are measured to be 131° h −1 and 1.15° h −1/2 , respectively

  15. 75 FR 9246 - Cooperative Share Loan Insurance

    Science.gov (United States)

    2010-03-01

    ... DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT [Docket No. FR-5376-N-14] Cooperative Share Loan... comments on the subject proposal. New guidance for cooperative housing loan insurance will be published to update existing policies, and better enable mortgagees to submit cooperative share loans for FHA...

  16. High Bandwidth Optical Links for Micro-Satellite Support

    Science.gov (United States)

    Chao, Tien-Hsin (Inventor); Wilson, Keith E. (Inventor); Coste, Keith (Inventor)

    2016-01-01

    A method, systems, apparatus and device enable high bandwidth satellite communications. An onboard tracking detector, installed in a low-earth orbit satellite, detects a position of an incoming optical beam received/transmitted from a first ground station of one or more ground stations. Tracker electronics determine orientation information of the incoming optical beam based on the position. Control electronics receive the orientation information from the tracker electronics, and control a waveguide drive electronics. The waveguide drive electronics control a voltage that is provided to an electro-optic waveguide beam steering device. The electro-optic waveguide beam steering device steers an outgoing optical beam to one of the one or more ground stations based on the voltage.

  17. Bandwidth Efficient Hybrid Synchronization for Wireless Sensor Network

    DEFF Research Database (Denmark)

    Dnyaneshwar, Mantri; Prasad, Neeli R.; Prasad, Ramjee

    2015-01-01

    Data collection and transmission are the fundamental operations of Wireless Sensor Networks (WSNs). A key challenge in effective data collection and transmission is to schedule and synchronize the activities of the nodes with the global clock. This paper proposes the Bandwidth Efficient Hybrid...... in the network and then perform the pair-wise synchronization. With the mobility of node, the structure frequently changes causing an increase in energy consumption. To mitigate the problem BESDA aggregate data with the notion of a global timescale throughout the network and schedule based time-division multiple...... accesses (TDMA) techniques as MAC layer protocol. It reduces the collision of packets. Simulation results show that BESDA is energy efficient, with increased throughput, and has less delay as compared with state-of-the-art....

  18. Ultrawide Bandwidth Receiver Based on a Multivariate Generalized Gaussian Distribution

    KAUST Repository

    Ahmed, Qasim Zeeshan

    2015-04-01

    Multivariate generalized Gaussian density (MGGD) is used to approximate the multiple access interference (MAI) and additive white Gaussian noise in pulse-based ultrawide bandwidth (UWB) system. The MGGD probability density function (pdf) is shown to be a better approximation of a UWB system as compared to multivariate Gaussian, multivariate Laplacian and multivariate Gaussian-Laplacian mixture (GLM). The similarity between the simulated and the approximated pdf is measured with the help of modified Kullback-Leibler distance (KLD). It is also shown that MGGD has the smallest KLD as compared to Gaussian, Laplacian and GLM densities. A receiver based on the principles of minimum bit error rate is designed for the MGGD pdf. As the requirement is stringent, the adaptive implementation of the receiver is also carried out in this paper. Training sequence of the desired user is the only requirement when implementing the detector adaptively. © 2002-2012 IEEE.

  19. Graphene metascreen for designing compact infrared absorbers with enhanced bandwidth

    KAUST Repository

    Chen, Pai-Yen; Farhat, Mohamed; Bagci, Hakan

    2015-01-01

    We propose a compact, wideband terahertz and infrared absorber, comprising a patterned graphene sheet on a thin metal-backed dielectric slab. This graphene-based nanostructure can achieve a low or negative effective permeability, necessary for realizing the perfect absorption. The dual-reactive property found in both the plasmonic graphene sheet and the grounded highpermittivity slab introduces extra poles into the equivalent circuit model of the system, thereby resulting in a dual-band or broadband magnetic resonance that enhances the absorption bandwidth. More interestingly, the two-dimensional patterned graphene sheet significantly simplifies the design and fabrication processes for achieving resonant magnetic response, and allows the frequency-reconfigurable operation via electrostatic gating.

  20. A Hybrid ACO Approach to the Matrix Bandwidth Minimization Problem

    Science.gov (United States)

    Pintea, Camelia-M.; Crişan, Gloria-Cerasela; Chira, Camelia

    The evolution of the human society raises more and more difficult endeavors. For some of the real-life problems, the computing time-restriction enhances their complexity. The Matrix Bandwidth Minimization Problem (MBMP) seeks for a simultaneous permutation of the rows and the columns of a square matrix in order to keep its nonzero entries close to the main diagonal. The MBMP is a highly investigated {NP}-complete problem, as it has broad applications in industry, logistics, artificial intelligence or information recovery. This paper describes a new attempt to use the Ant Colony Optimization framework in tackling MBMP. The introduced model is based on the hybridization of the Ant Colony System technique with new local search mechanisms. Computational experiments confirm a good performance of the proposed algorithm for the considered set of MBMP instances.

  1. Narrow bandwidth detection of vibration signature using fiber lasers

    Science.gov (United States)

    Moore, Sean; Soh, Daniel B.S.

    2018-05-08

    The various technologies presented herein relate to extracting a portion of each pulse in a series of pulses reflected from a target to facilitate determination of a Doppler-shifted frequency for each pulse and, subsequently, a vibration frequency for the series of pulses. Each pulse can have a square-wave configuration, whereby each pulse can be time-gated to facilitate discarding the leading edge and the trailing edge (and associated non-linear effects) of each pulse and accordingly, capture of the central portion of the pulse from which the Doppler-shifted frequency, and ultimately, the vibration frequency of the target can be determined. Determination of the vibration velocity facilitates identification of the target being in a state of motion. The plurality of pulses can be formed from a laser beam (e.g., a continuous wave), the laser beam having a narrow bandwidth.

  2. Graphene metascreen for designing compact infrared absorbers with enhanced bandwidth

    KAUST Repository

    Chen, Pai-Yen

    2015-03-31

    We propose a compact, wideband terahertz and infrared absorber, comprising a patterned graphene sheet on a thin metal-backed dielectric slab. This graphene-based nanostructure can achieve a low or negative effective permeability, necessary for realizing the perfect absorption. The dual-reactive property found in both the plasmonic graphene sheet and the grounded highpermittivity slab introduces extra poles into the equivalent circuit model of the system, thereby resulting in a dual-band or broadband magnetic resonance that enhances the absorption bandwidth. More interestingly, the two-dimensional patterned graphene sheet significantly simplifies the design and fabrication processes for achieving resonant magnetic response, and allows the frequency-reconfigurable operation via electrostatic gating.

  3. Auction-based bandwidth allocation in the Internet

    Science.gov (United States)

    Wei, Jiaolong; Zhang, Chi

    2002-07-01

    It has been widely accepted that auctioning which is the pricing approach with minimal information requirement is a proper tool to manage scare network resources. Previous works focus on Vickrey auction which is incentive compatible in classic auction theory. In the beginning of this paper, the faults of the most representative auction-based mechanisms are discussed. And then a new method called uniform-price auction (UPA), which has the simplest auction rule is proposed and it's incentive compatibility in the network environment is also proved. Finally, the basic mode is extended to support applications which require minimum bandwidth guarantees for a given time period by introducing derivative market, and a market mechanism for network resource allocation which is predictable, riskless, and simple for end-users is completed.

  4. Wide modulation bandwidth terahertz detection in 130 nm CMOS technology

    Science.gov (United States)

    Nahar, Shamsun; Shafee, Marwah; Blin, Stéphane; Pénarier, Annick; Nouvel, Philippe; Coquillat, Dominique; Safwa, Amr M. E.; Knap, Wojciech; Hella, Mona M.

    2016-11-01

    Design, manufacturing and measurements results for silicon plasma wave transistors based wireless communication wideband receivers operating at 300 GHz carrier frequency are presented. We show the possibility of Si-CMOS based integrated circuits, in which by: (i) specific physics based plasma wave transistor design allowing impedance matching to the antenna and the amplifier, (ii) engineering the shape of the patch antenna through a stacked resonator approach and (iii) applying bandwidth enhancement strategies to the design of integrated broadband amplifier, we achieve an integrated circuit of the 300 GHz carrier frequency receiver for wireless wideband operation up to/over 10 GHz. This is, to the best of our knowledge, the first demonstration of low cost 130 nm Si-CMOS technology, plasma wave transistors based fast/wideband integrated receiver operating at 300 GHz atmospheric window. These results pave the way towards future large scale (cost effective) silicon technology based terahertz wireless communication receivers.

  5. Deep neural network-based bandwidth enhancement of photoacoustic data.

    Science.gov (United States)

    Gutta, Sreedevi; Kadimesetty, Venkata Suryanarayana; Kalva, Sandeep Kumar; Pramanik, Manojit; Ganapathy, Sriram; Yalavarthy, Phaneendra K

    2017-11-01

    Photoacoustic (PA) signals collected at the boundary of tissue are always band-limited. A deep neural network was proposed to enhance the bandwidth (BW) of the detected PA signal, thereby improving the quantitative accuracy of the reconstructed PA images. A least square-based deconvolution method that utilizes the Tikhonov regularization framework was used for comparison with the proposed network. The proposed method was evaluated using both numerical and experimental data. The results indicate that the proposed method was capable of enhancing the BW of the detected PA signal, which inturn improves the contrast recovery and quality of reconstructed PA images without adding any significant computational burden. (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

  6. Development of high frequency and wide bandwidth Johnson noise thermometry

    International Nuclear Information System (INIS)

    Crossno, Jesse; Liu, Xiaomeng; Kim, Philip; Ohki, Thomas A.; Fong, Kin Chung

    2015-01-01

    We develop a high frequency, wide bandwidth radiometer operating at room temperature, which augments the traditional technique of Johnson noise thermometry for nanoscale thermal transport studies. Employing low noise amplifiers and an analog multiplier operating at 2 GHz, auto- and cross-correlated Johnson noise measurements are performed in the temperature range of 3 to 300 K, achieving a sensitivity of 5.5 mK (110 ppm) in 1 s of integration time. This setup allows us to measure the thermal conductance of a boron nitride encapsulated monolayer graphene device over a wide temperature range. Our data show a high power law (T ∼ 4) deviation from the Wiedemann-Franz law above T ∼ 100 K

  7. Bandwidth Reservation Using Velocity and Handoff Statistics for Cellular Networks

    Institute of Scientific and Technical Information of China (English)

    Chuan-Lin Zhang; Kam Yiu Lam; Wei-Jia Jia

    2006-01-01

    The percentages of blocking and forced termination rates as parameters representing quality of services (QoS)requirements are presented. The relation between the connection statistics of mobile users in a cell and the handoff number and new call number in next duration in each cell is explored. Based on the relation, statistic reservation tactics are raised.The amount of bandwidth for new calls and handoffs of each cell in next period is determined by using the strategy. Using this method can guarantee the communication system suits mobile connection request dynamic. The QoS parameters:forced termination rate and blocking rate can be maintained steadily though they may change with the offered load. Some numerical experiments demonstrate this is a practical method with affordable overhead.

  8. Fibre Bragg grating based accelerometer with extended bandwidth

    International Nuclear Information System (INIS)

    Basumallick, Nandini; Biswas, Palas; Dasgupta, Kamal; Bandyopadhyay, Somnath; Chakraborty, Rajib; Chakraborty, Sushanta

    2016-01-01

    We have shown experimentally that the operable bandwidth of a fibre Bragg grating (FBG) based accelerometer can be extended significantly, without compromising its sensitivity, using a post-signal processing technique which involves frequency domain weighting. It has been demonstrated that using the above technique acceleration can be correctly interpreted even when the operating frequency encroaches on the region where the frequency response of the sensor is non-uniform. Two different excitation signals, which we often encounter in structural health monitoring applications, e.g. (i) a signal composed of multi-frequency components and (ii) a sinusoidal excitation with a frequency sweep, have been considered in our experiment. The results obtained have been compared with a piezo accelerometer. (paper)

  9. Coarse-Grain Bandwidth Estimation Scheme for Large-Scale Network

    Science.gov (United States)

    Cheung, Kar-Ming; Jennings, Esther H.; Sergui, John S.

    2013-01-01

    A large-scale network that supports a large number of users can have an aggregate data rate of hundreds of Mbps at any time. High-fidelity simulation of a large-scale network might be too complicated and memory-intensive for typical commercial-off-the-shelf (COTS) tools. Unlike a large commercial wide-area-network (WAN) that shares diverse network resources among diverse users and has a complex topology that requires routing mechanism and flow control, the ground communication links of a space network operate under the assumption of a guaranteed dedicated bandwidth allocation between specific sparse endpoints in a star-like topology. This work solved the network design problem of estimating the bandwidths of a ground network architecture option that offer different service classes to meet the latency requirements of different user data types. In this work, a top-down analysis and simulation approach was created to size the bandwidths of a store-and-forward network for a given network topology, a mission traffic scenario, and a set of data types with different latency requirements. These techniques were used to estimate the WAN bandwidths of the ground links for different architecture options of the proposed Integrated Space Communication and Navigation (SCaN) Network. A new analytical approach, called the "leveling scheme," was developed to model the store-and-forward mechanism of the network data flow. The term "leveling" refers to the spreading of data across a longer time horizon without violating the corresponding latency requirement of the data type. Two versions of the leveling scheme were developed: 1. A straightforward version that simply spreads the data of each data type across the time horizon and doesn't take into account the interactions among data types within a pass, or between data types across overlapping passes at a network node, and is inherently sub-optimal. 2. Two-state Markov leveling scheme that takes into account the second order behavior of

  10. Global games with noisy sharing of information

    KAUST Repository

    Touri, Behrouz

    2014-12-15

    We provide a framework for the study of global games with noisy sharing of information. In contrast to the previous works where it is shown that an intuitive threshold policy is an equilibrium for such games, we show that noisy sharing of information leads to non-existence of such an equilibrium. We also investigate the group best-response dynamics of two groups of agents sharing the same information to threshold policies based on each group\\'s observation and show the convergence of such dynamics.

  11. Global games with noisy sharing of information

    KAUST Repository

    Touri, Behrouz; Shamma, Jeff S.

    2014-01-01

    We provide a framework for the study of global games with noisy sharing of information. In contrast to the previous works where it is shown that an intuitive threshold policy is an equilibrium for such games, we show that noisy sharing of information leads to non-existence of such an equilibrium. We also investigate the group best-response dynamics of two groups of agents sharing the same information to threshold policies based on each group's observation and show the convergence of such dynamics.

  12. Dynamic Bandwidth Allocation with Effective Utilization of Polling Interval over WDM/TDM PON

    Science.gov (United States)

    Ni, Cuiping; Gan, Chaoqin; Gao, Ziyue

    2014-12-01

    WDM/TDM (wavelength-division multiplexing/time-division multiplexing) PON (passive optical network) appears to be an attractive solution for the next generation optical access networks. Dynamic bandwidth allocation (DBA) plays a crucial role in efficiently and fairly allocating the bandwidth among all users in WDM/TDM PON. In this paper, two dynamic bandwidth allocation schemes (DBA1 and DBA2) are proposed to eliminate the idle time of polling cycles (i.e. polling interval), improve bandwidth utilization and make full use of bandwidth resources. The two DBA schemes adjust the time slot of sending request information and make fair scheduling among users to achieve the effective utilization of polling interval in WDM/TDM PON. The simulation and theoretical analyses verify that the proposed schemes outperform the conventional DBA scheme. We also make comparisons between the two schemes in terms of bandwidth utilization and average packet delay to further demonstrate the effectiveness of the scheme of DBA2.

  13. Manajemen Bandwidth Simple Queue dan Queue Tree pada PT. Endorsindo Makmur Selaras

    OpenAIRE

    Budiman, Arif

    2015-01-01

      The purpose of this study is to analyze and optimize the bandwidth management at PT. Endorsindo Makmur Selaras, with the expectation that the distribution of bandwidth can be evenly distributed to each employee so that the employee can improve performance and quality of the company. Research methods used include analysis methods (survey and interview system that runs directly on the user) and to optimize bandwidth management method to configure the proxy using the Queue Tree. The re...

  14. A distributed authentication and authorization scheme for in-network big data sharing

    Directory of Open Access Journals (Sweden)

    Ruidong Li

    2017-11-01

    Full Text Available Big data has a strong demand for a network infrastructure with the capability to support data sharing and retrieval efficiently. Information-centric networking (ICN is an emerging approach to satisfy this demand, where big data is cached ubiquitously in the network and retrieved using data names. However, existing authentication and authorization schemes rely mostly on centralized servers to provide certification and mediation services for data retrieval. This causes considerable traffic overhead for the secure distributed sharing of data. To solve this problem, we employ identity-based cryptography (IBC to propose a Distributed Authentication and Authorization Scheme (DAAS, where an identity-based signature (IBS is used to achieve distributed verifications of the identities of publishers and users. Moreover, Ciphertext-Policy Attribute-based encryption (CP-ABE is used to enable the distributed and fine-grained authorization. DAAS consists of three phases: initialization, secure data publication, and secure data retrieval, which seamlessly integrate authentication and authorization with the interest/data communication paradigm in ICN. In particular, we propose trustworthy registration and Network Operator and Authority Manifest (NOAM dissemination to provide initial secure registration and enable efficient authentication for global data retrieval. Meanwhile, Attribute Manifest (AM distribution coupled with automatic attribute update is proposed to reduce the cost of attribute retrieval. We examine the performance of the proposed DAAS, which shows that it can achieve a lower bandwidth cost than existing schemes.

  15. Bandwidth tunable microwave photonic filter based on digital and analog modulation

    Science.gov (United States)

    Zhang, Qi; Zhang, Jie; Li, Qiang; Wang, Yubing; Sun, Xian; Dong, Wei; Zhang, Xindong

    2018-05-01

    A bandwidth tunable microwave photonic filter based on digital and analog modulation is proposed and experimentally demonstrated. The digital modulation is used to broaden the effective gain spectrum and the analog modulation is to get optical lines. By changing the symbol rate of data pattern, the bandwidth is tunable from 50 MHz to 700 MHz. The interval of optical lines is set according to the bandwidth of gain spectrum which is related to the symbol rate. Several times of bandwidth increase are achieved compared to a single analog modulation and the selectivity of the response is increased by 3.7 dB compared to a single digital modulation.

  16. The Prediction of Bandwidth On Need Computer Network Through Artificial Neural Network Method of Backpropagation

    Directory of Open Access Journals (Sweden)

    Ikhthison Mekongga

    2014-02-01

    Full Text Available The need for bandwidth has been increasing recently. This is because the development of internet infrastructure is also increasing so that we need an economic and efficient provider system. This can be achieved through good planning and a proper system. The prediction of the bandwidth consumption is one of the factors that support the planning for an efficient internet service provider system. Bandwidth consumption is predicted using ANN. ANN is an information processing system which has similar characteristics as the biologic al neural network.  ANN  is  chosen  to  predict  the  consumption  of  the  bandwidth  because  ANN  has  good  approachability  to  non-linearity.  The variable used in ANN is the historical load data. A bandwidth consumption information system was built using neural networks  with a backpropagation algorithm to make the use of bandwidth more efficient in the future both in the rental rate of the bandwidth and in the usage of the bandwidth.Keywords: Forecasting, Bandwidth, Backpropagation

  17. Bandwidth-narrowed Bragg gratings inscribed in double-cladding fiber by femtosecond laser.

    Science.gov (United States)

    Shi, Jiawei; Li, Yuhua; Liu, Shuhui; Wang, Haiyan; Liu, Ningliang; Lu, Peixiang

    2011-01-31

    Bragg gratings with the bandwidth(FWHM) narrowed up to 79 pm were inscribed in double-cladding fiber with femtosecond radiation and a phase mask followed by an annealing treatment. With the annealing temperature below a critical value, the bandwidth of Bragg gratings induced by Type I-IR and Type II-IR index change was narrowed without the reduction of reflectivity. The bandwidth narrowing is due to the profile transformation of the refractive index modulation caused by the annealing treatment. This mechanism was verified by comparing bandwidth narrowing processes of FBGs written with different power densities.

  18. Bandwidth Reduction via Localized Peer-to-Peer (P2P Video

    Directory of Open Access Journals (Sweden)

    Ken Kerpez

    2010-01-01

    Full Text Available This paper presents recent research into P2P distribution of video that can be highly localized, preferably sharing content among users on the same access network and Central Office (CO. Models of video demand and localized P2P serving areas are presented. Detailed simulations of passive optical networks (PON are run, and these generate statistics of P2P video localization. Next-Generation PON (NG-PON is shown to fully enable P2P video localization, but the lower rates of Gigabit-PON (GPON restrict performance. Results here show that nearly all of the traffic volume of unicast video could be delivered via localized P2P. Strong growth in video delivery via localized P2P could lower overall future aggregation and core network bandwidth of IP video traffic by 58.2%, and total consumer Internet traffic by 43.5%. This assumes aggressive adoption of technologies and business practices that enable highly localized P2P video.

  19. Virtual laboratory strategies for data sharing, communications and development

    Directory of Open Access Journals (Sweden)

    Enrique Canessa

    2006-01-01

    Full Text Available We present an overview of the VL approach to promote research and education in developing countries and to help reduce the technology gap of the digital divide. We discuss software tools for instrument control, data sharing and e-collaboration and communications with special attention to low-bandwidth networks. We analyse the tentative costs involved in VL and the skills needed for VL administration. We conclude by identifying some VL strategies for development.

  20. High-bandwidth piezoresistive force probes with integrated thermal actuation

    International Nuclear Information System (INIS)

    Doll, Joseph C; Pruitt, Beth L

    2012-01-01

    We present high-speed force probes with on-chip actuation and sensing for the measurement of pN-scale forces at the microsecond timescale. We achieve a high resonant frequency in water (1–100 kHz) with requisite low spring constants (0.3–40 pN nm −1 ) and low integrated force noise (1–100 pN) by targeting probe dimensions on the order of 300 nm thick, 1–2 μm wide and 30–200 μm long. Forces are measured using silicon piezoresistors, while the probes are actuated thermally with an aluminum unimorph and silicon heater. The piezoresistive sensors are designed using the open-source numerical optimization code that incorporates constraints on operating temperature. Parylene passivation enables operation in ionic media and we demonstrate simultaneous actuation and sensing. The improved design and fabrication techniques that we describe enable a 10–20-fold improvement in force resolution or measurement bandwidth over prior piezoresistive cantilevers of comparable thickness. (paper)

  1. High bandwidth piezoresistive force probes with integrated thermal actuation

    Science.gov (United States)

    Doll, Joseph C.; Pruitt, Beth L.

    2012-01-01

    We present high-speed force probes with on-chip actuation and sensing for the measurement of pN-scale forces at the microsecond time scale. We achieve a high resonant frequency in water (1–100 kHz) with requisite low spring constants (0.3–40 pN/nm) and low integrated force noise (1–100 pN) by targeting probe dimensions on the order of 300 nm thick, 1–2 μm wide and 30–200 μm long. Forces are measured using silicon piezoresistors while the probes are actuated thermally with an aluminum unimorph and silicon heater. The piezoresistive sensors are designed using open source numerical optimization code that incorporates constraints on operating temperature. Parylene passivation enables operation in ionic media and we demonstrate simultaneous actuation and sensing. The improved design and fabrication techniques that we describe enable a 10–20 fold improvement in force resolution or measurement bandwidth over prior piezoresistive cantilevers of comparable thickness. PMID:23175616

  2. Finite bandwidth, nonlinear convective flow in a mushy layer

    Energy Technology Data Exchange (ETDEWEB)

    Riahi, D N, E-mail: daniel.riahi@utrgv.edu [School of Mathematical and Statistical Sciences, University of Texas Rio Grande Valley, One West University Boulevard, Brownsville, TX 78520 (United States)

    2017-04-15

    Finite amplitude convection with a continuous finite bandwidth of modes in a horizontal mushy layer during the solidification of binary alloys is investigated. We analyze the nonlinear convection for values of the Rayleigh number close to its critical value by using multiple scales and perturbation techniques. Applying a combined temporal and spatial evolution approach, we determine a set of three coupled differential equations for the amplitude functions of the convective modes. A large number of new subcritical or supercritical stable solutions to these equations in the form of steady rolls and hexagons with different horizontal length scales are detected. We find, in particular, that depending on the parameter values and on the magnitude and direction of the wave number vectors for the amplitude functions, hexagons with down-flow or up-flow at the cells’ centers or rolls can be stable. Rolls or hexagons with longer horizontal wave length can be stable at higher amplitudes, and there are cases where hexagons are unstable for any value of the Rayleigh number, while rolls are stable only for the values of the Rayleigh number beyond some value. We also detected new stable and irregular flow patterns with two different horizontal scales in the form of superposition of either two sets of hexagons or two sets of inclined rolls. (paper)

  3. Review of single transient oscillographic recorders with gigahertz bandwidth

    International Nuclear Information System (INIS)

    Campbell, D.E.

    1982-01-01

    In laser driven inertial confinement fusion research, at Livermore, we are diagnosing many phenomena that occur in a time frame that exceeds the capabilities of even the most advanced, present day oscillographic recording instruments. Many of the by-products of the interaction between the laser beam and fuel pellet are monitored to determine the specifics of the fusion process. By the use of appropriate detectors, we convert the information contained in the radiated by-products to electrical signals which are recorded on high bandwidth oscillographic recorders. Our present range of recording capabilities for one x-ray diagnostic measurement in use at Livermore is shown. A commonly used configuration consists of an XRD-31 x-ray detector connected to a direct access Tektronix R7912 transient digitizer using 1/2 in. diameter air dielectric coaxial cable. This configuration gives a system fwhm of approximately 335 ps. Our premier configuration, on the other hand, consists of an improved response detector and a French Thomson-CSF TSN-660 oscilloscope with a shorter length of coaxial cable (typically 20 feet). The system fwhm in this case is less than 120 ps which is our fastest oscillographic recording system at the present time

  4. Bandwidth-Enhanced Low-Profile Antenna with Parasitic Patches

    Directory of Open Access Journals (Sweden)

    Son Xuat Ta

    2017-01-01

    Full Text Available This paper presents low-profile broadband antennas, which are composed of four parasitic patches placed between planar radiators and a perfect electric conductor ground plane. Two types of planar radiators, a conventional dipole and a crossed dipole, are employed to produce linearly polarized (LP and circularly polarized (CP radiations, respectively. The radiator and parasitic patches are realized on thin substrates to lower the cost. Owing to the presence of parasitic patches, the antenna performance improves in terms of profile reduction, resonant frequency decrease, and bandwidth enhancement. These improvements are discussed and confirmed computationally and experimentally. The LP design with the overall dimensions of 120 mm × 120 mm × 16.3 mm (0.64λ0 × 0.64λ0 × 0.087λ0 at 1.6 GHz has a |S11|  96%. The CP design, which has the same physical size as the LP case, has a |S11|  90%.

  5. A high control bandwidth design method for aalborg inverter under weak grid condition

    DEFF Research Database (Denmark)

    Wu, Weimin; Zhou, Cong; Wang, Houqin

    2017-01-01

    Aalborg Inverter is a kind of high efficient Buck-Boost inverter. Since it may work in “Buck-Boost” mode, the control bandwidth should be high enough to ensure a good performance under any grid condition. However, during the “Boost” operation, the control bandwidth depends much on the grid...

  6. A Hybrid OFDM-TDM Architecture with Decentralized Dynamic Bandwidth Allocation for PONs

    Directory of Open Access Journals (Sweden)

    Taner Cevik

    2013-01-01

    Full Text Available One of the major challenges of passive optical networks is to achieve a fair arbitration mechanism that will prevent possible collisions from occurring at the upstream channel when multiple users attempt to access the common fiber at the same time. Therefore, in this study we mainly focus on fair bandwidth allocation among users, and present a hybrid Orthogonal Frequency Division Multiplexed/Time Division Multiplexed architecture with a dynamic bandwidth allocation scheme that provides satisfying service qualities to the users depending on their varying bandwidth requirements. Unnecessary delays in centralized schemes occurring during bandwidth assignment stage are eliminated by utilizing a decentralized approach. Instead of sending bandwidth demands to the optical line terminal (OLT which is the only competent authority, each optical network unit (ONU runs the same bandwidth demand determination algorithm. ONUs inform each other via signaling channel about the status of their queues. This information is fed to the bandwidth determination algorithm which is run by each ONU in a distributed manner. Furthermore, Light Load Penalty, which is a phenomenon in optical communications, is mitigated by limiting the amount of bandwidth that an ONU can demand.

  7. High-Q Variable Bandwidth Passive Filters for Software Defined Radio

    NARCIS (Netherlands)

    Arkesteijn, V.J.; Klumperink, Eric A.M.; Nauta, Bram

    2001-01-01

    An important aspect of Software Defined Radio is the ability to define the bandwidth of the filter that selects the desired channel. This paper describes a technique for channel filtering, in which two passive filters are combined to obtain a variable bandwidth. Passive filters have the advantage of

  8. High-Q variable bandwidth passive filters for Software Defined Radio

    NARCIS (Netherlands)

    Arkesteijn, V.J.; Klumperink, Eric A.M.; Nauta, Bram

    An important aspect of Software Defined Radio is the ability to define the bandwidth of the filter that selects the desired channel. This paper describes a technique for channel filtering, in which two passive filters are combined to obtain a variable bandwidth. Passive filters have the advantage of

  9. Bandwidth limitations in current mode and voltage mode integrated feedback amplifiers

    DEFF Research Database (Denmark)

    Bruun, Erik

    1995-01-01

    loop bandwidth remains constant for a feedback amplifier. The constant-bandwidth relations of such amplifier designs are reviewed in this paper and they are combined with the constraints imposed by technology when the feedback amplifier is to be designed in an integrated technology. From this analysis...

  10. Improvement of the bandwidth of the transient digitizers in the LIDAR Thomson scattering diagnostic on JET

    International Nuclear Information System (INIS)

    Kristensen, E.

    1990-06-01

    The main limitation on the spatial resolution of the LIDAR Thomson scattering diagnostic on the JET tokamak is due to the narrow bandwidth of the detection system. The transient digitizers, Tektronik 7912AD, are the main contributors to the narrow bandwidth. It is shown how the digitizers can be modified to improve the response time from approx. 480 to 410 ps. (author)

  11. A Hybrid OFDM-TDM Architecture with Decentralized Dynamic Bandwidth Allocation for PONs

    Science.gov (United States)

    Cevik, Taner

    2013-01-01

    One of the major challenges of passive optical networks is to achieve a fair arbitration mechanism that will prevent possible collisions from occurring at the upstream channel when multiple users attempt to access the common fiber at the same time. Therefore, in this study we mainly focus on fair bandwidth allocation among users, and present a hybrid Orthogonal Frequency Division Multiplexed/Time Division Multiplexed architecture with a dynamic bandwidth allocation scheme that provides satisfying service qualities to the users depending on their varying bandwidth requirements. Unnecessary delays in centralized schemes occurring during bandwidth assignment stage are eliminated by utilizing a decentralized approach. Instead of sending bandwidth demands to the optical line terminal (OLT) which is the only competent authority, each optical network unit (ONU) runs the same bandwidth demand determination algorithm. ONUs inform each other via signaling channel about the status of their queues. This information is fed to the bandwidth determination algorithm which is run by each ONU in a distributed manner. Furthermore, Light Load Penalty, which is a phenomenon in optical communications, is mitigated by limiting the amount of bandwidth that an ONU can demand. PMID:24194684

  12. 48 CFR 48.104-3 - Sharing collateral savings.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Sharing collateral savings... CONTRACT MANAGEMENT VALUE ENGINEERING Policies and Procedures 48.104-3 Sharing collateral savings. (a) The Government shares collateral savings with the contractor, unless the head of the contracting activity has...

  13. Design and fabrication of bandwidth tunable HTS transmit filter using {pi}-shaped waveguides

    Energy Technology Data Exchange (ETDEWEB)

    Sekiya, N., E-mail: nsekiya@yamanashi.ac.j [Department of Electrical Engineering, Yamanashi University, Nakagawa-Sekiya Laboratory, 4-3-11 Takeda, Kofu 400-8511 (Japan); Harada, H.; Nakagawa, Y. [Department of Electrical Engineering, Yamanashi University, Nakagawa-Sekiya Laboratory, 4-3-11 Takeda, Kofu 400-8511 (Japan); Ono, S.; Ohshima, S. [Yamagata University, 4-3-16 Johnan, Yonezawa 992-8510 (Japan)

    2010-11-01

    We have developed a method for tuning the bandwidth of a high-temperature superconducting (HTS) microstrip filter. Several {pi}-shaped waveguides are placed between the resonators, and the bandwidth is tuned in discrete steps by changing the switch states of the waveguides, which changes the coupling coefficient between the resonators. The filter contains 3-pole half-wavelength straight-line resonators and two {pi}-shaped waveguides for bandwidth tuning. It also has several electrical pads distributed around the feed lines for trimming after tuning. The filter was fabricated by depositing YBa{sub 2}Cu{sub 3}O{sub 7} thin film on an MgO substrate and has a measured center frequency of 5.17 GHz and bandwidth of 220 MHz. Use of the {pi}-shaped waveguides to adjust the coupling coefficients and the electrical pads to adjust the external quality factors resulted in 80-MHz bandwidth tuning without increased insertion loss.

  14. An Application-Level QoS Control Method Based on Local Bandwidth Scheduling

    Directory of Open Access Journals (Sweden)

    Yong Wang

    2018-01-01

    Full Text Available Quality of service (QoS is an important performance indicator for Web applications and bandwidth is a key factor affecting QoS. Current methods use network protocols or ports to schedule bandwidth, which require tedious manual configurations or modifications of the underlying network. Some applications use dynamic ports and the traditional port-based bandwidth control methods cannot deal with them. A new QoS control method based on local bandwidth scheduling is proposed, which can schedule bandwidth at application level in a user-transparent way and it does not require tedious manual configurations. Experimental results indicate that the new method can effectively improve the QoS for applications, and it can be easily integrated into current Web applications without the need to modify the underlying network.

  15. Governing EU employment policy

    DEFF Research Database (Denmark)

    Sørensen, Eva; Triantafillou, Peter; Damgaard, Bodil

    2015-01-01

    In the European Union (EU), employment policy is a prerogative of the member states. Therefore the EU's ability to govern in this area depends on its capability to involve national governments and relevant stakeholders in a collaborative effort to formulate and implement shared policy objectives....... of collaboration, the implementation phase mainly consists in the less demanding forms of cooperation and coordination....

  16. Knee implant imaging at 3 Tesla using high-bandwidth radiofrequency pulses.

    Science.gov (United States)

    Bachschmidt, Theresa J; Sutter, Reto; Jakob, Peter M; Pfirrmann, Christian W A; Nittka, Mathias

    2015-06-01

    To investigate the impact of high-bandwidth radiofrequency (RF) pulses used in turbo spin echo (TSE) sequences or combined with slice encoding for metal artifact correction (SEMAC) on artifact reduction at 3 Tesla in the knee in the presence of metal. Local transmit/receive coils feature increased maximum B1 amplitude, reduced SAR exposition and thus enable the application of high-bandwidth RF pulses. Susceptibility-induced through-plane distortion scales inversely with the RF bandwidth and the view angle, hence blurring, increases for higher RF bandwidths, when SEMAC is used. These effects were assessed for a phantom containing a total knee arthroplasty. TSE and SEMAC sequences with conventional and high RF bandwidths and different contrasts were tested on eight patients with different types of implants. To realize scan times of 7 to 9 min, SEMAC was always applied with eight slice-encoding steps and distortion was rated by two radiologists. A local transmit/receive knee coil enables the use of an RF bandwidth of 4 kHz compared with 850 Hz in conventional sequences. Phantom scans confirm the relation of RF bandwidth and through-plane distortion, which can be reduced up to 79%, and demonstrate the increased blurring for high-bandwidth RF pulses. In average, artifacts in this RF mode are rated hardly visible for patients with joint arthroplasties, when eight SEMAC slice-encoding steps are applied, and for patients with titanium fixtures, when TSE is used. The application of high-bandwidth RF pulses by local transmit coils substantially reduces through-plane distortion artifacts at 3 Tesla. © 2014 Wiley Periodicals, Inc.

  17. Rethinking the Sharing Economy

    DEFF Research Database (Denmark)

    Kornberger, Martin; Leixnering, Stephan; Meyer, Renate

    2017-01-01

    Our paper focuses on a non-standard sharing example that harbors the potential to disrupt received wisdom on the sharing economy. While originally entering the field to analyze, broadly from a governance perspective, how the 2015 refugee crisis was handled in Vienna, Austria, we found that the no...... of sharing: economic and moral. Our paper contributes to this Special Issue of the Academy of Management Discoveries by highlighting and explaining the two-fold economic and moral nature of sharing and the organization of sharing between movement and platform....... sharing of resources (i.e., the economic dimension): the sharing of a distinct concern (i.e., the moral dimension of sharing). Our discovery exemplifies such a moral dimension that is rather different from the status quo materialistic treatments focusing on economic transactions and property rights...

  18. Job Sharing in Education.

    Science.gov (United States)

    Davidson, Wilma; Kline, Susan

    1979-01-01

    The author presents the advantages of job sharing for all school personnel, saying that education is particularly adaptable to this new form of employment. Current job sharing programs in Massachusetts, California, and New Jersey schools are briefly discussed. (SJL)

  19. Production sharing agreements

    International Nuclear Information System (INIS)

    1994-01-01

    This paper, which was presented at the Production Sharing Agreement seminar, discusses economic rent, negotiations, trends in fiscal system development, and concessionary systems. Production sharing contracts, risk service contracts, joint ventures and the global market are examined. (UK)

  20. Improvement of multiprocessing performance by using optical centralized shared bus

    Science.gov (United States)

    Han, Xuliang; Chen, Ray T.

    2004-06-01

    With the ever-increasing need to solve larger and more complex problems, multiprocessing is attracting more and more research efforts. One of the challenges facing the multiprocessor designers is to fulfill in an effective manner the communications among the processes running in parallel on multiple multiprocessors. The conventional electrical backplane bus provides narrow bandwidth as restricted by the physical limitations of electrical interconnects. In the electrical domain, in order to operate at high frequency, the backplane topology has been changed from the simple shared bus to the complicated switched medium. However, the switched medium is an indirect network. It cannot support multicast/broadcast as effectively as the shared bus. Besides the additional latency of going through the intermediate switching nodes, signal routing introduces substantial delay and considerable system complexity. Alternatively, optics has been well known for its interconnect capability. Therefore, it has become imperative to investigate how to improve multiprocessing performance by utilizing optical interconnects. From the implementation standpoint, the existing optical technologies still cannot fulfill the intelligent functions that a switch fabric should provide as effectively as their electronic counterparts. Thus, an innovative optical technology that can provide sufficient bandwidth capacity, while at the same time, retaining the essential merits of the shared bus topology, is highly desirable for the multiprocessing performance improvement. In this paper, the optical centralized shared bus is proposed for use in the multiprocessing systems. This novel optical interconnect architecture not only utilizes the beneficial characteristics of optics, but also retains the desirable properties of the shared bus topology. Meanwhile, from the architecture standpoint, it fits well in the centralized shared-memory multiprocessing scheme. Therefore, a smooth migration with substantial

  1. Bandwidth Study on Energy Use and Potential Energy Savings Opportunities in U.S. Petroleum Refining

    Energy Technology Data Exchange (ETDEWEB)

    Sabine Brueske, Caroline Kramer, Aaron Fisher

    2015-06-01

    Energy bandwidth studies of U.S. manufacturing sectors can serve as foundational references in framing the range (or bandwidth) of potential energy savings opportunities. This bandwidth study examines energy consumption and potential energy savings opportunities in U.S. petroleum refining. The study relies on multiple sources to estimate the energy used in nine individual process areas, representing 68% of sector-wide energy consumption. Energy savings opportunities for individual processes are based on technologies currently in use or under development; these potential savings are then extrapolated to estimate sector-wide energy savings opportunity.

  2. Bandwidth Study on Energy Use and Potential Energy Saving Opportunities in U.S. Chemical Manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Sabine Brueske, Caroline Kramer, Aaron Fisher

    2015-06-01

    Energy bandwidth studies of U.S. manufacturing sectors can serve as foundational references in framing the range (or bandwidth) of potential energy savings opportunities. This bandwidth study examines energy consumption and potential energy savings opportunities in U.S. chemical manufacturing. The study relies on multiple sources to estimate the energy used in the production of 74 individual chemicals, representing 57% of sector-wide energy consumption. Energy savings opportunities for individual chemicals and for 15 subsectors of chemicals manufacturing are based on technologies currently in use or under development; these potential savings are then extrapolated to estimate sector-wide energy savings opportunity.

  3. Optimization of Quantum-Dot Molecular Beam Epitaxy for Broad Spectral Bandwidth Devices

    KAUST Repository

    Majid, Mohammed Abdul

    2012-12-01

    The optimization of the key growth parameters for broad spectral bandwidth devices based on quantum dots is reported. A combination of atomic force microscopy, photoluminescence of test samples, and optoelectronic characterization of superluminescent diodes (SLDs) is used to optimize the growth conditions to obtain high-quality devices with large spectral bandwidth, radiative efficiency (due to a reduced defective-dot density), and thus output power. The defective-dot density is highlighted as being responsible for the degradation of device performance. An SLD device with 160 nm of bandwidth centered at 1230 nm is demonstrated.

  4. Optimization of Quantum-Dot Molecular Beam Epitaxy for Broad Spectral Bandwidth Devices

    KAUST Repository

    Majid, Mohammed Abdul; Hugues, M.; Vézian, S.; Childs, D. T. D.; Hogg, R. A.

    2012-01-01

    The optimization of the key growth parameters for broad spectral bandwidth devices based on quantum dots is reported. A combination of atomic force microscopy, photoluminescence of test samples, and optoelectronic characterization of superluminescent diodes (SLDs) is used to optimize the growth conditions to obtain high-quality devices with large spectral bandwidth, radiative efficiency (due to a reduced defective-dot density), and thus output power. The defective-dot density is highlighted as being responsible for the degradation of device performance. An SLD device with 160 nm of bandwidth centered at 1230 nm is demonstrated.

  5. Acousto-optics bandwidth broadening in a Bragg cell based on arbitrary synthesized signal methods.

    Science.gov (United States)

    Peled, Itay; Kaminsky, Ron; Kotler, Zvi

    2015-06-01

    In this work, we present the advantages of driving a multichannel acousto-optical deflector (AOD) with a digitally synthesized multifrequency RF signal. We demonstrate a significant bandwidth broadening of ∼40% by providing well-tuned phase control of the array transducers. Moreover, using a multifrequency, complex signal, we manage to suppress the harmonic deflections and return most of the spurious energy to the main beam. This method allows us to operate the AOD with more than an octave of bandwidth with negligible spurious energy going to the harmonic beams and a total bandwidth broadening of over 70%.

  6. Job Sharing in Geography.

    Science.gov (United States)

    Kay, Jeanne

    1982-01-01

    Job sharing is an employment alternative in which two qualified individuals manage the responsibilities of a single position. Discusses the barriers to and the potential, advantages, disadvantages, pitfalls, and challenges of job sharing. Focuses on job sharing in the geography profession. (Author/JN)

  7. The Sharing Economy

    OpenAIRE

    Reinhold, Stephan; Dolnicar, Sara

    2017-01-01

    Peer-to-peer accommodation networks in general, and Airbnb in specific, are frequently referred to as part of the sharing economy. This chapter provides an overview of key characteristics of the sharing economy, discusses how these characteristics relate to peer-to-peer accommodation, and positions peer-to-peer accommodation networks within the sharing economy.

  8. Satisfaction and 'comparison sharing'

    DEFF Research Database (Denmark)

    Amilon, Anna

    2009-01-01

    the probability of satisfaction. Results show that comparison sharing impacts satisfaction for women, and that those women who share more equally than their peers are more likely to be satisfied, whereas comparison sharing has no influence on satisfaction for men. Also, parents are less likely to be satisfied...

  9. Sharing family and household:

    DEFF Research Database (Denmark)

    Winther, Ida Wentzel

    Keynote: Family relationships are normatively assumed to be characterized by ‘sharing’, such as living together in the same home, occupying the same place, sharing stuff, blood and biology, spending special and ordinary time together, and consequently creating shared biographical experiences....... In that way, families are thrown into togetherness. At the same time, we see families in varying forms where 'sharing' is lived and contested differently. In Denmark, many children live in nuclear families, and many live in different variations of more than one household. For those who share household...... and family, 'sharing' will be a basic condition. No matter what, they should share life circumstances, more stories, more places and spaces, more households families with both kin and non-kin. This keynote addresses the particular of children’s experiences of living apart and/or living together in sharing...

  10. Analysis of blocking probability for OFDM-based variable bandwidth optical network

    Science.gov (United States)

    Gong, Lei; Zhang, Jie; Zhao, Yongli; Lin, Xuefeng; Wu, Yuyao; Gu, Wanyi

    2011-12-01

    Orthogonal Frequency Division Multiplexing (OFDM) has recently been proposed as a modulation technique. For optical networks, because of its good spectral efficiency, flexibility, and tolerance to impairments, optical OFDM is much more flexible compared to traditional WDM systems, enabling elastic bandwidth transmissions, and optical networking is the future trend of development. In OFDM-based optical network the research of blocking rate has very important significance for network assessment. Current research for WDM network is basically based on a fixed bandwidth, in order to accommodate the future business and the fast-changing development of optical network, our study is based on variable bandwidth OFDM-based optical networks. We apply the mathematical analysis and theoretical derivation, based on the existing theory and algorithms, research blocking probability of the variable bandwidth of optical network, and then we will build a model for blocking probability.

  11. Spatial bandwidth enlargement and field enhancement of shear horizontal waves in finite graded piezoelectric layered media

    KAUST Repository

    Xu, Yanlong

    2015-01-01

    structure and transmission in this paper show that the graded layered media possess very large band gaps. Harmonic wave simulation by finite element method (FEM) confirms that the reason of bandwidth enlargement is that waves within the band gap ranges

  12. Making Better Use of Bandwidth: Data Compression and Network Management Technologies

    National Research Council Canada - National Science Library

    Pane, John F; Joe, Leland

    2005-01-01

    .... Furthermore, future demands seem likely to increase. Researchers from RAND Arroyo Center have been seeking ways in which the Army might use bandwidth better, specifically how new compression technologies might help improve information throughput...

  13. Bandwidth Controllable Tunable Filter for Hyper-/Multi-Spectral Imager, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR Phase I proposal introduces a fast speed bandwidth controllable tunable filter for hyper-/multi-spectral (HS/MS) imagers. It dynamically passes a variable...

  14. Towards Bandwidth Scalable Transceiver Technology for Optical Metro-Access Networks

    DEFF Research Database (Denmark)

    Spolitis, Sandis; Bobrovs, Vjaceslavs; Wagner, Christoph

    2015-01-01

    sliceable transceiver for 1 Gbit/s non-return to zero (NRZ) signal sliced into two slices is presented. Digital signal processing (DSP) power consumption and latency values for proposed sliceable transceiver technique are also discussed. In this research post FEC with 7% overhead error free transmission has......Massive fiber-to-the-home network deployment is creating a challenge for telecommunications network operators: exponential increase of the power consumption at the central offices and a never ending quest for equipment upgrades operating at higher bandwidth. In this paper, we report on flexible...... signal slicing technique, which allows transmission of high-bandwidth signals via low bandwidth electrical and optoelectrical equipment. The presented signal slicing technique is highly scalable in terms of bandwidth which is determined by the number of slices used. In this paper performance of scalable...

  15. Estimating individual listeners’ auditory-filter bandwidth in simultaneous and non-simultaneous masking

    DEFF Research Database (Denmark)

    Buchholz, Jörg; Caminade, Sabine; Strelcyk, Olaf

    2010-01-01

    Frequency selectivity in the human auditory system is often measured using simultaneous masking of tones presented in notched noise. Based on such masking data, the equivalent rectangular bandwidth (ERB) of the auditory filters can be derived by applying the power spectrum model of masking....... Considering bandwidth estimates from previous studies based on forward masking, only average data across a number of subjects have been considered. The present study is concerned with bandwidth estimates in simultaneous and forward masking in individual normal-hearing subjects. In order to investigate...... the reliability of the individual estimates, a statistical resampling method is applied. It is demonstrated that a rather large set of experimental data is required to reliably estimate auditory filter bandwidth, particularly in the case of simultaneous masking. The poor overall reliability of the filter...

  16. Afrika Statistika ISSN 2316-090X Uniform in Bandwidth Law of the ...

    African Journals Online (AJOL)

    simple mathematical correction to remove the boundary bias. More recently .... 2) The uniformity in h allows us to apply various bandwidth selection rules such as plug-in, ...... Journal of Statistical Planning and Inference, 46 (2), 195-214.

  17. Terahertz bandwidth photonic Hilbert transformers based on synthesized planar Bragg grating fabrication.

    Science.gov (United States)

    Sima, Chaotan; Gates, J C; Holmes, C; Mennea, P L; Zervas, M N; Smith, P G R

    2013-09-01

    Terahertz bandwidth photonic Hilbert transformers are proposed and experimentally demonstrated. The integrated device is fabricated via a direct UV grating writing technique in a silica-on-silicon platform. The photonic Hilbert transformer operates at bandwidths of up to 2 THz (~16 nm) in the telecom band, a 10-fold greater bandwidth than any previously reported experimental approaches. Achieving this performance requires detailed knowledge of the system transfer function of the direct UV grating writing technique; this allows improved linearity and yields terahertz bandwidth Bragg gratings with improved spectral quality. By incorporating a flat-top reflector and Hilbert grating with a waveguide coupler, an ultrawideband all-optical single-sideband filter is demonstrated.

  18. Ultra-low Noise, High Bandwidth, 1550nm HgCdTe APD, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — To meet the demands of future high-capacity free space optical communications links, a high bandwidth, near infrared (NIR), single photon sensitive optoelectronic...

  19. Kernel bandwidth estimation for non-parametric density estimation: a comparative study

    CSIR Research Space (South Africa)

    Van der Walt, CM

    2013-12-01

    Full Text Available We investigate the performance of conventional bandwidth estimators for non-parametric kernel density estimation on a number of representative pattern-recognition tasks, to gain a better understanding of the behaviour of these estimators in high...

  20. A 750MHz and a 8GHz High Bandwidth Digital FFT Spectrometer, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The scope of this project is to to develop a wide bandwidth, low power, and compact single board digital Fast Fourier Transform spectrometer (FFTS) optimized for the...

  1. An official American Thoracic Society/International Society for Heart and Lung Transplantation/Society of Critical Care Medicine/Association of Organ and Procurement Organizations/United Network of Organ Sharing Statement: ethical and policy considerations in organ donation after circulatory determination of death.

    Science.gov (United States)

    Gries, Cynthia J; White, Douglas B; Truog, Robert D; Dubois, James; Cosio, Carmen C; Dhanani, Sonny; Chan, Kevin M; Corris, Paul; Dark, John; Fulda, Gerald; Glazier, Alexandra K; Higgins, Robert; Love, Robert; Mason, David P; Nakagawa, Thomas A; Shapiro, Ron; Shemie, Sam; Tracy, Mary Fran; Travaline, John M; Valapour, Maryam; West, Lori; Zaas, David; Halpern, Scott D

    2013-07-01

    Donation after circulatory determination of death (DCDD) has the potential to increase the number of organs available for transplantation. Because consent and management of potential donors must occur before death, DCDD raises unique ethical and policy issues. To develop an ethics and health policy statement on adult and pediatric DCDD relevant to critical care and transplantation stakeholders. A multidisciplinary panel of stakeholders was convened to develop an ethics and health policy statement. The panel consisted of representatives from the American Thoracic Society, Society of Critical Care Medicine, International Society for Heart and Lung Transplantation, Association of Organ Procurement Organizations, and the United Network of Organ Sharing. The panel reviewed the literature, discussed important ethics and health policy considerations, and developed a guiding framework for decision making by stakeholders. A framework to guide ethics and health policy statement was established, which addressed the consent process, pre- and post mortem interventions, the determination of death, provisions of end-of-life care, and pediatric DCDD. The information presented in this Statement is based on the current evidence, experience, and clinical rationale. New clinical research and the development and dissemination of new technologies will eventually necessitate an update of this Statement.

  2. Achieving increased bandwidth for 4 degree of freedom self-tuning energy harvester

    Science.gov (United States)

    Staaf, L. G. H.; Smith, A. D.; Köhler, E.; Lundgren, P.; Folkow, P. D.; Enoksson, P.

    2018-04-01

    The frequency response of a self-tuning energy harvester composed of two piezoelectric cantilevers connected by a middle beam with a sliding mass is investigated. Measurements show that incorporation of a free-sliding mass increases the bandwidth. Using an analytical model, the system is explained through close investigation of the resonance modes. Resonance mode behavior further suggests that, by breaking the symmetry of the system, even broader bandwidths are achievable.

  3. A MAP blind image deconvolution algorithm with bandwidth over-constrained

    Science.gov (United States)

    Ren, Zhilei; Liu, Jin; Liang, Yonghui; He, Yulong

    2018-03-01

    We demonstrate a maximum a posteriori (MAP) blind image deconvolution algorithm with bandwidth over-constrained and total variation (TV) regularization to recover a clear image from the AO corrected images. The point spread functions (PSFs) are estimated by bandwidth limited less than the cutoff frequency of the optical system. Our algorithm performs well in avoiding noise magnification. The performance is demonstrated on simulated data.

  4. High modulation bandwidth of a light-emitting diode with surface plasmon coupling (Conference Presentation)

    Science.gov (United States)

    Lin, Chun-Han; Tu, Charng-Gan; Yao, Yu-Feng; Chen, Sheng-Hung; Su, Chia-Ying; Chen, Hao-Tsung; Kiang, Yean-Woei; Yang, Chih-Chung

    2017-02-01

    Besides lighting, LEDs can be used for indoor data transmission. Therefore, a large modulation bandwidth becomes an important target in the development of visible LED. In this regard, enhancing the radiative recombination rate of carriers in the quantum wells of an LED is a useful method since the modulation bandwidth of an LED is related to the carrier decay rate besides the device RC time constant To increase the carrier decay rate in an LED without sacrificing its output power, the technique of surface plasmon (SP) coupling in an LED is useful. In this paper, the increases of modulation bandwidth by reducing mesa size, decreasing active layer thickness, and inducing SP coupling in blue- and green-emitting LEDs are illustrated. The results are demonstrated by comparing three different LED surface structures, including bare p-type surface, GaZnO current spreading layer, and Ag nanoparticles (NPs) for inducing SP coupling. In a single-quantum-well, blue-emitting LED with a circular mesa of 10 microns in radius, SP coupling results in a modulation bandwidth of 528.8 MHz, which is believed to be the record-high level. A smaller RC time constant can lead to a higher modulation bandwidth. However, when the RC time constant is smaller than 0.2 ns, its effect on modulation bandwidth saturates. The dependencies of modulation bandwidth on injected current density and carrier decay time confirm that the modulation bandwidth is essentially inversely proportional to a time constant, which is inversely proportional to the square-root of carrier decay rate and injected current density.

  5. Can abnormal returns be earned on bandwidth-bounded currencies? Evidence from a genetic algorithm

    OpenAIRE

    Pedro Godinho

    2012-01-01

    Most of the studies about the Foreign Exchange market (Forex) analyse the behaviour of currencies that are allowed to float freely (or almost freely), but some currencies are still bounded by bandwidths (either disclosed or undisclosed). In this paper, I try to find out whether two bandwidth-bounded currencies, the Hong Kong dollar (HKD) and the Singapore dollar (SGD), present opportunities for abnormal returns. I consider a set of trading rules, and I use a genetic algorithm to optimise both...

  6. Tuning gain and bandwidth of traveling wave tubes using metamaterial beam-wave interaction structures

    International Nuclear Information System (INIS)

    Lipton, Robert; Polizzi, Anthony

    2014-01-01

    We employ metamaterial beam-wave interaction structures for tuning the gain and bandwidth of short traveling wave tubes. The interaction structures are made from metal rings of uniform cross section, which are periodically deployed along the length of the traveling wave tube. The aspect ratio of the ring cross sections is adjusted to control both gain and bandwidth. The frequency of operation is controlled by the filling fraction of the ring cross section with respect to the size of the period cell.

  7. Photon Sieve Bandwidth Broadening by Reduction of Chromatic Aberration Effects Using Second-Stage Diffractive Optics

    Science.gov (United States)

    2015-03-26

    to copyright protection in the United States. AFIT-ENP-MS-15-M-086 PHOTON SIEVE BANDWIDTH BROADENING BY REDUCTION OF CHROMATIC ABERRATION...RELEASE; DISTRIBUTION UNLIMITED. AFIT-ENP-MS-15-M-086 PHOTON SIEVE BANDWIDTH BROADENING BY REDUCTION OF CHROMATIC ABERRATION EFFECTS USING...A photon sieve is a lightweight diffractive optic which can be useful for space- based imaging applications. It is limited by chromatic

  8. THz Tube Waveguides With Low Loss, Low Dispersion, and High Bandwidth

    DEFF Research Database (Denmark)

    Bao, Hualong; Nielsen, Kristian; Bang, Ole

    2014-01-01

    We propose, model and experimentally characterize a novel class of terahertz hollow-core tube waveguides with high-loss cladding material, resulting in propagation with low loss, low dispersion, and high useful bandwidth.......We propose, model and experimentally characterize a novel class of terahertz hollow-core tube waveguides with high-loss cladding material, resulting in propagation with low loss, low dispersion, and high useful bandwidth....

  9. Coarse-grain bandwidth estimation techniques for large-scale network

    Science.gov (United States)

    Cheung, Kar-Ming; Jennings, E.

    In this paper, we describe a top-down analysis and simulation approach to size the bandwidths of a store-and-forward network for a given network topology, a mission traffic scenario, and a set of data types with different latency requirements. We use these techniques to estimate the wide area network (WAN) bandwidths of the ground links for different architecture options of the proposed Integrated Space Communication and Navigation (SCaN) Network.

  10. Coarse-Grain Bandwidth Estimation Techniques for Large-Scale Space Network

    Science.gov (United States)

    Cheung, Kar-Ming; Jennings, Esther

    2013-01-01

    In this paper, we describe a top-down analysis and simulation approach to size the bandwidths of a store-andforward network for a given network topology, a mission traffic scenario, and a set of data types with different latency requirements. We use these techniques to estimate the wide area network (WAN) bandwidths of the ground links for different architecture options of the proposed Integrated Space Communication and Navigation (SCaN) Network.

  11. Hybrid Online Labs: Making Remote Laboratories Usable Under Unfavorable Bandwidth Conditions

    OpenAIRE

    Kayode Peter Ayodele; Lawrence O. Kehinde; Olusola A. Komolafe

    2012-01-01

    One of few limitations of remote laboratory technology is the fact that access and usability of such laboratories depend largely on the existence of favorable bandwidth conditions between the remote user and the system under test. This dependence is regrettable because some of the institutions likely to find remote laboratories attractive are also those most likely to have severe bandwidth limitations. Also, a typical remote laboratory will be completely unusable to remote students in the eve...

  12. MPTCP Tunnel: An Architecture for Aggregating Bandwidth of Heterogeneous Access Networks

    Directory of Open Access Journals (Sweden)

    Xiaolan Liu

    2018-01-01

    Full Text Available Fixed and cellular networks are two typical access networks provided by operators. Fixed access network is widely employed; nevertheless, its bandwidth is sometimes not sufficient enough to meet user bandwidth requirements. Meanwhile, cellular access network owns unique advantages of wider coverage, faster increasing link speed, more flexible deployment, and so forth. Therefore, it is attractive for operators to mitigate the bandwidth shortage by bundling these two. Actually, there have been existing schemes proposed to aggregate the bandwidth of two access networks, whereas they all have their own problems, like packet reordering or extra latency overhead. To address this problem, we design new architecture, MPTCP Tunnel, to aggregate the bandwidth of multiple heterogeneous access networks from the perspective of operators. MPTCP Tunnel uses MPTCP, which solves the reordering problem essentially, to bundle multiple access networks. Besides, MPTCP Tunnel sets up only one MPTCP connection at play which adapts itself to multiple traffic types and TCP flows. Furthermore, MPTCP Tunnel forwards intact IP packets through access networks, maintaining the end-to-end TCP semantics. Experimental results manifest that MPTCP Tunnel can efficiently aggregate the bandwidth of multiple access networks and is more adaptable to the increasing heterogeneity of access networks than existing mechanisms.

  13. Design of bandwidth tunable HTS filter using H-shaped waveguides

    Energy Technology Data Exchange (ETDEWEB)

    Koike, Y. [Department of Electrical Engineering, University of Yamanashi, Nakagawa-Sekiya Laboratory, 4-3-11 Takeda, Kofu 400-8511 (Japan); Sekiya, N., E-mail: nsekiya@yamanashi.ac.j [Department of Electrical Engineering, University of Yamanashi, Nakagawa-Sekiya Laboratory, 4-3-11 Takeda, Kofu 400-8511 (Japan); Nakagawa, Y. [Department of Electrical Engineering, University of Yamanashi, Nakagawa-Sekiya Laboratory, 4-3-11 Takeda, Kofu 400-8511 (Japan); Ohshima, S. [Yamagata University, 4-3-16 Johnan, Yonezawa 992-8510 (Japan)

    2009-10-15

    We have developed a bandwidth tuning method for use in high-temperature superconducting (HTS) microstrip filters. Several H-shaped waveguides are placed between the resonators, and the bandwidth is adjusted by changing the switch states of the waveguides. The coupling coefficients between the resonators are controlled by switching the connection or isolation of the center gaps of the waveguides so as to tune the bandwidth. The effects of using this method were evaluated by simulation using a filter composed of 3-pole half-wavelength straight-line resonators with an H-shaped waveguide between each pair and additional electric pads for post-tuning trimming. The filter was designed to have a center frequency of 5 GHz and a bandwidth of 100 MHz by using an electromagnetic simulator based on the moment method. The simulation showed that bandwidth tuning of 150 MHz can be obtained by using H-shaped waveguides to adjust the coupling coefficients. It also showed that using additional electric pads around the feed lines, which was previously shown to be useful for trimming to improve insertion loss after center-frequency tuning, is also useful for bandwidth tuning.

  14. Compression of Video Tracking and Bandwidth Balancing Routing in Wireless Multimedia Sensor Networks

    Directory of Open Access Journals (Sweden)

    Yin Wang

    2015-12-01

    Full Text Available There has been a tremendous growth in multimedia applications over wireless networks. Wireless Multimedia Sensor Networks(WMSNs have become the premier choice in many research communities and industry. Many state-of-art applications, such as surveillance, traffic monitoring, and remote heath care are essentially video tracking and transmission in WMSNs. The transmission speed is constrained by the big file size of video data and fixed bandwidth allocation in constant routing paths. In this paper, we present a CamShift based algorithm to compress the tracking of videos. Then we propose a bandwidth balancing strategy in which each sensor node is able to dynamically select the node for the next hop with the highest potential bandwidth capacity to resume communication. Key to this strategy is that each node merely maintains two parameters that contain its historical bandwidth varying trend and then predict its near future bandwidth capacity. Then, the forwarding node selects the next hop with the highest potential bandwidth capacity. Simulations demonstrate that our approach significantly increases the data received by the sink node and decreases the delay on video transmission in Wireless Multimedia Sensor Network environments.

  15. Multi-granularity Bandwidth Allocation for Large-Scale WDM/TDM PON

    Science.gov (United States)

    Gao, Ziyue; Gan, Chaoqin; Ni, Cuiping; Shi, Qiongling

    2017-12-01

    WDM (wavelength-division multiplexing)/TDM (time-division multiplexing) PON (passive optical network) is being viewed as a promising solution for delivering multiple services and applications, such as high-definition video, video conference and data traffic. Considering the real-time transmission, QoS (quality of services) requirements and differentiated services model, a multi-granularity dynamic bandwidth allocation (DBA) in both domains of wavelengths and time for large-scale hybrid WDM/TDM PON is proposed in this paper. The proposed scheme achieves load balance by using the bandwidth prediction. Based on the bandwidth prediction, the wavelength assignment can be realized fairly and effectively to satisfy the different demands of various classes. Specially, the allocation of residual bandwidth further augments the DBA and makes full use of bandwidth resources in the network. To further improve the network performance, two schemes named extending the cycle of one free wavelength (ECoFW) and large bandwidth shrinkage (LBS) are proposed, which can prevent transmission from interruption when the user employs more than one wavelength. The simulation results show the effectiveness of the proposed scheme.

  16. Spin-torque diode with tunable sensitivity and bandwidth by out-of-plane magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Li, X.; Zheng, C.; Pong, Philip W. T. [Department of Electrical and Electronic Engineering, The University of Hong Kong (Hong Kong); Zhou, Y., E-mail: yanzhou@hku.hk [School of Electronics Science and Engineering, Nanjing University, Nanjing 210093 (China); Department of Physics, The University of Hong Kong (Hong Kong); Kubota, H.; Yuasa, S. [Spintronics Research Center, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8568 (Japan)

    2016-06-06

    Spin-torque diodes based on nanosized magnetic tunnel junctions are novel microwave detectors with high sensitivity and wide frequency bandwidth. While previous reports mainly focus on improving the sensitivity, the approaches to extend the bandwidth are limited. This work experimentally demonstrates that through optimizing the orientation of the external magnetic field, wide bandwidth can be achieved while maintaining high sensitivity. The mechanism of the frequency- and sensitivity-tuning is investigated through analyzing the dependence of resonant frequency and DC voltage on the magnitude and the tilt angle of hard-plane magnetic field. The frequency dependence is qualitatively explicated by Kittel's ferromagnetic resonance model. The asymmetric resonant frequency at positive and negative magnetic field is verified by the numerical simulation considering the in-plane anisotropy. The DC voltage dependence is interpreted through evaluating the misalignment angle between the magnetization of the free layer and the reference layer. The tunability of the detector performance by the magnetic field angle is evaluated through characterizing the sensitivity and bandwidth under 3D magnetic field. The frequency bandwidth up to 9.8 GHz or maximum sensitivity up to 154 mV/mW (after impedance mismatch correction) can be achieved by tuning the angle of the applied magnetic field. The results show that the bandwidth and sensitivity can be controlled and adjusted through optimizing the orientation of the magnetic field for various applications and requirements.

  17. Wide-bandwidth bilateral control using two-stage actuator system

    International Nuclear Information System (INIS)

    Kokuryu, Saori; Izutsu, Masaki; Kamamichi, Norihiro; Ishikawa, Jun

    2015-01-01

    This paper proposes a two-stage actuator system that consists of a coarse actuator driven by a ball screw with an AC motor (the first stage) and a fine actuator driven by a voice coil motor (the second stage). The proposed two-stage actuator system is applied to make a wide-bandwidth bilateral control system without needing expensive high-performance actuators. In the proposed system, the first stage has a wide moving range with a narrow control bandwidth, and the second stage has a narrow moving range with a wide control bandwidth. By consolidating these two inexpensive actuators with different control bandwidths in a complementary manner, a wide bandwidth bilateral control system can be constructed based on a mechanical impedance control. To show the validity of the proposed method, a prototype of the two-stage actuator system has been developed and basic performance was evaluated by experiment. The experimental results showed that a light mechanical impedance with a mass of 10 g and a damping coefficient of 2.5 N/(m/s) that is an important factor to establish good transparency in bilateral control has been successfully achieved and also showed that a better force and position responses between a master and slave is achieved by using the proposed two-stage actuator system compared with a narrow bandwidth case using a single ball screw system. (author)

  18. Dynamic quantum secret sharing

    International Nuclear Information System (INIS)

    Jia, Heng-Yue; Wen, Qiao-Yan; Gao, Fei; Qin, Su-Juan; Guo, Fen-Zhuo

    2012-01-01

    In this Letter we consider quantum secret sharing (QSS) between a sender and a dynamic agent group, called dynamic quantum secret sharing (DQSS). In the DQSS, the change of the agent group is allowable during the procedure of sharing classical and quantum information. Two DQSS schemes are proposed based on a special kind of entangled state, starlike cluster states. Without redistributing all the shares, the changed agent group can reconstruct the sender's secret by their cooperation. Compared with the previous quantum secret sharing scheme, our schemes are more flexible and suitable for practical applications. -- Highlights: ► We consider quantum secret sharing between a sender and a dynamic agent group, called dynamic quantum secret sharing (DQSS). ► In the DQSS, the change of the agent group is allowable during the procedure of sharing classical and quantum information. ► Two DQSS schemes are proposed based on a special kind of entangled state, starlike cluster states. ► Without redistributing all the shares, the changed agent group can reconstruct the sender's secret by their cooperation. ► Compared with the previous quantum secret sharing scheme, our schemes are more flexible and suitable for practical applications.

  19. Job sharing. Part 1.

    Science.gov (United States)

    Anderson, K; Forbes, R

    1989-01-01

    This article is the first of a three part series discussing the impact of nurses job sharing at University Hospital, London, Ontario. This first article explores the advantages and disadvantages of job sharing for staff nurses and their supervising nurse manager, as discussed in the literature. The results of a survey conducted on a unit with a large number of job sharing positions, concur with literature findings. The second article will present the evaluation of a pilot project in which two nurses job share a first line managerial position in the Operating Room. The third article will relate the effects of job sharing on women's perceived general well being. Job sharing in all areas, is regarded as a positive experience by both nurse and administrators.

  20. The Sharing Economy

    DEFF Research Database (Denmark)

    Avital, Michel; Carroll, John M.; Hjalmarsson, Anders

    2015-01-01

    The sharing economy is spreading rapidly worldwide in a number of industries and markets. The disruptive nature of this phenomenon has drawn mixed responses ranging from active conflict to adoption and assimilation. Yet, in spite of the growing attention to the sharing economy, we still do not know...... much about it. With the abundant enthusiasm about the benefits that the sharing economy can unleash and the weekly reminders about its dark side, further examination is required to determine the potential of the sharing economy while mitigating its undesirable side effects. The panel will join...... the ongoing debate about the sharing economy and contribute to the discourse with insights about how digital technologies are critical in shaping this turbulent ecosystem. Furthermore, we will define an agenda for future research on the sharing economy as it becomes part of the mainstream society as well...

  1. Sharing network resources

    CERN Document Server

    Parekh, Abhay

    2014-01-01

    Resource Allocation lies at the heart of network control. In the early days of the Internet the scarcest resource was bandwidth, but as the network has evolved to become an essential utility in the lives of billions, the nature of the resource allocation problem has changed. This book attempts to describe the facets of resource allocation that are most relevant to modern networks. It is targeted at graduate students and researchers who have an introductory background in networking and who desire to internalize core concepts before designing new protocols and applications. We start from the fun

  2. Probabilistic Infinite Secret Sharing

    OpenAIRE

    Csirmaz, László

    2013-01-01

    The study of probabilistic secret sharing schemes using arbitrary probability spaces and possibly infinite number of participants lets us investigate abstract properties of such schemes. It highlights important properties, explains why certain definitions work better than others, connects this topic to other branches of mathematics, and might yield new design paradigms. A probabilistic secret sharing scheme is a joint probability distribution of the shares and the secret together with a colle...

  3. Factors Impacting Knowledge Sharing

    DEFF Research Database (Denmark)

    Schulzmann, David; Slepniov, Dmitrij

    The purpose of this paper is to examine various factors affecting knowledge sharing at the R&D center of a Western MNE in China. The paper employs qualitative methodology and is based on the action research and case study research techniques. The findings of the paper advance our understanding...... about factors that affect knowledge sharing. The main emphasis is given to the discussion on how to improve knowledge sharing in global R&D organizations....

  4. Regulating the sharing economy

    OpenAIRE

    Erickson, Kristofer; Sorensen, Inge

    2016-01-01

    In this introductory essay, we explore definitions of the ‘sharing economy’, a concept indicating both social (relational, communitarian) and economic (allocative, profit-seeking) aspects which appear to be in tension. We suggest combining the social and economic logics of the sharing economy to focus on the central features of network enabled, aggregated membership in a pool of offers and demands (for goods, services, creative expressions). This definition of the sharing economy distinguishe...

  5. Medicare Program; Revisions to Payment Policies Under the Physician Fee Schedule and Other Revisions to Part B for CY 2017; Medicare Advantage Bid Pricing Data Release; Medicare Advantage and Part D Medical Loss Ratio Data Release; Medicare Advantage Provider Network Requirements; Expansion of Medicare Diabetes Prevention Program Model; Medicare Shared Savings Program Requirements. Final rule.

    Science.gov (United States)

    2016-11-15

    This major final rule addresses changes to the physician fee schedule and other Medicare Part B payment policies, such as changes to the Value Modifier, to ensure that our payment systems are updated to reflect changes in medical practice and the relative value of services, as well as changes in the statute. This final rule also includes changes related to the Medicare Shared Savings Program, requirements for Medicare Advantage Provider Networks, and provides for the release of certain pricing data from Medicare Advantage bids and of data from medical loss ratio reports submitted by Medicare health and drug plans. In addition, this final rule expands the Medicare Diabetes Prevention Program model.

  6. Phenomenology of experiential sharing

    DEFF Research Database (Denmark)

    León, Felipe; Zahavi, Dan

    2016-01-01

    The chapter explores the topic of experiential sharing by drawing on the early contributions of the phenomenologists Alfred Schutz and Gerda Walther. It is argued that both Schutz and Walther support, from complementary perspectives, an approach to experiential sharing that has tended to be overl......The chapter explores the topic of experiential sharing by drawing on the early contributions of the phenomenologists Alfred Schutz and Gerda Walther. It is argued that both Schutz and Walther support, from complementary perspectives, an approach to experiential sharing that has tended...

  7. A Data Sharing Story

    Directory of Open Access Journals (Sweden)

    Mercè Crosas

    2012-01-01

    Full Text Available From the early days of modern science through this century of Big Data, data sharing has enabled some of the greatest advances in science. In the digital age, technology can facilitate more effective and efficient data sharing and preservation practices, and provide incentives for making data easily accessible among researchers. At the Institute for Quantitative Social Science at Harvard University, we have developed an open-source software to share, cite, preserve, discover and analyze data, named the Dataverse Network. We share here the project’s motivation, its growth and successes, and likely evolution.

  8. Share your sweets

    DEFF Research Database (Denmark)

    Byrnit, Jill; Høgh-Olesen, Henrik; Makransky, Guido

    2015-01-01

    study to examine the sharing behavior of groups of captive chimpanzees and bonobos when introducing the same type of food (branches) manipulated to be of two different degrees of desirability (with or without syrup). Results showed that, the large majority of food transfers in both species came about...... as sharing in which group members were allowed to co-feed or remove food from the stock of the food possessor, and the introduction of high-value food resulted in more sharing, not less. Food sharing behavior differed between species in that chimpanzees displayed significantly more begging behavior than...

  9. Millennials and the Sharing Economy

    DEFF Research Database (Denmark)

    Ranzini, Giulia; Newlands, Gemma; Anselmi, Guido

    Report from the EU H2020 Research Project Ps2Share: Participation, Privacy, and Power in the Sharing Economy......Report from the EU H2020 Research Project Ps2Share: Participation, Privacy, and Power in the Sharing Economy...

  10. Mobile energy sharing futures

    DEFF Research Database (Denmark)

    Worgan, Paul; Knibbe, Jarrod; Plasencia, Diego Martinez

    2016-01-01

    We foresee a future where energy in our mobile devices can be shared and redistributed to suit our current task needs. Many of us are beginning to carry multiple mobile devices and we seek to re-evaluate the traditional view of a mobile device as only accepting energy. In our vision, we can...... sharing futures....

  11. 5G Spectrum Sharing

    OpenAIRE

    Nekovee, Maziar; Rudd, Richard

    2017-01-01

    In this paper an overview is given of the current status of 5G industry standards, spectrum allocation and use cases, followed by initial investigations of new opportunities for spectrum sharing in 5G using cognitive radio techniques, considering both licensed and unlicensed scenarios. A particular attention is given to sharing millimeter-wave frequencies, which are of prominent importance for 5G.

  12. NCSU Reactor Sharing Program

    International Nuclear Information System (INIS)

    Perez, P.B.

    1993-01-01

    The Nuclear Reactor Program at North Carolina State University provides the PULSTAR Research Reactor and associated facilities to eligible institutions with support, in part, from the Department of Energy Reactor Sharing Program. Participation in the NCSU Reactor Sharing Program continues to increase steadily with visitors ranging from advance high school physics and chemistry students to Ph.D. level research from neighboring universities

  13. 'An Arena for Sharing'

    DEFF Research Database (Denmark)

    la Cour, Karen; Ledderer, Loni; Hansen, Helle Ploug

    2015-01-01

    relatives). In-depth interviews were conducted in the participants' homes 1 month after the rehabilitation course. Data were analyzed by a constant comparative method. Results: Residential rehabilitation course was identified to serve as an "arena for sharing," underpinned by 3 dimensions of sharing...

  14. 10 CFR 603.575 - Repayment of Federal cost share.

    Science.gov (United States)

    2010-01-01

    ... Business Evaluation Accounting, Payments, and Recovery of Funds § 603.575 Repayment of Federal cost share. In accordance with the Energy Policy Act of 2005 (Public Law 109-58), section 988(e), the contracting...

  15. An Overview of Optical Network Bandwidth and Fault Management

    Directory of Open Access Journals (Sweden)

    J.A. Zubairi

    2010-09-01

    Full Text Available This paper discusses the optical network management issues and identifies potential areas for focused research. A general outline of the main components in optical network management is given and specific problems in GMPLS based model are explained. Later, protection and restoration issues are discussed in the broader context of fault management and the tools developed for fault detection are listed. Optical networks need efficient and reliable protection schemes that restore the communications quickly on the occurrence of faults without causing failure of real-time applications using the network. A holistic approach is required that provides mechanisms for fault detection, rapid restoration and reversion in case of fault resolution. Since the role of SDH/SONET is diminishing, the modern optical networks are poised towards the IP-centric model where high performance IP-MPLS routers manage a core intelligent network of IP over WDM. Fault management schemes are developed for both the IP layer and the WDM layer. Faults can be detected and repaired locally and also through centralized network controller. A hybrid approach works best in detecting the faults where the domain controller verifies the established LSPs in addition to the link tests at the node level. On detecting a fault, rapid restoration can perform localized routing of traffic away from the affected port and link. The traffic may be directed to pre-assigned backup paths that are established as shared or dedicated resources. We examine the protection issues in detail including the choice of layer for protection, implementing protection or restoration, backup path routing, backup resource efficiency, subpath protection, QoS traffic survival and multilayer protection triggers and alarm propagation. The complete protection cycle is described and mechanisms incorporated into RSVP-TE and other protocols for detecting and recording path errors are outlined. In addition, MPLS testbed

  16. Sharing Rare Attitudes Attracts.

    Science.gov (United States)

    Alves, Hans

    2018-04-01

    People like others who share their attitudes. Online dating platforms as well as other social media platforms regularly rely on the social bonding power of their users' shared attitudes. However, little is known about moderating variables. In the present work, I argue that sharing rare compared with sharing common attitudes should evoke stronger interpersonal attraction among people. In five studies, I tested this prediction for the case of shared interests from different domains. I found converging evidence that people's rare compared with their common interests are especially potent to elicit interpersonal attraction. I discuss the current framework's theoretical implications for impression formation and impression management as well as its practical implications for improving online dating services.

  17. Receiver bandwidth effects on complex modulation and detection using directly modulated lasers.

    Science.gov (United States)

    Yuan, Feng; Che, Di; Shieh, William

    2016-05-01

    Directly modulated lasers (DMLs) have long been employed for short- and medium-reach optical communications due to their low cost. Recently, a new modulation scheme called complex modulated DMLs has been demonstrated showing a significant optical signal to noise ratio sensitivity enhancement compared with the traditional intensity-only detection scheme. However, chirp-induced optical spectrum broadening is inevitable in complex modulated systems, which may imply a need for high-bandwidth receivers. In this Letter, we study the impact of receiver bandwidth effects on the performance of complex modulation and coherent detection systems based on DMLs. We experimentally demonstrate that such systems exhibit a reasonable tolerance for the reduced receiver bandwidth. For 10 Gbaud 4-level pulse amplitude modulation signals, the required electrical bandwidth is as low as 8.5 and 7.5 GHz for 7% and 20% forward error correction, respectively. Therefore, it is feasible to realize DML-based complex modulated systems using cost-effective receivers with narrow bandwidth.

  18. Impact of modulation bandwidth on multiplexing using principal modes in MMF links.

    Science.gov (United States)

    Prasad, Rohan; Appaiah, Kumar

    2018-01-22

    Multimode fibers (MMFs) are widely used for short fiber links. However, the data rates through MMFs is limited owing to modal dispersion. The so-called "principal modes" (PMs) permit transmission and multiplexing through the MMFs without modal dispersion for small modulation bandwidths. For larger modulation bandwidths, however, they lose their dispersion-free nature. In this paper, we model the impact of modulation bandwidth and mode coupling strength on the performance of PMs. We develop a simulator that characterizes the dispersion and cross-talk of the PMs of few-mode and large-core graded-index MMFs with mode-dependent losses (MDL). Simulations reveal that for fibers without MDL, for modulation frequencies beyond 10 GHz diminishes the PMs' frequency response by more than 1 dB for 100 m in large-core MMF links and 10 km few-mode fiber links. With MDL, simulations reveal that for modulation bandwidths beyond 2 GHz diminishes the frequency response by 3 dB for a 1 km few-mode fiber and by more than 4 dB for a 1 km large-core multimode fiber. While multiplexing using PMs in large-core MMFs with MDL, we find that for modulation bandwidths beyond 3 GHz, the cross-talk is 20 dB in 1 km large-core MMF links, thereby limiting system performance.

  19. Maximum Bandwidth Enhancement of Current Mirror using Series-Resistor and Dynamic Body Bias Technique

    Directory of Open Access Journals (Sweden)

    V. Niranjan

    2014-09-01

    Full Text Available This paper introduces a new approach for enhancing the bandwidth of a low voltage CMOS current mirror. The proposed approach is based on utilizing body effect in a MOS transistor by connecting its gate and bulk terminals together for signal input. This results in boosting the effective transconductance of MOS transistor along with reduction of the threshold voltage. The proposed approach does not affect the DC gain of the current mirror. We demonstrate that the proposed approach features compatibility with widely used series-resistor technique for enhancing the current mirror bandwidth and both techniques have been employed simultaneously for maximum bandwidth enhancement. An important consequence of using both techniques simultaneously is the reduction of the series-resistor value for achieving the same bandwidth. This reduction in value is very attractive because a smaller resistor results in smaller chip area and less noise. PSpice simulation results using 180 nm CMOS technology from TSMC are included to prove the unique results. The proposed current mirror operates at 1Volt consuming only 102 µW and maximum bandwidth extension ratio of 1.85 has been obtained using the proposed approach. Simulation results are in good agreement with analytical predictions.

  20. Distribute Off-Time Office Internet bandwidth Using Topology Mesh For Sorrounding Neighbour

    Science.gov (United States)

    Zendrato, Niskarto; Sihombing, Oloan; Laia, Yonata; Sabarita Barus, Ertina

    2018-04-01

    The Internet as one of the very rapidly growing information technology can provide data and information with wide world, complete, and up to date. Users can download and upload data such as the application file, multimedia and text through the Internet network. But for the Internet availability is still less equal access because of the lack of availability of adequate infrastructure, therefore the author make the utilization of bandwidth that can be establish Internet balancing although still on a small scale. By this research the authors use bandwidth from PT. Deltauli Home Teknikarya that where bandwidth necessity on when time off-time unused office, where the office always pay full for Internet connection even though at the time of the off-time. It’s many of the available bandwidth, so that the author is trying to take advantage of the bandwidth at the time of the off-time the office to be used by the community using radio connection link and use the radius server as user management and server to send sms and user and password to the users who want to enjoy free internet connection.

  1. Studies of bandwidth dependence of laser plasma instabilities driven by the Nike laser

    Science.gov (United States)

    Weaver, J.; Kehne, D.; Obenschain, S.; Serlin, V.; Schmitt, A. J.; Oh, J.; Lehmberg, R. H.; Brown, C. M.; Seely, J.; Feldman, U.

    2012-10-01

    Experiments at the Nike laser facility of the Naval Research Laboratory are exploring the influence of laser bandwidth on laser plasma instabilities (LPI) driven by a deep ultraviolet pump (248 nm) that incorporates beam smoothing by induced spatial incoherence (ISI). In early ISI studies with longer wavelength Nd:glass lasers (1054 nm and 527 nm),footnotetextObenschain, PRL 62(1989);Mostovych, PRL 62(1987);Peyser, Phys. Fluids B 3(1991). stimulated Raman scattering, stimulated Brillouin scattering, and the two plasmon decay instability were reduced when wide bandwidth ISI (δν/ν˜0.03-0.19%) pulses irradiated targets at moderate to high intensities (10^14-10^15 W/cm^2). The current studies will compare the emission signatures of LPI from planar CH targets during Nike operation at large bandwidth (δν˜1THz) to observations for narrower bandwidth operation (δν˜0.1-0.3THz). These studies will help clarify the relative importance of the short wavelength and wide bandwidth to the increased LPI intensity thresholds observed at Nike. New pulse shapes are being used to generate plasmas with larger electron density scale-lengths that are closer to conditions during pellet implosions for direct drive inertial confinement fusion.

  2. Design of ultrathin dual-resonant reflective polarization converter with customized bandwidths

    Science.gov (United States)

    Kundu, Debidas; Mohan, Akhilesh; Chakrabarty, Ajay

    2017-10-01

    In this paper, an ultrathin dual-resonant reflective polarization converter is proposed to obtain customized bandwidths using precise space-filling technique to its top geometry. The unit cell of the dual-resonant prototype consists of conductive square ring with two diagonally arranged slits, supported by metal-backed thin dielectric layer. It offers two narrow bands with fractional bandwidths of 3.98 and 6.65% and polarization conversion ratio (PCR) of 97.16 and 98.87% at 4.52 and 6.97 GHz, respectively. The resonances are brought in proximity to each other by changing the length of surface current paths of the two resonances. By virtue of this mechanism, two polarization converters with two different types of bandwidths are obtained. One polarization converter produces a full-width at half-maxima PCR bandwidth of 34%, whereas another polarization converter produces a 90% PCR bandwidth of 19%. All the proposed polarization converters are insensitive to wide variations of incident angle for both TE- and TM-polarized incident waves. Measured results show good agreement with the numerically simulated results.

  3. Collection Development Policies in Community College Libraries.

    Science.gov (United States)

    Mesling, Chris Fowler

    2003-01-01

    Emphasizes the need for collection development policy in community college academic libraries. Highlights areas of resource sharing, community analysis, and collection assessment. Also provides an overview of how to create a collection for development policy, and recommends books on writing such policy. Includes model policy statements. (NB)

  4. Cross-layer shared protection strategy towards data plane in software defined optical networks

    Science.gov (United States)

    Xiong, Yu; Li, Zhiqiang; Zhou, Bin; Dong, Xiancun

    2018-04-01

    In order to ensure reliable data transmission on the data plane and minimize resource consumption, a novel protection strategy towards data plane is proposed in software defined optical networks (SDON). Firstly, we establish a SDON architecture with hierarchical structure of data plane, which divides the data plane into four layers for getting fine-grained bandwidth resource. Then, we design the cross-layer routing and resource allocation based on this network architecture. Through jointly considering the bandwidth resource on all the layers, the SDN controller could allocate bandwidth resource to working path and backup path in an economical manner. Next, we construct auxiliary graphs and transform the shared protection problem into the graph vertex coloring problem. Therefore, the resource consumption on backup paths can be reduced further. The simulation results demonstrate that the proposed protection strategy can achieve lower protection overhead and higher resource utilization ratio.

  5. Data Sharing and Cardiology: Platforms and Possibilities.

    Science.gov (United States)

    Dey, Pranammya; Ross, Joseph S; Ritchie, Jessica D; Desai, Nihar R; Bhavnani, Sanjeev P; Krumholz, Harlan M

    2017-12-19

    Sharing deidentified patient-level research data presents immense opportunities to all stakeholders involved in cardiology research and practice. Sharing data encourages the use of existing data for knowledge generation to improve practice, while also allowing for validation of disseminated research. In this review, we discuss key initiatives and platforms that have helped to accelerate progress toward greater sharing of data. These efforts are being prompted by government, universities, philanthropic sponsors of research, major industry players, and collaborations among some of these entities. As data sharing becomes a more common expectation, policy changes will be required to encourage and assist data generators with the process of sharing the data they create. Patients also will need access to their own data and to be empowered to share those data with researchers. Although medicine still lags behind other fields in achieving data sharing's full potential, cardiology research has the potential to lead the way. Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  6. Chimpanzees share forbidden fruit.

    Directory of Open Access Journals (Sweden)

    Kimberley J Hockings

    2007-09-01

    Full Text Available The sharing of wild plant foods is infrequent in chimpanzees, but in chimpanzee communities that engage in hunting, meat is frequently used as a 'social tool' for nurturing alliances and social bonds. Here we report the only recorded example of regular sharing of plant foods by unrelated, non-provisioned wild chimpanzees, and the contexts in which these sharing behaviours occur. From direct observations, adult chimpanzees at Bossou (Republic of Guinea, West Africa very rarely transferred wild plant foods. In contrast, they shared cultivated plant foods much more frequently (58 out of 59 food sharing events. Sharing primarily consists of adult males allowing reproductively cycling females to take food that they possess. We propose that hypotheses focussing on 'food-for-sex and -grooming' and 'showing-off' strategies plausibly account for observed sharing behaviours. A changing human-dominated landscape presents chimpanzees with fresh challenges, and our observations suggest that crop-raiding provides adult male chimpanzees at Bossou with highly desirable food commodities that may be traded for other currencies.

  7. Description of the effort sharing approaches as presented in the Ecofys' policy brief The next step in Europe's climate action. Setting targets for 2030

    Energy Technology Data Exchange (ETDEWEB)

    Hoehne, N.; Hagemann, M.; Fekete, H. [Ecofys, Utrecht (Netherlands)

    2013-06-15

    The paper 'The next step in Europe's climate action. Setting targets for 2030' explains how setting 2030 targets will reinvigorate the ETS and will put EU emissions on track to limit global temperature increase below two degrees Celsius (2C). The paper describes four key findings for EU policymakers engaged in preparing EU energy and climate measures for 2030 and for the longer term. This document aims to provide background information on the effort sharing approaches, as presented in fore-mentioned paper.

  8. A dual shared stack for FSLM in Erika Enterprise

    NARCIS (Netherlands)

    Balasubramanian, S.M.N.; Afshar, S.; Gai, P.; Behnam, M.; Bril, R.J.

    2017-01-01

    Recently, the flexible spin-lock model (FSLM) has been introduced, unifying spin-based and suspension-based resource sharing protocols for real-time multi-core platforms. Unlike the multiprocessor stack resource policy (MSRP), FSLM doesn’t allow tasks on a core to share a single stack, however. In

  9. Design optimization of the distributed modal filtering rod fiber for increasing single mode bandwidth

    DEFF Research Database (Denmark)

    Jørgensen, Mette Marie; Petersen, Sidsel Rübner; Laurila, Marko

    2012-01-01

    . Large preform tolerances are compensated during the fiber draw resulting in ultra low NA fibers with very large cores. In this paper, design optimization of the SM bandwidth of the DMF rod fiber is presented. Analysis of band gap properties results in a fourfold increase of the SM bandwidth compared...... LMA fiber amplifiers having high pump absorption through a pump cladding that is decoupled from the outer fiber. However, achieving ultra low NA for single-mode (SM) guidance is challenging, and thus different design strategies must be applied to filter out higher order modes (HOMs). The novel...... distributed modal filtering (DMF) design presented here enables SM guidance, and previous results have shown a SM mode field diameter of 60 μm operating in a 20 nm SM bandwidth. The DMF rod fiber has high index ring-shaped inclusions acting as resonators enabling SM guidance through modal filtering of HOMs...

  10. Bandwidth Optimization of Normal Equation Matrix in Bundle Block Adjustment in Multi-baseline Rotational Photography

    Directory of Open Access Journals (Sweden)

    WANG Xiang

    2016-02-01

    Full Text Available A new bandwidth optimization method of normal equation matrix in bundle block adjustment in multi-baseline rotational close range photography by image index re-sorting is proposed. The equivalent exposure station of each image is calculated by its object space coverage and the relationship with other adjacent images. Then, according to the coordinate relations between equivalent exposure stations, new logical indices of all images are computed, based on which, the optimized bandwidth value can be obtained. Experimental results show that the bandwidth determined by our proposed method is significantly better than its original value, thus the operational efficiency, as well as the memory consumption of multi-baseline rotational close range photography in real-data applications, is optimized to a certain extent.

  11. Bayesian Bandwidth Selection for a Nonparametric Regression Model with Mixed Types of Regressors

    Directory of Open Access Journals (Sweden)

    Xibin Zhang

    2016-04-01

    Full Text Available This paper develops a sampling algorithm for bandwidth estimation in a nonparametric regression model with continuous and discrete regressors under an unknown error density. The error density is approximated by the kernel density estimator of the unobserved errors, while the regression function is estimated using the Nadaraya-Watson estimator admitting continuous and discrete regressors. We derive an approximate likelihood and posterior for bandwidth parameters, followed by a sampling algorithm. Simulation results show that the proposed approach typically leads to better accuracy of the resulting estimates than cross-validation, particularly for smaller sample sizes. This bandwidth estimation approach is applied to nonparametric regression model of the Australian All Ordinaries returns and the kernel density estimation of gross domestic product (GDP growth rates among the organisation for economic co-operation and development (OECD and non-OECD countries.

  12. Metamaterial composite bandpass filter with an ultra-broadband rejection bandwidth of up to 240 terahertz

    DEFF Research Database (Denmark)

    Strikwerda, Andrew; Zalkovskij, Maksim; Lorenzen, Dennis Lund

    2014-01-01

    We present a metamaterial, consisting of a cross structure and a metal mesh filter, that forms a composite with greater functional bandwidth than any terahertz (THz) metamaterial to date. Metamaterials traditionally have a narrow usable bandwidth that is much smaller than common THz sources......, such as photoconductive antennas and difference frequency generation. The composite structure shown here expands the usable bandwidth to exceed that of current THz sources. To highlight the applicability of this combination, we demonstrate a series of bandpass filters with only a single pass band, with a central...... frequency (f) that is scalable from 0.86–8.51 THz, that highly extinguishes other frequencies up to >240 THz. The performance of these filters is demonstrated in experiment, using both air biased coherent detection and a Fourier transform infrared spectrometer (FTIR), as well as in simulation. We present...

  13. Influences of finite gain bandwidth on pulse propagation in parabolic fiber amplifiers with distributed gain profiles

    International Nuclear Information System (INIS)

    Zhao Jia-Sheng; Li Pan; Chen Xiao-Dong; Feng Su-Juan; Mao Qing-He

    2012-01-01

    The evolutions of the pulses propagating in decreasing and increasing gain distributed fiber amplifiers with finite gain bandwidths are investigated by simulations with the nonlinear Schrödinger equation. The results show that the parabolic pulse propagations in both the decreasing and the increasing gain amplifiers are restricted by the finite gain bandwidth. For a given input pulse, by choosing a small initial gain coefficient and gain variation rate, the whole gain for the pulse amplification limited by the gain bandwidth may be higher, which is helpful for the enhancement of the output linearly chirped pulse energy. Compared to the decreasing gain distributed fiber amplifier, the increasing gain distributed amplifier may be more conducive to suppress the pulse spectral broadening and increase the critical amplifier length for achieving a larger output linearly chirped pulse energy

  14. Bandwidth Impacts of Localizing Peer-to-Peer IP Video Traffic in Access and Aggregation Networks

    Directory of Open Access Journals (Sweden)

    Kerpez Kenneth

    2008-01-01

    Full Text Available Abstract This paper examines the burgeoning impact of peer-to-peer (P2P traffic IP video traffic. High-quality IPTV or Internet TV has high-bandwidth requirements, and P2P IP video could severely strain broadband networks. A model for the popularity of video titles is given, showing that some titles are very popular and will often be available locally; making localized P2P attractive for video titles. The bandwidth impacts of localizing P2P video to try and keep traffic within a broadband access network area or within a broadband access aggregation network area are examined. Results indicate that such highly localized P2P video can greatly lower core bandwidth usage.

  15. Analysis of Blocking Rate and Bandwidth Usage of Mobile IPTV Services in Wireless Cellular Networks

    Directory of Open Access Journals (Sweden)

    Mingfu Li

    2014-01-01

    Full Text Available Mobile IPTV services over wireless cellular networks become more and more popular, owing to the significant growth in access bandwidth of wireless cellular networks such as 3G/4G and WiMAX. However, the spectrum resources of wireless cellular networks is rare. How to enhance the spectral efficiency of mobile networks becomes an important issue. Unicast, broadcast, and multicast are the most important transport schemes for offering mobile IPTV services over wireless cellular networks. Therefore, bandwidth usages and blocking rates of unicast, broadcast, and multicast IPTV services were analyzed and compared in this paper. Simulations were also conducted to validate the analytical results. Numerical results demonstrate that the presented analysis is correct, and multicast scheme achieves the best bandwidth usage and blocking rate performance, relative to the other two schemes.

  16. Bandwidth Impacts of Localizing Peer-to-Peer IP Video Traffic in Access and Aggregation Networks

    Directory of Open Access Journals (Sweden)

    Kenneth Kerpez

    2008-10-01

    Full Text Available This paper examines the burgeoning impact of peer-to-peer (P2P traffic IP video traffic. High-quality IPTV or Internet TV has high-bandwidth requirements, and P2P IP video could severely strain broadband networks. A model for the popularity of video titles is given, showing that some titles are very popular and will often be available locally; making localized P2P attractive for video titles. The bandwidth impacts of localizing P2P video to try and keep traffic within a broadband access network area or within a broadband access aggregation network area are examined. Results indicate that such highly localized P2P video can greatly lower core bandwidth usage.

  17. 360/degree/ digital phase detector with 100-kHz bandwidth

    International Nuclear Information System (INIS)

    Reid, D.W.; Riggin, D.; Fazio, M.V.; Biddle, R.S.; Patton, R.D.; Jackson, H.A.

    1981-01-01

    The general availability of digital circuit components with propagation delay times of a few nanoseconds makes a digital phase detector with good bandwidth feasible. Such a circuit has a distinct advantage over its analog counterpart because of its linearity over a wide range of phase shift. A description is given of a phase detector that is being built at Los Alamos National Laboratory for the Fusion Materials Irradiation Test (FMIT) project. The specifications are 100-kHz bandwidth, linearity of /plus or minus/1/degree/ over /plus or minus/180/degree/ of phase shift, and 0.66/degree/ resolution. To date, the circuit has achieved the bandwidth and resolution. The linearity is approximately /plus or minus/3/degree/ over /plus or minus/180/degree/ phase shift. 3 refs

  18. THz-bandwidth photonic Hilbert transformers based on fiber Bragg gratings in transmission.

    Science.gov (United States)

    Fernández-Ruiz, María R; Wang, Lixian; Carballar, Alejandro; Burla, Maurizio; Azaña, José; LaRochelle, Sophie

    2015-01-01

    THz-bandwidth photonic Hilbert transformers (PHTs) are implemented for the first time, to the best of our knowledge, based on fiber Bragg grating (FBG) technology. To increase the practical bandwidth limitation of FBGs (typically <200  GHz), a superstructure based on two superimposed linearly-chirped FBGs operating in transmission has been employed. The use of a transmission FBG involves first a conversion of the non-minimum phase response of the PHT into a minimum-phase response by adding an anticipated instantaneous component to the desired system temporal impulse response. Using this methodology, a 3-THz-bandwidth integer PHT and a fractional (order 0.81) PHT are designed, fabricated, and successfully characterized.

  19. Corrugated structure insertion for extending the SASE bandwidth up to 3% at the European XFEL

    Energy Technology Data Exchange (ETDEWEB)

    Zagorodnov, I.; Feng, G.; Limberg, T.

    2016-07-15

    The usage of X-ray free electron laser (XFEL) in femtosecond nanocrystallography involves sequential illumination of many small crystals of arbitrary orientation. Hence a wide radiation bandwidth will be useful in order to obtain and to index a larger number of Bragg peaks used for determination of the crystal orientation. Considering the baseline configuration of the European XFEL in Hamburg, and based on beam dynamics simulations, we demonstrate here that the usage of corrugated structures allows for a considerable increase in radiation bandwidth. Data collection with a 3% bandwidth, a few microjoule radiation pulse energy, a few femtosecond pulse duration, and a photon energy of 5.4 keV is possible. For this study we have developed an analytical modal representation of the short-range wake function of the flat corrugated structures for arbitrary offsets of the source and the witness particles.

  20. Controlling Laser Plasma Instabilities Using Temporal Bandwidths Under Shock Ignition Relevant Conditions

    Science.gov (United States)

    Tsung, Frank; Weaver, J.; Lehmberg, R.

    2017-10-01

    We are performing particle-in-cell simulations using the code OSIRIS to study the effects of laser plasma interactions in the presence of temporal bandwidth under plasma conditions relevant to experiments on the Nike laser with induced spatial incoherence (ISI). With ISI, the instantaneous laser intensity can be 3-4 times larger than the average intensity, leading to the excitation of additional TPD modes and producing electrons with larger angular spread. In our simulations, we observe that although ISI can increase the interaction regions for short bursts of time, time-averaged (over many pico-seconds) laser plasma interactions can be reduced by a factor of 2 in systems with sufficiently large bandwidths (where the inverse bandwidth is comparable with the linear growth time). We will quantify these effects and investigate higher dimensional effects such as laser speckles and the effects of Coulomb collisions. Work supported by NRL, NNSA, and NSF.

  1. Amplifying modeling for broad bandwidth pulse in Nd:glass based on hybrid-broaden mechanism

    International Nuclear Information System (INIS)

    Sujingqin; Lanqin, L; Wenyi, W; Feng, J; Xiaofeng, W; Xiaomin, Z; Bin, L

    2008-01-01

    In this paper, the cross relaxation time is proposed to combine the homogeneous and inhomogeneous broaden mechanism for broad bandwidth pulse amplification model. The corresponding velocity equation, which can describe the response of inverse population on upper and low energy level of gain media to different frequency of pulse, is also put forward. The gain saturation and energy relaxation effect are also included in the velocity equation. Code named CPAP has been developed to simulate the amplifying process of broad bandwidth pulse in multi-pass laser system. The amplifying capability of multi-pass laser system is evaluated and gain narrowing and temporal shape distortion are also investigated when bandwidth of pulse and cross relaxation time of gain media are different. Results can benefit the design of high-energy PW laser system in LFRC, CAEP

  2. Amplifying modeling for broad bandwidth pulse in Nd:glass based on hybrid-broaden mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Sujingqin; Lanqin, L; Wenyi, W; Feng, J; Xiaofeng, W; Xiaomin, Z [Research Center of Laser Fusion, China Academy of Engineering Physics, P. O. Box 919-988, Mianyang, China, 621900 (China); Bin, L [School of Computer and Communication Engineering, Southwest Jiaotong University, Chengdu. China, 610031 (China)], E-mail: sujingqin@tom.com

    2008-05-15

    In this paper, the cross relaxation time is proposed to combine the homogeneous and inhomogeneous broaden mechanism for broad bandwidth pulse amplification model. The corresponding velocity equation, which can describe the response of inverse population on upper and low energy level of gain media to different frequency of pulse, is also put forward. The gain saturation and energy relaxation effect are also included in the velocity equation. Code named CPAP has been developed to simulate the amplifying process of broad bandwidth pulse in multi-pass laser system. The amplifying capability of multi-pass laser system is evaluated and gain narrowing and temporal shape distortion are also investigated when bandwidth of pulse and cross relaxation time of gain media are different. Results can benefit the design of high-energy PW laser system in LFRC, CAEP.

  3. RF MEMS suspended band-stop resonator and filter for frequency and bandwidth continuous fine tuning

    International Nuclear Information System (INIS)

    Jang, Yun-Ho; Kim, Yong-Kweon; Llamas-Garro, Ignacio; Kim, Jung-Mu

    2012-01-01

    We firstly propose the concept of a frequency and bandwidth fine-tuning method using an RF MEMS-based suspended tunable band-stop resonator. We experimentally show the feasibility of the continuously tuned resonator, including a second-order filter, which consists of cascaded resonators to achieve center frequency and bandwidth fine tuning. The structure consists of a freestanding half-wavelength (λ/2) resonator connected to a large displacement comb actuator. The lateral movement of the λ/2 resonator over the main transmission line produces different electromagnetic decoupling values from the main transmission line. The decoupled energy leads to continuous center frequency and bandwidth tuning using the band-stop resonator circuit for fine-tuning applications. The freestanding λ/2 resonator plays the role of a variable capacitor as well as a decoupling resonator in the proposed structure. The fabricated tunable filter shows suitability for Ku-band wireless communication system applications with continuous reconfiguration

  4. Corrugated structure insertion for extending the SASE bandwidth up to 3% at the European XFEL

    International Nuclear Information System (INIS)

    Zagorodnov, I.; Feng, G.; Limberg, T.

    2016-07-01

    The usage of X-ray free electron laser (XFEL) in femtosecond nanocrystallography involves sequential illumination of many small crystals of arbitrary orientation. Hence a wide radiation bandwidth will be useful in order to obtain and to index a larger number of Bragg peaks used for determination of the crystal orientation. Considering the baseline configuration of the European XFEL in Hamburg, and based on beam dynamics simulations, we demonstrate here that the usage of corrugated structures allows for a considerable increase in radiation bandwidth. Data collection with a 3% bandwidth, a few microjoule radiation pulse energy, a few femtosecond pulse duration, and a photon energy of 5.4 keV is possible. For this study we have developed an analytical modal representation of the short-range wake function of the flat corrugated structures for arbitrary offsets of the source and the witness particles.

  5. Local intelligent electronic device (IED) rendering templates over limited bandwidth communication link to manage remote IED

    Science.gov (United States)

    Bradetich, Ryan; Dearien, Jason A; Grussling, Barry Jakob; Remaley, Gavin

    2013-11-05

    The present disclosure provides systems and methods for remote device management. According to various embodiments, a local intelligent electronic device (IED) may be in communication with a remote IED via a limited bandwidth communication link, such as a serial link. The limited bandwidth communication link may not support traditional remote management interfaces. According to one embodiment, a local IED may present an operator with a management interface for a remote IED by rendering locally stored templates. The local IED may render the locally stored templates using sparse data obtained from the remote IED. According to various embodiments, the management interface may be a web client interface and/or an HTML interface. The bandwidth required to present a remote management interface may be significantly reduced by rendering locally stored templates rather than requesting an entire management interface from the remote IED. According to various embodiments, an IED may comprise an encryption transceiver.

  6. Investigating the influence of chromatic aberration and optical illumination bandwidth on fundus imaging in rats

    Science.gov (United States)

    Li, Hao; Liu, Wenzhong; Zhang, Hao F.

    2015-10-01

    Rodent models are indispensable in studying various retinal diseases. Noninvasive, high-resolution retinal imaging of rodent models is highly desired for longitudinally investigating the pathogenesis and therapeutic strategies. However, due to severe aberrations, the retinal image quality in rodents can be much worse than that in humans. We numerically and experimentally investigated the influence of chromatic aberration and optical illumination bandwidth on retinal imaging. We confirmed that the rat retinal image quality decreased with increasing illumination bandwidth. We achieved the retinal image resolution of 10 μm using a 19 nm illumination bandwidth centered at 580 nm in a home-built fundus camera. Furthermore, we observed higher chromatic aberration in albino rat eyes than in pigmented rat eyes. This study provides a design guide for high-resolution fundus camera for rodents. Our method is also beneficial to dispersion compensation in multiwavelength retinal imaging applications.

  7. Optical Sideband Generation: a Longitudinal Electron Beam Diagnostic Beyond the Laser Bandwidth Resolution Limit

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence Berkeley National Laboratory; Tilborg, J. van; Matlis, N. H.; Plateau, G. R.; Leemans, W. P.

    2010-06-01

    Electro-optic sampling (EOS) is widely used as a technique to measure THz-domain electric field pulses such asthe self-fields of femtosecond electron beams. We present an EOS-based approach for single-shot spectral measurement that excels in simplicity (compatible with fiber integration) and bandwidth coverage (overcomes the laser bandwidth limitation), allowing few-fs electron beams or single-cycle THz pulses to be characterized with conventional picosecond probes. It is shown that the EOS-induced optical sidebands on the narrow-bandwidth optical probe are spectrally-shifted replicas of the THz pulse. An experimental demonstration on a 0-3 THz source is presented.

  8. Investigation of Diagonal Antenna-Chassis Mode in Mobile Terminal LTE MIMO Antennas for Bandwidth Enhancement

    DEFF Research Database (Denmark)

    Zhang, Shuai; Zhao, Kun; Ying, Zhinong

    2015-01-01

    mechanism of the mismatch of these three bandwidth ranges is also explained. Furthermore, the diagonal antenna-chassis mode is also studied for MIMO elements in the adjacent and diagonal corner locations. As a practical example, a wideband collocated LTE MIMO antenna is proposed and measured. It covers......A diagonal antenna-chassis mode is investigated in long-term evolution multiple-input-multiple-output (LTE MIMO) antennas. The MIMO bandwidth is defined in this paper as the overlap range of the low-envelope correlation coefficient, high total efficiency, and -6-dB impedance matching bandwidths...... the bands of 740960 and 1700-2700 MHz, where the total efficiencies are better than -3.4 and -1.8 dB, with lower than 0.5 and 0.1, respectively. The measurements agree well with the simulations. Since the proposed method only needs to modify the excitation locations of the MIMO elements on the chassis...

  9. High Dielectric Low Loss Transparent Glass Material Based Dielectric Resonator Antenna with Wide Bandwidth Operation

    Science.gov (United States)

    Mehmood, Arshad; Zheng, Yuliang; Braun, Hubertus; Hovhannisyan, Martun; Letz, Martin; Jakoby, Rolf

    2015-01-01

    This paper presents the application of new high permittivity and low loss glass material for antennas. This glass material is transparent. A very simple rectangular dielectric resonator antenna is designed first with a simple microstrip feeding line. In order to widen the bandwidth, the feed of the design is modified by forming a T-shaped feeding. This new design enhanced the bandwidth range to cover the WLAN 5 GHz band completely. The dielectric resonator antenna cut into precise dimensions is placed on the modified microstrip feed line. The design is simple and easy to manufacture and also very compact in size of only 36 × 28 mm. A -10 dB impedance bandwidth of 18% has been achieved, which covers the frequency range from 5.15 GHz to 5.95 GHz. Simulations of the measured return loss and radiation patterns are presented and discussed.

  10. Analysis of blocking rate and bandwidth usage of mobile IPTV services in wireless cellular networks.

    Science.gov (United States)

    Li, Mingfu

    2014-01-01

    Mobile IPTV services over wireless cellular networks become more and more popular, owing to the significant growth in access bandwidth of wireless cellular networks such as 3G/4G and WiMAX. However, the spectrum resources of wireless cellular networks is rare. How to enhance the spectral efficiency of mobile networks becomes an important issue. Unicast, broadcast, and multicast are the most important transport schemes for offering mobile IPTV services over wireless cellular networks. Therefore, bandwidth usages and blocking rates of unicast, broadcast, and multicast IPTV services were analyzed and compared in this paper. Simulations were also conducted to validate the analytical results. Numerical results demonstrate that the presented analysis is correct, and multicast scheme achieves the best bandwidth usage and blocking rate performance, relative to the other two schemes.

  11. Sharing the dance -

    DEFF Research Database (Denmark)

    He, Jing; Ravn, Susanne

    2018-01-01

    In his recent works on daily face-to-face encounters, Zahavi claims that the phenomenon of sharing involves reciprocity. Following Zahavi’s line of thought, we wonder what exactly reciprocity amounts to and how the shared experience emerges from the dynamic process of interaction. By turning...... to the highly specialized field of elite sports dance, we aim at exploring the way in which reciprocity unfolds in intensive deliberate practices of movement. In our analysis, we specifically argue that the ongoing dynamics of two separate flows of movement constitute a shared experience of dancing together...

  12. Global resource sharing

    CERN Document Server

    Frederiksen, Linda; Nance, Heidi

    2011-01-01

    Written from a global perspective, this book reviews sharing of library resources on a global scale. With expanded discovery tools and massive digitization projects, the rich and extensive holdings of the world's libraries are more visible now than at any time in the past. Advanced communication and transmission technologies, along with improved international standards, present a means for the sharing of library resources around the globe. Despite these significant improvements, a number of challenges remain. Global Resource Sharing provides librarians and library managers with a comprehensive

  13. Report endorses data sharing

    Science.gov (United States)

    The potential benefits of sharing data so outweigh its costs that investigators should be required to include plans for sharing data as part of their grant proposals, according to recommendations issued recently by the Committee on National Statistics (CNSTAT) of the National Research Council (NRC).In their report Sharing Research Data, CNSTAT also recommended that “Journals should give more emphasis to reports of secondary analyses and to replications,” provided that the original collections of data receive full credit. In addition, “Journal editors should require authors to provide access to data during the peer review process.”

  14. Theoretical study on the ultra-narrow bandwidth tunable atomic filter with electromagnetically induced transparency

    Science.gov (United States)

    Liu, Yang; Li, Shu-qing; Feng, Zhong-ying; Liu, Xiao-fei; Gao, Jin-yue

    2016-12-01

    To obtain the weak signal light detection from the high background noise, we present a theoretical study on the ultra-narrow bandwidth tunable atomic filter with electromagnetically induced transparency. In a three-level Λ -type atomic system in the rubidium D1 line, the bandwidth of the EIT atomic filter is narrowed to ~6.5 \\text{MHz} . And the single peak transmission of the filter can be up to 86% . Moreover, the transmission wavelength can be tuned by changing the coupling light frequency. This theoretical scheme can also be applied to other alkali atomic systems.

  15. Comparison of Available Bandwidth Estimation Techniques in Packet-Switched Mobile Networks

    DEFF Research Database (Denmark)

    López Villa, Dimas; Ubeda Castellanos, Carlos; Teyeb, Oumer Mohammed

    2006-01-01

    The relative contribution of the transport network towards the per-user capacity in mobile telecommunication systems is becoming very important due to the ever increasing air-interface data rates. Thus, resource management procedures such as admission, load and handover control can make use...... of information regarding the available bandwidth in the transport network, as it could end up being the bottleneck rather than the air interface. This paper provides a comparative study of three well known available bandwidth estimation techniques, i.e. TOPP, SLoPS and pathChirp, taking into account...

  16. Zero-Dispersion Slow Light with Wide Bandwidth in Photonic Crystal Coupled Waveguides

    International Nuclear Information System (INIS)

    Xiao-Yu, Mao; Geng-Yan, Zhang; Yi-Dong, Huang; Wei, Zhang; Jiang-De, Peng

    2008-01-01

    By introducing an adjustment waveguide besides the incident waveguide, zero-dispersion slow light with wide bandwidth can be realized due to anticrossing of the incident waveguide mode and the adjustment waveguide mode. The width of the adjustment waveguide (W 2 ) and the hole radii of the coupling region (r') will change the dispersion of incident waveguide mode. Theoretical investigation reveals that zero dispersion at various low group velocity ν g in incident waveguide can be achieved. In particular, proper W 2 and r' can lead to the lowest ν g of 0.0085c at 1550 nm with wide bandwidth of 202 GHz for zero dispersion

  17. Low Voltage CMOS Fully Differential Current Feedback Amplifier with Controllable 3-dB Bandwidth

    International Nuclear Information System (INIS)

    Madian, A.H.; Mahmoud, S.A.; Ashour, M.A.; Soliman, A.M.

    2008-01-01

    This paper presents a new CMOS fully differential current feedback operational amplifier with controllable 3-dB bandwidth suitable for analog data processing and acquisition applications. The FDCFOA has the advantage of a wide range controllable 3-dB bandwidth (∼57 MHz to 500 MHz) without changing the feedback resistance this guarantee the stability of the circuit. The FDCFOA has a standby current of 320μA. PSpice simulations of the FDCFOA block were given using 0.25μm CMOS technology from AMI MOSIS and dual supply voltages ±0.75 V

  18. High efficiency and broad bandwidth grating coupler between nanophotonic waveguide and fibre

    International Nuclear Information System (INIS)

    Yu, Zhu; Xue-Jun, Xu; Zhi-Yong, Li; Liang, Zhou; Yu-De, Yu; Jin-Zhong, Yu; Wei-Hua, Han; Zhong-Chao, Fan

    2010-01-01

    A high efficiency and broad bandwidth grating coupler between a silicon-on-insulator (SOI) nanophotonic waveguide and fibre is designed and fabricated. Coupling efficiencies of 46% and 25% at a wavelength of 1.55 μm are achieved by simulation and experiment, respectively. An optical 3 dB bandwidth of 45 nm from 1530 nm to 1575 nm is also obtained in experiment. Numerical calculation shows that a tolerance to fabrication error of 10 nm in etch depth is achievable. The measurement results indicate that the alignment error of ±2 μm results in less than 1 dB additional coupling loss. (classical areas of phenomenology)

  19. Optical Characteristics of a Multichannel Hybrid Integrated Light Source for Ultra-High-Bandwidth Optical Interconnections

    Directory of Open Access Journals (Sweden)

    Takanori Shimizu

    2015-11-01

    Full Text Available The optical characteristics of a multi-channel hybrid integrated light source were described for an optical interconnection with a bandwidth of over 10 Tbit/s. The power uniformity of the relative intensity of a 1000-channel light source was shown, and the minimum standard deviation s of the optical power of the 200 output ports at each 25-channel laser diode (LD array was estimated to be 0.49 dB. This hybrid integrated light source is expected to be easily adaptable to a photonics-electronics convergence system for ultra-high-bandwidth interchip interconnections.

  20. Study of the spectral bandwidth of a double-pass acousto-optic system [Invited].

    Science.gov (United States)

    Champagne, Justine; Kastelik, Jean-Claude; Dupont, Samuel; Gazalet, Joseph

    2018-04-01

    Acousto-optic tunable filters are known as efficient instruments for spectral and spatial filtering of light. In this paper, we analyze the bandwidth dependence of a double-pass filter. The interaction geometry chosen allows the simultaneous diffraction of the ordinary and the extraordinary optical modes by a single ultrasonic frequency. We present the main parameters of a custom device (design, optical range, driving frequency) and experimental results concerning the angular deviation of the beams including the effect of optical birefringence. The spectral resolution and the side lobes' significance are discussed. Spectral bandwidth of such a system is analyzed.

  1. Online file sharing innovations in media consumption

    CERN Document Server

    Andersson Schwarz, Jonas

    2013-01-01

    It is apparent that file sharing on the Internet has become an emerging norm of media consumption-especially among young people. This book provides a critical perspective on this phenomenon, exploring issues related to file sharing, downloading, peer-to-peer networks, ""piracy,"" and (not least) policy issues regarding these practices. Andersson Schwartz critically engages with the justificatory discourses of the actual file-sharers, taking Sweden as a geographic focus. By focusing on the example of Sweden-home to both The Pirate Bay and Spotify-he provides a unique insight into a mentality th

  2. Sharing casting technological data on web site

    Directory of Open Access Journals (Sweden)

    Li Hailan

    2008-11-01

    Full Text Available Based on database and asp.net technologies, a web platform of scientific data in the casting technology fi eld has been developed. This paper presents the relevant data system structure, the approaches to the data collection, the applying methods and policy in data sharing, and depicts the collected and shared data recently fi nished. Statistics showed that there are about 20,000 visitors in China every day visiting the related data through the web, proving that many engineers or other relevant persons are interested in the data.

  3. Facilitating Knowledge Sharing

    DEFF Research Database (Denmark)

    Holdt Christensen, Peter

    knowledge sharing is to ensure that the exchange is seen as equitable for the parties involved, and by viewing the problems of knowledge sharing as motivational problems situated in different organizational settings, the paper explores how knowledge exchange can be conceptualized as going on in four...... distinct situations of exchange denominated organizational exchange yielding extrinsic rewards, organizational exchange yielding intrinsic rewards, financial exchange, and social exchange. The paper argues that each situation of exchange has distinct assumptions about individual behaviour...... and the intermediaries regulating the exchange, and facilitating knowledge sharing should therefore be viewed as a continuum of practices under the influence of opportunistic behaviour, obedience or organizational citizenship behaviour. Keywords: Knowledge sharing, motivation, organizational settings, situations...

  4. A Sharing Proposition.

    Science.gov (United States)

    Sturgeon, Julie

    2002-01-01

    Describes how the University of Vermont and St. Michael's College in Burlington, Vermont cooperated to share a single card access system. Discusses the planning, financial, and marketplace advantages of the cooperation. (EV)

  5. Pricing Shared Appreciation Mortgages

    OpenAIRE

    Zhong, Yina

    2006-01-01

    This paper develops a model for the valuation of shared appreciation mortgage (SAM) and examines the effect of reduction in interest rate on the mortgage duration and share of property appreciation lender charges. The recent rise in SAM availability, as a result of some secondary market financial support and prerequisite standardization, motivates a more careful consideration of the underlying SAM value. The primary difference between the SAM model and the model for general traditional mor...

  6. Sharing resources@CERN

    CERN Multimedia

    Maximilien Brice

    2002-01-01

    The library is launching a 'sharing resources@CERN' campaign, aiming to increase the library's utility by including the thousands of books bought by individual groups at CERN. This will improve sharing of information among CERN staff and users. Photo 01: L. to r. Eduardo Aldaz, from the PS division, Corrado Pettenati, Head Librarian, and Isabel Bejar, from the ST division, read their divisional copies of the same book.

  7. SharePoint governance

    OpenAIRE

    Ali, Mudassar

    2013-01-01

    Masteroppgave i informasjons- og kommunikasjonsteknologi IKT590 2013 – Universitetet i Agder, Grimstad SharePoint is a web-based business collaboration platform from Microsoft which is very robust and dynamic in nature. The platform has been in the market for more than a decade and has been adapted by large number of organisations in the world. The platform has become larger in scale, richer in features and is improving consistently with every new version. However, SharePoint ...

  8. Generalized Load Sharing for Homogeneous Networks of Distributed Environment

    Directory of Open Access Journals (Sweden)

    A. Satheesh

    2008-01-01

    Full Text Available We propose a method for job migration policies by considering effective usage of global memory in addition to CPU load sharing in distributed systems. When a node is identified for lacking sufficient memory space to serve jobs, one or more jobs of the node will be migrated to remote nodes with low memory allocations. If the memory space is sufficiently large, the jobs will be scheduled by a CPU-based load sharing policy. Following the principle of sharing both CPU and memory resources, we present several load sharing alternatives. Our objective is to reduce the number of page faults caused by unbalanced memory allocations for jobs among distributed nodes, so that overall performance of a distributed system can be significantly improved. We have conducted trace-driven simulations to compare CPU-based load sharing policies with our policies. We show that our load sharing policies not only improve performance of memory bound jobs, but also maintain the same load sharing quality as the CPU-based policies for CPU-bound jobs. Regarding remote execution and preemptive migration strategies, our experiments indicate that a strategy selection in load sharing is dependent on the amount of memory demand of jobs, remote execution is more effective for memory-bound jobs, and preemptive migration is more effective for CPU-bound jobs. Our CPU-memory-based policy using either high performance or high throughput approach and using the remote execution strategy performs the best for both CPU-bound and memory-bound job in homogeneous networks of distributed environment.

  9. Regulating the sharing economy

    Directory of Open Access Journals (Sweden)

    Kristofer Erickson

    2016-06-01

    Full Text Available In this introductory essay, we explore definitions of the ‘sharing economy’, a concept indicating both social (relational, communitarian and economic (allocative, profit-seeking aspects which appear to be in tension. We suggest combining the social and economic logics of the sharing economy to focus on the central features of network enabled, aggregated membership in a pool of offers and demands (for goods, services, creative expressions. This definition of the sharing economy distinguishes it from other related peer-to-peer and collaborative forms of production. Understanding the social and economic motivations for and implications of participating in the sharing economy is important to its regulation. Each of the papers in this special issue contributes to knowledge by linking the social and economic aspects of sharing economy practices to regulatory norms and mechanisms. We conclude this essay by suggesting future research to further clarify and render intelligible the sharing economy, not as a contradiction in terms but as an empirically observable realm of socio-economic activity.

  10. A Variable Service Broker Routing Policy for data center selection in cloud analyst

    Directory of Open Access Journals (Sweden)

    Ahmad M. Manasrah

    2017-07-01

    Full Text Available Cloud computing depends on sharing distributed computing resources to handle different services such as servers, storage and applications. The applications and infrastructures are provided as pay per use services through data center to the end user. The data centers are located at different geographic locations. However, these data centers can get overloaded with the increase number of client applications being serviced at the same time and location; this will degrade the overall QoS of the distributed services. Since different user applications may require different configuration and requirements, measuring the user applications performance of various resources is challenging. The service provider cannot make decisions for the right level of resources. Therefore, we propose a Variable Service Broker Routing Policy – VSBRP, which is a heuristic-based technique that aims to achieve minimum response time through considering the communication channel bandwidth, latency and the size of the job. The proposed service broker policy will also reduce the overloading of the data centers by redirecting the user requests to the next data center that yields better response and processing time. The simulation shows promising results in terms of response and processing time compared to other known broker policies from the literature.

  11. Removal of eye blink artifacts in wireless EEG sensor networks using reduced-bandwidth canonical correlation analysis.

    Science.gov (United States)

    Somers, Ben; Bertrand, Alexander

    2016-12-01

    Chronic, 24/7 EEG monitoring requires the use of highly miniaturized EEG modules, which only measure a few EEG channels over a small area. For improved spatial coverage, a wireless EEG sensor network (WESN) can be deployed, consisting of multiple EEG modules, which interact through short-distance wireless communication. In this paper, we aim to remove eye blink artifacts in each EEG channel of a WESN by optimally exploiting the correlation between EEG signals from different modules, under stringent communication bandwidth constraints. We apply a distributed canonical correlation analysis (CCA-)based algorithm, in which each module only transmits an optimal linear combination of its local EEG channels to the other modules. The method is validated on both synthetic and real EEG data sets, with emulated wireless transmissions. While strongly reducing the amount of data that is shared between nodes, we demonstrate that the algorithm achieves the same eye blink artifact removal performance as the equivalent centralized CCA algorithm, which is at least as good as other state-of-the-art multi-channel algorithms that require a transmission of all channels. Due to their potential for extreme miniaturization, WESNs are viewed as an enabling technology for chronic EEG monitoring. However, multi-channel analysis is hampered in WESNs due to the high energy cost for wireless communication. This paper shows that multi-channel eye blink artifact removal is possible with a significantly reduced wireless communication between EEG modules.

  12. Generic policy in Bulgaria: a policy of failure or success?

    Directory of Open Access Journals (Sweden)

    Assena Stoimenova

    2016-09-01

    Full Text Available Generic medicines play a key role in managing the financial resources for pharmaceuticals in every country. This study analysed the generic policy legislative framework in Bulgaria with the aim to identify whether the policy implementation can be considered successful in the light of an international review of such policies introduced in other countries, or on the contrary, it has failed to deliver the main benefits. Legislative analysis, desktop study and macroeconomic overview of the Bulgarian pharmaceutical market were included. The study showed that only 3 out of 11 important policy elements are implemented in the country. Bulgaria has one of the highest shares of generics, an average of 81.39% (volume, for the studied period (2006–2014. However, further research is needed to evaluate the success of the existing generic policy in Bulgaria, as the market share of generic drugs is not the only measure of the policy efficiency.

  13. Bandwidth-adaptable silicon photonic differentiator employing a slow light effect

    DEFF Research Database (Denmark)

    Yan, Siqi; Cheng, Ziwei; Frandsen, Lars Hagedorn

    2017-01-01

    width to half-maximums (FWHMs) ranging from 2.7 to 81.4 ps are accurately differentiated using our PhCW-MZI. Our all-passive scheme circumvents the bandwidth bottlenecks of previously reported photonic DIFFs and can greatly broaden the application area of photonic DIFFs. (C) 2017 Optical Society...

  14. Coherence bandwidth characterization in an urban microcell at 62.4 GHz

    DEFF Research Database (Denmark)

    Sánchez, M. G.; Hammoudeh, A. M.; Grindrod, E.

    2000-01-01

    Results of experiments made at 62.4 GHz in an urban mobile radio environment to characterize the coherence bandwidth are presented. The correlation coefficients between signal envelopes separated in frequency are measured and expressed as functions of distance from the base station. Due to the hi...

  15. BHCDA: Bandwidth Efficient Heterogeneity aware Cluster based Data Aggregation for Wireless Sensor Network

    DEFF Research Database (Denmark)

    Dnyaneshwar, Mantri; Prasad, Neeli R.; Prasad, Ramjee

    2013-01-01

    The fundamental challenge in the design of Wireless sensor Network (WSNs) is proper utilization of resources which are scare. One of the critical challenges is to maximize the bandwidth utilization in data gathering from sensor nodes and forward to sink. The main design objective of this paper...

  16. Bandwidth efficient cluster-based data aggregation for Wireless Sensor Network

    DEFF Research Database (Denmark)

    Dnyaneshwar, Mantri; Prasad, Neeli R.; Prasad, Ramjee

    2015-01-01

    A fundamental challenge in the design of Wireless Sensor Network (WSNs) is the proper utilization of resources that are scarce. The critical challenge is to maximize the bandwidth utilization in data gathering and forwarding from sensor nodes to the sink. The main design objective is to utilize...

  17. A high performance long-reach passive optical network with a novel excess bandwidth distribution scheme

    Science.gov (United States)

    Chao, I.-Fen; Zhang, Tsung-Min

    2015-06-01

    Long-reach passive optical networks (LR-PONs) have been considered to be promising solutions for future access networks. In this paper, we propose a distributed medium access control (MAC) scheme over an advantageous LR-PON network architecture that reroutes the control information from and back to all ONUs through an (N + 1) × (N + 1) star coupler (SC) deployed near the ONUs, thereby overwhelming the extremely long propagation delay problem in LR-PONs. In the network, the control slot is designed to contain all bandwidth requirements of all ONUs and is in-band time-division-multiplexed with a number of data slots within a cycle. In the proposed MAC scheme, a novel profit-weight-based dynamic bandwidth allocation (P-DBA) scheme is presented. The algorithm is designed to efficiently and fairly distribute the amount of excess bandwidth based on a profit value derived from the excess bandwidth usage of each ONU, which resolves the problems of previously reported DBA schemes that are either unfair or inefficient. The simulation results show that the proposed decentralized algorithms exhibit a nearly three-order-of-magnitude improvement in delay performance compared to the centralized algorithms over LR-PONs. Moreover, the newly proposed P-DBA scheme guarantees low delay performance and fairness even when under attack by the malevolent ONU irrespective of traffic loads and burstiness.

  18. Note: Expanding the bandwidth of the ultra-low current amplifier using an artificial negative capacitor.

    Science.gov (United States)

    Xie, Kai; Liu, Yan; Li, XiaoPing; Guo, Lixin; Zhang, Hanlu

    2016-04-01

    The bandwidth and low noise characteristics are often contradictory in ultra-low current amplifier, because an inevitable parasitic capacitance is paralleled with the high value feedback resistor. In order to expand the amplifier's bandwidth, a novel approach was proposed by introducing an artificial negative capacitor to cancel the parasitic capacitance. The theory of the negative capacitance and the performance of the improved amplifier circuit with the negative capacitor are presented in this manuscript. The test was conducted by modifying an ultra-low current amplifier with a trans-impedance gain of 50 GΩ. The results show that the maximum bandwidth was expanded from 18.7 Hz to 3.3 kHz with more than 150 times of increase when the parasitic capacitance (∼0.17 pF) was cancelled. Meanwhile, the rise time decreased from 18.7 ms to 0.26 ms with no overshot. Any desired bandwidth or rise time within these ranges can be obtained by adjusting the ratio of cancellation of the parasitic and negative capacitance. This approach is especially suitable for the demand of rapid response to weak current, such as transient ion-beam detector, mass spectrometry analysis, and fast scanning microscope.

  19. Gain-switched, Yb-doped, all-fiber laser with narrow bandwidth

    DEFF Research Database (Denmark)

    Larsen, Casper; Giesberts, Martin; Nyga, Sebastian

    2013-01-01

    We demonstrate that an all-fiber, narrow bandwidth, high pulse energy pulsed laser can be constructed from commercially available components by applying gain-switching. After single-stage amplification the pulses are frequency doubled in ppSLT with high efficiency....

  20. Note: Expanding the bandwidth of the ultra-low current amplifier using an artificial negative capacitor

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Kai, E-mail: kaixie@mail.xidian.edu.cn; Liu, Yan; Li, XiaoPing [School of Aerospace Science and Technology, Xidian University, Xi’an 710071 (China); Guo, Lixin [School of Physics and Optoelectronic Engineering, Xidian University, Xi’an 710071 (China); Zhang, Hanlu [School of Communication & Information Engineering, Xi’an University of Posts & Telecommunication, Xi’an 710121 (China)

    2016-04-15

    The bandwidth and low noise characteristics are often contradictory in ultra-low current amplifier, because an inevitable parasitic capacitance is paralleled with the high value feedback resistor. In order to expand the amplifier’s bandwidth, a novel approach was proposed by introducing an artificial negative capacitor to cancel the parasitic capacitance. The theory of the negative capacitance and the performance of the improved amplifier circuit with the negative capacitor are presented in this manuscript. The test was conducted by modifying an ultra-low current amplifier with a trans-impedance gain of 50 GΩ. The results show that the maximum bandwidth was expanded from 18.7 Hz to 3.3 kHz with more than 150 times of increase when the parasitic capacitance (∼0.17 pF) was cancelled. Meanwhile, the rise time decreased from 18.7 ms to 0.26 ms with no overshot. Any desired bandwidth or rise time within these ranges can be obtained by adjusting the ratio of cancellation of the parasitic and negative capacitance. This approach is especially suitable for the demand of rapid response to weak current, such as transient ion-beam detector, mass spectrometry analysis, and fast scanning microscope.

  1. Physical and electrical bandwidths of integrated photodiodes in standard CMOS technology

    NARCIS (Netherlands)

    Radovanovic, S.; Annema, Anne J.; Nauta, Bram

    2003-01-01

    The influence of different geometries (layouts) and structures of high-speed photodiodes in fully standard 0.18 μm CMOS technology on their intrinsic (physical) and electrical bandwidths is analyzed. Three photodiode structures are studied: nwell/p-substrate, p+/nwell/p-substrate and p+/nwell. The

  2. Efficient Bandwidth Allocation for Integrated Services in Broadband Wireless ATM Networks

    DEFF Research Database (Denmark)

    Liu, Hong; Dittmann, Lars; Gliese, Ulrik Bo

    1999-01-01

    An efficient bandwidth allocation scheme is proposed for supporting intergrated services in wireless ATM networks. These include CBR, VBR amd ABR types of traffic. The proposed scheme is based om A-PRMA for carrying ATM traffic in a dynamic TDMA type access system. It allows mobile users to adjust...

  3. Optimization of Joint Power and Bandwidth Allocation in Multi-Spot-Beam Satellite Communication Systems

    Directory of Open Access Journals (Sweden)

    Heng Wang

    2014-01-01

    Full Text Available Multi-spot-beam technique has been widely applied in modern satellite communication systems. However, the satellite power and bandwidth resources in a multi-spot-beam satellite communication system are scarce and expensive; it is urgent to utilize the resources efficiently. To this end, dynamically allocating the power and bandwidth is an available way. This paper initially formulates the problem of resource joint allocation as a convex optimization problem, taking into account a compromise between the maximum total system capacity and the fairness among the spot beams. A joint bandwidth and power allocation iterative algorithm based on duality theory is then proposed to obtain the optimal solution of this optimization problem. Compared with the existing separate bandwidth or power optimal allocation algorithms, it is shown that the joint allocation algorithm improves both the total system capacity and the fairness among spot beams. Moreover, it is easy to be implemented in practice, as the computational complexity of the proposed algorithm is linear with the number of spot beams.

  4. High Bandwidth Communications Links Between Heterogeneous Autonomous Vehicles Using Sensor Network Modeling and Extremum Control Approaches

    Science.gov (United States)

    2008-12-01

    In future network-centric warfare environments, teams of autonomous vehicles will be deployed in a coorperative manner to conduct wide-area...of data back to the command station, autonomous vehicles configured with high bandwidth communication system are positioned between the command

  5. Bandwidth Dependence of Laser Plasma Instabilities Driven by the Nike KrF Laser

    Science.gov (United States)

    Weaver, J. L.; Oh, J.; Seely, J.; Kehne, D.; Brown, C. M.; Obenschain, S.; Serlin, V.; Schmitt, A. J.; Phillips, L.; Lehmberg, R. H.; McLean, E.; Manka, C.; Feldman, U.

    2011-10-01

    The Nike krypton-fluoride (KrF) laser at the Naval Research Laboratory operates in the deep UV (248 nm) and employs beam smoothing by induced spatial incoherence (ISI). In the first ISI studies at longer wavelengths (1054 nm and 527 nm) [Obenschain, PRL 62, 768(1989);Mostovych, PRL, 59, 1193(1987); Peyser, Phys. Fluids B 3, 1479(1991)], stimulated Raman scattering, stimulated Brillouin scattering, and the two plasmon decay instability were reduced when wide bandwidth ISI (δν / ν ~ 0.03-0.19%) pulses irradiated targets at moderate to high intensities (1014-1015W/cm2) . Recent Nike work showed that the threshold for quarter critical instabilities increased with the expected wavelength scaling, without accounting for the large bandwidth (δν ~ 1-3 THz). New experiments will compare laser plasma instabilities (LPI) driven by narrower bandwidth pulses to those observed with the standard operation. The bandwidth of KrF lasers can be reduced by adding narrow filters (etalons or gratings) in the initial stages of the laser. This talk will discuss the method used to narrow the output spectrum of Nike, the laser performance for this new operating mode, and target observations of LPI in planar CH targets. Work supported by DoE/NNSA.

  6. Bandwidth and power allocation for two-way relaying in overlay cognitive radio systems

    KAUST Repository

    Alsharoa, Ahmad M.; Ghazzai, Hakim; Yaacoub, Elias E.; Alouini, Mohamed-Slim

    2014-01-01

    In this paper, the problem of both bandwidth and power allocation for two-way multiple relay systems in overlay cognitive radio (CR) setup is investigated. In the CR overlay mode, primary users (PUs) cooperate with cognitive users (CUs) for mutual

  7. Cluster Formation and Joint Power-Bandwidth Allocation for Imperfect NOMA in DL-HetNets

    KAUST Repository

    Celik, Abdulkadir; Al-Qahtani, Fawaz; Radaydeh, Redha; Alouini, Mohamed-Slim

    2017-01-01

    and estimation errors. Then, a generic cluster formation (CF) and Power-Bandwidth Allocation (PBA) is formulated as a mixed-integer non-linear programming (MINLP) problem for downlink (DL) heterogeneous networks (HetNets). After dividing the MINLP problem

  8. High-bandwidth and flexible tracking control for precision motion with application to a piezo nanopositioner.

    Science.gov (United States)

    Feng, Zhao; Ling, Jie; Ming, Min; Xiao, Xiao-Hui

    2017-08-01

    For precision motion, high-bandwidth and flexible tracking are the two important issues for significant performance improvement. Iterative learning control (ILC) is an effective feedforward control method only for systems that operate strictly repetitively. Although projection ILC can track varying references, the performance is still limited by the fixed-bandwidth Q-filter, especially for triangular waves tracking commonly used in a piezo nanopositioner. In this paper, a wavelet transform-based linear time-varying (LTV) Q-filter design for projection ILC is proposed to compensate high-frequency errors and improve the ability to tracking varying references simultaneously. The LVT Q-filter is designed based on the modulus maximum of wavelet detail coefficients calculated by wavelet transform to determine the high-frequency locations of each iteration with the advantages of avoiding cross-terms and segmenting manually. The proposed approach was verified on a piezo nanopositioner. Experimental results indicate that the proposed approach can locate the high-frequency regions accurately and achieve the best performance under varying references compared with traditional frequency-domain and projection ILC with a fixed-bandwidth Q-filter, which validates that through implementing the LTV filter on projection ILC, high-bandwidth and flexible tracking can be achieved simultaneously by the proposed approach.

  9. Low-Bandwidth Channel Quality Indication for OFDMA Frequency Domain Packet Scheduling

    DEFF Research Database (Denmark)

    Kolding, Troels E.; Frederiksen, Frank; Pokhariyal, Akhilesh

    2007-01-01

    -relevant information in the CQI. We find that a 60-70% CQI bandwidth reduction is possible with less than 5-10% impact on scheduling performance. Further, we consider the impact of lowering the CQI reporting rate on both mobility performance and increased measuring accuracy due to longer averaging interval. We find...

  10. Experimental demonstration of an improved EPON architecture using OFDMA for bandwidth scalable LAN emulation

    DEFF Research Database (Denmark)

    Deng, Lei; Zhao, Ying; Yu, Xianbin

    2011-01-01

    We propose and demonstrate an improved Ethernet passive optical network (EPON) architecture supporting bandwidth-scalable physical layer local area network (LAN) emulation. Due to the use of orthogonal frequency division multiple access (OFDMA) technology for the LAN traffic transmission, there i...

  11. Open Access Data Sharing in Genomic Research

    Directory of Open Access Journals (Sweden)

    Stacey Pereira

    2014-08-01

    Full Text Available The current emphasis on broad sharing of human genomic data generated in research in order to maximize utility and public benefit is a significant legacy of the Human Genome Project. Concerns about privacy and discrimination have led to policy responses that restrict access to genomic data as the means for protecting research participants. Our research and experience show, however, that a considerable number of research participants agree to open access sharing of their genomic data when given the choice. General policies that limit access to all genomic data fail to respect the autonomy of these participants and, at the same time, unnecessarily limit the utility of the data. We advocate instead a more balanced approach that allows for individual choice and encourages informed decision making, while protecting against the misuse of genomic data through enhanced legislation.

  12. Financial Impact of Liver Sharing and Organ Procurement Organizations' Experience With Share 35: Implications for National Broader Sharing.

    Science.gov (United States)

    Fernandez, H; Weber, J; Barnes, K; Wright, L; Levy, M

    2016-01-01

    The Share 35 policy for organ allocation, which was adopted in June 2013, allocates livers regionally for candidates with Model for End-Stage Liver Disease scores of 35 or greater. The authors analyzed the costs resulting from the increased movement of allografts related to this new policy. Using a sample of nine organ procurement organizations, representing 17% of the US population and 19% of the deceased donors in 2013, data were obtained on import and export costs before Share 35 implementation (June 15, 2012, to June 14, 2013) and after Share 35 implementation (June 15, 2013, to June 14, 2014). Results showed that liver import rates increased 42%, with an increased cost of 51%, while export rates increased 112%, with an increased cost of 127%. When the costs of importing and exporting allografts were combined, the total change in costs for all nine organ procurement organizations was $11 011 321 after Share 35 implementation. Extrapolating these costs nationally resulted in an increased yearly cost of $68 820 756 by population or $55 056 605 by number of organ donors. Any alternative allocation proposal needs to account for the financial implications to the transplant infrastructure. © Copyright 2015 The American Society of Transplantation and the American Society of Transplant Surgeons.

  13. Labia Majora Share

    Directory of Open Access Journals (Sweden)

    Hanjing Lee

    2017-01-01

    Full Text Available Defects involving specialised areas with characteristic anatomical features, such as the nipple, upper eyelid, and lip, benefit greatly from the use of sharing procedures. The vulva, a complex 3-dimensional structure, can also be reconstructed through a sharing procedure drawing upon the contralateral vulva. In this report, we present the interesting case of a patient with chronic, massive, localised lymphedema of her left labia majora that was resected in 2011. Five years later, she presented with squamous cell carcinoma over the left vulva region, which is rarely associated with chronic lymphedema. To the best of our knowledge, our management of the radical vulvectomy defect with a labia majora sharing procedure is novel and has not been previously described. The labia major flap presented in this report is a shared flap; that is, a transposition flap based on the dorsal clitoral artery, which has consistent vascular anatomy, making this flap durable and reliable. This procedure epitomises the principle of replacing like with like, does not interfere with leg movement or patient positioning, has minimal donor site morbidity, and preserves other locoregional flap options for future reconstruction. One limitation is the need for a lax contralateral vulva. This labia majora sharing procedure is a viable option in carefully selected patients.

  14. Institutional shared resources and translational cancer research

    Directory of Open Access Journals (Sweden)

    De Paoli Paolo

    2009-06-01

    Full Text Available Abstract The development and maintenance of adequate shared infrastructures is considered a major goal for academic centers promoting translational research programs. Among infrastructures favoring translational research, centralized facilities characterized by shared, multidisciplinary use of expensive laboratory instrumentation, or by complex computer hardware and software and/or by high professional skills are necessary to maintain or improve institutional scientific competitiveness. The success or failure of a shared resource program also depends on the choice of appropriate institutional policies and requires an effective institutional governance regarding decisions on staffing, existence and composition of advisory committees, policies and of defined mechanisms of reporting, budgeting and financial support of each resource. Shared Resources represent a widely diffused model to sustain cancer research; in fact, web sites from an impressive number of research Institutes and Universities in the U.S. contain pages dedicated to the SR that have been established in each Center, making a complete view of the situation impossible. However, a nation-wide overview of how Cancer Centers develop SR programs is available on the web site for NCI-designated Cancer Centers in the U.S., while in Europe, information is available for individual Cancer centers. This article will briefly summarize the institutional policies, the organizational needs, the characteristics, scientific aims, and future developments of SRs necessary to develop effective translational research programs in oncology. In fact, the physical build-up of SRs per se is not sufficient for the successful translation of biomedical research. Appropriate policies to improve the academic culture in collaboration, the availability of educational programs for translational investigators, the existence of administrative facilitations for translational research and an efficient organization

  15. Institutional shared resources and translational cancer research.

    Science.gov (United States)

    De Paoli, Paolo

    2009-06-29

    The development and maintenance of adequate shared infrastructures is considered a major goal for academic centers promoting translational research programs. Among infrastructures favoring translational research, centralized facilities characterized by shared, multidisciplinary use of expensive laboratory instrumentation, or by complex computer hardware and software and/or by high professional skills are necessary to maintain or improve institutional scientific competitiveness. The success or failure of a shared resource program also depends on the choice of appropriate institutional policies and requires an effective institutional governance regarding decisions on staffing, existence and composition of advisory committees, policies and of defined mechanisms of reporting, budgeting and financial support of each resource. Shared Resources represent a widely diffused model to sustain cancer research; in fact, web sites from an impressive number of research Institutes and Universities in the U.S. contain pages dedicated to the SR that have been established in each Center, making a complete view of the situation impossible. However, a nation-wide overview of how Cancer Centers develop SR programs is available on the web site for NCI-designated Cancer Centers in the U.S., while in Europe, information is available for individual Cancer centers. This article will briefly summarize the institutional policies, the organizational needs, the characteristics, scientific aims, and future developments of SRs necessary to develop effective translational research programs in oncology.In fact, the physical build-up of SRs per se is not sufficient for the successful translation of biomedical research. Appropriate policies to improve the academic culture in collaboration, the availability of educational programs for translational investigators, the existence of administrative facilitations for translational research and an efficient organization supporting clinical trial recruitment

  16. Orientation masking and cross-orientation suppression (XOS): implications for estimates of filter bandwidth.

    Science.gov (United States)

    Meese, Tim S; Holmes, David J

    2010-10-01

    Most contemporary models of spatial vision include a cross-oriented route to suppression (masking from a broadly tuned inhibitory pool), which is most potent at low spatial and high temporal frequencies (T. S. Meese & D. J. Holmes, 2007). The influence of this pathway can elevate orientation-masking functions without exciting the target mechanism, and because early psychophysical estimates of filter bandwidth did not accommodate this, it is likely that they have been overestimated for this corner of stimulus space. Here we show that a transient 40% contrast mask causes substantial binocular threshold elevation for a transient vertical target, and this declines from a mask orientation of 0° to about 40° (indicating tuning), and then more gently to 90°, where it remains at a factor of ∼4. We also confirm that cross-orientation masking is diminished or abolished at high spatial frequencies and for sustained temporal modulation. We fitted a simple model of pedestal masking and cross-orientation suppression (XOS) to our data and those of G. C. Phillips and H. R. Wilson (1984) and found the dependency of orientation bandwidth on spatial frequency to be much less than previously supposed. An extension of our linear spatial pooling model of contrast gain control and dilution masking (T. S. Meese & R. J. Summers, 2007) is also shown to be consistent with our results using filter bandwidths of ±20°. Both models include tightly and broadly tuned components of divisive suppression. More generally, because XOS and/or dilution masking can affect the shape of orientation-masking curves, we caution that variations in bandwidth estimates might reflect variations in processes that have nothing to do with filter bandwidth.

  17. Collaborate, compete and share

    Science.gov (United States)

    Pugliese, Emanuele; Castellano, Claudio; Marsili, Matteo; Pietronero, Luciano

    2009-02-01

    We introduce and study a model of an interacting population of agents who collaborate in groups which compete for limited resources. Groups are formed by random matching agents and their worth is determined by the sum of the efforts deployed by agents in group formation. Agents, on their side, have to share their effort between contributing to their group’s chances to outcompete other groups and resource sharing among partners, when the group is successful. A simple implementation of this strategic interaction gives rise to static and evolutionary properties with a very rich phenomenology. A robust emerging feature is the separation of the population between agents who invest mainly in the success of their group and agents who concentrate in getting the largest share of their group’s profits.

  18. Urban sharing culture

    DEFF Research Database (Denmark)

    Fjalland, Emmy Laura Perez

    of the structures of the networked urban mobilities and holds the potentials to change the future mobilities. References Bauman, Zygmunt. 2000. Liquid Modernity. Cambridge: Polity. Beck, Ulrich. 1992. Risk Society: Towards a New Modernity (Published in Association with Theory, Culture & Society). London: SAGE......In urban areas sharing cultures, services and economies are rising. People share, rent and recycle their homes, cars, bikes, rides, tools, cloths, working space, knowhow and so on. The sharing culture can be understood as mobilities (Kesselring and Vogl 2013) of goods, values and ideas reshaping...... problems and side effects from concentration of consumption and contamination; and due to the shift from ownership to access it change our basic social cultural norms (Sayer 2005; Sayer 2011) about the ‘good’ life and social status (Freudendal-Pedersen 2007), commons and individuality, responsibility...

  19. Promoting cooperative federalism through state shared savings.

    Science.gov (United States)

    Weil, Alan

    2013-08-01

    The Affordable Care Act is transforming American federalism and creating strain between the states and the federal government. By expanding the scale of intergovernmental health programs, creating new state requirements, and setting the stage for increased federal fiscal oversight, the act has disturbed an uneasy truce in American federalism. This article outlines a policy proposal designed to harness cooperative federalism, based on the shared state and federal desire to control health care cost growth. The proposal, which borrows features of the Medicare Shared Savings Program, would provide states with an incentive in the form of an increased share of the savings they generate in programs that have federal financial participation, as long as they meet defined performance standards.

  20. Catch shares slow the race to fish

    Science.gov (United States)

    Birkenbach, Anna M.; Kaczan, David J.; Smith, Martin D.

    2017-04-01

    In fisheries, the tragedy of the commons manifests as a competitive race to fish that compresses fishing seasons, resulting in ecological damage, economic waste, and occupational hazards. Catch shares are hypothesized to halt the race by securing each individual’s right to a portion of the total catch, but there is evidence for this from selected examples only. Here we systematically analyse natural experiments to test whether catch shares reduce racing in 39 US fisheries. We compare each fishery treated with catch shares to an individually matched control before and after the policy change. We estimate an average policy treatment effect in a pooled model and in a meta-analysis that combines separate estimates for each treatment-control pair. Consistent with the theory that market-based management ends the race to fish, we find strong evidence that catch shares extend fishing seasons. This evidence informs the current debate over expanding the use of market-based regulation to other fisheries.

  1. The Audit Logic: Policy Compliance in Distributed Systems

    NARCIS (Netherlands)

    Cederquist, J.G.; Corin, R.J.; Dekker, M.A.C.; Etalle, Sandro; den Hartog, Jeremy; Lenzini, Gabriele

    2006-01-01

    We present a distributed framework where agents can share data along with usage policies. We use an expressive policy language including conditions, obligations and delegation. Our framework also supports the possibility to refine policies. Policies are not enforced a-priori. Instead policy

  2. Information Sharing and Knowledge Sharing as Communicative Activities

    Science.gov (United States)

    Savolainen, Reijo

    2017-01-01

    Introduction: This paper elaborates the picture of information sharing and knowledge sharing as forms of communicative activity. Method: A conceptual analysis was made to find out how researchers have approached information sharing and knowledge sharing from the perspectives of transmission and ritual. The findings are based on the analysis of one…

  3. Shared Care in Diabetes?

    DEFF Research Database (Denmark)

    Bødker, Keld

    2006-01-01

    The Danish National Board of Health has recently released a report that is intended to mark the start of a new project to establish it support for shared care in diabetes. In this paper I raise a number of concerns where lack of attention towards participation from prospective users constitute...

  4. Sharing (and) familiarities

    DEFF Research Database (Denmark)

    Rasmussen, Jon Dag; Winther, Ida Wentzel; Davies, Hayley

    but not exclusive to lifestories/biographies, travels, times, spaces and material items, bodies and intimate knowledge of one another, surnames - in the subjective lives of family members? Sociology has traditionally been preoccupied with notions and logics of sharing in homely contexts (e.g. Simmel’s work...

  5. The Sharing Economy

    DEFF Research Database (Denmark)

    Hamari, Juho; Sjöklint, Mimmi; Ukkonen, Antti

    2016-01-01

    Information and communications technologies (ICTs) have enabled the rise of so-called “Collaborative Consumption” (CC): the peer-to-peer-based activity of obtaining, giving, or sharing the access to goods and services, coordinated through community-based online services. CC has been expected to a...

  6. Shared goals and development

    DEFF Research Database (Denmark)

    Blomberg, Olle

    2015-01-01

    undemanding for children to engage in, and therefore has the potential to play a part in fostering their understanding of other minds. Part of the functional role of shared goals is to enable agents to choose means that are appropriate to realising a goal with others rather than individually. By offering...

  7. Inclusive Education in Progress: Policy Evolution in Four European Countries

    Science.gov (United States)

    Smyth, Fiona; Shevlin, Michael; Buchner, Tobias; Biewer, Gottfried; Flynn, Paula; Latimier, Camille; Šiška, Jan; Toboso-Martín, Mario; Rodríguez Díaz, Susana; Ferreira, Miguel A. V.

    2014-01-01

    This paper seeks to compare the evolution of inclusive education policy in the four countries of an EU-funded research project (QualiTYDES) operating under the shared policy environment of the UN, EU and European Commission. A shared policy cannot of course be assumed to result in common legislative or provisional outcomes at national level. The…

  8. Experimental demonstration of bandwidth on demand (BoD) provisioning based on time scheduling in software-defined multi-domain optical networks

    Science.gov (United States)

    Zhao, Yongli; Li, Yajie; Wang, Xinbo; Chen, Bowen; Zhang, Jie

    2016-09-01

    A hierarchical software-defined networking (SDN) control architecture is designed for multi-domain optical networks with the Open Daylight (ODL) controller. The OpenFlow-based Control Virtual Network Interface (CVNI) protocol is deployed between the network orchestrator and the domain controllers. Then, a dynamic bandwidth on demand (BoD) provisioning solution is proposed based on time scheduling in software-defined multi-domain optical networks (SD-MDON). Shared Risk Link Groups (SRLG)-disjoint routing schemes are adopted to separate each tenant for reliability. The SD-MDON testbed is built based on the proposed hierarchical control architecture. Then the proposed time scheduling-based BoD (Ts-BoD) solution is experimentally demonstrated on the testbed. The performance of the Ts-BoD solution is evaluated with respect to blocking probability, resource utilization, and lightpath setup latency.

  9. Gender diversity policies in universities: a multi-perspective framework of policy measures

    NARCIS (Netherlands)

    Timmers, T.M.; Willemsen, T.M.; Tijdens, K.G.

    2009-01-01

    Are policies to increase women’s share among university professors effective? The importance of gender equality on the labor market has been well established, but our understanding of what kind of policy is effective to increase the share of women is still unclear. Three sets of factors explain

  10. A simple tool for neuroimaging data sharing

    Directory of Open Access Journals (Sweden)

    Christian eHaselgrove

    2014-05-01

    Full Text Available Data sharing is becoming increasingly common, but despite encouragement and facilitation by funding agencies, journals, and some research efforts, most neuroimaging data acquired today is still not shared due to political, financial, social, and technical barriers to sharing data that remain. In particular, technical solutions are few for researchers that are not a part of larger efforts with dedicated sharing infrastructures, and social barriers such as the time commitment required to share can keep data from becoming publicly available.We present a system for sharing neuroimaging data, designed to be simple to use and to provide benefit to the data provider. The system consists of a server at the International Neuroinformatics Coordinating Facility (INCF and user tools for uploading data to the server. The primary design principle for the user tools is ease of use: the user identifies a directory containing DICOM data, provides their INCF Portal authentication, and provides identifiers for the subject and imaging session. The user tool anonymizes the data and sends it to the server. The server then runs quality control routines on the data, and the data and the quality control reports are made public. The user retains control of the data and may change the sharing policy as they need. The result is that in a few minutes of the user’s time, DICOM data can be anonymized and made publicly available, and an initial quality control assessment can be performed on the data. The system is currently functional, and user tools and access to the public image database are available at http://xnat.incf.org/.

  11. Bandwidth broadening of a graphene-based circular polarization converter by phase compensation.

    Science.gov (United States)

    Gao, Xi; Yang, Wanli; Cao, Weiping; Chen, Ming; Jiang, Yannan; Yu, Xinhua; Li, Haiou

    2017-10-02

    We present a broadband tunable circular polarization converter composed of a single graphene sheet patterned with butterfly-shaped holes, a dielectric spacer, and a 7-layer graphene ground plane. It can convert a linearly polarized wave into a circularly polarized wave in reflection mode. The polarization converter can be dynamically tuned by varying the Fermi energy of the single graphene sheet. Furthermore, the 7-layer graphene acting as a ground plane can modulate the phase of its reflected wave by controlling the Femi energy, which provides constructive interference condition at the surface of the single graphene sheet in a broad bandwidth and therefore significantly broadens the tunable bandwidth of the proposed polarization converter.

  12. Influence of Reduced Graphene Oxide on Effective Absorption Bandwidth Shift of Hybrid Absorbers.

    Directory of Open Access Journals (Sweden)

    Shahid Ameer

    Full Text Available The magnetic nanoparticle composite NiFe2O4 has traditionally been studied for high-frequency microwave absorption with marginal performance towards low-frequency radar bands (particularly L and S bands. Here, NiFe2O4 nanoparticles and nanohybrids using large-diameter graphene oxide (GO sheets are prepared via solvothermal synthesis for low-frequency wide bandwidth shielding (L and S radar bands. The synthesized materials were characterized using XRD, SEM, FTIR and microwave magneto dielectric spectroscopy. The dimension of these solvothermally synthesized pristine particles and hybrids lies within 30-58 nm. Microwave magneto-dielectric spectroscopy was performed in the low-frequency region in the 1 MHz-3 GHz spectrum. The as-synthesized pristine nanoparticles and hybrids were found to be highly absorbing for microwaves throughout the L and S radar bands ( 4 GHz with limited selective bandwidth.

  13. End-to-End Flow Control for Visual-Haptic Communication under Bandwidth Change

    Science.gov (United States)

    Yashiro, Daisuke; Tian, Dapeng; Yakoh, Takahiro

    This paper proposes an end-to-end flow controller for visual-haptic communication. A visual-haptic communication system transmits non-real-time packets, which contain large-size visual data, and real-time packets, which contain small-size haptic data. When the transmission rate of visual data exceeds the communication bandwidth, the visual-haptic communication system becomes unstable owing to buffer overflow. To solve this problem, an end-to-end flow controller is proposed. This controller determines the optimal transmission rate of visual data on the basis of the traffic conditions, which are estimated by the packets for haptic communication. Experimental results confirm that in the proposed method, a short packet-sending interval and a short delay are achieved under bandwidth change, and thus, high-precision visual-haptic communication is realized.

  14. Single-photon Coulomb explosion of methanol using broad bandwidth ultrafast EUV pulses.

    Science.gov (United States)

    Luzon, Itamar; Jagtap, Krishna; Livshits, Ester; Lioubashevski, Oleg; Baer, Roi; Strasser, Daniel

    2017-05-31

    Single-photon Coulomb explosion of methanol is instigated using the broad bandwidth pulse achieved through high-order harmonics generation. Using 3D coincidence fragment imaging of one molecule at a time, the kinetic energy release (KER) and angular distributions of the products are measured in different Coulomb explosion (CE) channels. Two-body CE channels breaking either the C-O or the C-H bonds are described as well as a proton migration channel forming H 2 O + , which is shown to exhibit higher KER. The results are compared to intense-field Coulomb explosion measurements in the literature. The interpretation of broad bandwidth single-photon CE data is discussed and supported by ab initio calculations of the predominant C-O bond breaking CE channel. We discuss the importance of these findings for achieving time resolved imaging of ultrafast dynamics.

  15. High-speed 405-nm superluminescent diode (SLD) with 807-MHz modulation bandwidth

    KAUST Repository

    Shen, Chao

    2016-08-25

    III-nitride LEDs are fundamental components for visible-light communication (VLC). However, the modulation bandwidth is inherently limited by the relatively long carrier lifetime. In this letter, we present the 405 nm emitting superluminescent diode (SLD) with tilted facet design on semipolar GaN substrate, showing a broad emission of ∼9 nm at 20 mW optical power. Owing to the fast recombination (τ<0.35 ns) through the amplified spontaneous emission, the SLD exhibits a significantly large 3-dB bandwidth of 807 MHz. A data rate of 1.3 Gbps with a bit-error rate of 2.9 × 10 was obtained using on-off keying modulation scheme, suggesting the SLD being a high-speed transmitter for VLC applications.

  16. Advances in broad bandwidth light sources for ultrahigh resolution optical coherence tomography

    International Nuclear Information System (INIS)

    Unterhuber, A; Povazay, B; Bizheva, K; Hermann, B; Sattmann, H; Stingl, A; Le, T; Seefeld, M; Menzel, R; Preusser, M; Budka, H; Schubert, Ch; Reitsamer, H; Ahnelt, P K; Morgan, J E; Cowey, A; Drexler, W

    2004-01-01

    Novel ultra-broad bandwidth light sources enabling unprecedented sub-2 μm axial resolution over the 400 nm-1700 nm wavelength range have been developed and evaluated with respect to their feasibility for clinical ultrahigh resolution optical coherence tomography (UHR OCT) applications. The state-of-the-art light sources described here include a compact Kerr lens mode locked Ti:sapphire laser (λ c = 785 nm, Δλ = 260 nm, P out = 50 mW) and different nonlinear fibre-based light sources with spectral bandwidths (at full width at half maximum) up to 350 nm at λ c = 1130 nm and 470 nm at λ c = 1375 nm. In vitro UHR OCT imaging is demonstrated at multiple wavelengths in human cancer cells, animal ganglion cells as well as in neuropathologic and ophthalmic biopsies in order to compare and optimize UHR OCT image contrast, resolution and penetration depth

  17. Bandwidth enhancement of a microstrip patch antenna for ultra-wideband applications

    Science.gov (United States)

    Anum, Khanda; Singh, Milind Saurabh; Mishra, Rajan; Tripathi, G. S.

    2018-04-01

    The microstrip antennas are used where size, weight, cost, and performance are constraints. Microstrip antennas (MSA) are being used in many government and commercial applications among which it is mostly used in wireless communication. The proposed antenna is designed for Ultra-wideband (UWB), it is designed on FR4 substrate material with ɛr = 4.3 and 0.0025 loss tangent. The shape and size of patch in microstrip patch antenna plays an important role in its performance. In the proposed antenna design the respective changes have been introduced which includes slotting the feedline,adding a curved slot in patch and change in patch shape itself to improve the bandwidth of the conventional antenna. The simulated results of proposed antenna shows impedance bandwidth (defined by 10 dB return loss) of 2-11.1GHz, VSWRcommunication at 7.25-8.395 GHz.

  18. Banded all-optical OFDM super-channels with low-bandwidth receivers.

    Science.gov (United States)

    Song, Binhuang; Zhu, Chen; Corcoran, Bill; Zhuang, Leimeng; Lowery, Arthur James

    2016-08-08

    We propose a banded all-optical orthogonal frequency division multiplexing (AO-OFDM) transmission system based on synthesising a number of truncated sinc-shaped subcarriers for each sub-band. This approach enables sub-band by sub-band reception and therefore each receiver's electrical bandwidth can be significantly reduced compared with a conventional AO-OFDM system. As a proof-of-concept experiment, we synthesise 6 × 10-Gbaud subcarriers in both conventional and banded AO-OFDM systems. With a limited receiver electrical bandwidth, the experimental banded AO-OFDM system shows 2-dB optical signal to noise ratio (OSNR) benefit over conventional AO-OFDM at the 7%-overhead forward error correction (FEC) threshold. After transmission over 800-km of single-mode fiber, ≈3-dB improvement in Q-factor can be achieved at the optimal launch power at a cost of increasing the spectral width by 14%.

  19. Frequency tracking and variable bandwidth for line noise filtering without a reference.

    Science.gov (United States)

    Kelly, John W; Collinger, Jennifer L; Degenhart, Alan D; Siewiorek, Daniel P; Smailagic, Asim; Wang, Wei

    2011-01-01

    This paper presents a method for filtering line noise using an adaptive noise canceling (ANC) technique. This method effectively eliminates the sinusoidal contamination while achieving a narrower bandwidth than typical notch filters and without relying on the availability of a noise reference signal as ANC methods normally do. A sinusoidal reference is instead digitally generated and the filter efficiently tracks the power line frequency, which drifts around a known value. The filter's learning rate is also automatically adjusted to achieve faster and more accurate convergence and to control the filter's bandwidth. In this paper the focus of the discussion and the data will be electrocorticographic (ECoG) neural signals, but the presented technique is applicable to other recordings.

  20. High-fidelity polarization storage in a gigahertz bandwidth quantum memory

    International Nuclear Information System (INIS)

    England, D G; Michelberger, P S; Champion, T F M; Reim, K F; Lee, K C; Sprague, M R; Jin, X-M; Langford, N K; Kolthammer, W S; Nunn, J; Walmsley, I A

    2012-01-01

    We demonstrate a dual-rail optical Raman memory inside a polarization interferometer; this enables us to store polarization-encoded information at GHz bandwidths in a room-temperature atomic ensemble. By performing full process tomography on the system, we measure up to 97 ± 1% process fidelity for the storage and retrieval process. At longer storage times, the process fidelity remains high, despite a loss of efficiency. The fidelity is 86 ± 4% for 1.5 μs storage time, which is 5000 times the pulse duration. Hence, high fidelity is combined with a large time-bandwidth product. This high performance, with an experimentally simple setup, demonstrates the suitability of the Raman memory for integration into large-scale quantum networks. (paper)

  1. Terahertz bandwidth all-optical Hilbert transformers based on long-period gratings.

    Science.gov (United States)

    Ashrafi, Reza; Azaña, José

    2012-07-01

    A novel, all-optical design for implementing terahertz (THz) bandwidth real-time Hilbert transformers is proposed and numerically demonstrated. An all-optical Hilbert transformer can be implemented using a uniform-period long-period grating (LPG) with a properly designed amplitude-only grating apodization profile, incorporating a single π-phase shift in the middle of the grating length. The designed LPG-based Hilbert transformers can be practically implemented using either fiber-optic or integrated-waveguide technologies. As a generalization, photonic fractional Hilbert transformers are also designed based on the same optical platform. In this general case, the resulting LPGs have multiple π-phase shifts along the grating length. Our numerical simulations confirm that all-optical Hilbert transformers capable of processing arbitrary optical signals with bandwidths well in the THz range can be implemented using feasible fiber/waveguide LPG designs.

  2. A High-Linearity Low-Noise Amplifier with Variable Bandwidth for Neural Recoding Systems

    Science.gov (United States)

    Yoshida, Takeshi; Sueishi, Katsuya; Iwata, Atsushi; Matsushita, Kojiro; Hirata, Masayuki; Suzuki, Takafumi

    2011-04-01

    This paper describes a low-noise amplifier with multiple adjustable parameters for neural recording applications. An adjustable pseudo-resistor implemented by cascade metal-oxide-silicon field-effect transistors (MOSFETs) is proposed to achieve low-signal distortion and wide variable bandwidth range. The amplifier has been implemented in 0.18 µm standard complementary metal-oxide-semiconductor (CMOS) process and occupies 0.09 mm2 on chip. The amplifier achieved a selectable voltage gain of 28 and 40 dB, variable bandwidth from 0.04 to 2.6 Hz, total harmonic distortion (THD) of 0.2% with 200 mV output swing, input referred noise of 2.5 µVrms over 0.1-100 Hz and 18.7 µW power consumption at a supply voltage of 1.8 V.

  3. Analysis of mobile fronthaul bandwidth and wireless transmission performance in split-PHY processing architecture.

    Science.gov (United States)

    Miyamoto, Kenji; Kuwano, Shigeru; Terada, Jun; Otaka, Akihiro

    2016-01-25

    We analyze the mobile fronthaul (MFH) bandwidth and the wireless transmission performance in the split-PHY processing (SPP) architecture, which redefines the functional split of centralized/cloud RAN (C-RAN) while preserving high wireless coordinated multi-point (CoMP) transmission/reception performance. The SPP architecture splits the base stations (BS) functions between wireless channel coding/decoding and wireless modulation/demodulation, and employs its own CoMP joint transmission and reception schemes. Simulation results show that the SPP architecture reduces the MFH bandwidth by up to 97% from conventional C-RAN while matching the wireless bit error rate (BER) performance of conventional C-RAN in uplink joint reception with only 2-dB signal to noise ratio (SNR) penalty.

  4. Cavity resonance absorption in ultra-high bandwidth CRT deflection structure by a resistive load

    Science.gov (United States)

    Dunham, M.E.; Hudson, C.L.

    1993-05-11

    An improved ultra-high bandwidth helical coil deflection structure for a cathode ray tube is described comprising a first metal member having a bore therein, the metal walls of which form a first ground plane; a second metal member coaxially mounted in the bore of the first metal member and forming a second ground plane; a helical deflection coil coaxially mounted within the bore between the two ground planes; and a resistive load disposed in one end of the bore and electrically connected to the first and second ground planes, the resistive load having an impedance substantially equal to the characteristic impedance of the coaxial line formed by the two coaxial ground planes to inhibit cavity resonance in the structure within the ultra-high bandwidth of operation. Preferably, the resistive load comprises a carbon film on a surface of an end plug in one end of the bore.

  5. Wideband Spectroscopy: The Design and Implementation of a 3 GHz Bandwidth, 8192 Channel, Polyphase Digital Spectrometer

    Science.gov (United States)

    Monroe, Ryan M.

    2011-01-01

    A family of state-of-the-art digital Fourier transform spectrometers has been developed, with a combination of high bandwidth and fine resolution unavailable elsewhere. Analog signals consisting of radiation emitted by constituents in planetary atmospheres or galactic sources are downconverted and subsequently digitized by a pair of interleaved Analog-to-Digital Converters, (ADC). This 6 Gsps (giga-sample per second) digital representation of the analog signal is then processed through an FPGA-based streaming Fast Fourier Transform (FFT), the key development described below. Digital spectrometers have many advantages over previously used analog spectrometers, especially in terms of accuracy and resolution, both of which are particularly important for the type of scientific questions to be addressed with next-generation radiometers. the implementation, results and underlying math for this spectrometer, as well as, potential for future extension to even higher bandwidth, resolution and channel orthogonality, needed to support proposed future advanced atmospheric science and radioastronomy, are discussed.

  6. High-speed 405-nm superluminescent diode (SLD) with 807-MHz modulation bandwidth

    KAUST Repository

    Shen, Chao; Lee, Changmin; Ng, Tien Khee; Nakamura, Shuji; Speck, James S.; DenBaars, Steven P.; Alyamani, Ahmed Y.; El-Desouki, Munir M.; Ooi, Boon S.

    2016-01-01

    III-nitride LEDs are fundamental components for visible-light communication (VLC). However, the modulation bandwidth is inherently limited by the relatively long carrier lifetime. In this letter, we present the 405 nm emitting superluminescent diode (SLD) with tilted facet design on semipolar GaN substrate, showing a broad emission of ∼9 nm at 20 mW optical power. Owing to the fast recombination (τ<0.35 ns) through the amplified spontaneous emission, the SLD exhibits a significantly large 3-dB bandwidth of 807 MHz. A data rate of 1.3 Gbps with a bit-error rate of 2.9 × 10 was obtained using on-off keying modulation scheme, suggesting the SLD being a high-speed transmitter for VLC applications.

  7. GHz-bandwidth upconversion detector using a unidirectional ring cavity to reduce multilongitudinal mode pump effects

    DEFF Research Database (Denmark)

    Meng, Lichun; Høgstedt, Lasse; Tidemand-Lichtenberg, Peter

    2017-01-01

    We demonstrate efficient upconversion of modulated infrared (IR) signals over a wide bandwidth (up to frequencies in excess of 1 GHz) via cavity-enhanced sum-frequency generation (SFG) in a periodically poled LiNbO3. Intensity modulated IR signal is produced by combining beams from two 1547 nm...... narrow-linewidth lasers in a fiber coupler while tuning their wavelength difference down to 10 pm or less. The SFG crystal is placed inside an Nd:YVO4 ring cavity that provides 1064 nm circulating pump powers of up to 150 W in unidirectional operation. Measured Fabry-Perot spectrum at 1064 nm confirms...... the enhanced spectral stability from multiple to single longitudinal mode pumping condition. We describe analytically and demonstrate experimentally the deleterious effects of using a multimode pump to the high-bandwidth RF spectrum of the 630 nm SFG output. Offering enhanced sensitivity without the need...

  8. Optimal design of similariton fiber lasers without gain-bandwidth limitation.

    Science.gov (United States)

    Li, Xingliang; Zhang, Shumin; Yang, Zhenjun

    2017-07-24

    We have numerically investigated broadband high-energy similariton fiber lasers, demonstrated that the self-similar evolution of pulses can locate in a segment of photonic crystal fiber without gain-bandwidth limitation. The effects of various parameters, including the cavity length, the spectral filter bandwidth, the pump power, the length of the photonic crystal fiber and the output coupling ratio have also been studied in detail. Using the optimal parameters, a single pulse with spectral width of 186.6 nm, pulse energy of 23.8 nJ, dechirped pulse duration of 22.5 fs and dechirped pulse peak power of 1.26 MW was obtained. We believe that this detailed analysis of the behaviour of pulses in the similariton regime may have major implications in the development of broadband high-energy fiber lasers.

  9. Multi-directional plasmonic surface-wave splitters with full bandwidth isolation

    International Nuclear Information System (INIS)

    Gao, Zhen; Gao, Fei; Zhang, Baile

    2016-01-01

    We present a multidirectional plasmonic surface-wave splitter with full bandwidth isolation experimentally based on coupled defect surface modes in a surface-wave photonic crystal. In contrast to conventional plasmonic surface-wave frequency splitters with polaritonic dispersion relations that overlap at low frequencies, this multidirectional plasmonic surface-wave splitter based on coupled defect surface modes can split different frequency bands into different waveguide branches without bandwidth overlap. Transmission spectra and near-field imaging measurements have been implemented in the microwave frequencies to verify the performance of the multidirectional plasmonic surface-wave splitter. This surface wave structure can be used as a plasmonic wavelength-division multiplexer that may find potential applications in the surface-wave integrated circuits from microwave to terahertz frequencies.

  10. Simulation and Analysis of Spectral Response Function and Bandwidth of Spectrometer

    Directory of Open Access Journals (Sweden)

    Zhenyu Gao

    2016-01-01

    Full Text Available A simulation method for acquiring spectrometer’s Spectral Response Function (SRF based on Huygens Point Spread Function (PSF is suggested. Taking into account the effects of optical aberrations and diffraction, the method can obtain the fine SRF curve and corresponding spectral bandwidth at any nominal wavelength as early as in the design phase. A prism monochromator is proposed for illustrating the simulation procedure. For comparison, a geometrical ray-tracing method is also provided, with bandwidth deviations varying from 5% at 250 nm to 25% at 2400 nm. Further comparison with reported experiments shows that the areas of the SRF profiles agree to about 1%. However, the weak scattered background light on the level of 10−4 to 10−5 observed by experiment could not be covered by this simulation. This simulation method is a useful tool for forecasting the performance of an underdesigned spectrometer.

  11. Harbor porpoise clicks do not have conditionally minimum time bandwidth product

    DEFF Research Database (Denmark)

    Beedholm, Kristian

    2008-01-01

    The hypothesis that odontocete clicks have minimal time frequency product given their delay and center frequency values is tested by using an in-phase averaged porpoise click compared with a pure tone weighted with the same envelope. These signals have the same delay and the same center frequency...... values but the time bandwidth product of the artificial click is only 0.76 that of the original. Therefore signals with the same parameters exist that have a lower time bandwidth product. The observation that porpoise clicks are in fact minimum phase is confirmed for porpoise clicks and this property...... is argued to be incompatible with optimal reception, if auditory filters are also minimum phase....

  12. Bandwidth Limitations in Characterization of High Intensity Focused Ultrasound Fields in the Presence of Shocks

    Science.gov (United States)

    Khokhlova, V. A.; Bessonova, O. V.; Soneson, J. E.; Canney, M. S.; Bailey, M. R.; Crum, L. A.

    2010-03-01

    Nonlinear propagation effects result in the formation of weak shocks in high intensity focused ultrasound (HIFU) fields. When shocks are present, the wave spectrum consists of hundreds of harmonics. In practice, shock waves are modeled using a finite number of harmonics and measured with hydrophones that have limited bandwidths. The goal of this work was to determine how many harmonics are necessary to model or measure peak pressures, intensity, and heat deposition rates of the HIFU fields. Numerical solutions of the Khokhlov-Zabolotskaya-Kuznetzov-type (KZK) nonlinear parabolic equation were obtained using two independent algorithms, compared, and analyzed for nonlinear propagation in water, in gel phantom, and in tissue. Measurements were performed in the focus of the HIFU field in the same media using fiber optic probe hydrophones of various bandwidths. Experimental data were compared to the simulation results.

  13. Pickup design for high bandwidth bunch arrival-time monitors in free-electron lasers

    Energy Technology Data Exchange (ETDEWEB)

    Angelovski, Aleksandar; Penirschke, Andreas; Jakoby, Rolf [TU Darmstadt (Germany). Institut fuer Mikrowellentechnik und Photonik; Kuhl, Alexander; Schnepp, Sascha [TU Darmstadt (Germany). Graduate School of Computational Engineering; Bock, Marie Kristin; Bousonville, Michael; Schlarb, Holger [Deutsches Elektronen-Synchrotron DESY, Hamburg (Germany); Weiland, Thomas [TU Darmstadt (Germany). Institut fuer Theorie Elektromagnetischer Felder

    2012-07-01

    The increased demands for low bunch charge operation mode in the free-electron lasers (FELs) require an upgrade of the existing synchronization equipment. As a part of the laser-based synchronization system, the bunch arrival-time monitors (BAMs) should have a sub-10 femtosecond precision for high and low bunch charge operation. In order to fulfill the resolution demands for both modes of operation, the bandwidth of such a BAM should be increased up to a cutoff frequency of 40 GHz. In this talk, we present the design and the realization of high bandwidth cone-shaped pickup electrodes as a part of the BAM for the FEL in Hamburg (FLASH) and the European X-ray free-electron laser (European XFEL). The proposed pickup was simulated with CST STUDIO SUITE, and a non-hermetic model was built up for radio frequency (rf) measurements.

  14. Practical continuous-variable quantum key distribution without finite sampling bandwidth effects.

    Science.gov (United States)

    Li, Huasheng; Wang, Chao; Huang, Peng; Huang, Duan; Wang, Tao; Zeng, Guihua

    2016-09-05

    In a practical continuous-variable quantum key distribution system, finite sampling bandwidth of the employed analog-to-digital converter at the receiver's side may lead to inaccurate results of pulse peak sampling. Then, errors in the parameters estimation resulted. Subsequently, the system performance decreases and security loopholes are exposed to eavesdroppers. In this paper, we propose a novel data acquisition scheme which consists of two parts, i.e., a dynamic delay adjusting module and a statistical power feedback-control algorithm. The proposed scheme may improve dramatically the data acquisition precision of pulse peak sampling and remove the finite sampling bandwidth effects. Moreover, the optimal peak sampling position of a pulse signal can be dynamically calibrated through monitoring the change of the statistical power of the sampled data in the proposed scheme. This helps to resist against some practical attacks, such as the well-known local oscillator calibration attack.

  15. A HIGH BANDWIDTH BIPOLAR POWER SUPPLY FOR THE FAST CORRECTORS IN THE APS UPGRADE*

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Ju; Sprau, Gary

    2017-06-25

    The APS Upgrade of a multi-bend achromat (MBA) storage ring requires a fast bipolar power supply for the fast correction magnets. The key performance requirement of the power supply includes a small-signal bandwidth of 10 kHz for the output current. This requirement presents a challenge to the design because of the high inductance of the magnet load and a limited input DC voltage. A prototype DC/DC power supply utilizing a MOSFET H-bridge circuit with a 500 kHz PWM has been developed and tested successfully. The prototype achieved a 10-kHz bandwidth with less than 3-dB attenuation for a signal 0.5% of the maximum operating current of 15 amperes. This paper presents the design of the power circuit, the PWM method, the control loop, and the test results.

  16. Sharing data increases citations

    DEFF Research Database (Denmark)

    Drachen, Thea Marie; Ellegaard, Ole; Larsen, Asger Væring

    2016-01-01

    This paper presents some indications to the existence of a citation advantage related to sharing data using astrophysics as a case. Through bibliometric analyses we find a citation advantage for astrophysical papers in core journals. The advantage arises as indexed papers are associated with data...... by bibliographical links, and consists of papers receiving on average significantly more citations per paper per year, than do papers not associated with links to data.......This paper presents some indications to the existence of a citation advantage related to sharing data using astrophysics as a case. Through bibliometric analyses we find a citation advantage for astrophysical papers in core journals. The advantage arises as indexed papers are associated with data...

  17. Does Knowledge Sharing Pay?

    DEFF Research Database (Denmark)

    Mahnke, Volker; Pedersen, Torben; Venzin, Markus

    are developed using a simultaneous equation model applied to a unique dataset encompassing a German MNC, HeidelbergCement. Enablers and impediments of knowledge outflows are assessed in order to explain why subsidiaries share their knowledge with other MNC units. Implications are examined by studying the link......This empirical paper explores knowledge outflow from MNC subsidiaries and its impact on the MNC performance. We develop and test hypotheses derived from literature on MNC knowledge flows integrated with the perspective of knowledge-creating, self-interested MNC subsidiaries. The hypotheses...... between knowledge outflows and subsidiary performance. Our findings suggest that knowledge outflows increase a subsidiary's performance only up to a certain point and that too much knowledge sharing may be detrimental to the contributing subsidiary's performance....

  18. Robustness and Actuator Bandwidth of MRP-Based Sliding Mode Control for Spacecraft Attitude Control Problems

    Science.gov (United States)

    Keum, Jung-Hoon; Ra, Sung-Woong

    2009-12-01

    Nonlinear sliding surface design in variable structure systems for spacecraft attitude control problems is studied. A robustness analysis is performed for regular form of system, and calculation of actuator bandwidth is presented by reviewing sliding surface dynamics. To achieve non-singular attitude description and minimal parameterization, spacecraft attitude control problems are considered based on modified Rodrigues parameters (MRP). It is shown that the derived controller ensures the sliding motion in pre-determined region irrespective of unmodeled effects and disturbances.

  19. Model-Based Evaluation Of System Scalability: Bandwidth Analysis For Smartphone-Based Biosensing Applications

    DEFF Research Database (Denmark)

    Patou, François; Madsen, Jan; Dimaki, Maria

    2016-01-01

    Scalability is a design principle often valued for the engineering of complex systems. Scalability is the ability of a system to change the current value of one of its specification parameters. Although targeted frameworks are available for the evaluation of scalability for specific digital systems...... re-engineering of 5 independent system modules, from the replacement of a wireless Bluetooth interface, to the revision of the ADC sample-and-hold operation could help increase system bandwidth....

  20. ICE-Based Custom Full-Mesh Network for the CHIME High Bandwidth Radio Astronomy Correlator

    Science.gov (United States)

    Bandura, K.; Cliche, J. F.; Dobbs, M. A.; Gilbert, A. J.; Ittah, D.; Mena Parra, J.; Smecher, G.

    2016-03-01

    New generation radio interferometers encode signals from thousands of antenna feeds across large bandwidth. Channelizing and correlating this data requires networking capabilities that can handle unprecedented data rates with reasonable cost. The Canadian Hydrogen Intensity Mapping Experiment (CHIME) correlator processes 8-bits from N=2,048 digitizer inputs across 400MHz of bandwidth. Measured in N2× bandwidth, it is the largest radio correlator that is currently commissioning. Its digital back-end must exchange and reorganize the 6.6terabit/s produced by its 128 digitizing and channelizing nodes, and feed it to the 256 graphics processing unit (GPU) node spatial correlator in a way that each node obtains data from all digitizer inputs but across a small fraction of the bandwidth (i.e. ‘corner-turn’). In order to maximize performance and reliability of the corner-turn system while minimizing cost, a custom networking solution has been implemented. The system makes use of Field Programmable Gate Array (FPGA) transceivers to implement direct, passive copper, full-mesh, high speed serial connections between sixteen circuit boards in a crate, to exchange data between crates, and to offload the data to a cluster of 256 GPU nodes using standard 10Gbit/s Ethernet links. The GPU nodes complete the corner-turn by combining data from all crates and then computing visibilities. Eye diagrams and frame error counters confirm error-free operation of the corner-turn network in both the currently operating CHIME Pathfinder telescope (a prototype for the full CHIME telescope) and a representative fraction of the full CHIME hardware providing an end-to-end system validation. An analysis of an equivalent corner-turn system built with Ethernet switches instead of custom passive data links is provided.

  1. 300 nm bandwidth adiabatic SOI polarization splitter-rotators exploiting continuous symmetry breaking.

    Science.gov (United States)

    Socci, Luciano; Sorianello, Vito; Romagnoli, Marco

    2015-07-27

    Adiabatic polarization splitter-rotators are investigated exploiting continuous symmetry breaking thereby achieving significant device size and losses reduction in a single mask fabrication process for both SOI channel and ridge waveguides. A crosstalk lower than -25 dB is expected over 300nm bandwidth, making the device suitable for full grid CWDM and diplexer/triplexer FTTH applications at 1310, 1490 and 1550nm.

  2. Globalization and Risk Sharing

    OpenAIRE

    Jaume Ventura; Fernando A. Broner

    2006-01-01

    We study the effects of globalization on risk sharing and welfare. Like the previous literature, we assume that governments cannot commit to enforce the repayment of debts owed by their citizens. Unlike the previous literature, we assume that governments cannot discriminate between domestic and foreign creditors when enforcing debt payments. This creates novel interactions between domestic and international trade in assets. (i) Increases in domestic trade raise the benefits of enforcement and...

  3. Decreasing Serial Cost Sharing

    DEFF Research Database (Denmark)

    Hougaard, Jens Leth; Østerdal, Lars Peter

    The increasing serial cost sharing rule of Moulin and Shenker [Econometrica 60 (1992) 1009] and the decreasing serial rule of de Frutos [Journal of Economic Theory 79 (1998) 245] have attracted attention due to their intuitive appeal and striking incentive properties. An axiomatic characterization...... of the increasing serial rule was provided by Moulin and Shenker [Journal of Economic Theory 64 (1994) 178]. This paper gives an axiomatic characterization of the decreasing serial rule...

  4. Decreasing serial cost sharing

    DEFF Research Database (Denmark)

    Hougaard, Jens Leth; Østerdal, Lars Peter Raahave

    2009-01-01

    The increasing serial cost sharing rule of Moulin and Shenker (Econometrica 60:1009-1037, 1992) and the decreasing serial rule of de Frutos (J Econ Theory 79:245-275, 1998) are known by their intuitive appeal and striking incentive properties. An axiomatic characterization of the increasing serial...... rule was provided by Moulin and Shenker (J Econ Theory 64:178-201, 1994). This paper gives an axiomatic characterization of the decreasing serial rule....

  5. Towards A Shared Mission

    DEFF Research Database (Denmark)

    Staunstrup, Jørgen; Orth Gaarn-Larsen, Carsten

    A mission shared by stakeholders, management and employees is a prerequisite for an engaging dialog about the many and substantial changes and challenges currently facing universities. Too often this essen-tial dialog reveals mistrust and misunderstandings about the role and outcome of the univer......A mission shared by stakeholders, management and employees is a prerequisite for an engaging dialog about the many and substantial changes and challenges currently facing universities. Too often this essen-tial dialog reveals mistrust and misunderstandings about the role and outcome...... on a shared mission aiming at value creation (in the broadest interpretation). One important aspect of choosing value as the cornerstone of the mission of universities is to stress that the outcome is measured by external stakeholders and by their standards. Most of the paper is devoted to discussing value...... it possible to lead through processes that engage and excite while creating transparency and accountability. The paper will be illustrated with examples from Denmark and the Helios initiative taken by the Danish Academy of Technical Sciences (ATV) under the headline “The value creating university – courage...

  6. Bonobos share with strangers.

    Directory of Open Access Journals (Sweden)

    Jingzhi Tan

    Full Text Available Humans are thought to possess a unique proclivity to share with others--including strangers. This puzzling phenomenon has led many to suggest that sharing with strangers originates from human-unique language, social norms, warfare and/or cooperative breeding. However, bonobos, our closest living relative, are highly tolerant and, in the wild, are capable of having affiliative interactions with strangers. In four experiments, we therefore examined whether bonobos will voluntarily donate food to strangers. We show that bonobos will forego their own food for the benefit of interacting with a stranger. Their prosociality is in part driven by unselfish motivation, because bonobos will even help strangers acquire out-of-reach food when no desirable social interaction is possible. However, this prosociality has its limitations because bonobos will not donate food in their possession when a social interaction is not possible. These results indicate that other-regarding preferences toward strangers are not uniquely human. Moreover, language, social norms, warfare and cooperative breeding are unnecessary for the evolution of xenophilic sharing. Instead, we propose that prosociality toward strangers initially evolves due to selection for social tolerance, allowing the expansion of individual social networks. Human social norms and language may subsequently extend this ape-like social preference to the most costly contexts.

  7. Sharing resources@CERN

    CERN Multimedia

    2002-01-01

    The library is launching a 'sharing resources@CERN' campaign, aiming to increase the library's utility by including the thousands of books bought by individual groups at CERN. This will improve sharing of information among CERN staff and users. Until now many people were unaware that copies of the same book (or standard, or journal) are often held not only by the library but by different divisions. (Here Eduardo Aldaz, from the PS division, and Isabel Bejar, from the ST division, read their divisional copies of the same book.) The idea behind the library's new sharing resources@CERN' initiative is not at all to collect the books in individual collections at the CERN library, but simply to register them in the Library database. Those not belonging to the library will in principle be unavailable for loan, but should be able to be consulted by anybody at CERN who is interested. "When you need a book urgently and it is not available in the library,' said PS Division engineer Eduardo Aldaz Carroll, it is a sham...

  8. Shared care and boundaries:

    DEFF Research Database (Denmark)

    Winthereik, Brit Ross

    2008-01-01

    Purpose – The paper seeks to examine how an online maternity record involving pregnant women worked as a means to create shared maternity care. Design/methodology/approach – Ethnographic techniques have been used. The paper adopts a theoretical/methodological framework based on science and techno......Purpose – The paper seeks to examine how an online maternity record involving pregnant women worked as a means to create shared maternity care. Design/methodology/approach – Ethnographic techniques have been used. The paper adopts a theoretical/methodological framework based on science...... and technology studies. Findings – The paper shows how a version of “the responsible patient” emerges from the project which is different from the version envisioned by the project organisation. The emerging one is concerned with the boundary between primary and secondary sector care, and not with the boundary......, IT designers and project managers should attend to the specific ways in which boundaries are inevitably enacted and to the ways in which care is already shared. This will provide them with opportunities to use the potentials of new identities and concerns that emerge from changing the organisation...

  9. IMPROVING BANDWIDTH OF FLIPPED VOLTAGE FOLLOWER USING GATE-BODY DRIVEN TECHNIQUE

    Directory of Open Access Journals (Sweden)

    VANDANA NIRANJAN

    2017-01-01

    Full Text Available In this paper, a new approach to enhance the bandwidth of flipped voltage follower is explored. The proposed approach is based on gate-body driven technique. This technique boosts the transconductance in a MOS transistor as both gate and body/bulk terminals are tied together and used as signal input. This novel technique appears as a good solution to merge the advantages of gate-driven and bulk-driven techniques and suppress their disadvantages. The gate-body driven technique utilizes body effect to enable low voltage low power operation and improves the overall performance of flipped voltage follower, providing it with low output impedance, high input impedance and bandwidth extension ratio of 2.614. The most attractive feature is that bandwidth enhancement has been achieved without use of any passive component or extra circuitry. Simulations in PSpice environment for 180 nm CMOS technology verified the predicted theoretical results. The improved flipped voltage follower is particularly interesting for high frequency low noise signal processing applications.

  10. Influence of Reduced Graphene Oxide on Effective Absorption Bandwidth Shift of Hybrid Absorbers.

    Science.gov (United States)

    Ameer, Shahid; Gul, Iftikhar Hussain

    2016-01-01

    The magnetic nanoparticle composite NiFe2O4 has traditionally been studied for high-frequency microwave absorption with marginal performance towards low-frequency radar bands (particularly L and S bands). Here, NiFe2O4 nanoparticles and nanohybrids using large-diameter graphene oxide (GO) sheets are prepared via solvothermal synthesis for low-frequency wide bandwidth shielding (L and S radar bands). The synthesized materials were characterized using XRD, SEM, FTIR and microwave magneto dielectric spectroscopy. The dimension of these solvothermally synthesized pristine particles and hybrids lies within 30-58 nm. Microwave magneto-dielectric spectroscopy was performed in the low-frequency region in the 1 MHz-3 GHz spectrum. The as-synthesized pristine nanoparticles and hybrids were found to be highly absorbing for microwaves throughout the L and S radar bands (graphene sheet coupling shows application of these materials with absorption bandwidth which is tailored such that these could be used for low frequency. Previously, these were used for high frequency absorptions (typically > 4 GHz) with limited selective bandwidth.

  11. A Study on the Bandwidth Characteristics of Pleated Pneumatic Artificial Muscles

    Directory of Open Access Journals (Sweden)

    Rino Versluys

    2009-01-01

    Full Text Available Pleated pneumatic artificial muscles have interesting properties that can be of considerable significance in robotics and automation. With a view to the potential use of pleated pneumatic artificial muscles as actuators for a fatigue test bench (high forces and small displacements, the bandwidth characteristics of a muscle-valve system were investigated. Bandwidth is commonly used for linear systems, as the Bode plot is independent of the amplitude of the input signal. However, due to the non-linear behaviour of pleated pneumatic artificial muscles, the system's gain becomes dependent on the amplitude of the input sine wave. As a result, only one Bode plot is insufficient to clearly describe or identify a non-linear system. In this study, the bandwidth of a muscle-valve system was assessed from two perspectives: a varying amplitude and a varying offset of the input sine wave. A brief introduction to pneumatic artificial muscles is given. The concept of pleated pneumatic artificial muscles is explained. Furthermore, the different test methods and experimental results are presented.

  12. Application of Tryptophan Fluorescence Bandwidth-Maximum Plot in Analysis of Monoclonal Antibody Structure.

    Science.gov (United States)

    Huang, Cheng-Yen; Hsieh, Ming-Ching; Zhou, Qinwei

    2017-04-01

    Monoclonal antibodies have become the fastest growing protein therapeutics in recent years. The stability and heterogeneity pertaining to its physical and chemical structures remain a big challenge. Tryptophan fluorescence has been proven to be a versatile tool to monitor protein tertiary structure. By modeling the tryptophan fluorescence emission envelope with log-normal distribution curves, the quantitative measure can be exercised for the routine characterization of monoclonal antibody overall tertiary structure. Furthermore, the log-normal deconvolution results can be presented as a two-dimensional plot with tryptophan emission bandwidth vs. emission maximum to enhance the resolution when comparing samples or as a function of applied perturbations. We demonstrate this by studying four different monoclonal antibodies, which show the distinction on emission bandwidth-maximum plot despite their similarity in overall amino acid sequences and tertiary structures. This strategy is also used to demonstrate the tertiary structure comparability between different lots manufactured for one of the monoclonal antibodies (mAb2). In addition, in the unfolding transition studies of mAb2 as a function of guanidine hydrochloride concentration, the evolution of the tertiary structure can be clearly traced in the emission bandwidth-maximum plot.

  13. High-Bandwidth Dynamic Full-Field Profilometry for Nano-Scale Characterization of MEMS

    International Nuclear Information System (INIS)

    Chen, L-C; Huang, Y-T; Chang, P-B

    2006-01-01

    The article describes an innovative optical interferometric methodology to delivery dynamic surface profilometry with a measurement bandwidth up to 10MHz or higher and a vertical resolution up to 1 nm. Previous work using stroboscopic microscopic interferometry for dynamic characterization of micro (opto)electromechanical systems (M(O)EMS) has been limited in measurement bandwidth mainly within a couple of MHz. For high resonant mode analysis, the stroboscopic light pulse is insufficiently short to capture the moving fringes from dynamic motion of the detected structure. In view of this need, a microscopic prototype based on white-light stroboscopic interferometry with an innovative light superposition strategy was developed to achieve dynamic full-field profilometry with a high measurement bandwidth up to 10MHz or higher. The system primarily consists of an optical microscope, on which a Mirau interferometric objective embedded with a piezoelectric vertical translator, a high-power LED light module with dual operation modes and light synchronizing electronics unit are integrated. A micro cantilever beam used in AFM was measured to verify the system capability in accurate characterisation of dynamic behaviours of the device. The full-field seventh-mode vibration at a vibratory frequency of 3.7MHz can be fully characterized and nano-scale vertical measurement resolution as well as tens micrometers of vertical measurement range can be performed

  14. Theoretical investigation of injection-locked high modulation bandwidth quantum cascade lasers.

    Science.gov (United States)

    Meng, Bo; Wang, Qi Jie

    2012-01-16

    In this study, we report for the first time to our knowledge theoretical investigation of modulation responses of injection-locked mid-infrared quantum cascade lasers (QCLs) at wavelengths of 4.6 μm and 9 μm, respectively. It is shown through a three-level rate equations model that the direct intensity modulation of QCLs gives the maximum modulation bandwidths of ~7 GHz at 4.6 μm and ~20 GHz at 9 μm. By applying the injection locking scheme, we find that the modulation bandwidths of up to ~30 GHz and ~70 GHz can be achieved for QCLs at 4.6 μm and 9 μm, respectively, with an injection ratio of 5 dB. The result also shows that an ultrawide modulation bandwidth of more than 200 GHz is possible with a 10 dB injection ratio for QCLs at 9 μm. An important characteristic of injection-locked QCLs is the nonexistence of unstable locking region in the locking map, in contrast to their diode laser counterparts. We attribute this to the ultra-short upper laser state lifetimes of QCLs.

  15. Bandwidths of micro-twisted-pair cables and fusion-spliced SIMM-GRIN fiber

    International Nuclear Information System (INIS)

    Gan, K.K.; Kagan, H.P.; Kass, R.D.; Smith, D.S.

    2007-01-01

    The SLHC is designed to increase the luminosity of the LHC by a factor of 10. In the present ATLAS pixel detector, electrical signals between the pixel modules and the optical modules (opto-boards) are transmitted in ∼1 m of micro-twisted-pair cables. The optical signals between the opto-boards and the off-detector optical modules are transmitted in fiber ribbons. Each fiber link consists of 8 m of rad-hard/low bandwidth SIMM fiber fusion spliced to 70 m of rad-tolerant/medium bandwidth GRIN fiber. We currently transmit optical signals at 80 Mb/s and expect to transmit signals at 1 Gb/s in the SLHC. For the SLHC optical link, we would like to take advantage of some of the design features of the present pixel optical links and the many years of R and D effort and production experience. If the present architecture can transmit signals at the higher speed required by the SLHC, the constraint of requiring no extra service space is automatically satisfied. We have measured the bandwidths of the transmission lines and our preliminary results indicate that the micro-twisted-pair cables can transmit signals up to ∼1 Gb/s and the fusion-spliced fiber ribbon can transmit signals up to ∼2 Gb/s

  16. A new metasurface reflective structure for simultaneous enhancement of antenna bandwidth and gain

    International Nuclear Information System (INIS)

    Habib Ullah, M; Islam, M T

    2014-01-01

    A new bi-layered metasurface reflective structure (MRS) on a high-permittivity, low-loss, ceramic-filled, bio-plastic, sandwich-structured, dielectric substrate is proposed for the simultaneous enhancement of the bandwidth and gain of a dual band patch antenna. By incorporating the MRS with a 4 mm air gap between the MRS and the antenna, the bandwidth and gain of the dual band patch antenna are significantly enhanced. The reflection coefficient (S11 < −10 dB) bandwidth of the proposed MRS-loaded antenna increased by 240% (178%), and the average peak gain improved by 595% (128%) compared to the antenna alone in the lower (upper) band. Incremental improvements of the magnitude and directional patterns have been observed from the measured radiation patterns at the three resonant frequencies of 0.9 GHz, 3.7 GHz and 4.5 GHz. The effects of different configurations of the radiating patch and the ground plane on the reflection coefficient have been analyzed. In addition, the voltage standing wave ratio and input impedance have also been validated using a Smith chart. (paper)

  17. A new metasurface reflective structure for simultaneous enhancement of antenna bandwidth and gain

    Science.gov (United States)

    Ullah, M. Habib; Islam, M. T.

    2014-08-01

    A new bi-layered metasurface reflective structure (MRS) on a high-permittivity, low-loss, ceramic-filled, bio-plastic, sandwich-structured, dielectric substrate is proposed for the simultaneous enhancement of the bandwidth and gain of a dual band patch antenna. By incorporating the MRS with a 4 mm air gap between the MRS and the antenna, the bandwidth and gain of the dual band patch antenna are significantly enhanced. The reflection coefficient (S11 < -10 dB) bandwidth of the proposed MRS-loaded antenna increased by 240% (178%), and the average peak gain improved by 595% (128%) compared to the antenna alone in the lower (upper) band. Incremental improvements of the magnitude and directional patterns have been observed from the measured radiation patterns at the three resonant frequencies of 0.9 GHz, 3.7 GHz and 4.5 GHz. The effects of different configurations of the radiating patch and the ground plane on the reflection coefficient have been analyzed. In addition, the voltage standing wave ratio and input impedance have also been validated using a Smith chart.

  18. SiGe HBT cryogenic preamplification for higher bandwidth donor spin read-out

    Science.gov (United States)

    Curry, Matthew; Carr, Stephen; Ten-Eyck, Greg; Wendt, Joel; Pluym, Tammy; Lilly, Michael; Carroll, Malcolm

    2014-03-01

    Single-shot read-out of a donor spin can be performed using the response of a single-electron-transistor (SET). This technique can produce relatively large changes in current, on the order of 1 (nA), to distinguish between the spin states. Despite the relatively large signal, the read-out time resolution has been limited to approximately 100 (kHz) of bandwidth because of noise. Cryogenic pre-amplification has been shown to extend the response of certain detection circuits to shorter time resolution and thus higher bandwidth. We examine a SiGe HBT circuit configuration for cryogenic preamplification, which has potential advantages over commonly used HEMT configurations. Here we present 4 (K) measurements of a circuit consisting of a Silicon-SET inline with a Heterojunction-Bipolar-Transistor (HBT). We compare the measured bandwidth with and without the HBT inline and find that at higher frequencies the signal-to-noise-ratio (SNR) with the HBT inline exceeds the SNR without the HBT inline. This work was performed, in part, at the Center for Integrated Nanotechnologies, a U.S. DOE, Office of Basic Energy Sciences user facility. The work was supported by the Sandia National Laboratories Directed Research and Development Program. Sandia National Laboratories is a multi-program laboratory operated by Sandia Corporation, a Lockheed-Martin Company, for the U. S. Department of Energy under Contract No. DE-AC04-94AL85000.

  19. Breaking Lorentz reciprocity to overcome the time-bandwidth limit in physics and engineering

    Science.gov (United States)

    Tsakmakidis, K. L.; Shen, L.; Schulz, S. A.; Zheng, X.; Upham, J.; Deng, X.; Altug, H.; Vakakis, A. F.; Boyd, R. W.

    2017-06-01

    A century-old tenet in physics and engineering asserts that any type of system, having bandwidth Δω, can interact with a wave over only a constrained time period Δt inversely proportional to the bandwidth (Δt·Δω ~ 2π). This law severely limits the generic capabilities of all types of resonant and wave-guiding systems in photonics, cavity quantum electrodynamics and optomechanics, acoustics, continuum mechanics, and atomic and optical physics but is thought to be completely fundamental, arising from basic Fourier reciprocity. We propose that this “fundamental” limit can be overcome in systems where Lorentz reciprocity is broken. As a system becomes more asymmetric in its transport properties, the degree to which the limit can be surpassed becomes greater. By way of example, we theoretically demonstrate how, in an astutely designed magnetized semiconductor heterostructure, the above limit can be exceeded by orders of magnitude by using realistic material parameters. Our findings revise prevailing paradigms for linear, time-invariant resonant systems, challenging the doctrine that high-quality resonances must invariably be narrowband and providing the possibility of developing devices with unprecedentedly high time-bandwidth performance.

  20. High-Bandwidth Dynamic Full-Field Profilometry for Nano-Scale Characterization of MEMS

    Energy Technology Data Exchange (ETDEWEB)

    Chen, L-C [Graduate Institute of Automation Technology, National Taipei University of Technology, 1 Sec. 3 Chung-Hsiao East Rd., Taipei, 106, Taiwan (China); Huang, Y-T [Graduate Institute of Automation Technology, National Taipei University of Technology, 1 Sec. 3 Chung-Hsiao East Rd., Taipei, 106, Taiwan (China); Chang, P-B [Graduate Institute of Mechanical and Electrical Engineering, National Taipei University of Technology, 1 Sec. 3 Chung-Hsiao East Rd., Taipei, 106, Taiwan (China)

    2006-10-15

    The article describes an innovative optical interferometric methodology to delivery dynamic surface profilometry with a measurement bandwidth up to 10MHz or higher and a vertical resolution up to 1 nm. Previous work using stroboscopic microscopic interferometry for dynamic characterization of micro (opto)electromechanical systems (M(O)EMS) has been limited in measurement bandwidth mainly within a couple of MHz. For high resonant mode analysis, the stroboscopic light pulse is insufficiently short to capture the moving fringes from dynamic motion of the detected structure. In view of this need, a microscopic prototype based on white-light stroboscopic interferometry with an innovative light superposition strategy was developed to achieve dynamic full-field profilometry with a high measurement bandwidth up to 10MHz or higher. The system primarily consists of an optical microscope, on which a Mirau interferometric objective embedded with a piezoelectric vertical translator, a high-power LED light module with dual operation modes and light synchronizing electronics unit are integrated. A micro cantilever beam used in AFM was measured to verify the system capability in accurate characterisation of dynamic behaviours of the device. The full-field seventh-mode vibration at a vibratory frequency of 3.7MHz can be fully characterized and nano-scale vertical measurement resolution as well as tens micrometers of vertical measurement range can be performed.