WorldWideScience

Sample records for bandwidth sharing policy

  1. State space collapse and diffusion approximation for a network operating under a fair bandwidth sharing policy

    CERN Document Server

    Kang, W N; Lee, N H; Williams, R J; 10.1214/08-AAP591

    2009-01-01

    We consider a connection-level model of Internet congestion control, introduced by Massouli\\'{e} and Roberts [Telecommunication Systems 15 (2000) 185--201], that represents the randomly varying number of flows present in a network. Here, bandwidth is shared fairly among elastic document transfers according to a weighted $\\alpha$-fair bandwidth sharing policy introduced by Mo and Walrand [IEEE/ACM Transactions on Networking 8 (2000) 556--567] [$\\alpha\\in (0,\\infty)$]. Assuming Poisson arrivals and exponentially distributed document sizes, we focus on the heavy traffic regime in which the average load placed on each resource is approximately equal to its capacity. A fluid model (or functional law of large numbers approximation) for this stochastic model was derived and analyzed in a prior work [Ann. Appl. Probab. 14 (2004) 1055--1083] by two of the authors. Here, we use the long-time behavior of the solutions of the fluid model established in that paper to derive a property called multiplicative state space col...

  2. Bandwidth sharing networks with multiscale traffic

    Directory of Open Access Journals (Sweden)

    Mathieu Feuillet

    2015-03-01

    Full Text Available In multi-class communication networks, traffic surges due to one class of users can significantly degrade the performance for other classes. During these transient periods, it is thus of crucial importance to implement priority mechanisms that conserve the quality of service experienced by the affected classes, while ensuring that the temporarily unstable class is not entirely neglected. In this paper, we examine the complex interaction occurring between several classes of traffic when classes obtain bandwidth proportionally to their incoming traffic. We characterize the evolution of the performance measures of the network from the moment the initial surge takes place until the system reaches its equilibrium. Using a time-space-transition-scaling, we show that the trajectories of the temporarily unstable class can be described by a differential equation, while those of the stable classes retain their stochastic nature. In particular, we show that the temporarily unstable class evolves at a time-scale which is much slower than that of the stable classes. Although the time-scales decouple, the dynamics of the temporarily unstable and the stable classes continue to influence one another. We further proceed to characterize the obtained differential equations for several simple network examples. In particular, the macroscopic asymptotic behavior of the unstable class allows us to gain important qualitative insights on how the bandwidth allocation affects performance. We illustrate these results on several toy examples and we finally build a penalization rule using these results for a network integrating streaming and surging elastic traffic.

  3. Fair sharing of bandwidth in VANETs

    OpenAIRE

    Hartenstein, Hannes

    2005-01-01

    We address the challenge of how to share the limited wireless channel capacity for the exchange of safety-related information in a fully deployed vehicular ad hoc network (VANET). In particular, we study the situation that arises when the number of nodes sending periodic safety messages is too high in a specific area. In order to achieve a good performance of safety-related protocols, we propose to limit the load sent to the channel using a strict fairness criterion among...

  4. 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.

  5. Location Aware Opportunistic Bandwidth Sharing between Static and Mobile Users with Stochastic Learning in Cellular Networks

    OpenAIRE

    Chattopadhyay, Arpan; Błaszczyszyn, Bartłomiej; Altman, Eitan

    2016-01-01

    We consider location-dependent opportunistic bandwidth sharing between static and mobile downlink users in a cellular network. Each cell has some fixed number of static users. Mobile users enter the cell, move inside the cell for some time and then leave the cell. In order to provide higher data rate to mobile users, we propose to provide higher bandwidth to the mobile users at favourable times and locations, and provide higher bandwidth to the static users in other times. We formulate the pr...

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

    NARCIS (Netherlands)

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

    2011-01-01

    Bandwidth-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 models of bandwid

  7. Data Sharing from a Policy Perspective

    Science.gov (United States)

    Cheville, R. Alan

    2016-01-01

    This paper addresses questions of data sharing from the perspective of a former NSF program officer. A brief comparison of policy and research perspectives is made to highlight different values in these two communities. Data sharing is framed as one means to support dialog between researchers and those involved in policy. Other uses of data…

  8. Information Sharing and Environmental Policies

    Directory of Open Access Journals (Sweden)

    Nikos Tsakiris

    2010-10-01

    Full Text Available Based on the assumption that in a standard eco-dumping model governments are uncertain about future product demand and allowing governments to obtain information from firms, we examine governments’ and firms’ incentives to share information. We show that when governments regulate polluting firms through emission standards, then governments and firms will reach an agreement concerning information sharing. The opposite holds when governments regulate pollution through emission taxes.

  9. Limited sharing with traffic prediction for dynamic bandwidth allocation and QoS provisioning over Ethernet passive optical networks

    Science.gov (United States)

    Luo, Yuanqiu; Ansari, Nirwan

    2005-09-01

    Feature Issue on Optical Access Networks (OAN) As an inexpensive, simple, and scalable solution for broadband access, Ethernet passive optical networks (EPONs) have the capability of delivering integrated broadband services to the end users. A critical issue of EPONs is the utility of a shared upstream channel among the local users, and thus an efficient bandwidth allocation mechanism is required to facilitate statistical multiplexing among the local network traffic. In this paper we propose a dynamic bandwidth allocation scheme, i.e., limited sharing with traffic prediction (LSTP), for upstream channel sharing over EPONs. LSTP enables dynamic bandwidth negotiation between the optical line terminal (OLT) and its associated optical network units (ONUs), alleviates data delay by predicting the traffic arrived during the waiting time and prereserving a portion of bandwidth for delivery, and avoids the aggressive bandwidth competition by upper bounding the allocated bandwidth to each ONU. Theoretical analysis and simulation results verify the feasibility of LSTP by showing that LSTP outperforms other existing schemes with respect to QoS metrics of data delay and data loss.

  10. A Markov Model for Evaluating Resource Sharing Policies for DASH Assisting Network Elements

    NARCIS (Netherlands)

    Kleinrouweler, J.W.M.; Cabrero Barros, S.; Mei, R.D. van der; Cesar Garcia, P.S.

    2016-01-01

    In this paper, we present a model for evaluating bandwidth sharing policies, that can be applied to networks that handle both video streaming traffic, as well as other traffic. Video streaming is a demanding network application. In crowded networks, resources need to be properly divided in order not

  11. Adaptive Slot Allocation And Bandwidth Sharing For Prioritized Handoff Calls In Mobile Netwoks

    CERN Document Server

    Malathy, S; Murugan, K; Lokesh, S

    2010-01-01

    Mobility management and bandwidth management are two major research issues in a cellular mobile network. Mobility management consists of two basic components: location management and handoff management. To Provide QoS to the users Handoff is a key element in wireless cellular networks. It is often initiated either by crossing a cell boundary or by deterioration in the quality of signal in the current channel. In this paper, a new admission control policy for cellular mobile network is being proposed. Two important QoS parameter in cellular networks are Call Dropping Probability (CDP) and Handoff Dropping Probability (HDP). CDP represents the probability that a call is dropped due to a handoff failure. HDP represents the probability of a handoff failure due to insufficient available resources in the target cell. Most of the algorithms try to limit the HDP to some target maximum but not CDP. In this paper, we show that when HDP is controlled, the CDP is also controlled to a minimum extent while maintaining lowe...

  12. Comparison of the Discriminatory Processor Sharing Policies

    CERN Document Server

    Osipova, Natalia

    2008-01-01

    Discriminatory Processor Sharing policy introduced by Kleinrock is of a great interest in many application areas, including telecommunications, web applications and TCP flow modelling. Under the DPS policy the job priority is controlled by the vector of weights. Verifying the vector of weights it is possible to modify the service rates of the jobs and optimize system characteristics. In the present paper we present the results concerning the comparison of two DPS policies with different weight vectors. We show the monotonicity of the expected sojourn time of the system depending on the weight vector under certain condition on the system. Namely, the system has to consist of classes with means which are quite different from each other. The classes with similar means can be organized together and considered as one class, so the given restriction can be overcame.

  13. Community Shared Solar: Policy and Regulatory Considerations (Brochure)

    Energy Technology Data Exchange (ETDEWEB)

    2014-09-01

    This brochure explores the ways in which the shared solar business model interacts with existing policy and regulations, including net metering, tax credits, and securities regulation. It presents some of the barriers that shared solar projects may face, and provides options for creating a supportive policy environment.

  14. A Cooperative Game Based Data Center Backbone Network Bandwidth Allocation Policy%基于合作博弈的数据中心骨干网带宽分配策略

    Institute of Scientific and Technical Information of China (English)

    孟飞; 兰巨龙; 胡宇翔

    2016-01-01

    数据中心(data center ,DC)之间通过部署流量工程来提高连接各个数据中心骨干网的利用率,虽然效率提升显著,但对不同类型汇聚流的带宽分配的公平性没有考虑。将多个汇聚流对带宽分配的竞争行为建模为一个合作博弈,通过寻求此博弈的纳什谈判解(Nash bargaining solution ,NBS)来确定优化的带宽分配策略 CGBA(cooperation game based bandwidth allocation ),权衡各汇聚流的最小带宽保证与带宽分配的公平性。在 Mininet 平台上进行实验仿真并和典型的带宽分配策略对比,结果表明CGBA 不但可保证各汇聚流的最小带宽需求,还确保了各类流对带宽资源竞争的公平性。%Currently ,traffic engineering is typically deployed to improve the utilization of data centers (DC) backbone networks ,which usually belongs to the same online service providers .Although the efficiency is remarkable ,the bandwidth allocation fairness of different aggregate flow isn’t considered . Hence ,the QoS guarantee is restricted .Because the bandwidth resource is expensive and packet loss is typically thought unacceptable ,the bandwidth utilization should be maximized ,at the same time , the QoS guarantee of different flow should be improved .In this paper ,the problem of contending the share bandwidth is modeled as a cooperative game ,and different aggregate flow compets the share bandwidth and maximizes the overall bandwidth resource utilization simultaneously ,and the optimal bandwidth allocation policy ,called cooperation game based bandwidth allocation (CGBA) ,is obtained through searching the Nash bargaining solution (NBS) of the game and balancing the tradeoff between minimum bandwidth guarantee and bandwidth allocation fairness .Simulation on a Mininet testbed shows that the proposed policy can effectively guarantee minimum bandwidth of each aggregate flow while ensuring the allocation fairness , compared with three

  15. Distributed Access Control Policies for Spectrum Sharing

    OpenAIRE

    Baldini, Gianmarco; NAI-FOVINO Igor; Trombetta, Alberto; Braghin, Stefano

    2012-01-01

    Cognitive Radio (CR) is a novel wireless communication technology that allows for adaptive configuration of the reception parameters of a terminal, based on the information collected from the environment. Cognitive radio (CR) technology can be used in innovative spectrum management approaches like spectrum sharing, where radio frequency spectral bands can be shared among various users through a dynamic exclusive-use spectrum access model. Spectrum sharing can be applied to various...

  16. An ECN-Based Bandwidth Sharing Algorithm for Unicast and Multicast Flows%基于ECN的单播流与多播流间带宽共享算法

    Institute of Scientific and Technical Information of China (English)

    杨明; 张福炎

    2003-01-01

    An ECN-based implementing bandwidth-sharing algorithm for unicast and multicast flows is presented.The algorithm uses a bandwidth allocation strategy to give an incentive to multicast flows in bandwidth allocation according to algorithm of the number of receivers, and to assure the unicast flows get their bandwidth shares fairly.Provided best-effort networks, an ECN-based congestion control algorithm is used to implement differentiated service in bandwidth allocation between unicast flows and multicast flows. In implementation, we solve the problems such asreceiver's number estimation, the RTT estimation and compromise between convergence and stability.The simulation results show that the algorithm can implement bandwidth sharing for TCP flows and multicast flows. Atthe same time, the algorithm not only allocates more bandwidth to multicast flows, but promises TCP flows to get their fair bandwidth share.

  17. Sharing the Caring: Rethinking Current Policies.

    Science.gov (United States)

    Edgar, Don

    1992-01-01

    This article presents an argument for reforming Australian public policy in favor of social care, rather than family, residential, or community care, for the elderly, sick, and disabled. After noting policy assumptions that families are the focus of caring and women are the natural caregivers, the paper describes changes in Australian family…

  18. ABB: active bandwidth broker

    Science.gov (United States)

    Wong, Kason; Law, Eddie

    2001-07-01

    In this paper, we shall discuss a novel design on the policy-based management for the Internet. This design deploys the concept of active networking. As opposed to the traditional network design, active network empowers network node with the ability to manipulate data and program code in packets, and configure the network properties according to the needs of different applications. The policy-based management can control network routers in order to realize end-to-end Quality of Service (QoS), such as differentiated and integrated services, across the Internet. For the moment, the Internet Engineering Task Force (IETF) has defined the framework of the policy-based management. It employs a simple client/server model that uses Common Open Policy Service (COPS) protocol to facilitate policy management and control. Our design of Active Bandwidth Broker (ABB) belongs to an active application. Our goals are to distribute centralized workload of the policy-based management over multiple active nodes in the active networks, introduce mobility of the bandwidth brokers, and allows load sharing to the policy-based management. This results a network-wide intelligent, highly available, and consistent QoS control that allows performance protection for voice, video and Internet business application while reducing costs for growing networks.

  19. 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)

  20. Fiscal policy and intranational risk-sharing

    OpenAIRE

    von Hagen, Jürgen

    1998-01-01

    A general feature of national fiscal systems is that they provide buffers against regional fluctuations in output and employment by redistributing income between the different regions of a country. Recent literature in connection with European monetary integration has stressed the insurance aspect of this function: Through the fiscal system, regions obtain insurance against asymmetric shocks. In this paper, we review the literature on risk-sharing through fiscal mechanisms. While consumption ...

  1. Share Valuation and Corporate Equity Policy

    OpenAIRE

    Auerbach, Alan J.

    1980-01-01

    In recent years many contributions have appeared which examine the effects of corporate and personal taxation on firm financial policy. However, there has yet to appear an adequate explanation of why corporations continue to distribute dividends despite their disadvantageous tax treatment. We study this problem anew, in the context of an overlapping generations growth model with corporations financed by equity. Among our findings are: (1) capital owned by corporations may well be undervalued,...

  2. Stacked-VLAN-Based Modeling of Hybrid ISP Traffic Control Schemes and Service Plans Exploiting Excess Bandwidth in Shared Access Networks

    OpenAIRE

    Kim, Kyeong Soo

    2016-01-01

    The current practice of shaping subscriber traffic using a token bucket filter by Internet service providers may result in a severe waste of network resources in shared access networks; except for a short period of time proportional to the size of a token bucket, it cannot allocate excess bandwidth among active subscribers even when there are only a few active subscribers. To better utilize the network resources in shared access networks, therefore, we recently proposed and analyzed the perfo...

  3. 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.

  4. 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...

  5. 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…

  6. 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 firm cha

  7. AD SHARING IN SOCIAL NETWORKS : ROLE OF USER DEFINED POLICIES

    Directory of Open Access Journals (Sweden)

    Venkata N Inukollu

    2014-09-01

    Full Text Available Security policies describe the demeanor of a system through specific rules and are becoming an increasingly popular approach for static and dynamic environment applications.Online social networks have become a de facto portal for Internet access for millions of users. Users share different content on social media sometimes which includes personal information.However, users entrust the social network providers with such personal information.Although social networking sites offer privacy controls, the sites provide insufficient controls to restrict data sharing and let users restrict how their data is handled and viewed by other users.To match the privacy demands of an online social network user, we have suggested a new security policy and have tested the policy successfully on various levels

  8. Codifying Collegiality: Recent Developments in Data Sharing Policy in the Life Sciences

    OpenAIRE

    Pham-Kanter, Genevieve; Zinner, Darren E; Campbell, Eric G.

    2014-01-01

    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 infr...

  9. A preliminary quantitative research on dividend policy and its impact on share prices

    OpenAIRE

    Xiao, Dezhi

    2013-01-01

    This report is designed to find out the relationship between dividend policy and share price, generally, there are two camps theories within this area, one of them argues the dividend policy do not influence share value while the other one argues the dividend policy can affect share value via different approaches. Therefore, this report attempts to identify the relationship between dividend policy and share price via conducting an OLS analysis in 60 UK listed companies. Then, the result can b...

  10. 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…

  11. Cost Sharing in Higher Education in Kenya: Examining the Undesired Policy Outcomes

    Science.gov (United States)

    Ngolovoi, Mary S.

    2010-01-01

    Cost sharing in higher education is a policy that comes from the United States. The policy advocates that costs of higher education should be shared between the government, parents, students and/or donor organizations. Proponents of the policy (such as the World Bank) have over the years been advocating for its implementation in African countries.…

  12. 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.

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

    OpenAIRE

    Hossein Askari; Abbas Mirakhor

    2014-01-01

    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 ...

  14. The Dividend and Share Repurchase Policies of Canadian Firms : Empirical Evidence based on New Research Design

    NARCIS (Netherlands)

    de Jong, A.; van Dijk, R.; Veld, C.H.

    2000-01-01

    We empirically investigate dividend and share repurchase policies of Canadian firms. We use several logit regression analyses to test the structure and determinants of the dividend and share repurchase choice. We have sent a questionnaire to the 500 largest non-financial Canadian companies listed on

  15. 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.

  16. DYNAMIC BANDWIDTH ALLOCATION ALGORITHM UTILIZING FULL BAND

    Institute of Scientific and Technical Information of China (English)

    Han Guodong; Wen Jianhua; Wu Jiangxing

    2006-01-01

    A kind of Dynamic Full Bandwidth Utilized (DFBU) allocation algorithm is introduced. This algorithm allows a single link to use bandwidth far beyond its fair share bandwidth in a multi-service packet transporting system. Three important parameters as the bound on maximum and minimum bandwidth, the maximum packet delay and the minimum band width utilization are discussed and analyzed. Results of experiments show that the DFBU-algorithm is capable of making a single link in the system to use all the spare bandwidth (up to full-bandwidth) while the performance of fairness and QoS requirement is still guaranteed.

  17. [Shared governance and reasonableness as ethical contributions to health policy].

    Science.gov (United States)

    Costa-Alcaraz, Ana M; Calvo-Rigual, Fernando; Siurana-Aparisi, Juan Carlos

    2013-01-01

    Health is one of the fundamental human rights. Recognizing it as a right means that the State has an obligation to ensure a minimum level of opportunities is maintained, and to restore it when lost. This minimum level may not be covered in periods of economic crisis, such as the one we are currently experiencing.Managed care, focused on economic questions, emerged after the crisis of 1973 in order to help make clinical decisions based on economic factors. In practice, the result of managed care was to turn economic cost control into an end in itself while forgetting about equity; something for which it has been challenged from an ethical perspective. Since then, many authors have attempted to reconcile efficiency and equity in health management, but the debate remains open.In this article, and basing our approach on the theories of P. Ruger and Norman Daniels, we argue that shared health governance and accountability for reasonableness can offer significant ethical contributions in the process of achieving an efficient and fair health system. In the model we propose, citizens, professionals and health institutions all play an active role in capacity building in the field of health. These capacities are related to healthy lifestyles, accessible and transparent information, the promotion of self-care, the acquisition of knowledge, skills and appropriate attitudes, leadership based on values and co-responsibility to achieve set goals in a reasonable way. If we develop these capacities, we will have used the current economic crisis as an opportunity for improving ethical practice in the field of health.

  18. [Shared governance and reasonableness as ethical contributions to health policy].

    Science.gov (United States)

    Costa-Alcaraz, Ana M; Calvo-Rigual, Fernando; Siurana-Aparisi, Juan Carlos

    2013-01-01

    Health is one of the fundamental human rights. Recognizing it as a right means that the State has an obligation to ensure a minimum level of opportunities is maintained, and to restore it when lost. This minimum level may not be covered in periods of economic crisis, such as the one we are currently experiencing.Managed care, focused on economic questions, emerged after the crisis of 1973 in order to help make clinical decisions based on economic factors. In practice, the result of managed care was to turn economic cost control into an end in itself while forgetting about equity; something for which it has been challenged from an ethical perspective. Since then, many authors have attempted to reconcile efficiency and equity in health management, but the debate remains open.In this article, and basing our approach on the theories of P. Ruger and Norman Daniels, we argue that shared health governance and accountability for reasonableness can offer significant ethical contributions in the process of achieving an efficient and fair health system. In the model we propose, citizens, professionals and health institutions all play an active role in capacity building in the field of health. These capacities are related to healthy lifestyles, accessible and transparent information, the promotion of self-care, the acquisition of knowledge, skills and appropriate attitudes, leadership based on values and co-responsibility to achieve set goals in a reasonable way. If we develop these capacities, we will have used the current economic crisis as an opportunity for improving ethical practice in the field of health. PMID:23775103

  19. Managing ISR sharing policies at the network edge using Controlled English

    Science.gov (United States)

    Parizas, Christos; Pizzocaro, Diego; Preece, Alun; Zerfos, Petros

    2013-05-01

    In domains such as emergency response and military operations the sharing of Intelligence, Surveillance and Reconnaissance (ISR) assets among different coalition partners is regulated through policies. Traditionally, poli­ cies are created at the center of a coalitions network by high-level decision makers and expressed in low-level policy languages (e.g. Common Information Model SPL) by technical personnel, which makes them difficult to be understood by non-technical users at the edge of the network. Moreover, policies must often be modified by negotiation among coalition partners, typically in rapid response to the changing operational situation. Com­ monly, the users who must cope first with situational changes are those on the edge, so it would be very effective if they were able to create and negotiate policies themselves. We investigate the use of Controlled English (CE) as a means to define a policy representation that is both human-friendly and machine processable. We show how a CE model can capture a variety of policy types, including those based on a traditional asset ownership model, and those defining team-based asset sharing across a coalition. The use of CE is intended to benefit coalition networks by bridging the gap between technical and non-technical users in terms of policy creation and negoti­ ation, while at the same time being directly processable by a policy-checking system without transformation to any other technical representation.

  20. HFC宽带接入网上行带宽分配策略的改进%Improving the Upstream Bandwidth Allocation Policy for the HFC Broadband Access Networks

    Institute of Scientific and Technical Information of China (English)

    宋军; 甘育裕; 吴资玉

    2003-01-01

    The request/transmit based upstream bandwidth resource allocation policy of DOCSIS introduces a trouble to the quality of the data service provided in the I-IFC networks. In this paper, the mechanism of the upstream data transrmitting and the process of data service transmitting in the HFC networks are described in detail, and the perfor- mance of the data service in HFC networks is analyzed. An advanced upstream bandwidth resource allocation policy is proposed to improve the quality of the data service in the HFC networks.

  1. Financing Higher Education in Ethiopia: Analysis of Cost-Sharing Policy and its Implementation

    Science.gov (United States)

    Ayalew, Sewale Abate

    2013-01-01

    Cost-sharing as a policy in Ethiopian higher education institutions (HEIs) has been adopted since 2003 to achieve a set of objectives such as supplementing revenue as an alternative non-governmental source, maintaining and enhancing access to higher education, addressing equity in terms of opportunity in higher education and making students…

  2. Sharing Best Practices in Barbados and Trinidad and Tobago: Patterns of Policy Implementation and Resistance

    Science.gov (United States)

    Lam, Elaine

    2011-01-01

    This article outlines policies from multilateral organisations that advocate sharing best practices between developing nations. The article discusses the degree to which these best practices are implemented by small states as indicated by teachers, academics and policymakers in Barbados and Trinidad and Tobago. For the purpose of this article, a…

  3. Data Sharing for Context-Sensitive Access Control Policy Evaluation and Enforcement

    Directory of Open Access Journals (Sweden)

    Hassan Rasheed

    2012-10-01

    Full Text Available Context-awareness has long been an important building block in designing systems that vary their operating behavior based on an analysis of rapidly changing operating conditions. There is the need however to define context more formally so that context data-sharing can take place between systems and more complex interactions between connected systems can be developed. The area of computer security is examined in particular as an area where the representation and sharing of context data can lead to more effective policy enforcement. A framework is proposed for sharing data between assessment sensors and enforcement mechanisms in order to facilitate more accurate policy enforcement. A detailed performance analysis of the proposed system is offered along with conclusions on the feasibility of such systems.

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

    International Nuclear Information System (INIS)

    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. 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

    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...... information between converter units. The droop controller is employed to achieve independent operation and average voltage and current controllers are used in each converter to simultaneously enhance the current sharing accuracy and restore the dc bus voltage. All of the controllers are realized locally...

  6. Study On Dividend Policy: Antecedent and Its Impact On Share Price

    OpenAIRE

    Murhadi, Werner-Ria

    2008-01-01

    This research aims to test dividend signaling theory in an Indonesian capital market. Signaling theory states that dividend policy has information content that can influence to share price. Examination of theory of signaling is related to research phenomena in other countries indicating that by percentage there is degradation of company which is pay dividend and there even exist mentioning this as phenomenon of disappearing dividend. Examination of theory of signaling is also related to the r...

  7. 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...

  8. 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.

  9. 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.

  10. 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)

  11. Dynamic bandwidth allocation algorithm for full-band utilization

    Institute of Scientific and Technical Information of China (English)

    Han Guodong; Wang Hui; Wu Jiangxing

    2006-01-01

    To improve and optimize the bandwidth utilization for multi-service packet transporting system, a kind of Dynamic Full Bandwidth Utilized (DFBU) allocation algorithm allowing a single link to use far beyond its fair share bandwidth is presented. Three important parameters as the bound on max and minimum bandwidth, the maximum packet delay and the minimum bandwidth utilization are discussed and analyzed. Results of experiments show that the DFBU-algorithm is capable of making a single link in the system use all the spare bandwidth (up to full-bandwidth) while the performance of fairness and QoS requirement is still guaranteed.

  12. A time-shared machine repair problem with mixed spares under N-policy

    Science.gov (United States)

    Jain, Madhu; Shekhar, Chandra; Shukla, Shalini

    2016-02-01

    The present investigation deals with a machine repair problem consisting of cold and warm standby machines. The machines are subject to breakdown and are repaired by the permanent repairman operating under N-policy. There is provision of one additional removable repairman who is called upon when the work load of failed machines crosses a certain threshold level and is removed as soon as the work load again ceases to that level. Both repairmen recover the failed machines by following the time sharing concept which means that the repairmen share their repair job simultaneously among all the failed machines that have joined the system for repair. Markovian model has been developed by considering the queue dependent rates and solved analytically using the recursive technique. Various performance indices are derived which are further used to obtain the cost function. By taking illustration, numerical simulation and sensitivity analysis have been provided.

  13. Policy based QoS architecture in MUSE

    NARCIS (Netherlands)

    Rajan, G.; Elizondo Armengol, A.J.; Nooren, P.; Foglar, A.

    2006-01-01

    This paper presents the architecture and framework for a policy based QoS control in a shared medium type of network such as Ethernet. QoS is achieved by a combination of traffic engineering of bandwidth pipes, priority scheduling of traffic at network nodes and controlled access to the bandwidth pi

  14. P2P流媒体网络中基于博弈理论的带宽请求分配策略%Game Theoretical Bandwidth Request Allocation Policy in P2P Streaming Network

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

      基于对等网(P2P)技术的视频流媒体系统以其较低的服务器开销和良好的可扩展性被广泛应用。但由于在这类系统中普遍存在节点的资源及视频播放位置的异构性,使得节点负载不均衡的问题极易发生,进而严重影响到节点的视频播放质量。该文重点研究面向节点负载均衡的节点带宽请求分配策略,将服务请求节点竞争服务提供节点带宽的行为建模为一个非协作博弈,通过寻求该博弈问题的 Nash 均衡解的方法确定优化的带宽请求分配(GBRA)策略。通过和典型的带宽请求分配策略进行实验对比,数值结果表明该文提出的GBRA 策略能有效改善P2P流媒体网络节点负载不均的问题并降低节点获取所需视频数据的平均延迟。%Due to the merits of lower bandwidth consumption at streaming server and higher scalability, P2P streaming systems are widely adopted and deployed. However, the heterogeneity of bandwidth resource and playback position at peers may easily lead to load unbalancing problem. This may severely deteriorate video playback quality at peers. This paper focuses on the issue of bandwidth request allocation, aiming at substantially balancing the load at the peers in P2P streaming network. The problem of contending service from multiple neighboring peers is modeled as a non-cooperative game, and the optimal bandwidth request allocation policy, called Game based Bandwidth Request Allocation (GBRA), is obtained through searching the Nash equilibrium of this game. Numerical results show that the proposed policy can effectively improve the load balancing of the P2P streaming networks and decrease the latency of streaming data retrieval at peers when compared with the classical bandwidth request allocation policies.

  15. 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. PMID:27366833

  16. Bandwidth sharing with heterogeneous service requirements

    NARCIS (Netherlands)

    Borst, S.C.; Núñez Queija, R.; Zwart, A.P.

    2003-01-01

    We consider a system with two heterogeneous traffic classes. The users from both classes randomly generate service requests, one class having light-tailed properties, the other one exhibiting heavy-tailed characteristics. The heterogeneity in service requirements reflects the extreme variability in

  17. 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.

  18. 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.

  19. 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.

  20. Study of the Option Ordering Policy concerning Perishable Farm Produce Based on Revenue Sharing Contract

    Institute of Scientific and Technical Information of China (English)

    Xiaojing; LIU

    2014-01-01

    This paper considers the two-echelon supply chain system which consists of single agricultural producers and retailers,and analyzes the impact of sharing ratio on the option ordering quantity,and retailers and producers’ expected profits.Studies have shown that in the case of decentralization,when the revenue sharing ratio is between 0 and 0.3,the option ordering quantity of farm produce is a decreasing function of the sharing ratio; when the revenue sharing ratio is between 0.3 and 1,the option ordering quantity of farm produce is an increasing function of sharing ratio; when the revenue sharing ratio is between 0.421 and 1,the agricultural producers and retailers’ expected profits are an increasing function of sharing ratio.Finally,through the numerical calculation,the applicability of the conclusions is verified,to provide a reference for the supply chain management practices.

  1. Bandwidth Reconfigurable Metamaterial Arrays

    Directory of Open Access Journals (Sweden)

    Nathanael J. Smith

    2014-01-01

    Full Text Available Metamaterial structures provide innovative ways to manipulate electromagnetic wave responses to realize new applications. This paper presents a conformal wideband metamaterial array that achieves as much as 10 : 1 continuous bandwidth. This was done by using interelement coupling to concurrently achieve significant wave slow-down and cancel the inductance stemming from the ground plane. The corresponding equivalent circuit of the resulting array is the same as that of classic metamaterial structures. In this paper, we present a wideband Marchand-type balun with validation measurements demonstrating the metamaterial (MTM array’s bandwidth from 280 MHz to 2800 MHz. Bandwidth reconfiguration of this class of array is then demonstrated achieving a variety of band-pass or band-rejection responses within its original bandwidth. In contrast with previous bandwidth and frequency response reconfigurations, our approach does not change the aperture’s or ground plane’s geometry, nor does it introduce external filtering structures. Instead, the new responses are realized by making simple circuit changes into the balanced feed integrated with the wideband MTM array. A variety of circuit changes can be employed using MEMS switches or variable lumped loads within the feed and 5 example band-pass and band-rejection responses are presented. These demonstrate the potential of the MTM array’s reconfiguration to address a variety of responses.

  2. INFERENCE OF PRIVACY POLICY FOR USER-UPLOADED IMAGES ON CONTENT SHARING SOCIAL SITES

    OpenAIRE

    S.Keerthivarshini*, Prof. . Janarthanan

    2016-01-01

    Increasingly developed social sharing websites, like Flickr and YouTube, allow users to create, share, annotate and comment Medias. The large-scale user-generated meta-data not only facilitate users in sharing and organizing multimedia content, but provide useful information to improve media retrieval and management. Personalized search serves as one of such examples where the web search experience is improved by generating the returned list according to the modified user search intents. In t...

  3. 78 FR 57860 - Draft NIH Genomic Data Sharing Policy Request for Public Comments

    Science.gov (United States)

    2013-09-20

    ... prevent disease. The NIH has promoted data sharing for many years, and in 2003, the NIH issued a general... human diseases, conditions, and traits. To facilitate the sharing of genomic and phenotypic data from... Submission Expectations and Timeline Nonhuman data (including microbial and microbiome data) and data...

  4. Residential Access to Bandwidth: Exploring New Paradigms. A Report of the Annual Aspen Institute Conference on Telecommunications Policy (13th, August 9-13, 1998, Aspen, Colorado).

    Science.gov (United States)

    Entman, Robert M.

    The 1998 Aspen Systems Conference on Telecommunications Policy met to consider ways of speeding the deployment of telecommunication systems that allow for robust, reliable, and innovative communications services to the home. By organizing participants into three working groups, the session was able to come up with analytical suggestions and policy…

  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. Low-bandwidth authentication.

    Energy Technology Data Exchange (ETDEWEB)

    Donnelly, Patrick Joseph; McIver, Lauren; Gaines, Brian R.; Anderson, Erik; Collins, Michael Joseph; Thomas,Kurt Adam; McDaniel, Austin

    2007-09-01

    Remotely-fielded unattended sensor networks generally must operate at very low power--in the milliwatt or microwatt range--and thus have extremely limited communications bandwidth. Such sensors might be asleep most of the time to conserve power, waking only occasionally to transmit a few bits. RFID tags for tracking or material control have similarly tight bandwidth constraints, and emerging nanotechnology devices will be even more limited. Since transmitted data is subject to spoofing, and since sensors might be located in uncontrolled environments vulnerable to physical tampering, the high-consequence data generated by such systems must be protected by cryptographically sound authentication mechanisms; but such mechanisms are often lacking in current sensor networks. One reason for this undesirable situation is that standard authentication methods become impractical or impossible when bandwidth is severely constrained; if messages are small, a standard digital signature or HMAC will be many times larger than the message itself, yet it might be possible to spare only a few extra bits per message for security. Furthermore, the authentication tags themselves are only one part of cryptographic overhead, as key management functions (distributing, changing, and revoking keys) consume still more bandwidth. To address this problem, we have developed algorithms that provide secure authentication while adding very little communication overhead. Such techniques will make it possible to add strong cryptographic guarantees of data integrity to a much wider range of systems.

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

    Science.gov (United States)

    McQuilton, Peter; Gonzalez-Beltran, Alejandra; 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 biological sciences; an educational resource for librarians and information advisors; a publicising platform for standard and database developers/curators; and a research tool for bench and computer scientists to plan their work. BioSharing is working with an increasing number of journals and other registries, for example linking standards and databases to training material and tools. Driven by an international Advisory Board, the BioSharing user-base has grown by over 40% (by unique IP address), in the last year thanks to successful engagement with researchers, publishers, librarians, developers and other stakeholders via several routes, including a joint RDA/Force11 working group and a collaboration with the International Society for Biocuration. In this article, we describe BioSharing, with a particular focus on community-led curation.Database URL: https://www.biosharing.org. PMID:27189610

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

    Science.gov (United States)

    McQuilton, Peter; Gonzalez-Beltran, Alejandra; 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 biological sciences; an educational resource for librarians and information advisors; a publicising platform for standard and database developers/curators; and a research tool for bench and computer scientists to plan their work. BioSharing is working with an increasing number of journals and other registries, for example linking standards and databases to training material and tools. Driven by an international Advisory Board, the BioSharing user-base has grown by over 40% (by unique IP address), in the last year thanks to successful engagement with researchers, publishers, librarians, developers and other stakeholders via several routes, including a joint RDA/Force11 working group and a collaboration with the International Society for Biocuration. In this article, we describe BioSharing, with a particular focus on community-led curation.Database URL: https://www.biosharing.org.

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

    OpenAIRE

    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 policies in the United States of America and the Netherlands. Mothers and fathers were individually interviewed face to face regarding satisfaction with family leave polices, if and why they did or di...

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

    OpenAIRE

    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 universityrelated 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...

  11. 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.

  12. 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...

  13. Adaptable bandwidth planning using reinforcement learning

    Directory of Open Access Journals (Sweden)

    Dirk Hetzer

    2006-08-01

    Full Text Available In order to improve the bandwidth allocation considering feedback of operational environment, adaptable bandwidth planning based on reinforcement learning is proposed. The approach is based on new constrained scheduling algorithms controlled by reinforcement learning techniques. Different constrained scheduling algorithms,, such as "conflict free scheduling with minimum duration", "partial displacement" and "pattern oriented scheduling" are defined and implemented. The scheduling algorithms are integrated into reinforcement learning strategies. These strategies include: - Q-learning for selection of optimal planning schedule using Q-values; - Informed Q-learning for exploitation and handling of prior-knowledge (patterns of network behaviour; - Relational Q-learning for improving of bandwidth allocation policies dynamically in operational networks considering actual network performance data. Scenarios based on integration of the scheduling algorithms and reinforcement learning techniques in the experimental monitoring and bandwidth planning system called QORE (QoS and resource optimisation are given. The proposed adaptable bandwidth planning is required for more efficient usage of network resources.

  14. 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 p

  15. "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…

  16. Shared hesitance, joint success : Denmark, Finland, and Sweden in the European Union policy process

    NARCIS (Netherlands)

    Selck, TJ; Kuipers, S

    2005-01-01

    This paper analyses the roles of Denmark, Finland, and Sweden in the area of EU legislative decision-making. After reviewing the literature, a research design is presented which incorporates information on the policy preferences of these three political states for seventy recent EU legislative decis

  17. Secured Resource Sharing in Cloud Storage using Policy based Access Control

    Directory of Open Access Journals (Sweden)

    S. Imavathy

    2015-11-01

    Full Text Available Cloud computing is a general term anything that involves delivering hosted services, Anything as a Service (AaaS, over the web on demand basis. It uses the web and central remote servers to maintain data and applications. The lack of confidence in trusting information flow(users data are usually processes remotely in unknown machines that do not owned or operated by user in cloud has become common, as users fears of losing control of their own data (like personal, professional, financial, Health. In this approach, a secured cloud storage system that achieves policy-based access control is proposed with an information accountability cloud framework to keep track of the actual usage of the clients data.The access policy generated for the file controls the file accesses and policy revocation makes the file permanently inaccessible. The system is built upon a set of cryptographic key operations that are self- maintained by a set of key managers and adds security features. The access details of the data are logged and auditing also performed.

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

    OpenAIRE

    Erjiang E; Geng Peng; Xin Tian; Qinghong Chen

    2016-01-01

    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 shar...

  19. 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

  20. 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

  1. 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

  2. File sharing

    NARCIS (Netherlands)

    N. van Eijk

    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 impact

  3. 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.

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

    Directory of Open Access Journals (Sweden)

    Stephen M. Mutula

    2013-02-01

    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.

  5. A Bandwidth Allocation Model Provisioning Framework with Autonomic Characteristics

    OpenAIRE

    Rafael F. Reale; Romildo M. da S. Bezerra; Martins, Joberto S. B.

    2013-01-01

    The Bandwidth Allocation Models (MAM, RDM, G-RDM and AllocTC-Sharing) are managementalternatives currently available which propose different resource (bandwidth) allocation strategies inmultiservice networks. The BAM adoption by a network is typically a management choice andconfiguration task executed by the network operations and management system setup in a static or nearlystatic way. This paper proposes and explores the alternative ofallowing BAM definition and configurationon a more dynam...

  6. A Study on the Tool Sharing Policy in FMS with Tool Center

    Science.gov (United States)

    Zhang, Xiaoming; Fujii, Susumu; Kaihara, Toshiya

    In this paper we examine the issue of tool management in a Flexible Manufacturing System (FMS). A tool center storing all tools for jobs is introduced and all tools can be shared by the machining centers through tool change between the machining centers and the tool center. Two tool-change methods, “Augmented Magazine Method (AMM)” and “Magazine Carrier Method (MCM)”, are proposed and evaluated using the methods for the allocation of tools and jobs proposed in this study. A job in this study is defined as a sequence of processing operations and is thus processed by a single machining center. We propose a two-stage method to integrate tool planning and the allocation of tools and jobs. The method in the second stage for the allocation of tools and jobs is proposed on the basis of an auction method including a dispatching rule. For the tool planning with AMM at the first stage, we propose a greedy search method to decide the total number of tools. By simulation, we investigate the characteristics and effectiveness of the proposed two-stage method and the tool-change methods together with the effectiveness of several dispatching rules.

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

    Science.gov (United States)

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

    2014-01-23

    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, copayments for adult enrollees. Our study was completed between October 2011 and September 2012 using a document review and a survey of Medicaid administrators that assessed coverage and cost-sharing policy for fee-for-service programs. Results were compared to a similar review, conducted in 2003. Over the past 10 years, Medicaid programs have typically maintained or expanded vaccination coverage benefits for adults and nearly half have explicitly prohibited copayments. The 17 programs that cover all recommended vaccines while prohibiting, copayments demonstrate a commitment to providing increased access to vaccinations for adult enrollees. When developing responses to fiscal and political challenges, the programs that do not cover all ACIP recommended adult vaccines or those that permit copayments for vaccinations, should consider all strategies to increase vaccinations and reduce costs to enrollees.

  8. Ultrahigh bandwidth signal processing

    Science.gov (United States)

    Oxenløwe, Leif Katsuo

    2016-04-01

    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, and hence useful for all types of data signals including coherent multi-level modulation formats. This has enabled processing of phase-modulated spectrally efficient data signals, such as orthogonal frequency division multiplexed (OFDM) signals. In that case, a spectral telescope system was used, using two time lenses with different focal lengths (chirp rates), yielding a spectral magnification of the OFDM signal. Utilising such telescopic arrangements, it has become possible to perform a number of interesting functionalities, which will be described in the presentation. This includes conversion from OFDM to Nyquist WDM, compression of WDM channels to a single Nyquist channel and WDM regeneration. These operations require a broad bandwidth nonlinear platform, and novel photonic integrated nonlinear platforms like aluminum gallium arsenide nano-waveguides used for 1.28 Tbaud optical signal processing will be described.

  9. Limits To Certainty in QoS Pricing and Bandwidth

    OpenAIRE

    Gideon, Carolyn; Camp, L Jean

    2001-01-01

    Advanced services require more reliable bandwidth than currently provided by the Internet Protocol, even with the reliability enhancements provided by TCP. More reliable bandwidth will be provided through QoS (quality of service), as currently discussed widely. Yet QoS has some implications beyond providing ubiquitous access to advance Internet service, which are of interest from a policy perspective. In particular, what are the implications for price of Internet services? Further, how will t...

  10. Bandwidth of Gaussian weighted Chirp

    DEFF Research Database (Denmark)

    Wilhjelm, Jens E.

    1993-01-01

    Four major time duration and bandwidth expressions are calculated for a linearly frequency modulated sinusoid with Gaussian shaped envelope. This includes a Gaussian tone pulse. The bandwidth is found to be a nonlinear function of nominal time duration and nominal frequency excursion of the chirp...

  11. Community-based shared values as a 'Heart-ware' driver for integrated watershed management: Japan-Malaysia policy learning perspective

    Science.gov (United States)

    Mohamad, Zeeda Fatimah; Nasaruddin, Affan; Abd Kadir, Siti Norasiah; Musa, Mohd Noor; Ong, Benjamin; Sakai, Nobumitsu

    2015-11-01

    This paper explores the case for using "community-based shared values" as a potential driver for the "Heartware" aspects of governance in Integrated Watershed Management (IWM) - from a Japan-Malaysia policy learning perspective. This policy approach was originally inspired by the Japanese experience, and the paper investigates whether a similar strategy can be adapted in the Malaysian context-based on a qualitative exploratory case study of a local downstream watershed community. The community-based shared values are categorized into six functional values that can be placed on a watershed: industry, ecosystem, lifestyle, landscape, water resource and spirituality. The study confirmed the availability of a range of community-based shared values in each category that are promising to drive the heartware for integrated watershed management in the local Malaysian context. However, most of these shared values are either declining in its appreciation or nostalgic in nature. The paper ends with findings on key differences and similarities between the Malaysian and Japanese contexts, and concludes with lessons for international transfer of IWM heartware policy strategies between the two countries.

  12. Inaugural Asia-Pacific Dialogue on Clean Energy Governance, Policy, and Regulation: Sharing New Ideas for Asia Clean Energy Future

    OpenAIRE

    Asian Development Bank

    2010-01-01

    In response to the growing demand of energy policy makers and regulators in the Asia and Pacific region for additional knowledge support on clean energy, this publication—prepared under the Law and Policy Reform Program of the Office of the General Counsel—presents lessons learned from countries’ clean energy policy and regulatory measures and approaches discussed during the Inaugural Asia-Pacific Dialogue on Clean Energy Governance, Policy, and Regulation held on 21–22 June 2010 at the Asian...

  13. Steel Industry Energy Bandwidth Study

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2004-10-01

    ITP conducted a study on energy use and potential savings, or "bandwidth" study, in major steelmaking 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 based on the 2nd law of thermodynamics. The Steel Industry Energy Bandwidth Study (PDF 133 KB) also estimates steel industry energy use in the year 2010, and uses that value as a basis for comparison against the minimum requirements. This energy savings opportunity for 2010 will aid focus on longer term R&D.

  14. Mining Industry Energy Bandwidth Study

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2007-07-01

    The Industrial Technologies Program (ITP) relies on analytical studies to identify large energy reduction opportunities in energy-intensive industries and uses these results to guide its R&D portfolio. The energy bandwidth illustrates the total energy-saving opportunity that exists in the industry if the current processes are improved by implementing more energy-efficient practices and by using advanced technologies. This bandwidth analysis report was conducted to assist the ITP Mining R&D program in identifying energy-saving opportunities in coal, metals, and mineral mining. These opportunities were analyzed in key mining processes of blasting, dewatering, drilling, digging, ventilation, materials handling, crushing, grinding, and separations.

  15. A Preliminary Evaluation of Bandwidth Allocation Model Dynamic Switching

    Directory of Open Access Journals (Sweden)

    Rafael F. Reale

    2014-06-01

    Full Text Available Bandwidth Allocation Models (BAMs are used in order to define Bandwidth Constraints (BCs in a per-class basis for MPLS/DS-TE networks and effectively define how network resources like bandwidth are obtained and shared by applications. The BAMs proposed (MAM – Maximum Allocation Model, RDM – Russian Dolls Model, G-RDM – Generic RDM and AllocTC-Sharing attempt to optimize the use of bandwidth resources on a per-link basis with different allocation and resource sharing characteristics. As such, the adoption of distinct BAMs and/or changes in network resource demands (network traffic profile may result in different network traffic allocation and operational behavior for distinct BAMs. This paper evaluates the resulting network characteristics (li nk utilization, preemption and flows blocking of using BAMs dynamically with different traffic scenarios. In brief, it is investigated the dynamics of BAM switching with distinct traffic scenarios. The paper presents initially the investigated BAMs in relation to their behavior and resource allocation characteristics. Then, distinct BAMs are compared using different traffic scenarios in order to investigate the impact of a dynamic change of the BAM configured in the network. Finally, the paper shows that the adoption of a dynamic BAM allocation strategy may result in benefits for network operation in terms of link utilization, preemption and flows blocking.

  16. Performance Investigation of Virtual Private Networks with Different Bandwidth Allocations

    Directory of Open Access Journals (Sweden)

    Ramaswamy Muthiah

    2010-01-01

    Full Text Available A Virtual Private Network (VPN provides private network connections over a publicly accessible shared network. The effective allocation of bandwidth for VPNs assumes significance in the present scenario due to varied traffic. Each VPN endpoint specifies bounds on the total amount of traffic that it is likely to send or receive at any time. The network provider tailors the VPN so that there is sufficient bandwidth for any traffic matrix that is consistent with these bounds. The approach incorporates the use of Ad-hoc On demand Distance Vector (AODV protocol, with a view to accomplish an enhancement in the performance of the mobile networks. The NS2 based simulation results are evaluated in terms of its metrics for different bandwidth allocations, besides analyzing its performance in the event of exigencies such as link failures. The results highlight the suitability of the proposed strategy in the context of real time applications.

  17. PRIORITY BASED BANDWIDTH ALLOCATION IN WIRELESS SENSOR NETWORKS

    Directory of Open Access Journals (Sweden)

    Mary Cherian

    2014-12-01

    Full Text Available Most of the sensor network applications need real time communication and the need for deadline aware real time communication is becoming eminent in these applications. These applications have different dead line requirements also. The real time applications of wireless sensor networks are bandwidth sensitive and need higher share of bandwidth for higher priority data to meet the dead line requirements. In this paper we focus on the MAC layer modifications to meet the real time requirements of different priority data. Bandwidth partitioning among different priority transmissions is implemented through MAC layer modifications. The MAC layer implements a queuing model that supports lower transfer rate for lower priority packets and higher transfer rate for real time packets with higher priority, minimizing the end to end delay. The performance of the algorithm is evaluated with varying node distribution.

  18. Performance Investigation of Virtual Private Networks with Different Bandwidth Allocations

    CERN Document Server

    Natarajan, Mahalakshmi Chidambara; Nachiappan, Alamelu

    2010-01-01

    A Virtual Private Network (VPN) provides private network connections over a publicly accessible shared network. The effective allocation of bandwidth for VPNs assumes significance in the present scenario due to varied traffic. Each VPN endpoint specifies bounds on the total amount of traffic that it is likely to send or receive at any time. The network provider tailors the VPN so that there is sufficient bandwidth for any traffic matrix that is consistent with these bounds. The approach incorporates the use of Ad-hoc On demand Distance Vector (AODV) protocol, with a view to accomplish an enhancement in the performance of the mobile networks. The NS2 based simulation results are evaluated in terms of its metrics for different bandwidth allocations, besides analyzing its performance in the event of exigencies such as link failures. The results highlight the suitability of the proposed strategy in the context of real time applications.

  19. Economic Perspectives on Automated Demand Responsive Transportation and Shared Taxi Services - Analytical models and simulations for policy analysis

    OpenAIRE

    Jokinen, Jani-Pekka

    2016-01-01

    The automated demand responsive transportation (DRT) and modern shared taxi services provide shared trips for passengers, adapting dynamically to trip requests by routing a fleet of vehicles operating without any fixed routes or schedules. Compared with traditional public transportation, these new services provide trips without transfers and free passengers from the necessity of using timetables and maps of route networks. Furthermore, automated DRT applies real-time traffic information in ve...

  20. 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.

  1. Transportation dynamic on coupled networks with limited bandwidth

    CERN Document Server

    Li, Ming; Wang, Bing-Hong

    2016-01-01

    The communication networks in real world often couple with each other to save costs, which results in any network does not have a stand-alone function and efficiency. To investigate this, in this paper we propose a transportation model on two coupled networks with bandwidth sharing. We find that the free-flow state and the congestion state can coexist in the two coupled networks, and the free-flow path and congestion path can coexist in each network. Considering three bandwidth-sharing mechanisms, random, assortative and disassortative couplings, we also find that the transportation capacity of the network only depends on the coupling mechanism, and the fraction of coupled links only affects the performance of the system in the congestion state, such as the traveling time. In addition, with assortative coupling, the traffic capacity of the system will decrease significantly. However, the disassortative coupling has little influence on the transportation capacity of the system, which provides a good strategy t...

  2. Novel Bandwidth Sensor Based Fiber Grating

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    In this paper, the basic principle and the design method of the bandwidth sensing of fiber grating are expounded, respectively. Several novel bandwidth sensor based fiber grating are analyzed and discussed.

  3. Algorithms and Requirements for Measuring Network Bandwidth

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Guojun

    2002-12-08

    This report unveils new algorithms for actively measuring (not estimating) available bandwidths with very low intrusion, computing cross traffic, thus estimating the physical bandwidth, provides mathematical proof that the algorithms are accurate, and addresses conditions, requirements, and limitations for new and existing algorithms for measuring network bandwidths. The paper also discusses a number of important terminologies and issues for network bandwidth measurement, and introduces a fundamental parameter -Maximum Burst Size that is critical for implementing algorithms based on multiple packets.

  4. 75 FR 2557 - Interim Policy for the Sharing of Information Collected by the Coast Guard Nationwide Automatic...

    Science.gov (United States)

    2010-01-15

    ... in the January 17, 2008, issue of the Federal Register (73 FR 3316). Background and Purpose The Coast... the global maritime environment that could affect the security, safety, economy, or environment of the... by the NAIS that is less than 12 hours from transmission. Level A information may be shared with...

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

    NARCIS (Netherlands)

    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 S

  6. Dynamic bandwidth allocation in GPON networks

    DEFF Research Database (Denmark)

    Ozimkiewiez, J.; Ruepp, Sarah Renée; Dittmann, Lars;

    2009-01-01

    Two Dynamic Bandwidth Allocation algorithms used for coordination of the available bandwidth between end users in a GPON network have been simulated using OPNET to determine and compare the performance, scalability and efficiency of status reporting and non status reporting dynamic bandwidth...

  7. 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.

  8. 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…

  9. A Scheduling Discipline for Latency and Bandwidth Guarantees in Asynchronous Network-on-Chip

    DEFF Research Database (Denmark)

    Bjerregaard, Tobias; Sparsø, Jens

    2005-01-01

    Guaranteed services (GS) are important in that they provide predictability in the complex dynamics of shared communication structures. This paper discusses the implementation of GS in asynchronous Network-on-Chip. We present a novel scheduling discipline called Asynchronous Latency Guarantee (ALG......) scheduling, which provides latency and bandwidth guarantees in accessing a shared media, e.g. a physical link shared between a number of virtual channels. ALG overcomes the drawbacks of existing scheduling disciplines, in particular the coupling between latency and bandwidth guarantees. A 0.12 &956;m CMOS...

  10. Bandwidth requirements for fine resolution squinted SAR

    Energy Technology Data Exchange (ETDEWEB)

    DOERRY,ARMIN W.

    2000-03-01

    The conventional rule-of-thumb for Synthetic Aperture Radar is that an RF bandwidth of c/(2{rho}{sub r}) is required to image a scene at the desired slant-range resolution {rho}{sub r}, and perhaps a little more to account for window functions and sidelobe control. This formulation is based on the notion that the total bandwidth required is the same bandwidth that is required for a single pulse. What is neglected is that efficient processing of an entire synthetic aperture of pulses will often require different frequency content for each of the different pulses that makeup a synthetic aperture. Consequently, the total RF bandwidth required of a Synthetic Aperture Radar may then be substantially wider than the bandwidth of any single pulse. The actual RF bandwidth required depends strongly on flight geometry, owing to the desire for a radar to maintain a constant projection of the Fourier space collection surface onto the {omega}{sub y} axis. Long apertures required for fine azimuth resolution, and severe squint angles with steep depression angles may require total RF bandwidths well beyond the minimum bandwidth required of any single transmitted pulse, perhaps even by a factor of two or more. Accounting for this is crucial to designing efficient versatile high-performance imaging radars. This paper addresses how a data set conducive to efficient processing might increase the total RF bandwidth, and presents examples of how a fixed RF bandwidth might then limit SAR geometries.

  11. Allocating Bandwidth in Datacenter Networks:A Survey

    Institute of Scientific and Technical Information of China (English)

    陈丽; 李葆春; 李波

    2014-01-01

    Datacenters have played an increasingly essential role as the underlying infrastructure in cloud computing. As implied by the essence of cloud computing, resources in these datacenters are shared by multiple competing entities, which can be either tenants that rent virtual machines (VMs) in a public cloud such as Amazon EC2, or applications that embrace data parallel frameworks like MapReduce in a private cloud maintained by Google. It has been generally observed that with traditional transport-layer protocols allocating link bandwidth in datacenters, network traffic from competing applications interferes with each other, resulting in a severe lack of predictability and fairness of application performance. Such a critical issue has drawn a substantial amount of recent research attention on bandwidth allocation in datacenter networks, with a number of new mechanisms proposed to efficiently and fairly share a datacenter network among competing entities. In this article, we present an extensive survey of existing bandwidth allocation mechanisms in the literature, covering the scenarios of both public and private clouds. We thoroughly investigate their underlying design principles, evaluate the trade-off involved in their design choices and summarize them in a unified design space, with the hope of conveying some meaningful insights for better designs in the future.

  12. Variable bandwidth and one-step local M-estimator

    Institute of Scientific and Technical Information of China (English)

    范剑青; 蒋建成

    2000-01-01

    A robust version of local linear regression smoothers augmented with variable bandwidth is studied. The proposed method inherits the advantages of local polynomial regression and overcomes the shortcoming of lack of robustness of least-squares techniques. The use of variable bandwidth enhances the flexibility of the resulting local M- estimators and makes them possible to cope well with spatially inho-mogeneous curves, heteroscedastic errors and nonuniform design densities. Under appropriate regularity conditions, it is shown that the proposed estimators exist and are asymptotically normal. Based on the robust estimation equation, one-step local M-estimators are introduced to reduce computational burden. It is demonstrated that the one-step local M-estimators share the same asymptotic distributions as the fully iterative M-estimators, as long as the initial estimators are good enough. In other words, the one-step local M-estimators reduce significantly the computation cost of the fully iterative M-estim

  13. Multiple-bandwidth photoacoustic tomography

    International Nuclear Information System (INIS)

    Photoacoustic tomography, also referred to as optoacoustic tomography, employs short laser pulses to generate ultrasonic waves in biological tissues. The reconstructed images can be characterized by the convolution of the structure of samples, the laser pulse and the impulse response of the ultrasonic transducer used for detection. Although the laser-induced ultrasonic waves cover a wide spectral range, a single transducer can receive only part of the spectrum because of its limited bandwidth. To systematically analyse this problem, we constructed a photoacoustic tomographic system that uses multiple ultrasonic transducers simultaneously, each at a different central frequency. The photoacoustic images associated with the different transducers were compared and analysed. The system was tested by imaging both mouse brains and phantom samples. The vascular vessels in the brain were revealed by all of the transducers, but the image resolutions differed. The higher frequency detectors provided better image resolution while the lower frequency detectors delineated the major structural traits with a higher signal-noise ratio

  14. Improving the Bandwidth Utilization by Recycling the Unused Bandwidth in IEEE 802.16 Networks

    Directory of Open Access Journals (Sweden)

    Gowri T

    2012-03-01

    Full Text Available The Physical and MAC layers have been specified in IEEE 802.16 networks. The quality of service is ensured by the bandwidth reservation. The subscriber station should reserve the bandwidth more than its demand. But the bandwidth is fully utilized by SS but not all the time. So the bandwidth has recycled by the process of recycling the unused bandwidth. The main objective of the proposed scheme is to utilize the unused bandwidth by recycling and maintain the QOS service. By recycling the throughput can be improved which maintains the QOS in the proposed scheme. During this recycling process to maintain the QOS services, the amount of reserved bandwidth is not changed. The proposed scheme can utilize the unused bandwidth up to 70% on average. Protocols and the scheduling algorithms are used to improve the utilization and throughput.

  15. 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…

  16. Bandwidth engineering of photonic crystal waveguide bends

    DEFF Research Database (Denmark)

    Borel, Peter Ingo; Frandsen, Lars Hagedorn; Harpøth, Anders;

    2004-01-01

    An effective design principle has been applied to photonic crystal waveguide bends fabricated in silicon-on-insulator material using deep UV lithography resulting in a large increase in the low-loss bandwidth of the bends. Furthermore, it is experimentally demonstrated that the absolute bandwidth...

  17. Energy Bandwidth for Petroleum Refining Processes

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2006-10-01

    The petroleum refining energy bandwidth report analyzes the most energy-intensive unit operations used in U.S. refineries: crude oil distillation, fluid catalytic cracking, catalytic hydrotreating, catalytic reforming, and alkylation. The "bandwidth" provides a snapshot of the energy losses that can potentially be recovered through best practices and technology R&D.

  18. 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)

    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

  19. A Novel Framework for Distributed Dynamic Bandwidth Allocation in EPONWiMAX Networks

    Directory of Open Access Journals (Sweden)

    S.Ramya

    2014-01-01

    Full Text Available In Ethernet Passive Optical Networks (EPON, allocation of bandwidth to the Optical Network Units (ONU is a critical issue in determining the performance of the network. The resource allocation process in EPON is carried out by the Dynamic Bandwidth Allocation (DBA algorithm. The onus of resource allocation or DBA estimation is bore solely by Optical Line Terminal (OLT which results in more idle time at the OLT, thereby resulting in wastage of bandwidth and increased delay in data transmission. In this paper, a new framework for EPON is proposed, wherein, the DBA estimation is shared by the OLT and ONU, thereby reducing the idle time in OLT and improving the bandwidth utilization. The proposed framework is evaluated under heavy load conditions with the help of OPNET simulations and it has been demonstrated that the proposed framework outperforms the conventional scheme in terms of throughput, percentage of utilization and other QoS services.

  20. High-Bandwidth Hybrid Sensor (HYSENS) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ATA has demonstrated the primary innovation of combining a precision MEMS gyro (BAE SiRRS01) with a high bandwidth angular rate sensor, ATA's ARS-14 resulting in a...

  1. Bandwidth challenge teams at SC2003 conference

    CERN Multimedia

    2003-01-01

    Results from the fourth annual High-Performance Bandwidth Challenge, held in conjunction with SC2003, the international conference on high-performance computing and networking which occurred last week in Phoenix, AZ (1 page).

  2. 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.

  3. Large scale probabilistic available bandwidth estimation

    CERN Document Server

    Thouin, Frederic; Rabbat, Michael

    2010-01-01

    The common utilization-based definition of available bandwidth and many of the existing tools to estimate it suffer from several important weaknesses: i) most tools report a point estimate of average available bandwidth over a measurement interval and do not provide a confidence interval; ii) the commonly adopted models used to relate the available bandwidth metric to the measured data are invalid in almost all practical scenarios; iii) existing tools do not scale well and are not suited to the task of multi-path estimation in large-scale networks; iv) almost all tools use ad-hoc techniques to address measurement noise; and v) tools do not provide enough flexibility in terms of accuracy, overhead, latency and reliability to adapt to the requirements of various applications. In this paper we propose a new definition for available bandwidth and a novel framework that addresses these issues. We define probabilistic available bandwidth (PAB) as the largest input rate at which we can send a traffic flow along a pa...

  4. 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.

  5. Reconstruction in Time-Bandwidth Compression Systems

    CERN Document Server

    Chan, Jacky; Asghari, Mohammad H; Jalali, Bahram

    2014-01-01

    Recently it has been shown that the intensity time-bandwidth product of optical signals can be engineered to match that of the data acquisition instrument. In particular, it is possible to slow down an ultrafast signal, resulting in compressed RF bandwidth - a similar benefit to that offered by the Time-Stretch Dispersive Fourier Transform (TS-DFT) - but with reduced temporal record length leading to time-bandwidth compression. The compression is implemented using a warped group delay dispersion leading to non-uniform time stretching of the signal's intensity envelope. Decoding requires optical phase retrieval and reconstruction of the input temporal profile, for the case where information of interest is resides in the complex field. In this paper, we present results on the general behavior of the reconstruction process and its dependence on the signal-to-noise ratio. We also discuss the role of chirp in the input signal.

  6. Teleoperation over low bandwidth communication links

    International Nuclear Information System (INIS)

    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)

  7. Sharing big biomedical data

    OpenAIRE

    Toga, Arthur W.; Dinov, Ivo D.

    2015-01-01

    Background The promise of Big Biomedical Data may be offset by the enormous challenges in handling, analyzing, and sharing it. In this paper, we provide a framework for developing practical and reasonable data sharing policies that incorporate the sociological, financial, technical and scientific requirements of a sustainable Big Data dependent scientific community. Findings Many biomedical and healthcare studies may be significantly impacted by using large, heterogeneous and incongruent data...

  8. 47 CFR 2.202 - Bandwidths.

    Science.gov (United States)

    2010-10-01

    ... carrier Bn=2M+2DK, M=B÷2 B=50, D=35 Hz (70 Hz shift), K=1.2, Bandwidth: 134 Hz 134HJ2B Telegraphy, single... on 6.5 MHz frequency modulated subcarrier deviation=50 kHz: C=6.5×106 D=50×103 Hz, M=15,000...; Synchronized channels; B=100, M=50, D=600 Hz, Bandwidth: 1420 Hz=1.42 kHz 1K42F7B 2. Telephony......

  9. 47 CFR 87.135 - Bandwidth of emission.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Bandwidth of emission. 87.135 Section 87.135... Technical Requirements § 87.135 Bandwidth of emission. (a) Occupied bandwidth is the width of a frequency... equal to 0.5 percent of the total mean power of a given emission. (b) The authorized bandwidth is...

  10. Shared Services Management: Critical Factors

    OpenAIRE

    Shouhong Wang; Hai Wang

    2015-01-01

    The cloud computing technology has accelerated shared services in the government and private sectors. This paper proposes a research framework of critical success factors of shared services in the aspects of strategy identification, collaborative partnership networking, optimal shared services process re-designing, and new policies and regulations. A survey has been employed to test the hypotheses. The test results indicate that clear vision of strategies of shared services, long term busines...

  11. Variable bandwidth and one-step local M-estimator

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A robust version of local linear regression smoothers augmented with variable bandwidth is studied. The proposed method inherits the advantages of local polynomial regression and overcomes the shortcoming of lack of robustness of least-squares techniques. The use of variable bandwidth enhances the flexibility of the resulting local M-estimators and makes them possible to cope well with spatially inhomogeneous curves, heteroscedastic errors and nonuniform design densities. Under appropriate regularity conditions, it is shown that the proposed estimators exist and are asymptotically normal. Based on the robust estimation equation, one-step local M-estimators are introduced to reduce computational burden. It is demonstrated that the one-step local M-estimators share the same asymptotic distributions as the fully iterative M-estimators, as long as the initial estimators are good enough. In other words, the one-step local M-estimators reduce significantly the computation cost of the fully iterative M-estimators without deteriorating their performance. This fact is also illustrated via simulations.

  12. A Bandwidth Allocation Model Provisioning Framework with Autonomic Characteristics

    Directory of Open Access Journals (Sweden)

    Rafael F. Reale

    2013-11-01

    Full Text Available The Bandwidth Allocation Models (MAM, RDM, G-RDM and AllocTC-Sharing are managementalternatives currently available which propose different resource (bandwidth allocation strategies inmultiservice networks. The BAM adoption by a network is typically a management choice andconfiguration task executed by the network operations and management system setup in a static or nearlystatic way. This paper proposes and explores the alternative ofallowing BAM definition and configurationon a more dynamic way. In effect, one of the basic motivations towards BAM dynamic allocation is the factthat multiservice networks characteristics (traffic loadmay change considerably in daily networkoperation and, as such, some dynamics in BAM allocation should be introduced in order to improveperformance. A framework is presented supporting BAM dynamicallocation. The framework adopts anOpenFlow-based software-defined networking (SDN implementation approach in order to supportscalability issues with a centralized controller and managementnetwork view. The framework architecturealso supports the implementation of some autonomic characteristics which, in brief, look for improving andfacilitating the decision-making process involved with BAM provisioning in a multiservice network. Aproof of concept is presented evaluating different BAM performance under different traffic loads in order todemonstrate the framework strategy adopted.

  13. Polybinary modulation for bandwidth limited optical links

    DEFF Research Database (Denmark)

    Vegas Olmos, Juan José; Jurado-Navas, Antonio

    2015-01-01

    Optical links using traditional modulation formats are reaching a plateau in terms of capacity, mainly due to bandwidth limitations in the devices employed at the transmitter and receivers. Advanced modulation formats, which boost the spectral efficiency, provide a smooth migration path towards e...

  14. Bandwidth Enhancement Techniques of Dielectric Resonator Antenna

    Directory of Open Access Journals (Sweden)

    ARCHANA SHARMA

    2011-07-01

    Full Text Available The paper briefly reviews the historical background of dielectric resonator antenna and its bandwidth enhancement techniques. The main focus is on a compact DRA that can offer broad band operation. It has been illustrated that dual resonance and multi resonance operation can be much effective to give wide band characteristics of DRA.

  15. Dynamic resource management using bandwidth brokers

    Institute of Scientific and Technical Information of China (English)

    Yu Chengzhi; Song Hantao; Hou Xianjun; Pan Chengsheng

    2006-01-01

    The admission control issue in the design of a centralized bandwidth broker model for dynamic control and management of QoS provisioning is studied. A two-phase differentiated flow treatment based dynamic admission control scheme under the centralized bandwidth broker model is proposed. In the proposed scheme, the flow requests are classified into two classes and get differentiated treatment according to their QoS demands. We demonstrate that this admission control scheme can not only improve the resource utilization but also guarantee the flows' QoS. Furthermore, the admission control is divided into two phases: edge admission control and interior admissio-n control. During the interior phase, the PoQ scheme is adopted, which enhances the call processing capability of the bandwidth broker. The simulation results show that the proposed scheme can result in lower flow blocking probability and higher resource utilization. And it also reduces the number of QoS state accesses/updates, thereby increasing the overall call processing capability of the bandwidth broker.

  16. Sharing Economy

    DEFF Research Database (Denmark)

    Marton, Attila; Constantiou, Ioanna; Thoma, Antonela

    De spite the hype the notion of the sharing economy is surrounded by, our understanding of sharing is surprisingly undertheorized. In this paper, we make a first step towards rem edying this state of affairs by analy sing sharing as a s ocial practice. Based on a multi ple - case study, we analys...

  17. Shared pledge shared vision

    International Nuclear Information System (INIS)

    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

  18. JOINT RESOURCE ALLOCATION FOR WLAN&WCDMA INTEGRATED NETWORKS BASED ON SPECTRAL BANDWIDTH MAPPING

    Institute of Scientific and Technical Information of China (English)

    Pan Su; Ye Qiang; Liu Shengmei; Zhou Dawei

    2011-01-01

    Next wireless network aims to integrate heterogeneous wireless access networks by sharing wireless resource.The spectral bandwidth mapping concept is proposed to uniformly describe the resource in heterogeneous wireless networks.The resources of codes and power levels in WCDMA system as well as statistical time slots in WLAN are mapped into equivalent bandwidth which can be allocated in different networks and layers.The equivalent bandwidth is jointly distributed in call admission and vertical handoff control process in an integrated WLAN/WCDMA system to optimize the network utility and guarantee the heterogeneous QoS required by calls.Numerical results show that,when the incoming traffic is moderate,the proposed scheme could receive 5%-10% increase of system revenue compared to the MDP based algorithms.

  19. Reconstitution of Low Bandwidth Reaction History

    International Nuclear Information System (INIS)

    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

  20. 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....

  1. All-optical bandwidth-tailorable radar

    CERN Document Server

    Zou, Weiwen; Long, Xin; Zhang, Siteng; Cui, Yuanjun; Chen, Jianping

    2015-01-01

    Radar has been widely used in military, security, and rescue. Metamaterial cloak is employed in stealth targets to evade radar detection. Hence modern radar should be reconfigurable at multi-bands for detecting stealth targets, which might be realized based on microwave photonics. Here, we demonstrate an all-optical bandwidth-tailorable radar architecture. It is a coherent system utilizing one mode-locked laser for both signal generation and reception. Heterodyning of two individually filtered optical pulses that are pre-chirped via wavelength-to-time mapping generates wideband linearly-chirped radar signal. The working bands can be flexibly tailored with desired bandwidth at user-preferred carrier frequency. After modulated onto the pre-chirped optical pulse, radar echoes are time-stretched and frequency-compressed by several times. The digitization becomes much easier without loss of detection ability. We believe that the demonstration can innovate the radar's architecture with ultra-high range resolution.

  2. Maximum-Bandwidth Node-Disjoint Paths

    Directory of Open Access Journals (Sweden)

    Mostafa H. Dahshan

    2012-03-01

    Full Text Available This paper presents a new method for finding the node-disjoint paths with maximum combined bandwidth in communication networks. This problem is an NP-complete problem which can be optimally solved in exponential time using integer linear programming (ILP. The presented method uses a maximum-cost variant of Dijkstra algorithm and a virtual-node representation to obtain the maximum-bandwidth node-disjoint path. Through several simulations, we compare the performance of our method to a modern heuristic technique and to the ILP solution. We show that, in a polynomial execution time, our proposed method produces results that are almost identical to ILP in a significantly lower execution time

  3. Dynamic Bandwidth Allocation Scheme in Multi-user VBR Communication System

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Much work has been done to study the rate control problem in variable bit rate ( VBR) video coding system. Most of them consider the point-to-point cases, wher e the rate control problem can often be abstracted as how to allocate bits among frames or among blocks when available bandwidth is limited. While in some other cases, such as some wireless ATM systems, multi-users share the common limited bandwidth. In such conditions, the bandwidth allocation among different users b ecomes a rather important problem.In this paper, a novel bandwidth allocation s cheme is presented, where the available bandwidth is dynamically allocated a mong different users based on a so-called "equal distortion" criterion. Simulatio n results show that the proposed scheme considerably improves the overall subjec tive performance in multi-user VBR communication systems. It is noticed that th e proposed join source and channel rate control idea is a very general concept t hat can be useful in many similar problems.

  4. Efficient Periodic Broadcasting for Mobile Networks at Small Client Receiving Bandwidth and Buffering Space

    Directory of Open Access Journals (Sweden)

    Hsiang-Fu Yu

    2013-01-01

    Full Text Available Periodic broadcasting is an effective approach for delivering popular videos. In general, this approach does not provide interactive (i.e., VCR functions, and thus a client can tolerate playback latency from a video server. The concept behind the approach is partitioning a video into multiple segments, which are then broadcast across individual communication channels in terms of IP multicast. The method improves system throughput by allowing numerous clients to share the channels. For many broadcasting schemes, client receiving bandwidth must equal server broadcasting bandwidth. This limitation causes these schemes to be infeasible in mobile networks because increasing receiving bandwidth at all client sites is expensive, as well as difficult. To alleviate this problem, the fibonacci broadcasting (FiB scheme allows a client with only two-channel bandwidth to receive video segments. In comparison with other similar schemes, FiB yields smallest waiting time. Extending FiB, this work proposes a new scheme (called FiB+ to achieve smaller client buffering space and the same waiting time under two-channel receiving bandwidth. Extensive analysis shows that FiB+ can yield 34.5% smaller client buffer size than that of FiB. Further simulation results also indicate that FiB+ requires lower client buffering space than several previous schemes.

  5. 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...... with the output decimator. The filter required by the other channel is optimized through global search using the system level performance metrics integrated sidelobe level ratio (ISLR) and peak sidelobe level ratio (PSLR)....

  6. Gaussian entanglement distribution with GHz bandwidth

    CERN Document Server

    Ast, Stefan; Mehmet, Moritz; Schnabel, Roman

    2016-01-01

    The distribution of Gaussian entanglement can be used to generate a mathematically-proven secure key for quantum cryptography. The distributed secret key rate is limited by the bandwidth of the nonlinear resonators used for entanglement generation, which is less than 100 MHz for current state-of-the-art setups. The development of an entanglement source with a higher bandwidth promises an increased measurement speed and a linear boost in the secure data rate. Here, we present the experimental realization of a continuous-variable entanglement source with a bandwidth of more than 1.25 GHz. The measured entanglement spectrum was quantified via the inseparability criterion introduced by Duan and coworkers with a critical value of 4 below which entanglement is certified. The measurements yielded an inseparability value of about 1.8 at a frequency of 300 MHz to about 2.8 at 1.2 GHz extending further to about 3.1 at 1.48 GHz. In the experiment we used two 2.6 mm long monolithic PPKTP crystal resonators to generate tw...

  7. Spectrum sharing for future mobile cellular systems

    OpenAIRE

    Bennis, M

    2009-01-01

    Abstract Spectrum sharing has become a high priority research area over the past few years. The motivation behind this lies in the fact that the limited spectrum is currently inefficiently utilized. As recognized by the World radio communication conference (WRC)-07, the amount of identified spectrum is not large enough to support large bandwidths for a substantial number of operators. Therefore, it is paramount for future mobile cellular systems to share the frequency spectrum and coexist ...

  8. Sharing Graphs

    CERN Document Server

    Sahasranand, K R

    2010-01-01

    Almost all known secret sharing schemes work on numbers. Such methods will have difficulty in sharing graphs since the number of graphs increases exponentially with the number of nodes. We propose a secret sharing scheme for graphs where we use graph intersection for reconstructing the secret which is hidden as a sub graph in the shares. Our method does not rely on heavy computational operations such as modular arithmetic or polynomial interpolation but makes use of very basic operations like assignment and checking for equality, and graph intersection can also be performed visually. In certain cases, the secret could be reconstructed using just pencil and paper by authorised parties but cannot be broken by an adversary even with unbounded computational power. The method achieves perfect secrecy for (2, n) scheme and requires far fewer operations compared to Shamir's algorithm. The proposed method could be used to share objects such as matrices, sets, plain text and even a heterogeneous collection of these. S...

  9. 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....

  10. Shared Attention.

    Science.gov (United States)

    Shteynberg, Garriy

    2015-09-01

    Shared attention is extremely common. In stadiums, public squares, and private living rooms, people attend to the world with others. Humans do so across all sensory modalities-sharing the sights, sounds, tastes, smells, and textures of everyday life with one another. The potential for attending with others has grown considerably with the emergence of mass media technologies, which allow for the sharing of attention in the absence of physical co-presence. In the last several years, studies have begun to outline the conditions under which attending together is consequential for human memory, motivation, judgment, emotion, and behavior. Here, I advance a psychological theory of shared attention, defining its properties as a mental state and outlining its cognitive, affective, and behavioral consequences. I review empirical findings that are uniquely predicted by shared-attention theory and discuss the possibility of integrating shared-attention, social-facilitation, and social-loafing perspectives. Finally, I reflect on what shared-attention theory implies for living in the digital world. PMID:26385997

  11. 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…

  12. Confocal microscopy via multimode fibers: fluorescence bandwidth

    Science.gov (United States)

    Loterie, Damien; Psaltis, Demetri; Moser, Christophe

    2016-03-01

    We recently described a method for confocal reflection imaging through fibers, as a way to increase contrast when imaging unstained biological specimens. Using a transmission matrix, focused spots can be created at the distal end of a fiber. The backscattered field coming back from the sample can be filtered using optical correlation to obtain spatial selectivity in the detection. In this proceedings article, we briefly review the working principle of this method, and we discuss how the scheme could be adapted to confocal fluorescence imaging. In particular, we show simulations of the achievable detection bandwidth when using step-index multimode fibers as imaging devices.

  13. QFII持股与上市公司的现金股利政策——来自2008~2011年中国A股上市公司的证据%QFII Share-holding and Cash Dividend Policy of Listed Companies——Evidence of Chinese A-share Listed Companies from 2008 to 2011

    Institute of Scientific and Technical Information of China (English)

    吴卫华; 万迪昉

    2012-01-01

    This paper collects the data from the top ten stockholders and the top ten shareholders of tradable shares disclosed in the annual reports during 2008-2011 in Chinese A-share market,and examines the relationship between QFII share ratio and the cash dividend policy of listed company.The empirical results show that QFII prefers companies which pay cash dividends,and the payout companies can also attract QFII;QFII can promote the increasing of the list companies' payout ratio,but the companies which have higher payout ratio can not attract more QFII share-holding.The above results indicate that QFII plays a positive role in improving the dividend policy of China's listed companies,and this institution contributes to the stable and healthy development of China's stock market.%通过搜集2008~2011年我国A股上市公司年报中十大股东和十大流通股东的数据,研究了QFII持股比例与上市公司现金股利政策之间的关系。实证结果表明:QFII偏好现金分红的公司,而现金分红的公司也能够吸引QFII持股;QFII持股能够促进上市公司提高现金股利支付率,但是具有更高现金股利支付率的上市公司并不能吸引更多的QFII持股。这表明,QFII在改善我国上市公司现金股利政策方面起到了积极的作用,引入QFII制度有助于我国证券市场的健康稳定发展。

  14. Bandwidth reconfigurable microwave photonic filter based on stimulated Brillouin scattering

    Science.gov (United States)

    Xiao, Yongchuan; Wang, Xin; Zhang, Youdi; Dong, Wei; Zhang, Xindong; Liu, Caixia; Ruan, Shengping; Chen, Weiyou

    2015-01-01

    A bandwidth reconfigurable microwave photonic filter is proposed and numerically analyzed employing Brillouin gain spectrum narrowing and broadening. The stimulated Brillouin scattering (SBS) process is used to convert the phase modulation to intensity modulation to generate filter passband. Due to the fact that the passband is formed by mapping the Brillouin gain spectrum, bandwidth reconfiguration can be implemented by changing Brillouin gain linewidth. In this paper, both bandwidth reduction and increase are included in a single system and the details of gain spectrum narrowing and broadening are demonstrated. Theoretically, nearly 60% bandwidth reduction and hundreds times of bandwidth increase are achieved as compared to the case without gain spectrum process.

  15. 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....

  16. Bandwidth Estimation For Mobile Ad hoc Network (MANET

    Directory of Open Access Journals (Sweden)

    Rabia Ali

    2011-09-01

    Full Text Available In this paper we presents bandwidth estimation scheme for MANET, which uses some components of the two methods for the bandwidth estimation: 'Hello Bandwidth Estimation 'Listen Bandwidth Estimation. This paper also gives the advantages of the proposed method. The proposed method is based on the comparison of these two methods. Bandwidth estimation is an important issue in the Mobile Ad-hoc Network (MANET because bandwidth estimation in MANET is difficult, because each host has imprecise knowledge of the network status and links change dynamically. Therefore, an effective bandwidth estimation scheme for MANET is highly desirable. Ad hoc networks present unique advanced challenges, including the design of protocols for mobility management, effective routing, data transport, security, power management, and quality-of-service (QoS provisioning. Once these problems are solved, the practical use of MANETs will be realizable.

  17. Bandwidth Partitioning in Decentralized Wireless Networks

    CERN Document Server

    Jindal, Nihar; Weber, Steven

    2007-01-01

    This paper addresses the following question, which is of interest in the design of a multiuser decentralized network. Given a total system bandwidth of W Hz and a fixed data rate constraint of R bps for each transmission, how many frequency slots N of size W/N should the band be partitioned into in order to maximize the number of simultaneous links in the network? Dividing the available spectrum results in two competing effects. On the positive side, a larger N allows for more parallel, non-interfering communications to take place in the same area. On the negative side, a larger N increases the SINR requirement for each link because the same information rate must be achieved over less bandwidth, which in turn increases the area consumed by each transmission. Exploring this tradeoff and determining the optimum value of N in terms of the system parameters is the focus of the paper. Using stochastic geometry, the optimal SINR threshold - which directly corresponds to the optimal spectral efficiency - is derived ...

  18. Development Trend and Policy Recommendations of“Sharing Economy”%“分享经济”发展态势及政策建议

    Institute of Scientific and Technical Information of China (English)

    朱欣乐; 郭戎

    2016-01-01

    “分享经济”作为一种新型商业模式,在国内外发展迅速。本文从“分享经济”的发展态势、面临的主要问题出发,分析了当前世界主要发达国家和我国发展“分享经济”的做法以及“分享经济”兴起的原因。同时指出“,分享经济”对推动经济转型升级具有积极作用,但与传统经济发展模式仍然存在摩擦,且制度机制升级不畅、区域基础设施分配不均等原因也会阻碍“分享经济”发展。基于此,本文认为,应继续完善社会信用体系建设、推进精细监管体制建设,并通过设立“分享经济”专项试点推广“分享经济”在全国开展。%As a new business model, “Sharing Economy” is developing rapidly in the world. After describing development and problems of the “Sharing Economy”, this paper mainly analyzes some practice examples and reasons that the “Sharing Economy” raised in China and some developed countries. It also points out that “Share Economy” plays an active role in economic transformation and upgrading promotion, but conlficts with traditional economic developing modes are also existed, and its developed process maybe obstructed by smoothless mechanism upgrade, and unequal regional infrastructure distribution. It is ifnally recommended that social credit system construction should be continually improved, ifne supervision system construction be promoted, and some special pilots should be established ,in order to promote the “Sharing Economy” of China.

  19. An Improved QoS Multipath Routing Using Bandwidth Estimation and Rate Adaptation

    Directory of Open Access Journals (Sweden)

    S. Suganya

    2014-06-01

    Full Text Available Mobile Adhoc Networks (MANETs are composed of nodes which communicate with one another without network infrastructure. Their advantage being that they can be used in isolation or along with wired infrastructure, usually via a gateway node to ensure traffic relay for both networks. Quality of Service (QoS is harder to ensure in ad hoc networks than in other network types, as wireless bandwidth is shared by adjacent nodes with network topology changing as nodes move. Most QoS protocols are implemented for specific scenarios and consider parameters such as network topologies, bandwidth, mobility, security and so on. This work proposes a novel multipath routing protocol which is an extension of AOMDV by discovering routes based on available bandwidth and rate adaptation. The method with Hello message box is used to calculate available bandwidth for a route. Relative Fairness and Optimized Throughput is an approach for rate adaptation in this paper which is to ensure fairness and allow nodes to adapt transmission rates and contention windows to channel quality. In sequence this is determined by calculating the access probability of a channel for each node in a distributed manner approximating successful and failed transmissions.

  20. Bandwidth Analysis of Smart Meter Network Infrastructure

    DEFF Research Database (Denmark)

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

    2014-01-01

    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......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...... 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...

  1. A high-bandwidth spintronic position sensor.

    Science.gov (United States)

    Tuma, Tomas; Pantazi, Angeliki; Sahoo, Deepak R; Eib, Philipp; Salis, Gian; Pozidis, Haris; Sebastian, Abu

    2014-09-19

    Position sensing with resolution down to the scale of a single atom is of key importance in nanoscale science and engineering. However, only optical-sensing methods are currently capable of non-contact sensing at such resolution over a high bandwidth. Here, we report a new non-contact, non-optical position-sensing concept based on detecting changes in a high-gradient magnetic field of a microscale magnetic dipole by means of spintronic sensors. Experimental measurements show a sensitivity of up to 40 Ω/μm, a linear range greater than 10 μm and a noise floor of 0.5 pm/√[Hz]. Also shown is the use of the sensor for position measurements for closed-loop control of a high-speed atomic force microscope with a frame rate of more than 1 frame/s.

  2. 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.

  3. Shared parenting or shared care?:Learning from children's experiences of a post-divorce shared care arrangement

    OpenAIRE

    Davies, Hayley

    2015-01-01

    This article examines three issues raised by three primary-aged siblings experiencing a post-divorce shared parenting arrangement. It argues that the conceptualisation of shared parenting in academic and policy discourse concentrates on parent-child relationships, overlooks children's relationships with siblings, and fails to fully recognise the social and material resources necessary for shared parenting arrangements to work. It suggests that current policy discourse takes for granted that s...

  4. Effective Bandwidth Utilization in IEEE802.11 for VOIP

    CERN Document Server

    Bhanu, S Vijay; Balakrishnan, V

    2010-01-01

    Voice over Internet protocol (VoIP) is one of the most important applications for the IEEE 802.11 wireless local area networks (WLANs). For network planners who are deploying VoIP over WLANs, one of the important issues is the VoIP capacity. VoIP bandwidth consumption over a WAN is one of the most important factors to consider when building a VoIP infrastructure. Failure to account for VoIP bandwidth requirements will severely limit the reliability of a VoIP system and place a huge burden on the WAN infrastructure. Less bandwidth utilization is the key reasons for reduced number of channel accesses in VOIP. But in the QoS point of view the free bandwidth of atleast 1-5% will improve the voice quality. This proposal utilizes the maximum bandwidth by leaving 1-5% free bandwidth. A Bandwidth Data rate Moderation (BDM) algorithm has been proposed which correlates the data rate specified in IEEE802.11b with the free bandwidth. At each time BDM will calculate the bandwidth utilization before sending the packet to i...

  5. Frequency Bandwidth Optimization of Left-Handed Metamaterial

    Science.gov (United States)

    Chevalier, Christine T.; Wilson, Jeffrey D.

    2004-01-01

    Recently, left-handed metamaterials (LHM s) have been demonstrated with an effective negative index of refraction and with antiparallel group and phase velocities for microwave radiation over a narrow frequency bandwidth. In order to take advantage of these characteristics for practical applications, it will be beneficial to develop LHM s with increased frequency bandwidth response and lower losses. In this paper a commercial three-dimensional electromagnetic simulation code is used to explore the effects of geometry parameter variations on the frequency bandwidth of a LHM at microwave frequencies. Utilizing an optimizing routine in the code, a geometry was generated with a bandwidth more than twice as large as the original geometry.

  6. 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.

  7. 考虑风险偏好的定价决策与需求信息共享价值分析%An Analysis of Pricing Policy and Demand Information Sharing Values with Risk Preference

    Institute of Scientific and Technical Information of China (English)

    陈琴; 祁明

    2015-01-01

    为了分析零售商的风险偏好对定价决策及信息共享价值的影响,以期望利润与条件风险估值的加权平均作为目标准则来刻画零售商的决策目标函数,构建供应链的需求信息共享决策模型,通过该模型,深入地分析和研究零售商不同风险偏好下供应链的最优定价决策以及需求信息共享的价值。研究表明,信息不共享情况下最优批发价与λ无关;当市场不确定信息显示需求增加时,最优批发价、最优零售价、零售商信息共享价值随着λ的增大而增大,而供应商和供应链的信息共享价值随着λ的增大而减小;而当市场不确定信息显示需求减少时,最优批发价、最优零售价、零售商信息共享价值随着λ的增大而减小,而供应商和供应链的信息共享价值随着λ的增大而增大。%In order to analyze the impact of the retailer's risk preference on pricing policy and information sharing value , the retailer's decision objective function is characterized by using expected profit and conditional value-at-risk( CvaR) as a weighted average of objective criteria and the optimal pricing policies and the demand information sharing values with the retailer's different risk preference are studied.The results show that the wholesale price does not matter λwhen there is no information sharing.The optimal wholesale price , the optimal retail price and retailer's information sharing value will increase when the market uncertainty information shows demand will increase , and the supplier's and supply chain's information sharing value will decrease with the increasing of λ.And when the market uncertainty information shows demand will decrease , the optimal wholesale price , the optimal retail price and retailer's information sharing value will decrease with the increasing of λ, but the supplier's and supply chain's information sharing value will increase .

  8. 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)

    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.

  9. 我国股票发行注册制的制度条件及其政策研究%On Institutional Conditions of Share Issue Registration System in China and Relevant Policies

    Institute of Scientific and Technical Information of China (English)

    陈淮; 顾连书

    2012-01-01

    Based on the theoretical framework that the institution is divided into regulatory factors,normative factors,and cultural-cognitive factors by institutional school,this paper analyzes the basic market conditions of share issue registration system and the defects in China's securities market.Finally,it puts forward some relevant policy recommendations.%本文以制度主义学派将制度分为规制性因素、规范性因素和文化—认知性因素这一基本理论框架为基础,分析股票发行注册制所需的基本市场条件,比较了我国证券市场存在的不足,并有针对性地提出相关政策建议。

  10. E-Readiness Assessment Model for Low Bandwidth Environment

    Directory of Open Access Journals (Sweden)

    Nazir Ahmad Suhail

    Full Text Available This paper reports on assessment of an e-readiness model for low bandwidth environment. The main focus of the model is on technological (bandwidth related critical factors that are barrier to the adoption of technology mediated learning in developing cou ...

  11. Evaluation of dynamic bandwidth allocation algorithms in GPON networks

    DEFF Research Database (Denmark)

    Ozimkiewicz, J.; Ruepp, Sarah Renée; Dittmann, Lars;

    2010-01-01

    In this paper, two approaches for Dynamic Bandwidth Allocation in GPON networks are proposed, and validated through simulations in the OPNET modeler. One approach address a Status Reporting scheme, where the bandwidth allocation originates from the client request. The second use a centralized Non...... services....

  12. Modeling of Bandwidth Aggregation over Heterogeneous Wireless Access Networks

    DEFF Research Database (Denmark)

    Popovska Avramova, Andrijana; Dittmann, Lars

    2012-01-01

    transfer deals with the problem on how to effectively aggregate the bandwidth by simultaneous usage of heterogeneous networks that a host is attached to in order to improve the throughput. This paper deals with a simulation based analysis of bandwidth aggregation techniques and their impact on higher layer...

  13. Libraries Sharing Technology for Sharing

    OpenAIRE

    Morrison, Heather; Stranack, Kevin; Mussell, Jessica

    2006-01-01

    Recent resource sharing technology developments in the western Canadian consortia, BC Electronic Library Network and COPPUL are discussed. Highlights include the shelf status project of BC ELN, combining the functionality of a union catalogue with live lookup of circulation status via Z39.50, a tagging feature for the locally developed A to Z list CJDB (CUFTS Journal Database), a locally developed federated search tool, dbwiz, the Open Journal Systems software of the Public Knowledge Project,...

  14. 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.

  15. Managing Supply and Demand of Bandwidth in Peer-to-Peer Communities

    OpenAIRE

    Meulpolder, M

    2011-01-01

    On today's Internet, millions of people participate in peer-to-peer communities where they share content such as audio and video files. Contrary to websites such as Youtube, which rely on large and expensive computer servers to store and deliver all of their content, peer-to-peer communities rely on storage and delivery by the PCs of the users themselves. Because of this, a peer-to-peer community can only be successful if there are enough users willing to provide content and bandwidth to othe...

  16. Dividend Policy Controverses

    OpenAIRE

    Ljiljana Vidučić

    2005-01-01

    Dividend theory shares with capital structure theories the attribute of area of high controversy. Financial literature discusses whether there is an interdependency of dividends and share price, i.e. value of the firm. The main views may be defined with three theories of dividend policy. However, unambiguous solutions are still lacking. Literature on dividends highlights several concepts that may be important in defining the dividend policy. Dividend policy aims to define payout ratio, sort o...

  17. A Study of Bandwidth Measurement Technique in Wireless Mesh Networks

    Directory of Open Access Journals (Sweden)

    Ajeet Kumar Singh

    2011-09-01

    Full Text Available Wireless mesh networks (WMNs have been proposed as a key technology for next generation wireless networking to provide last-mile broadband access. H ere we have given our observation and study for end to-end bandwidth estimation in WMNs. End-to-end Ban dwidth Estimation is an important metric for network management and monitoring. It can also impr ove the effectiveness of congestion control mechanism, audio/video stream adoration and dynamic overlay. In recent years, many techniques have been developed for bandwidth estimation in the wire d as well as the last-hop wireless networks, but th ey under-perform in WMNs. We investigate attributes th at can affect the bandwidth estimation in WNMs; we found existing techniques do not consider the effec t of attributes like CSMA/CA-based contending traff ic and high interference interference that leads to th e error full estimation. In this paper, we present an active bandwidth measu rement technique called Bandwidth Probe based on th e packet dispersion principle. It measures the steady state bandwidth of the system while considering th e effects of the FIFO cross and CSMA/CA-based contend ing traffic. It is also mitigating the effect of interference. We also show how to achieve the stati onary state behaviour of the system to limit the nu mber of probe packets. On simulation, Bandwidth Probe gi ves a accurate estimation of the available bandwidt h using average convergence time and lower intrusiven ess.

  18. Utility-based bandwidth allocation algorithm for heterogeneous wireless networks

    Institute of Scientific and Technical Information of China (English)

    CHAI Rong; WANG XiuJuan; CHEN QianBin; SVENSSON Tommy

    2013-01-01

    In next generation wireless network (NGWN), mobile users are capable of connecting to the core network through various heterogeneous wireless access networks, such as cellular network, wireless metropolitan area network (WMAN), wireless local area network (WLAN), and ad hoc network. NGWN is expected to provide high-bandwidth connectivity with guaranteed quality-of-service to mobile users in a seamless manner; however, this desired function demands seamless coordination of the heterogeneous radio access network (RAN) technologies. In recent years, some researches have been conducted to design radio resource management (RRM) architectures and algorithms for NGWN; however, few studies stress the problem of joint network performance optimization, which is an essential goal for a cooperative service providing scenario. Furthermore, while some authors consider the competition among the service providers, the QoS requirements of users and the resource competition within access networks are not fully considered. In this paper, we present an interworking integrated network architecture, which is responsible for monitoring the status information of different radio access technologies (RATs) and executing the resource allocation algorithm. Within this architecture, the problem of joint bandwidth allocation for heterogeneous integrated networks is formulated based on utility function theory and bankruptcy game theory. The proposed bandwidth allocation scheme comprises two successive stages, i.e., service bandwidth allocation and user bandwidth allocation. At the service bandwidth allocation stage, the optimal amount of bandwidth for different types of services in each network is allocated based on the criterion of joint utility maximization. At the user bandwidth allocation stage, the service bandwidth in each network is optimally allocated among users in the network according to bankruptcy game theory. Numerical results demonstrate the efficiency of

  19. 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 towar

  20. Ultra-broad bandwidth parametric amplification at degeneracy.

    Science.gov (United States)

    Limpert, J; Aguergaray, C; Montant, S; Manek-Hönninger, I; Petit, S; Descamps, D; Cormier, E; Salin, F

    2005-09-19

    We report on a novel approach of ultra-broad bandwidth parametric amplification around degeneracy. A bandwidth of up to 400 nm centered around 800 nm is amplified in a BBO crystal by using chirped pump pulses with a bandwitdth as broad as 10 nm. A supercontinuum signal is generated in a microstructured fiber, having to first order a quadratic chirp, which is necessary to ensure temporal overlap of the interacting waves over this broad bandwidth. Furthermore, we discuss the potential of this approach for an octave-spanning parametric amplification.

  1. Phase locking and bandwidth in a gyrotron oscillator

    Science.gov (United States)

    Latham, P. E.; Granatstein, V. L.; Carmel, Y.

    1993-06-01

    For imaging radar and for satellite and space communication (e.g. NASA's deep space network), it is important that the bandwidth be as large as possible. Here we derive a formalism for computing the phase locking bandwidth that can be achieved in a gyrotron oscillator while varying the beam voltage. As an example, a second harmonic TE02/03 gyrotron is considered. For this device, the effective bandwidth can be increased by a factor of about 3 compared with the fixed voltage case by allowing the beam voltage to change together with the input locking signal.

  2. Microwave photonic bandstop filter with wide tunability and adjustable bandwidth.

    Science.gov (United States)

    Li, Wei; Yang, Chengwu; Wang, Ling; Yuan, Zhilin; Liu, Jianguo; Li, Ming; Zhu, Ninghua

    2015-12-28

    A microwave photonic bandstop filter is proposed and experimentally demonstrated in this work. The filter exhibits promising performance combination of reconfigurability, frequency tunability, and bandwidth adjustment. The phase modulation on two orthogonal polarization states produces a bandpass and a lowpass MPF, respectively. The key concept of destructive interference between the bandpass and lowpass MPF enables the reconfiguration of MPF from bandpass to bandstop. By adjusting the wavelength of two orthogonally polarized optical carriers and the bandwidth of an optical bandpass filter, the bandstop filter is tunable in terms of center frequency and bandwidth. PMID:26832021

  3. Ultra-broad bandwidth parametric amplification at degeneracy.

    Science.gov (United States)

    Limpert, J; Aguergaray, C; Montant, S; Manek-Hönninger, I; Petit, S; Descamps, D; Cormier, E; Salin, F

    2005-09-19

    We report on a novel approach of ultra-broad bandwidth parametric amplification around degeneracy. A bandwidth of up to 400 nm centered around 800 nm is amplified in a BBO crystal by using chirped pump pulses with a bandwitdth as broad as 10 nm. A supercontinuum signal is generated in a microstructured fiber, having to first order a quadratic chirp, which is necessary to ensure temporal overlap of the interacting waves over this broad bandwidth. Furthermore, we discuss the potential of this approach for an octave-spanning parametric amplification. PMID:19498762

  4. Information Sharing in a Multi-Echelon Inventory System

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The influence of different information sharing scenarios in a single supplier-single retailer supply chain is analyzed. The five information sharing scenarios are centralized information sharing, full information sharing, supplier-dominated information sharing, retailer-dominated information sharing, and noninformation sharing. Iterative procedures are developed to obtain the inventory policies and the system costs at equilibrium points. Numerical examples show that the cost of a centralized inventory system is about 20% - 40% lower than that of a decentralized system with non-information sharing. Furthermore, a higher information sharing level does not always lead to a lower system cost in a decentralized supply chain due to inventory competition.

  5. Sharing values, sharing a vision

    Energy Technology Data Exchange (ETDEWEB)

    1993-12-31

    Teamwork, partnership and shared values emerged as recurring themes at the Third Technology Transfer/Communications Conference. The program drew about 100 participants who sat through a packed two days to find ways for their laboratories and facilities to better help American business and the economy. Co-hosts were the Lawrence Livermore National Laboratory and the Lawrence Berkeley Laboratory, where most meetings took place. The conference followed traditions established at the First Technology Transfer/Communications Conference, conceived of and hosted by the Pacific Northwest Laboratory in May 1992 in Richmond, Washington, and the second conference, hosted by the National Renewable Energy Laboratory in January 1993 in Golden, Colorado. As at the other conferences, participants at the third session represented the fields of technology transfer, public affairs and communications. They came from Department of Energy headquarters and DOE offices, laboratories and production facilities. Continued in this report are keynote address; panel discussion; workshops; and presentations in technology transfer.

  6. A Bandwidth Control Method Providing Entrance QoS for Multimedia Communication

    Institute of Scientific and Technical Information of China (English)

    LUO Qiang-qiang; ZHU Zhi-xiang; HUANG Ting-xue

    2005-01-01

    With the development of wideband IP network, many new IP-Based multimedia applications appear ceaselessly. The real-time multimedia application requires that the IP network provides QoS. To the end-to-end real-time multimedia communication, the QoS service includes the trunk QoS and the entrance QoS. The trunk QoS has some feasible technologies, such as RSVP and DiffServ. But, the entrance QoS has few technologies at the moment. So, this paper introduces the entrance bandwidth control to get the end-to-end QoS. The design and scheme of bandwidth controller applying to the usual Internet application and real-time media communication is provided in this paper. It distinguishes between the usual Internet applications, such as HTTP and FTP, and the real-time multimedia applications, such as Internet telephony and videoconferencing. Then they will be dealt with in different ways in order to satisfy the QoS requirements of different types of services. In this paper, we propose a new bandwidth control method for real-time multimedia communication. The principle, the implementing flow, the control policy and the application scheme are discussed.

  7. Shared Memories?

    DEFF Research Database (Denmark)

    Wæhrens, Anne

    2011-01-01

    This paper analyses how the memory of the Holocaust has been addressed in the European Parliament from 1989 to 2009. I identify two major changes that occurred in the 1990s and after the 2004 enlargement of the European Union respectively. In the 1990s the war in Bosnia and the question of restit......This paper analyses how the memory of the Holocaust has been addressed in the European Parliament from 1989 to 2009. I identify two major changes that occurred in the 1990s and after the 2004 enlargement of the European Union respectively. In the 1990s the war in Bosnia and the question...... of restitution universalised the memory of the Holocaust and made it present. The 2004 enlargement brought the memory of Soviet Communism into the Union and made it a central task to construct a community of memory that includes both the memory of the Holocaust and of Soviet Communism. The analysis also...... identifies what seems to be a political memory split between Left and Right; and it shows that the time might not be ripe for a shared European memory....

  8. 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

  9. 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

  10. Available Bandwidth Estimation Strategy Based on the Network Allocation Vector

    Directory of Open Access Journals (Sweden)

    Hongtao Liu

    2012-12-01

    Full Text Available Available bandwidth is of great importance to network Quality of Service assurance, network load balancing, streaming media rate control, routing, and congestion control, etc.. In this paper, the available bandwidth estimation strategy based on the Network Allocation Vector for Wireless Sensor Networks is proposed. According to the size of the average contention window, network nodes predict the probability of collision in process of frame transmission, and then estimate the number of retransmission. Through the collection of Hello packets periodically sent by neighbors, nodes obtain their Network Allocation Vector, and then estimate the available bandwidth. The simulation results show that the strategy is simple and effective, can accurately estimate the collision of data frames as well as the available bandwidth of Wireless Sensor Networks.

  11. MULTILAYER MICROSTRIP ANTENNA QUALITY FACTOR OPTIMIZATION FOR BANDWIDTH ENHANCEMENT

    Directory of Open Access Journals (Sweden)

    M.C. SRIVASTAVA

    2012-12-01

    Full Text Available The impedance bandwidth, one of the important characteristics of microstrip patch antennas, can be significantly improved by using a multilayer dielectric configuration. In this paper the focus is on bandwidth enhancement technique of a multilayer patch antenna for X-band applications. In order to enhance the bandwidth, antenna losses are contained by controlling those quality factors which can have a significant impact on the bandwidth for a given permittivity and thickness of the substrate. This has been achieved by conformal transformation of the multidielectric microstrip antenna. For the ease of analysis Wheelers transformation is used to map the complex permittivity of a multilayer substrate to a single layer. Method of Moments and Finite Difference Time Domain approaches are used for the computation of results.

  12. 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.

  13. Highly efficient frequency conversion with bandwidth compression of quantum light

    CERN Document Server

    Allgaier, Markus; Sansoni, Linda; Quiring, Viktor; Ricken, Raimund; Harder, Georg; Brecht, Benjamin; Silberhorn, Christine

    2016-01-01

    Hybrid quantum networks rely on efficient interfacing of dissimilar quantum nodes, since elements based on parametric down-conversion sources, quantum dots, color centres or atoms are fundamentally different in their frequencies and bandwidths. While pulse manipulation has been demonstrated in very different systems, to date no interface exists that provides both an efficient bandwidth compression and a substantial frequency translation at the same time. Here, we demonstrate an engineered sum-frequency-conversion process in Lithium Niobate that achieves both goals. We convert pure photons at telecom wavelengths to the visible range while compressing the bandwidth by a factor of 7.47 under preservation of non-classical photon-number statistics. We achieve internal conversion efficiencies of 75.5%, significantly outperforming spectral filtering for bandwidth compression. Our system thus makes the connection between previously incompatible quantum systems as a step towards usable quantum networks.

  14. An Improved Dynamic Bandwidth Allocation Algorithm for Ethernet PON

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    This paper proposes an improved Dynamic Bandwidth Allocation (DBA) algorithm for EPON, which combines static and traditional dynamic allocation schemes. Simulation result shows that the proposed algorithm may effectively improve the performance of packet delay.

  15. Minimum bandwidth requirements for recording of pediatric electrocardiograms

    NARCIS (Netherlands)

    P.R. Rijnbeek (Peter); J.A. Kors (Jan); M. Witsenburg (Maarten)

    2001-01-01

    textabstractBACKGROUND: Previous studies that determined the frequency content of the pediatric ECG had their limitations: the study population was small or the sampling frequency used by the recording system was low. Therefore, current bandwidth recommendations for recording pedia

  16. Effect of bandwidth and numerical aperture in optical scatterometry

    Science.gov (United States)

    Germer, Thomas A.; Patrick, Heather J.

    2010-03-01

    We consider the effects of finite spectral bandwidth and numerical aperture in scatterometry measurements and discuss efficient integration methods based upon Gaussian quadrature in one dimension (for spectral bandwidth averaging) and two dimensions inside a circle (for numerical aperture averaging). Provided the wavelength is not near a Wood's anomaly for the grating, we find that the resulting methods converge very quickly to a level suitable for most measurement applications. In the vicinity of a Wood's anomaly, however, the methods provide rather poor behavior. We also describe a method that can be used to extract the effective spectral bandwidth and numerical aperture for a scatterometry tool. We find that accounting for spectral bandwidth and numerical aperture is necessary to obtain satisfactory results in scatterometry.

  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. Laser frequency bandwidth narrowing by photorefractive two-beam coupling.

    Science.gov (United States)

    Chomsky, D; Sternklar, S; Zigler, A; Jackel, S

    1992-04-01

    We present a theoretical analysis and experimental demonstration of a new method for spectral narrowing of laser radiation. The bandwidth narrowing is experienced by a laser beam subjected to a photorefractive two-beam coupling process. Contrary to the conventional method of frequency filtering by a Fabry-Perot étalon, this technique has no intrinsic finesse limitation on its resolution. A factor of 2 in frequency bandwidth narrowing is achieved with an argon-ion laser.

  19. Available Bandwidth Estimation Strategy Based on the Network Allocation Vector

    OpenAIRE

    Hongtao Liu; Lianglun Cheng

    2012-01-01

    Available bandwidth is of great importance to network Quality of Service assurance, network load balancing, streaming media rate control, routing, and congestion control, etc.. In this paper, the available bandwidth estimation strategy based on the Network Allocation Vector for Wireless Sensor Networks is proposed. According to the size of the average contention window, network nodes predict the probability of collision in process of frame transmission, and then estimate the number of retrans...

  20. Review of high bandwidth fiber optics radiation sensors

    International Nuclear Information System (INIS)

    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

  1. ADAPTIVE VIDEO DATA STREAMING AND SHARING IN CLOUD

    OpenAIRE

    P.N.Lokeswari; Chandrasekhar, K.; Mr.Sathiyaraj

    2014-01-01

    As we know that cloud is a drastic data center for outsourced data. Cloud is a familiar tool because of its useful architectural tools. Data sharing is another common habituated property to the common people. These data sharing include video data in social networks, this was done regularly through mobile devices like smart phones, tablets, laptops etc. we focused on demands on video traffic over mobile networks. Mobile network consist limited bandwidth and long buffering time. To ...

  2. 学前教育成本分担:理论模型、实证检验及政策分析%Cost Sharing of Pre school Education:Analysis of Theoretical Model,Empirical Test and Policy

    Institute of Scientific and Technical Information of China (English)

    王春元

    2014-01-01

    Based on preference and motivation of main bodies in preschool education,establish the corre-sponding mathematical model,and analyze the influence of different conditions on the kindergarten attend-ance rate of children.Use the provincial panel data of China 1998-2009 to verify the main body of cost sha-ring and other factors on the rate.Finally and put forward relevant policy recommendations.%在综合考虑学前教育成本分担中各主体的偏好及动因的前提下,建立相应的数理模型,分析不同条件对幼儿入园率的影响。运用我国1998-2009年的省级面板数据验证各成本分担主体及其他因素对幼儿入园率的作用及效果,提出相关的政策建议。

  3. 75 FR 9246 - Cooperative Share Loan Insurance

    Science.gov (United States)

    2010-03-01

    ... URBAN DEVELOPMENT Cooperative Share Loan Insurance AGENCY: Office of the Chief Information Officer, HUD... cooperative housing loan insurance will be published to update existing policies, and better enable mortgagees to submit cooperative share loans for FHA insurance. This new publication will provide...

  4. Islamic Finance, Risk Sharing and Macroeconomic Policies

    OpenAIRE

    Mirakhor, Abbas

    2012-01-01

    At one point it was estimated that in 2007, the total financial instruments, mostly derivatives, in the world was 12.5 times larger than the total global GDP. Similar development could be awaiting Islamic finance if the ingenuity of financial engineers continues to serve the demand-driven appetite for liquid, low risk, and short-term instruments. In that case, the configuration of Islamic finance would have failed to achieve the hopes and aspirations that expectations generated by the vision ...

  5. Enhancing bandwidth of Josephson parametric amplifiers with impedance engineering

    Science.gov (United States)

    Roy, Tanay; A M, Vadiraj; Kundu, Suman; Patankar, Meghan; Vijayaraghavan, Rajamani

    2015-03-01

    Josephson parametric amplifiers (JPAs) are a crucial component of superconducting quantum information processing systems since they enable fast, high-fidelity measurement of qubits. However, JPAs based on a single SQUID oscillator suffer from two major drawbacks - narrow bandwidth and gain saturation at low signal powers, and are typically suited to single qubit experiments only. With the rapid development of multi-qubit systems, there is a practical need to develop an amplifier with larger bandwidth and signal handling capacity, while maintaining gain and noise performance. We will describe a new method to enhance the bandwidth by introducing a frequency dependent shunting impedance for the JPA. To prevent gain saturation, we also replace the single SQUID with a SQUID array. With an appropriate choice of device parameters, numerical calculations indicate the possibility of obtaining 20 dB gain with 700 MHz of bandwidth and near quantum limited noise performance. We will present experimental results demonstrating bandwidth enhancement and discuss strategies for optimizing overall amplifier performance.

  6. Effective bandwidth guaranteed routing schemes for MPLS traffic engineering

    Science.gov (United States)

    Wang, Bin; Jain, Nidhi

    2001-07-01

    In this work, we present online algorithms for dynamic routing bandwidth guaranteed label switched paths (LSPs) where LSP set-up requests (in terms of a pair of ingress and egress routers as well as its bandwidth requirement) arrive one by one and there is no a priori knowledge regarding future LSP set-up requests. In addition, we consider rerouting of LSPs in this work. Rerouting of LSPs has not been well studied in previous work on LSP routing. The need of LSP rerouting arises in a number of ways: occurrence of faults (link and/or node failures), re-optimization of existing LSPs' routes to accommodate traffic fluctuation, requests with higher priorities, and so on. We formulate the bandwidth guaranteed LSP routing with rerouting capability as a multi-commodity flow problem. The solution to this problem is used as the benchmark for comparing other computationally less costly algorithms studied in this paper. Furthermore, to more efficiently utilize the network resources, we propose online routing algorithms which route bandwidth demands over multiple paths at the ingress router to satisfy the customer requests while providing better service survivability. Traffic splitting and distribution over the multiple paths are carefully handled using table-based hashing schemes while the order of packets within a flow is preserved. Preliminary simulations are conducted to show the performance of different design choices and the effectiveness of the rerouting and multi-path routing algorithms in terms of LSP set-up request rejection probability and bandwidth blocking probability.

  7. 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.

  8. 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.

  9. Simple High-Bandwidth Sideband Locking with Heterodyne Readout

    CERN Document Server

    Reinhardt, Christoph; Sankey, Jack C

    2016-01-01

    We present a robust sideband laser locking technique that is ideally suited for applications requiring low probe power and heterodyne readout. By feeding back to a high-bandwidth voltage controlled oscillator, we lock a first-order phase-modulation sideband to a table-top high-finesse Fabry-Perot cavity, achieving a feedback bandwidth of 3.5 MHz with a single integrator, limited fundamentally by the signal delay. The directly measured transfer function of the closed feedback loop agrees with a model assuming ideal system components, and from this we suggest a modified design that should realistically achieve a bandwidth exceeding 6 MHz with a near-causally limited feedback gain of $4\\times 10^7$ at 1 kHz. The off-resonance optical carrier is used for alignment-free heterodyne readout, alleviating the need for a second laser or additional optical modulators.

  10. Gain/bandwidth predictions for travelling-wave gyrotron

    Science.gov (United States)

    Sangster, A. J.

    1980-10-01

    Small signal gain computations based on a Pierce description of the traveling-wave gyrotron have been performed for cases involving beam voltages in the range 70-300 kV. Interactions at both the first and the second harmonics of the cyclotron resonance frequency have been considered in order to identify a range of operating parameters for the gyro-traveling-wave amplifier configuration which will potentially produce gain and bandwidth figures of significance to radar and communication systems operating at millimeter-wave frequencies. It is shown that when operated fundamentally and well away from cutoff, the gyro-traveling-wave amplifier can be magnetically tuned over a wide frequency range, with instantaneous bandwidths in the range 4-8% depending on the beam voltage; at voltages in excess of 200 kV, instantaneous bandwidths approaching 10% can be achieved.

  11. Analysis of bandwidth measurement methodologies over WLAN systems

    CERN Document Server

    Portoles-Comeras, Marc; Mangues-Bafalluy, Josep; Domingo-Pascual, Jordi

    2009-01-01

    WLAN devices have become a fundamental component of nowadays network deployments. However, even though traditional networking applications run mostly unchanged over wireless links, the actual interaction between these applications and the dynamics of wireless transmissions is not yet fully understood. An important example of such applications are bandwidth estimation tools. This area has become a mature research topic with well-developed results. Unfortunately recent studies have shown that the application of these results to WLAN links is not straightforward. The main reasons for this is that the assumptions taken to develop bandwidth measurements tools do not hold any longer in the presence of wireless links (e.g. non-FIFO scheduling). This paper builds from these observations and its main goal is to analyze the interaction between probe packets and WLAN transmissions in bandwidth estimation processes. The paper proposes an analytical model that better accounts for the particularities of WLAN links. The mod...

  12. Lasercomm system development for high-bandwidth terrestrial communications

    Science.gov (United States)

    Juarez, Juan C.; Souza, Katherine T.; Bos, Natalie G.; Brown, Andrea M.; Cannon, Brice M.; Petrillo, Keith G.; Riggins, James L.; Sluz, Joseph E.; Tomey, Hala J.; Venkat, Radha A.

    2016-05-01

    In recent years, various terrestrial free-space optical (FSO) communications systems have been demonstrated to achieve high-bandwidth communications between mobile platforms. The terminal architectures fall into three general categories: (1) single aperture systems with tip/tilt control, (2) multi-aperture system with tip/tilt control, and (3) single aperture systems with tip/tilt control and higher order adaptive optics correction. Terrestrial modem approaches generally use direct detection receivers because they provide high bandwidth capability (0.1-10 Gbps) without the complexity of coherent detection. Modems are often augmented with a mix of forward error correction (FEC), interleaving, and/or retransmission for improved data transport. This paper will present a terminal and modem architecture for a low-SWAP FSO communications system that enables robust, high-bandwidth communications under highly scintillated links as found in terrestrial applications such as air-to-air, air-to-surface, and surface-to-surface links.

  13. Development of a bandwidth limiting neutron chopper for CSNS

    Energy Technology Data Exchange (ETDEWEB)

    Wang, P., E-mail: wangping@ihep.ac.cn [China Spallation Neutron Source (CSNS), Institute of High Energy Physics (IHEP), Chinese Academy of Sciences - CAS, Dongguan 523803 (China); Dongguan Institute of Neutron Science (DINS), Dongguan 523808 (China); Yang, B.; Cai, W.L. [China Spallation Neutron Source (CSNS), Institute of High Energy Physics (IHEP), Chinese Academy of Sciences - CAS, Dongguan 523803 (China); Dongguan Institute of Neutron Science (DINS), Dongguan 523808 (China)

    2015-08-21

    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{sup −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.

  14. Bandwidth Extension of Speech Signals: A Comprehensive Review

    Directory of Open Access Journals (Sweden)

    N.Prasad

    2016-02-01

    Full Text Available Telephone systems commonly transmit narrowband (NB speech with an audio bandwidth limited to the traditional telephone band of 300-3400 Hz. To improve the quality and intelligibility of speech degraded by narrow bandwidth, researchers have tried to standardize the telephonic networks by introducing wideband (50-7000 Hz speech codecs. Wideband (WB speech transmission requires the transmission network and terminal devices at both ends to be upgraded to the wideband that turns out to be time-consuming. In this situation, novel Bandwidth extension (BWE techniques have been developed to overcome the limitations of NB speech. This paper discusses the basic principles, realization, and applications of BWE. Challenges and limitations of BWE are also addressed.

  15. Programmable bandwidth management in software-defined EPON architecture

    Science.gov (United States)

    Li, Chengjun; Guo, Wei; Wang, Wei; Hu, Weisheng; Xia, Ming

    2016-07-01

    This paper proposes a software-defined EPON architecture which replaces the hardware-implemented DBA module with reprogrammable DBA module. The DBA module allows pluggable bandwidth allocation algorithms among multiple ONUs adaptive to traffic profiles and network states. We also introduce a bandwidth management scheme executed at the controller to manage the customized DBA algorithms for all date queues of ONUs. Our performance investigation verifies the effectiveness of this new EPON architecture, and numerical results show that software-defined EPONs can achieve less traffic delay and provide better support to service differentiation in comparison with traditional EPONs.

  16. Extending the Bandwidth of Electric Ring Resonator Metamaterial Absorber

    Institute of Scientific and Technical Information of China (English)

    LUO Hao; WANG Tao; GONG Rong-Zhou; NIE Yan; WANG Xian

    2011-01-01

    An efficient method is proposed to extend the bandwidth of a metamaterial absorber with multi-resonance structure. The basic unit cell of a metamaterial absorber consists of the electric ring resonator, dielectric substrate (FR-4)and split-wire. By assembling five sandwiched structures with different geometric dimensions into a unit cell, we obtain the superposition of five different absorption peaks.Finally the bandwidth of metamaterial absorption is extended and the full width at half maximum is up to 1.3 GHz. The simulated and experimental results are consistent.

  17. A meta-substrate to enhance the bandwidth of metamaterials.

    Science.gov (United States)

    Chen, Hongsheng; Wang, Zuojia; Zhang, Runren; Wang, Huaping; Lin, Shisheng; Yu, Faxin; Moser, Herbert O

    2014-06-12

    We propose the concept of a meta-substrate to broaden the bandwidth of left-handed metamaterials. The meta-substrate, which behaves like an inhomogeneous magnetic substrate, is composed of another kind of magnetic metamaterials like metallic closed rings. When conventional metamaterial rings are printed on this kind of meta-substrate in a proper way, the interaction of the metamaterials units can be greatly enhanced, yielding an increased bandwidth of negative permeability. An equivalent circuit analytical model is used to quantitatively characterize this phenomenon. Both numerical and experimental demonstrations are carried out, showing good agreement with theoretical predictions.

  18. Bandwidth Enhancement of Probe Fed Microstrip Patch Antenna

    Directory of Open Access Journals (Sweden)

    Parminder Singh

    2013-01-01

    Full Text Available Microstrip patch antenna becomes verypopular day by day because of its ease of analysis andfabrication, low cost, light weight, easy to feed and theirattractive radiation characteristics. Although patchantenna has numerous advantages, it has also somedrawbacks such as restricted bandwidth, and a potentialdecrease in radiation pattern. Different techniques forbandwidth enhancement of conventional rectangularmicrostrip antenna are proposed in this paper. Byincreasing the height of patch , increasing the substratethickness and decreasing the permittivity of substrate the%bandwidth is increased. HFSS Software is used for thesimulation and design calculation of microstrip patchantenna. The return loss, vswr curve, directivity and gainare evaluated.

  19. 120 nm Bandwidth Erbium-doped Fiber Amplifier

    Institute of Scientific and Technical Information of China (English)

    姜淳; 曾庆济; 肖石林

    2002-01-01

    A new dual band erbium-doped fiber amplifier configuration that provides 120 nm of optical bandwidth is simulated. This configuration employs a split-band architecture in which optical signals are splitted using a 1550/1610 nm port filter into two independent sub-bands which then pass in parallel through separate branches of the optical amplifier. Each branch may be optimized for the sub-band that traverses it. The independent sub-bands are combined and flattened before output, resulting in a 120 nm bandwidth gain-flattened optical amplifier.

  20. Dividend Policy Controverses

    Directory of Open Access Journals (Sweden)

    Ljiljana Vidučić

    2005-06-01

    Full Text Available Dividend theory shares with capital structure theories the attribute of area of high controversy. Financial literature discusses whether there is an interdependency of dividends and share price, i.e. value of the firm. The main views may be defined with three theories of dividend policy. However, unambiguous solutions are still lacking. Literature on dividends highlights several concepts that may be important in defining the dividend policy. Dividend policy aims to define payout ratio, sort of dividend and way of maintaining dividend stability, since stability of dividend is found to be of interest in practice. Managers, namely, prefer stability of dividend policy and the amount of dividends taking in account the signalling effect. If stability of dividends is preferred by investors it follows that stable dividend policy will lead to minimization of cost of capital and maximization of share price.

  1. Optimization of bandwidth in 60^o photonic crystal waveguide bends

    DEFF Research Database (Denmark)

    Xing, P. F.; Borel, Peter Ingo; Frandsen, Lars Hagedorn;

    2005-01-01

    A systematic scheme utilizing 2D and 3D finite-difference time-domain calculations to design 60^o photonic crystal waveguide bends is presented. The method results in an improved transmission bandwidth from 70 to 160 nm in 2D simulations, and from 50 to 100 nm in 3D simulations. The design...

  2. 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.

  3. QoS-aware bandwidth provisioning for IP network links

    NARCIS (Netherlands)

    Berg, J.L. van den; Mandjes, M.; Meent, R. van de; Pras, A.; Roijers, F.; Venemans, P.

    2006-01-01

    Current bandwidth provisioning procedures for IP network links are mostly based on simple rules of thumb, using coarse traffic measurements made on a time scale of e.g., 5 or 15 min. A crucial question, however, is whether such coarse measurements give any useful insight into the capacity actually n

  4. 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...

  5. High speed and wide bandwidth delta-sigma ADCs

    CERN Document Server

    Bolatkale, Muhammed; Makinwa, Kofi A A

    2014-01-01

    This book describes techniques for realizing wide bandwidth (125MHz) over-sampled analog-to-digital converters (ADCs) in nanometer-CMOS processes.  The authors offer a clear and complete picture of system level challenges and practical design solutions in high-speed Delta-Sigma modulators.  Readers will be enabled to implement ADCs as continuous-time delta-sigma (CT∆Σ) modulators, offering simple resistive inputs, which do not require the use of power-hungry input buffers, as well as offering inherent anti-aliasing, which simplifies system integration. The authors focus on the design of high speed and wide-bandwidth ΔΣMs that make a step in bandwidth range which was previously only possible with Nyquist converters. More specifically, this book describes the stability, power efficiency, and linearity limits of ΔΣMs, aiming at a GHz sampling frequency.   • Provides overview of trends in Wide Bandwidth and High Dynamic Range analog-to-digital converters (ADCs); • Enables the design of a wide band...

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

    NARCIS (Netherlands)

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

    2006-01-01

    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 aggregat

  7. Frequency Selective Surfaces for Extended Bandwidth Backing Reflector Functions

    NARCIS (Netherlands)

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

    2010-01-01

    This paper deals with the use of frequency selective surfaces (FSS) to increase the efficiency bandwidth product in wideband antenna arrays, whose efficiency is limited by the front-to-back ratio. If the backing reflector for the antenna is realized through a single metal plane solution, its locatio

  8. Microstrip Patch Antenna Bandwidth Enhancement Using AMC/EBG Structures

    Directory of Open Access Journals (Sweden)

    R. C. Hadarig

    2012-01-01

    Full Text Available A microstrip patch antenna with bandwidth enhancement by means of artificial magnetic conductor (AMC/electromagnetic band-gap structure (EGB is presented. The electrical characteristics of the embedded structure are evaluated using MoM simulations. The manufactured prototypes are characterized in terms of return loss, gain, and radiation pattern measurements in an anechoic chamber.

  9. 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

  10. Virtual queueing techniques for UBR+ service in ATM with fair access and minimum bandwidth guarantee

    Energy Technology Data Exchange (ETDEWEB)

    Siu, K.Y.; Wu, Y.; Ren, W.

    1998-11-01

    The ATM Forum is currently discussing the need for a new best-effort service called UBR+, which is an enhancement to the existing UBR service, to support data traffic. The objective of the UBR+ service is to provide each user with a minimum service rate guarantee and a fair access to any excess available bandwidth. In this paper, the authors present a new efficient scheme for supporting this service. The key advantage of the scheme is that it employs only FIFO queueing (instead of per-VC queueing) and admits simple implementation in ATM switches. The ideas involve a simple scheduling mechanism that is based on per-VC queueing and incorporate the virtual queueing technique that can efficiently emulate per-VC queueing on a shared FIFO queue. Simulation results are presented to show that the schemes can deliver almost ideal performance for supporting the new service requirements of UBR+.

  11. 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....... Drawing an analytical distinction between cooperation, coordination and collaboration, the article analyses the formulation and implementation of EU employment policies. It concludes that while the formulation of policy objectives and the discussion of national policy approaches do involve elements...

  12. 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....... Drawing an analytical distinction between cooperation, coordination and collaboration, the article analyses the formulation and implementation of EU employment policies. It concludes that while the formulation of policy objectives and the discussion of national policy approaches do involve elements of...

  13. Sequential sharing rules for river sharing problems

    OpenAIRE

    Ansink, Erik; Weikard, Hans-Peter

    2009-01-01

    We analyse the redistribution of a resource amongst agents who have claims to the resource and who are ordered linearly. A well known example of this particular situation is the river sharing problem. We exploit the linear order of agents to transform the river sharing problem to a sequence of two-agent river sharing problems. These reduced problems are mathematically equivalent to bankruptcy problems and can therefore be solved using any bankruptcy rule. Our proposed class of solutions, that...

  14. A system-level bandwidth design method for wormhole network-on-chip

    Science.gov (United States)

    Wang, Jian; Li, Yubai; Liao, Changjun

    2016-11-01

    To improve the Network-on-Chip (NoC) performance, we propose a system-level bandwidth design method customising the bandwidths of the NoC links. In details, we first built a mathematical model to catch the relationship between the NoC commutation latency and the NoC link bandwidth, and then develop a bandwidth allocation algorithm to automatically optimise the bandwidth for each NoC link. The experimental results show that our bandwidth-customising method improves the NoC performance compared to the traditional uniform bandwidth allocation method. Besides, it can also make our NoC to achieve the same communication performance level as the uniform bandwidth NoC but using fewer bandwidth resources, which is beneficial to save the NoC area and power.

  15. Share Prices and Investment

    OpenAIRE

    Michael Andersen; Robert Subbaraman

    1996-01-01

    In this paper we examine two related propositions: the efficiency of pricing of Australian shares and the influences of share prices on business investment. In line with similar studies overseas, we find that the Australian share market may deviate from efficient pricing over short time horizons but that there is little evidence of inefficiency over longer time horizons. To investigate the influence of share prices on investment decisions we use a simple model of real share prices to identify...

  16. Leveraging shared caches for parallel temporal blocking of stencil codes on multicore processors and clusters

    CERN Document Server

    Wittmann, Markus; Treibig, Jan; Wellein, Gerhard

    2010-01-01

    Bandwidth-starved multicore chips have become ubiquitous. It is well known that the performance of stencil codes can be improved by temporal blocking, lessening the pressure on the memory interface. We introduce a new pipelined approach that makes explicit use of shared caches in multicore environments and minimizes synchronization and boundary overhead. Benchmark results are presented for three current x86-based microprocessors, showing clearly that our optimization works best on designs with high-speed shared caches and low memory bandwidth per core. We furthermore demonstrate that simple bandwidth-based performance models are inaccurate for this kind of algorithm and employ a more elaborate, synthetic modeling procedure. Finally we show that temporal blocking can be employed successfully in a hybrid shared/distributed-memory environment, albeit with limited benefit at strong scaling.

  17. 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.

  18. Long-pulse-width narrow-bandwidth solid state laser

    Science.gov (United States)

    Dane, C.B.; Hackel, L.A.

    1997-11-18

    A long pulse laser system emits 500-1000 ns quasi-rectangular pulses at 527 nm with near diffraction-limited divergence and near transform-limited bandwidth. The system consists of one or more flashlamp-pumped Nd:glass zig-zag amplifiers, a very low threshold stimulated-Brillouin-scattering (SBS) phase conjugator system, and a free-running single frequency Nd:YLF master oscillator. Completely passive polarization switching provides eight amplifier gain passes. Multiple frequency output can be generated by using SBS cells having different pressures of a gaseous SBS medium or different SBS materials. This long pulse, low divergence, narrow-bandwidth, multi-frequency output laser system is ideally suited for use as an illuminator for long range speckle imaging applications. Because of its high average power and high beam quality, this system has application in any process which would benefit from a long pulse format, including material processing and medical applications. 5 figs.

  19. 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 0.6Hzto1.4MHz, 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.

  20. 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.

  1. Two genetic algorithms for the bandwidth multicoloring problem

    Directory of Open Access Journals (Sweden)

    Fijuljanin Jasmina

    2012-01-01

    Full Text Available In this paper the Bandwidth Multicoloring Problem (BMCP and the Bandwidth Coloring Problem (BCP are considered. The problems are solved by two genetic algorithms (GAs which use the integer encoding and standard genetic operators adapted to the problems. In both proposed implementations, all individuals are feasible by default, so search is directed into the promising regions. The first proposed method named GA1 is a constructive metaheuristic that construct solution, while the second named GA2 is an improving metaheuristic used to improve an existing solution. Genetic algorithms are tested on the publicly-available GEOM instances from the literature. Proposed GA1 has achieved a much better solution than the calculated upper bound for a given problem, and GA2 has significantly improved the solutions obtained by GA1. The obtained results are also compared with the results of the existing methods for solving BCP and BMCP.

  2. Exploiting material softening in hard PZTs for resonant bandwidth enhancement

    Science.gov (United States)

    Leadenham, S.; Moura, A.; Erturk, A.

    2016-04-01

    Intentionally designed nonlinearities have been employed by several research groups to enhance the frequency bandwidth of vibration energy harvesters. Another type of nonlinear resonance behavior emerges from the piezoelectric constitutive behavior for high excitation levels and is manifested in the form of softening stiffness. This material nonlinearity does not result in the jump phenomenon in soft piezoelectric ceramics, e.g. PZT-5A and PZT-5H, due to their large internal dissipation. This paper explores the potential for wideband energy harvesting using a hard (relatively high quality factor) PZT-8 bimorph by exploiting its material softening. A wide range of base excitation experiments conducted for a set of resistive electrical loads confirms the frequency bandwidth enhancement.

  3. Coherent temporal imaging with analog time-bandwidth compression

    CERN Document Server

    Asghari, Mohammad H

    2013-01-01

    We introduce the concept of coherent temporal imaging and its combination with the anamorphic stretch transform. The new system can measure both temporal profile of fast waveforms as well as their spectrum in real time and at high-throughput. We show that the combination of coherent detection and warped time-frequency mapping also performs time-bandwidth compression. By reducing the temporal width without sacrificing spectral resolution, it addresses the Big Data problem in real time instruments. The proposed method is the first application of the recently demonstrated Anamorphic Stretch Transform to temporal imaging. Using this method narrow spectral features beyond the spectrometer resolution can be captured. At the same time the output bandwidth and hence the record length is minimized. Coherent detection allows the temporal imaging and dispersive Fourier transform systems to operate in the traditional far field as well as in near field regimes.

  4. Long-pulse-width narrow-bandwidth solid state laser

    Science.gov (United States)

    Dane, C. Brent; Hackel, Lloyd A.

    1997-01-01

    A long pulse laser system emits 500-1000 ns quasi-rectangular pulses at 527 nm with near diffraction-limited divergence and near transform-limited bandwidth. The system consists of one or more flashlamp-pumped Nd:glass zig-zag amplifiers, a very low threshold stimulated-Brillouin-scattering (SBS) phase conjugator system, and a free-running single frequency Nd:YLF master oscillator. Completely passive polarization switching provides eight amplifier gain passes. Multiple frequency output can be generated by using SBS cells having different pressures of a gaseous SBS medium or different SBS materials. This long pulse, low divergence, narrow-bandwidth, multi-frequency output laser system is ideally suited for use as an illuminator for long range speckle imaging applications. Because of its high average power and high beam quality, this system has application in any process which would benefit from a long pulse format, including material processing and medical applications.

  5. Conical Emission Patterns by Femtosecond Pulses with Different Spectral Bandwidths

    Institute of Scientific and Technical Information of China (English)

    LI Yue-Xun; ZENG Zhi-Nan; GE Xiao-Chun; CHEN Xiao-Wei; LI Ru-Xin; XU Zhi-Zhan

    2008-01-01

    @@ Different conical emission (CE) patterns are obtained experimentally at various incident powers and beam sizes of pump laser pulses with pulse durations of 7fs, 44fs and lOOfs.The results show that it is the incident power but not the incident power density that determines a certain CE pattern.In addition, the critical powers for similar CE patterns are nearly the same for the laser pulses with the same spectral bandwidth.Furthermore, as far as a certain CE pattern is concerned, the wider the spectral bandwidth of pump laser pulse is, the higher the critical power is.This will hopefully provide new insights for the generation of CE pattern in optical medium.

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

    OpenAIRE

    Ke Chen; Zhongjie Yang; Yijun Feng; Bo Zhu; Junming Zhao; Tian Jiang

    2015-01-01

    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 ch...

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

    OpenAIRE

    Carlos Gañán; Muñoz, Jose L.; Oscar Esparza; Jonathan Loo; Jorge Mata-Díaz; Juanjo Alins

    2013-01-01

    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 (CA)needs to revoke a certificate, itglobally distributes CRLs.Transmitting these lists pose a problem as they require high update frequencies and a lot of bandwidth. I...

  8. 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.

  9. Biometric recognition system using low bandwidth ECG signals

    OpenAIRE

    Matos, André Cigarro; Lourenço, André Ribeiro; Nascimento, José M. P.

    2013-01-01

    Biometric recognition has recently emerged as part of applications where the privacy of the information is crucial, as in the health care field. This paper presents a biometric recognition system based on the Electrocardiographic signal (ECG). The proposed system is based on a state-of-the-art recognition method which extracts information from the frequency domain. In this paper we propose a new method to increase the spectral resolution of low bandwidth ECG signals due to the limited bandwid...

  10. 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...

  11. Bandwidth Enhancement Technique of the Meandered Monopole Antenna

    OpenAIRE

    Chien-Jen Wang; Dai-Heng Hsieh

    2015-01-01

    A small dual-band monopole antenna with coplanar waveguide (CPW) feeding structure is presented in this paper. The antenna is composed of a meandered monopole, an extended conductor tail, and an asymmetrical ground plane. Tuning geometrical structure of the ground plane excites an additional resonant frequency band and thus enhances the impedance bandwidth of the meandered monopole antenna. Unlike the conventional monopole antenna, the new resonant mode is excited by a slot trace of the CPW t...

  12. 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.

  13. 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.

  14. Bandwidth Enhancement Technique of the Meandered Monopole Antenna

    Directory of Open Access Journals (Sweden)

    Chien-Jen Wang

    2015-01-01

    Full Text Available A small dual-band monopole antenna with coplanar waveguide (CPW feeding structure is presented in this paper. The antenna is composed of a meandered monopole, an extended conductor tail, and an asymmetrical ground plane. Tuning geometrical structure of the ground plane excites an additional resonant frequency band and thus enhances the impedance bandwidth of the meandered monopole antenna. Unlike the conventional monopole antenna, the new resonant mode is excited by a slot trace of the CPW transmission line. The radiation performance of the slot mode is as similar as that of the monopole. The parametrical effect of the size of the one-side ground plane on impedance matching condition has been derived by the simulation. The measured impedance bandwidths, which are defined by the reflection coefficient of −6 dB, are 186 MHz (863–1049 MHz, 19.4% at the lower resonant band and 1320 MHz (1490–2810 MHz, 61.3% at the upper band. From the results of the reflection coefficients of the proposed monopole antenna, the operated bandwidths of the commercial wireless communication systems, such as GSM 900, DCS, IMT-2000, UMTS, WLAN, LTE 2300, and LTE 2500, are covered for uses.

  15. Improved Radiation and Bandwidth of Triangular and Star Patch Antenna

    Directory of Open Access Journals (Sweden)

    M. Ramkumar Prabhu

    2012-06-01

    Full Text Available This study presents a hexagonal shape Defected Ground Structure (DGS implemented on two element triangular patch microstrip antenna array. The radiation performance of the antenna is characterized by varying the geometry and dimension of the DGS and also by locating the DGS at specific position which were simulated. Simulation and measurement results have verified that the antenna with DGS had improved the antenna without DGS. Measurement results of the hexagonal DGS have axial ratio bandwidth enhancement of 10 MHz, return loss improvement of 35%, mutual coupling reduction of 3 dB and gain enhancement of 1 dB. A new wideband and small size star shaped patch antenna fed capacitively by a small diamond shape patch is proposed. To enhance the impedance bandwidth, posts are incorporated under the patch antenna. HFSS high frequency simulator is employed to analyze the proposed antenna and simulated results on the return loss, the E- and H-plane radiation patterns and Gain of the proposed antenna are presented at various frequencies. The antenna is able to achieve in the range of 4-8.8 GHz an impedance bandwidth of 81% for return loss of less than-10 dB.

  16. Efficient capacity sharing for path protection in meshed optical networks

    Science.gov (United States)

    Dziong, Zbigniew; Nagarajan, Ramesh

    2004-03-01

    Efficient resource management in meshed optical networks is critical for supporting differentiated services, such as network restoration, in a cost-competitive manner. We propose and study several alternatives for dynamic and distributed selection of primary and protection paths. The focus is on algorithms where the bandwidth can be shared efficiently among protection paths, although other alternatives are considered as well. The routing algorithm and link cost function are based on a Markov decision-process framework. In particular, we use this framework to justify the link cost structure for primary and shared bandwidth. We also propose and study several options for describing the link state, which in turn determines the link cost, with the objective of minimizing the amount of data to be advertised without sacrificing performance. The proposed solutions can be implemented without changing the existing set of protocols. The numerical results show performance and cost savings for the different algorithm options.

  17. Two Bandwidth Packing Algorithms for the Centralized Wireless Network and Their Average-case Analysis

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This paper presents a detail analysis of two bandwidth packing algorithms, used for processing connection requests in the centralized wireless network. Each call comes with a specific bandwidth request. A request can be satisfied only if there is sufficient bandwidth available during resource scheduling and allocation. Unsatisfied requests were held in a queue. The metric of bandwidth utilization ratio was used to quantify the performance of our algorithms. By theoretical analysis, our algorithms can improve the average bandwidth usage ratio significantly,about 8%~ 10% without adding much computation complexity. Moreover, our algorithms outperform next fit with fragmentation (NFF) algorithm when the bandwidth resource is scarce. In this paper, the contributions follows: Introducing bandwidth packing problem into wireless network; Proposing two new bandwidth packing algorithms for wireless network where the complicate scheduling algorithms are prohibited; Studying the average performance of our algorithms mathematically, which agree well with the simulation results.

  18. Gender Diversity Policies in Universities: A Multi-Perspective Framework of Policy Measures

    Science.gov (United States)

    Timmers, Tanya M.; Willemsen, Tineke M.; Tijdens, Kea G.

    2010-01-01

    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 women's low shares at higher job levels, notably…

  19. A Multidisciplinary Analysis of Cyber Information Sharing

    Directory of Open Access Journals (Sweden)

    Aviram Zrahia

    2014-12-01

    Full Text Available The emergence of the cyber threat phenomenon is forcing organizations to change the way they think about security. One of these changes relates to organizations’ policy on sharing cyber information with outside parties. This means shifting away from the view of the organization as an isolated, compartmentalized entity towards a view of the organization as a sharing one. Sharing generates a complex, multifaceted challenge to technology, law, organizational culture and even politics. Establishing a system of sharing serves many parties, including regulatory bodies, governments, legal authorities, intelligence agencies, the manufacturers of solutions and services, as well as the organizations themselves, but it also arouses opposition among elements within the organization, and organizations defending the right for privacy. The purpose of this essay is to present the various challenges posed by cyber information sharing, expose the reader to its conceptual world, and present some insights and forecasts for its future development.

  20. 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....

  1. 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)

  2. Expectations and Share Prices

    OpenAIRE

    Edwin J. Elton; Martin J. Gruber; Mustafa Gultekin

    1981-01-01

    It is generally believed that security prices are determined by expectations concerning firm and economic variables. Despite this belief there is very little research examining expectational data. In this paper we examine how expectations concerning earning per share effect share price. We first show that knowledge concerning analyst's forecasts of earnings per share cannot by itself lead to excess returns. Any information contained in the consensus estimate of earnings per share is already i...

  3. 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)

  4. Optimization of bandwidth of communication channels of corporate networks

    Directory of Open Access Journals (Sweden)

    G. I. Bondarenko

    2014-09-01

    Full Text Available Introduction. This article contains overview of the organization of communication between applications on the corporate network. It is stated that the main digital channel (channel B - 64 kbit/s and the primary digital channel (channel E1 the digital stream - 2048 kbit/s are used as the main channels in corporate networks. Problem areas of the functioning of the corporate network are identified. There are the rent of communication channels, which is growing rapidly with increasing the quality and speed of data transmission, and optimal use of bandwidth of communication channels. Setting of task. Optimal use of transmission channels bandwidth and minimizing the rent cost of channels is possible in two ways - the use of compression techniques of voice and video information and the application of variable structure of channels by using various-speed transmission channels. Differential pulse code modulation, adaptive differential pulse code modulation are the modern methods of speech signals processing. Organization of various-speed channels is performed in the structure of the BCC (for speech signals or PCR (for video. Suggestions for optimizing the structure of the channel signals. Proposed method of various-speed channels formation by using the channel intervals appropriate BCC (octets in the structure of signals E1 as envelopes containing various-speed channels. Channels can be selected for synchronization procedure CRC to simplify recognition of channels in the structure of E1. In this case, the minimal speed in the channel is 4 kbit/s. Conclusions. The proposed structure of envelopes is based on octet channel intervals of standard group signal of the primary group plesiochronous hierarchy E1 when transferring various-speed digital signals maximum allows to use the bandwidth at a fixed structure of channel interval, it makes possible to agree on the structure of the various-speed signals with the existing in communication networks.

  5. 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

  6. Frequency Bandwidth of Half-Wave Impedance Repeater

    Directory of Open Access Journals (Sweden)

    Marek Dvorsky

    2012-01-01

    Full Text Available This article brings in the second part general information about half-wave impedance repeater. The third part describes the basic functional principles of the half-wave impedance repeater using Smith chart. The main attention is focused in part four on the derivation of repeater frequency bandwidth depending on characteristics and load impedance of unknown feeder line. Derived dependences are based on the elementary features of the feeder lines with specific length. The described functionality is proved in part 4.3 by measurement of transformed impedance using vector several unbalanced feeder lines and network analyzer VNWA3+.

  7. Measurement of formant frequencies and bandwidths in singing.

    Science.gov (United States)

    Schutte, H K; Miller, D G; Svec, J G

    1995-09-01

    That singers under certain circumstances adjust the articulation of the vocal tract (formant tuning) to enhance acoustic output is both apparent from measurements and understood in theory. The precise effect of a formant on an approaching (retreating) harmonic as the latter varies in frequency during actual singing, however, is difficult to isolate. In this study variations in amplitude of radiated sound components as well as supraglottal and subglottal (esophageal) pressures accompanying the vibrato-related sweep of voice harmonics were used as a basis for estimating the effective center frequencies and bandwidths of the first and second formants. PMID:8541972

  8. Efficient and Fair Bandwidth Allocation AQM Scheme for Wireless Networks

    Directory of Open Access Journals (Sweden)

    Rafe Alasem

    2010-05-01

    Full Text Available Heterogeneous Wireless Networks are considered nowadays as one of the potential areas in research and development. The traffic management’s schemes that have been used at the fusion points between the different wireless networks are classical and conventional. This paper is focused on developing a novel scheme to overcome the problem of traffic congestion in the fusion point router interconnected the heterogeneous wireless networks. The paper proposed an EF-AQM algorithm which provides an efficient and fair allocation of bandwidth among different established flows. Finally, the proposed scheme developed, tested and validated through a set of experiments to demonstrate the relative merits and capabilities of a proposed scheme

  9. 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...

  10. 配股行为对股价冲击的现实困境及对策%Practical Puzzledom of the Strike of Rights Issues on Share Prices and the Relevant Suggestions on Policies

    Institute of Scientific and Technical Information of China (English)

    于研; 檀向球

    2005-01-01

    In China, right issue is one of the main methods of external equity financing used by listed companies. But the current way of right issue usually results in the decline of share price, thus causing the systematic risk. Adopting warrants in right issue can efficiently improve the allocation of resources in our securities market.

  11. Study and Analysis of Bandwidth Flow Estimation Techniques for Wired/Wireless Networks

    Directory of Open Access Journals (Sweden)

    Pallavi Sharma

    2012-01-01

    Full Text Available In this topic, an analysis will be made on bandwidth flow estimation technique which comes under networking domain. Correct bandwidth constrained applications and tools are required for proper bandwidth estimation. A proper monitoring of available bandwidth is required during execution to avoid degradation in performance. A several measurement tools have been proposed in the last few years. After the implementation of 802.11e Wireless Sensor Networks are capable to provide good level of QoS but research works are not much for improving performance of bandwidth constraint applications by checking sufficiency of bandwidth available in transmission route. In this topic we will do the analysis of bandwidth flow estimation technique for wired/wireless networks and we will do comparisons of existing estimation tools.

  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. 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.

  14. 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.

  15. An exponential time 2-approximation algorithm for bandwidth

    Energy Technology Data Exchange (ETDEWEB)

    Kasiviswanathan, Shiva [Los Alamos National Laboratory; Furer, Martin [PENNSYLVANIA STATE U; Gaspers, Serge [U OF MONTPELLIER, FRANCE

    2009-01-01

    The bandwidth of a graph G on n vertices is the minimum b such that the vertices of G can be labeled from 1 to n such that the labels of every pair of adjacent vertices differ by at most b. In this paper, we present a 2-approximation algorithm for the Bandwidth problem that takes worst-case {Omicron}(1.9797{sup n}) = {Omicron}(3{sup 0.6217n}) time and uses polynomial space. This improves both the previous best 2- and 3-approximation algorithms of Cygan et al. which have an {Omicron}*(3{sup n}) and {Omicron}*(2{sup n}) worst-case time bounds, respectively. Our algorithm is based on constructing bucket decompositions of the input graph. A bucket decomposition partitions the vertex set of a graph into ordered sets (called buckets) of (almost) equal sizes such that all edges are either incident on vertices in the same bucket or on vertices in two consecutive buckets. The idea is to find the smallest bucket size for which there exists a bucket decomposition. The algorithm uses a simple divide-and-conquer strategy along with dynamic programming to achieve this improved time bound.

  16. 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.

  17. Bandwidth characteristics for the stepped conical-zoned antenna

    Science.gov (United States)

    Wiltse, James C.

    2002-07-01

    The stepped conical zoned lens antenna has better overall efficiency than a true lens, and provides an excellent antenna pattern. It also exhibits somewhat different bandwidth characteristics than the Fresnel zone plate antenna. This paper examines the frequency behavior in detail, particularly for microwave and millimeter-wave applications. For the usual zone plate antenna employed at microwave or millimeter wavelengths, path length adjustment (i.e., phase correction) is accomplished by cutting different depths (grooves) in a dielectric plate or by using two or more dielectrics having different dielectric constants. The new design uses a tilted cut in a flat dielectric plate, which more accurately matches the shape of a true lens and produces much lower phase error. The construction is still linear (i.e. spherical or hyperboloidal curves do not have to be cut), and can be made, for example, by a milling machine with a tilted bit. For a circular zone plate, the lens is a stepped conical shape. The phase correction steps are small, usually a few degrees, which is much smaller than for the typical Fresnel zone plate. The bandwidth characteristics are calculated for specific cases.

  18. Explicit Codes Minimizing Repair Bandwidth for Distributed Storage

    CERN Document Server

    Shah, Nihar B; Kumar, P Vijay; Ramchandran, Kannan

    2009-01-01

    We consider the problem of data storage across n nodes in a distributed manner. A data collector (DC) should be able to reconstruct the entire data by connecting to any k out of the n nodes and downloading all the data stored in them. When a node fails, it has to be regenerated back using the existing nodes. In a recent paper, Wu et al. have obtained an information theoretic lower bound for the repair bandwidth. Recently, there has been additional interest in storing data in systematic form as no post processing is required when DC connects to k systematic nodes. Because of their preferred status there is a need to regenerate back any systematic node quickly and exactly. Replacement of a failed node by an exact replica is termed Exact Regeneration.In this paper, we consider the problem of minimizing the repair bandwidth for exact regeneration of the systematic nodes. The file to be stored is of size B and each node can store alpha = B/k units of data. A failed systematic node is regenerated by downloading bet...

  19. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Ke; Yang, Zhongjie; Feng, Yijun, E-mail: yjfeng@nju.edu.cn; Zhu, Bo; Zhao, Junming; Jiang, Tian [Department of Electronic Engineering, School of Electronic Science and Engineering, Nanjing University, Nanjing, 210093 (China)

    2015-06-15

    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.

  1. Modulator-Based, High Bandwidth Optical Links for HEP Experiments

    CERN Document Server

    Underwood, D G; Fernando, W S; Stanek, R W

    2012-01-01

    As a concern with the reliability, bandwidth and mass of future optical links in LHC experiments, we are investigating CW lasers and light modulators as an alternative to VCSELs. These links will be particularly useful if they utilize light modulators which are very small, low power, high bandwidth, and are very radiation hard. We have constructed a test system with 3 such links, each operating at 10 Gb/s. We present the quality of these links (jitter, rise and fall time, BER) and eye mask margins (10GbE) for 3 different types of modulators: LiNbO3-based, InP-based, and Si-based. We present the results of radiation hardness measurements with up to ~1012 protons/cm2 and ~65 krad total ionizing dose (TID), confirming no single event effects (SEE) at 10 Gb/s with either of the 3 types of modulators. These optical links will be an integral part of intelligent tracking systems at various scales from coupled sensors through intra-module and off detector communication. We have used a Si-based photonic transceiver to...

  2. Dynamic quantum secret sharing

    International Nuclear Information System (INIS)

    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.

  3. 基于P2P的短视频点播相似度分享系统%Research on Similarity Sharing System of P2P Based Online Short Video

    Institute of Scientific and Technical Information of China (English)

    李彦; 张华

    2013-01-01

    在线共享短视频改变了传统的客户/服务器(C/S)视频观看方式,但也增加了服务器带宽压力.针对这一问题,引入P2P技术,构建了SShare系统.研究了重叠网构建和基于点播相似度资源查找算法.仿真实验表明,SShare系统可大大减少服务器带宽资源的消耗.%Online short video sharing is changing the watching way of the tradition client/server, but it increases the server bandwidth with pressure. Introduced P2P technology, this paper proposed an On-demand Similarity based online short video sharing policy-SShare. SShare includes On-demand Similarity based peers clustering scheme, streaming source peers searching algorithm. Simulation shows SShare has a high efficient streaming source peers searching ability and can greatly reduce the bandwidth consumption of streaming server.

  4. Gender diversity policies in universities: a multi-perspective framework of policy measures

    OpenAIRE

    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 women’s low shares at higher job levels, notably individual, cultural, and structural or institutional perspectives, and policies to increase the proportion of women therefore should address these fact...

  5. 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...

  6. Efficient Sharing of Application using Fairness Data in Distributed Environment

    Directory of Open Access Journals (Sweden)

    K.Kalpana

    2013-04-01

    Full Text Available Torrent is used to download the same data by applying the bit torrent communication protocol. Some of the common terminologies used in torrent are peers, leechers, seeders and trackers. The peers are sometimes referred as leechers, the leecher is somebody who is currently downloading the file, the seeder is somebody who is currently uploading a file and tracker is the one who keeps track of all the activities of leecher and seeder. This paper mainly focuses on file sharing in cheap and effective peer to peer system, which suffers due to slow uploading and downloading and bandwidth lacking fairness. In this paper we report on experiments conducted to pin point the cause to increase the Bandwidth in uploading the data.And so we are proposing a new system using the k-nearest neighbour algorithm to ensure fairness. KNN algorithm is the simplest of all machines learning algorithms. By using this algorithm the objects areclassified and grouped by neighbour’s voting providing rendering the shortest path among varying neighbours. K-is the smallest integer. If K=+1, then the object is grouped to the class of nearest neighbours. Thus our proposed methodology results in bandwidth fairness by increasing the performance of downloading and providing bandwidth in a uniform manner.

  7. The Share Price Puzzle

    OpenAIRE

    Edward A. Dyl

    2006-01-01

    We document substantial variation in the prices of common stocks in U.S. markets due to firms selecting particular price ranges for their shares. Cross-sectional evidence indicates that variables consistent with Merton's model of capital market equilibrium explain roughly two-thirds of this variation in share prices. In addition, measures of trading range and share price appreciation predict stock splits, and the "investor base" of firms that split their stock increases compared to other firm...

  8. Chimpanzees Share Forbidden Fruit

    OpenAIRE

    Hockings, Kimberley; Humle, Tatyana; Anderson, James; Biro, Dora; Sousa, Cláudia; Ohashi, Gaku; Matsuzawa, Tetsuro

    2007-01-01

    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 wil...

  9. Facilitating Knowledge Sharing

    OpenAIRE

    Holdt Christensen, Peter

    2005-01-01

    Abstract This paper argues that knowledge sharing can be conceptualized as different situations of exchange in which individuals relate to each other in different ways, involving different rules, norms and traditions of reciprocity regulating the exchange. The main challenge for facilitating 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 organization...

  10. Efficiency in Shared Services

    OpenAIRE

    Prachýl, Lukáš

    2010-01-01

    The thesis describes and analyzes shared services organizations as a management tool to achieve efficiency in the organizations' processes. Paper builds on established theoretical principles, enhance them with up-to-date insights on the current situation and development and create a valuable knowledge base on shared services organizations. Strong emphasis is put on concrete means on how exactly efficiency could be achieved. Major relevant topics such as reasons for shared services, people man...

  11. 47 CFR 27.1182 - Reimbursement under the Cost-Sharing Plan.

    Science.gov (United States)

    2010-10-01

    ... Cost-Sharing Policies Governing Broadband Radio Service Relocation from the 2150-2160/62 Mhz Band § 27... will not be subject to depreciation under the cost-sharing formula. (d) Good Faith Requirement....

  12. Mine, yours or ours? : sharing in Swedish couples

    OpenAIRE

    Nyman, Charlott

    2002-01-01

    The topic of this thesis is the sharing of resources in families. Equal sharing has often been taken for granted by policy makers as well as researchers. However, a considerable body of research has now shown that unequal sharing can and does occur in families. The aim of this thesis has been to study sharing in Swedish couples and the degree to which equality can be said to exist in these. The outcomes of sharing, i e partners’ access to money and consumption have been a major focus, as has ...

  13. 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.

  14. 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...

  15. Pragma Directed Shared Memory Centric Optimizations on GPUs

    Institute of Scientific and Technical Information of China (English)

    Jing Li; Lei Liu; Yuan Wu; Xiang-Hua Liu; Yi Gao; Xiao-Bing Feng; Cheng-Yong Wu

    2016-01-01

    GPUs become a ubiquitous choice as coprocessors since they have excellent ability in concurrent processing. In GPU architecture, shared memory plays a very important role in system performance as it can largely improve bandwidth utilization and accelerate memory operations. However, even for affine GPU applications that contain regular access patterns, optimizing for shared memory is not an easy work. It often requires programmer expertise and nontrivial parameter selection. Improper shared memory usage might even underutilize GPU resource. Even using state-of-the-art high level programming models (e.g., OpenACC and OpenHMPP), it is still hard to utilize shared memory since they lack inherent support in describing shared memory optimization and selecting suitable parameters, let alone maintaining high resource utilization. Targeting higher productivity for affine applications, we propose a data centric way to shared memory optimization on GPU. We design a pragma extension on OpenACC so as to convey data management hints of programmers to compiler. Meanwhile, we devise a compiler framework to automatically select optimal parameters for shared arrays, using the polyhedral model. We further propose optimization techniques to expose higher memory and instruction level parallelism. The experimental results show that our shared memory centric approaches effectively improve the performance of five typical GPU applications across four widely used platforms by 3.7x on average, and do not burden programmers with lots of pragmas.

  16. 学校知识管理视野下的教师知识共享策略研究%The school knowledge management under the view of teachers' knowledge sharing policy research

    Institute of Scientific and Technical Information of China (English)

    郭东爽

    2015-01-01

    本文从教师个人知识意愿、认知结构,教师知识的特点和学校的组织形式与环境等方面分析阻碍教师知识共享的原因。促进教师知识共享的管理策略有:建构知识型学校学习型组织;建立健全的激励保障制度;设立知识共享网上平台等。%This article from the teachers' personal knowledge aspiration, cognitive structure, the characteristics of teacher knowledge and the organization form of the school and the environment, etc., analyses the reason of obstacles to teachers' knowledge sharing. Promote the teacher's knowledge sharing management strategy: construct the knowledge school learning organization; To establish and perfect the system of incentive guarantee; Set up the knowledge sharing online platform, etc.

  17. Triple functional shared channel in WDM PON by orthogonal modulation and network coding

    Science.gov (United States)

    Lu, Yang; Wei, Yizhen; Hu, Miao; Zhou, Xuefang; Qian, Zhengfeng; Li, Qiliang

    2015-02-01

    A triple functional shared channel in WDM PON is proposed. The channel can be applied for broadcasting, duplex inter-ONU-communication or dynamical bandwidth allocation, increasing the flexibility and the resource utilization of the scheme. The three applications could be achieved by the same hardware, with different software operations. One example scheme is demonstrated. The test results show error free operation is achieved after for the downstream transmission, upstream transmission and the proposed three applications in shared channel after 25 km transmission.

  18. A Reputation System with Anti-Pollution Mechanism in P2P File Sharing Systems

    OpenAIRE

    Qi Mei; Guo Yajun; Yan Huifang

    2009-01-01

    File pollution has become a very serious problem in peer-to-peer file sharing systems, because of which it greatly reduces the effectiveness of systems. Users downloaded pollution files not only consumed bandwidth, but were also likely to share polluted files without checking. If these polluted files carry a virus, Trojan horse, or other malicious code, the loss of users would be disastrous. There is much research done on reputation-based anti-pollution mechanisms. Peer reputation systems and...

  19. Memory bandwidth-scalable motion estimation for mobile video coding

    Science.gov (United States)

    Hsieh, Jui-Hung; Tai, Wei-Cheng; Chang, Tian-Sheuan

    2011-12-01

    The heavy memory access of motion estimation (ME) execution consumes significant power and could limit ME execution when the available memory bandwidth (BW) is reduced because of access congestion or changes in the dynamics of the power environment of modern mobile devices. In order to adapt to the changing BW while maintaining the rate-distortion (R-D) performance, this article proposes a novel data BW-scalable algorithm for ME with mobile multimedia chips. The available BW is modeled in a R-D sense and allocated to fit the dynamic contents. The simulation result shows 70% BW savings while keeping equivalent R-D performance compared with H.264 reference software for low-motion CIF-sized video. For high-motion sequences, the result shows our algorithm can better use the available BW to save an average bit rate of up to 13% with up to 0.1-dB PSNR increase for similar BW usage.

  20. 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.

  1. 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.

  2. 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...... Synchronization Data Aggregation Algorithm (BESDA) using spanning tree mechanism (SPT). It uses static sink and mobile nodes in the network. BESDA considers the synchronization of a local clock of node with global clock of the network. In the initial stage algorithm established the hierarchical structure...... 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...

  3. Techniques in molecular spectroscopy: from broad bandwidth to high resolution

    Science.gov (United States)

    Cossel, Kevin C.

    This thesis presents a range of different experiments all seeking to extended the capabilities of molecular spectroscopy and enable new applications. The new technique of cavity-enhanced direct frequency comb spectroscopy (CE-DFCS) provides a unique combination of broad bandwidth, high resolution, and high sensitivity that can be useful for a wide range of applications. Previous demonstrations of CE-DFCS were confined to the visible or near-infrared and operated over a limited bandwidth: for many applications it is desirable to increase the spectral coverage and to extend to the mid-infrared where strong, fundamental vibrational modes of molecules occur. There are several key requirements for CE-DFCS: a frequency comb source that provides broad bandwidth and high resolution, an optical cavity for high sensitivity, and a detection system capable of multiplex detection of the comb spectrum transmitted through the cavity. We first discuss comb sources with emphasis on the coherence properties of spectral broadening in nonlinear fiber and the development of a high-power frequency comb source in the mid-infrared based on an optical-parametric oscillator (OPO). To take advantage of this new mid-infrared comb source for spectroscopy, we also discuss the development of a rapid-scan Fourier-transform spectrometer (FTS). We then discuss the first demonstration of CE-DFCS with spectrally broadened light from a highly nonlinear fiber with the application to measurements of impurities in semiconductor manufacturing gases. We also cover our efforts towards extending CE-DFCS to the mid-infrared using the mid-infrared OPO and FTS to measure ppb levels of various gases important for breath analysis and atmospheric chemistry and highlight some future applications of this system. In addition to the study of neutral molecules, broad-bandwidth and high-resolution spectra of molecular ions are useful for astrochemistry where many of the observed molecules are ionic, for studying

  4. 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.

  5. 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.

  6. Efficiently parallelized modeling of tightly focused, large bandwidth laser pulses

    CERN Document Server

    Dumont, Joey; Lefebvre, Catherine; Gagnon, Denis; MacLean, Steve

    2016-01-01

    The Stratton-Chu integral representation of electromagnetic fields is used to study the spatio-temporal properties of large bandwidth laser pulses focused by high numerical aperture mirrors. We review the formal aspects of the derivation of diffraction integrals from the Stratton-Chu representation and discuss the use of the Hadamard finite part in the derivation of the physical optics approximation. By analyzing the formulation we show that, for the specific case of a parabolic mirror, the integrands involved in the description of the reflected field near the focal spot do not possess the strong oscillations characteristic of diffraction integrals. Consequently, the integrals can be evaluated with simple and efficient quadrature methods rather than with specialized, more costly approaches. We report on the development of an efficiently parallelized algorithm that evaluates the Stratton-Chu diffraction integrals for incident fields of arbitrary temporal and spatial dependence. We use our method to show that t...

  7. High bandwidth absorption spectroscopy with a dispersed supercontinuum source.

    Science.gov (United States)

    Hult, Johan; Watt, Rosalynne S; Kaminski, Clemens F

    2007-09-01

    An optical gas sensor is presented, making use of a dispersed supercontinuum source, capable of acquiring broad bandwidth spectra at ultrahigh wavelength sweep and repetition rates. Wavelength sweeps from 1100 nm to 1700 nm can be performed in 800 ns at a spectral resolution of 40 pm. This is comparable to line-widths of molecular spectra at atmospheric pressure. Quantitative measurements are presented of CH(4) employing 80 nm wide sweeps over the P- Q- and R-branches of the 2nu(3) transition near 1665 nm, at rates exceeding 100 kHz. The effective acquisition rate is determined by the amount of averaging required, and the effect of this averaging on observed precision is investigated. PMID:19547496

  8. An improved harmony search algorithm with dynamically varying bandwidth

    Science.gov (United States)

    Kalivarapu, J.; Jain, S.; Bag, S.

    2016-07-01

    The present work demonstrates a new variant of the harmony search (HS) algorithm where bandwidth (BW) is one of the deciding factors for the time complexity and the performance of the algorithm. The BW needs to have both explorative and exploitative characteristics. The ideology is to use a large BW to search in the full domain and to adjust the BW dynamically closer to the optimal solution. After trying a series of approaches, a methodology inspired by the functioning of a low-pass filter showed satisfactory results. This approach was implemented in the self-adaptive improved harmony search (SIHS) algorithm and tested on several benchmark functions. Compared to the existing HS algorithm and its variants, SIHS showed better performance on most of the test functions. Thereafter, the algorithm was applied to geometric parameter optimization of a friction stir welding tool.

  9. High-bandwidth continuous-flow arc furnace

    Science.gov (United States)

    Hardt, David E.; Lee, Steven G.

    1996-01-01

    A high-bandwidth continuous-flow arc furnace for stream welding applications includes a metal mass contained in a crucible having an orifice. A power source charges an electrode for generating an arc between the electrode and the mass. The arc heats the metal mass to a molten state. A pressurized gas source propels the molten metal mass through the crucible orifice in a continuous stream. As the metal is ejected, a metal feeder replenishes the molten metal bath. A control system regulates the electrode current, shielding gas pressure, and metal source to provide a continuous flow of molten metal at the crucible orifice. Independent control over the electrode current and shield gas pressure decouples the metal flow temperature and the molten metal flow rate, improving control over resultant weld characteristics.

  10. UNIFORM—PRICE AUCTION FOR BANDWIDTH ALLOCATION IN THE INTERNET

    Institute of Scientific and Technical Information of China (English)

    WeiJiaolong; ZhangChi

    2002-01-01

    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 letter,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 auctiopn rule is proposed and its 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 eng-users is completed.

  11. 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.

  12. UNIFORM-PRICE AUCTION FOR BANDWIDTH ALLOCATION IN THE INTERNET

    Institute of Scientific and Technical Information of China (English)

    Wei Jiaolong; Zhang Chi

    2002-01-01

    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 letter, 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 its 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.

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

    International Nuclear Information System (INIS)

    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

  14. Narrow-Bandwidth Diode-Laser-Based Ultraviolet Light Source

    Institute of Scientific and Technical Information of China (English)

    PENG Yu; FANG Zhan-Jun; ZANG Er-Jun

    2011-01-01

    A compact, tunable and narrow-bandwidth laser source for ultraviolet radiation is presented. A grating stabilized diode laser at 1064 nm is frequency-stabilized to below 10 kHz by using a ultra low expansion (ULE) cavity. Injecting light of the diode laser into a tapered amplifier yields a power of 290mW. In a first frequency-doubling stage, about 47 mW of green light at 532nm is generated by using a periodical// poled KTP crystal. Subsequent second-harwonic generation employing a BBO crystal leads to about 30μW of ultraviolet light at 266nm.%A compact,tunable and narrow-bandwidth laser source for ultraviolet radiation is presented.A grating stabilized diode laser at 1064nm is frequency-stabilized to below 10kHz by using a ultra low expansion (ULE) cavity.Injecting light of the diode laser into a tapered amplifier yields a power of 290 mW.In a first frequency-doubling stage,about 47mW of green light at 532nm is generated by using a periodically poled KTP crystal.Subsequent second-harmonic generation employing a BBO crystal leads to about 30 μ W of ultraviolet light at 266nm.Hg is,so far,the heaviest nonradioactive atom that has been laser-cooled and trapped.Systematic evaluation of various sources of uncertainty for the Hg-based optical lattice clock is obtained and an accuracy of better than 10-1s is attainable,which is an order of magnitude of improvement over Sr or Yb based clocks because of the reduced susceptibility to the blackbody radiation field,which sets a major limitation on the accuracy of atomic clocks.[1] The 1S0-3p0 transition at 265.6 nm will be exploited as a clock transition.

  15. Transforming Education Research through Open Video Data Sharing

    Science.gov (United States)

    Gilmore, Rick O.; Adolph, Karen E.; Millman, David S.; Gordon, Andrew

    2016-01-01

    Open data sharing promises to accelerate the pace of discovery in the developmental and learning sciences, but significant technical, policy, and cultural barriers have limited its adoption. As a result, most research on learning and development remains shrouded in a culture of isolation. Data sharing is the rare exception (Gilmore, 2016). Many…

  16. A Text Analysis Approach to Motivate Knowledge Sharing via Microsoft SharePoint

    Energy Technology Data Exchange (ETDEWEB)

    Patton, Robert M [ORNL; McNair, Wade [ORNL; Symons, Christopher T [ORNL; Treadwell, Jim N [ORNL; Potok, Thomas E [ORNL

    2012-01-01

    Creating incentives for knowledge workers to share their knowledge within an organization continues to be a challenging task. Strong, innate behaviors of the knowledge worker, such as self-preservation and self- advancement, are difficult to overcome, regardless of the level of knowledge. Many incentive policies simply focus on providing external pressure to promote knowledge sharing. This work describes a technical approach to motivate sharing. Utilizing text analysis and machine learning techniques to create an enhanced knowledge sharing experience, a prototype system was developed and tested at Oak Ridge National Laboratory that reduces the overhead cost of sharing while providing a quick, positive payoff for the knowledge worker. This work describes the implementation and experiences of using the prototype in a corporate production environment.

  17. Limitations to sharing entanglement

    CERN Document Server

    Kim, Jeong San; Sanders, Barry C

    2011-01-01

    We discuss limitations to sharing entanglement known as monogamy of entanglement. Our pedagogical approach commences with simple examples of limited entanglement sharing for pure three-qubit states and progresses to the more general case of mixed-state monogamy relations with multiple qudits.

  18. Shared Parenting Dysfunction.

    Science.gov (United States)

    Turkat, Ira Daniel

    2002-01-01

    Joint custody of children is the most prevalent court ordered arrangement for families of divorce. A growing body of literature indicates that many parents engage in behaviors that are incompatible with shared parenting. This article provides specific criteria for a definition of the Shared Parenting Dysfunction. Clinical aspects of the phenomenon…

  19. 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.

  20. 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....... Utilizing the diagonal mode analysis, the MIMO bandwidth of the collocated MIMO antennas is improved efficiently at the frequencies of lower than 960 MHz. This is realized through moving the three bandwidths to the same range without the degradation of impedance bandwidth and total efficiency. The physical...

  1. 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.

  2. 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.

  3. Effect of Free Bandwidth on VoIP Performance in 802.11b WLAN Networks

    OpenAIRE

    Narbutt, Miroslaw; Davis, Mark

    2006-01-01

    In this paper we experimentally study the relationship between bandwidth utilization in the wireless LAN and the quality of VoIP calls transmitted over the wireless medium. Specifically we evaluate how the amount of free bandwidth decreases as the number of calls increases and how this influences transmission impairments (i.e. delay, loss and jitter) and thus degrades call quality. We show that the amount of free bandwidth is a good indicator for predicting VoIP call quality.

  4. Real-Time Virtual Instruments for Remote Sensor Monitoring Using Low Bandwidth Wireless Networks

    OpenAIRE

    Biruk Gebre; Liwen Guo; Nishit Patel; Kishore Pochiraju

    2008-01-01

    The development of a peer-to-peer virtual instrumentation system for remote acquisition, analysis and transmission of data on low bandwidth networks is described. The objective of this system is to collect high frequency/high bandwidth data from multiple sensors placed at remote locations and adaptively adjust the resolution of this data so that it can be transmitted on bandwidth limited networks to a central monitoring and command center. This is achieved by adaptively re-sampling (decimatin...

  5. Sharing casting technological data on web site

    Institute of Scientific and Technical Information of China (English)

    Sun Xun; Li Hailan; Wang Junqing; Piao Dongxue; Hou Gang; Guan Yang; Wang Penghua; Zhu Qiang; Xle Huasheng

    2008-01-01

    Based on database and asp.net technologies, a web platform of scientific data in the casting technology field 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 finished. 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.

  6. 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

  7. Scaling Mesa Indium Phosphide DHBTs to Record Bandwidths

    Science.gov (United States)

    Lobisser, Evan

    Indium phosphide heterojunction bipolar transistors are able to achieve higher bandwidths at a given feature size than transistors in the Silicon material system for a given feature size. Indium phosphide bipolar transistors demonstrate higher breakdown voltages at a given bandwidth than both Si bipolars and field effect transistors in the InP material system. The high bandwidth of InP HBTs results from both intrinsic material parameters and bandgap engineering through epitaxial growth. The electron mobility in the InGaAs base and saturation velocity in the InP collector are both approximately three times higher than their counterparts in the SiGe material system. Resistance of the base can be made very low due to the large offset in the valence band between the InP emitter and the InGaAs base, which allows the base to be doped on the order of 1020 cm-3 with negligible reduction in emitter injection efficiency. This thesis deals with type-I, NPN dual-heterojunction bipolar transistors. The emitters are InP, and the base is InGaAs. There is a thin (˜ 10 nm) n-type InGaAs "setback" region, followed by a chirped superlattice InGaAs/InAlAs grade to the InP collector. The setback, grade, and collector are all lightly doped n-type. The emitter and collector are contacted through thin (˜ 5 nm) heavily doped n-type InGaAs layers to reduce contact resistivity. The primary focus of this work is increasing the bandwidth of InP HBTs through the proportional scaling of the device dimensions, both layer thicknesses and junction areas, as well as the reduction of the contact resistivities associated with the transistor. Essentially, all RC time constants and transit times must be reduced by a factor of two to double a transistor's bandwidth. Chapter 2 describes in detail the scaling laws and design principles for high frequency bipolar transistor design. A low-stress, blanket sputter deposited composite emitter metal process was developed. Refractory metal base contacts were

  8. Chimpanzees share forbidden fruit.

    Science.gov (United States)

    Hockings, Kimberley J; Humle, Tatyana; Anderson, James R; Biro, Dora; Sousa, Claudia; Ohashi, Gaku; Matsuzawa, Tetsuro

    2007-01-01

    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. PMID:17849015

  9. Chimpanzees share forbidden fruit.

    Science.gov (United States)

    Hockings, Kimberley J; Humle, Tatyana; Anderson, James R; Biro, Dora; Sousa, Claudia; Ohashi, Gaku; Matsuzawa, Tetsuro

    2007-01-01

    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.

  10. Chimpanzees share forbidden fruit.

    Directory of Open Access Journals (Sweden)

    Kimberley J Hockings

    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.

  11. 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

  12. Bandwidth allocation strategy for traffic systems of scale-free network

    International Nuclear Information System (INIS)

    In this Letter, the bandwidth resource allocation strategy is considered for traffic systems of complex networks. With a finite resource of bandwidth, an allocation strategy with preference parameter α is proposed considering the links importance. The performance of bandwidth allocation strategy is studied for the local routing protocol and the shortest path protocol. When important links are slightly favored in the bandwidth allocation, the system can achieve the optimal traffic performance for the two routing protocols. For the shortest path protocol, we also give a method to estimate the network traffic capacity theoretically.

  13. Minimum cost maximum flow algorithm for upstream bandwidth allocation in OFDMA passive optical networks

    Science.gov (United States)

    Wu, Yating; Kuang, Bin; Wang, Tao; Zhang, Qianwu; Wang, Min

    2015-12-01

    This paper presents a minimum cost maximum flow (MCMF) based upstream bandwidth allocation algorithm, which supports differentiated QoS for orthogonal frequency division multiple access passive optical networks (OFDMA-PONs). We define a utility function as the metric to characterize the satisfaction degree of an ONU on the obtained bandwidth. The bandwidth allocation problem is then formulated as maximizing the sum of the weighted total utility functions of all ONUs. By constructing a flow network graph, we obtain the optimized bandwidth allocation using the MCMF algorithm. Simulation results show that the proposed scheme improves the performance in terms of mean packet delay, packet loss ratio and throughput.

  14. High-Bandwidth Photon-Counting Detectors with Enhanced Near-Infrared Response Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Long-range optical telecommunications (LROT) impose challenging requirements on detector array sensitivity at 1064nm and arrays timing bandwidth. Large photonic...

  15. A Novel Dynamic Bandwidth Assignment Algorithm for Multi-Services EPONs

    Institute of Scientific and Technical Information of China (English)

    CHEN Xue; ZHANG Yang; HUANG Xiang; DENG Yu; SUN Shu-he

    2005-01-01

    In this paper we propose a novel Dynamic Bandwidth Assignment (DBA) algorithm for Ethernet-based Passive Optical Networks (EPON) which offers multiple kinds of services. To satisfy crucial Quality of Service (QoS) requirement for Time Division Multiplexing (TDM) service and achieve fair and high bandwidth utilization simultaneously, the algorithm integrates periodic, for TDM service, and polling granting for Ethernet service. Detailed simulation shows that the algorithm guarantees carrier-grade QoS for TDM service, high bandwidth utilization and good fairness of bandwidth assignment among Optical Network Units (ONU).

  16. Bandwidth-Aware Scheduling of Workflow Application on Multiple Grid Sites

    Directory of Open Access Journals (Sweden)

    Harshadkumar B. Prajapati

    2014-01-01

    Full Text Available Bandwidth-aware workflow scheduling is required to improve the performance of a workflow application in a multisite Grid environment, as the data movement cost between two low-bandwidth sites can adversely affect the makespan of the application. Pegasus WMS, an open-source and freely available WMS, cannot fully utilize its workflow mapping capability due to unavailability of integration of any bandwidth monitoring infrastructure in it. This paper develops the integration of Network Weather Service (NWS in Pegasus WMS to enable the bandwidth-aware mapping of scientific workflows. Our work demonstrates the applicability of the integration of NWS by making existing Heft site-selector of Pegasus WMS bandwidth aware. Furthermore, this paper proposes and implements a new workflow scheduling algorithm—Level based Highest Input and Processing Weight First. The results of the performed experiments indicate that the bandwidth-aware workflow scheduling algorithms perform better than bandwidth-unaware algorithms: Random and Heft of Pegasus WMS. Moreover, our proposed workflow scheduling algorithm performs better than the bandwidth-aware Heft algorithms. Thus, the proposed bandwidth-aware workflow scheduling enhances capability of Pegasus WMS and can increase performance of workflow applications.

  17. Reducing Network Traffic of Token Protocol Using Sharing Relation Cache

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Token protocol provides a new coherence framework for shared-memory multiprocessor systems.It avoids indirections of directory protocols for common cache-to-cache transfer misses, and achieves higher interconnect bandwidth and lower interconnect latency compared with snooping protocols. However, the broadcasting increases network traffic, limiting the scalability of token protocol. This paper describes an efficient technique to reduce the token protocol network traffic, called sharing relation cache. This cache provides destination set information for cache-to-cache miss requests by caching directory information for recent shared data. This paper introduces how to implement the technique in a token protocol. Simulations using SPLASH-2 benchmarks show that in a 16-core chip multiprocessor system, the cache reduced the network traffic by 15% on average.

  18. Student aid policy of Chinese higher education

    OpenAIRE

    2008-01-01

    Student aid policy of Chinese higher education was made in the form of free higher education before 1989. It changed into the form of direct assisting and rewarding students afterwards with the cost sharing policy into operation in China. This paper analyses four main questions of Chinese student aid policy. Firstly, it explores the background in which the policy is formulated and identifies the policy development stages. Secondly, human capital theory and modernization theory are applied...

  19. Getting Behind B Shares

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    China Ocean Shipping(Group)Co.(COSCO) employs an experimental strategy of making acquisitions through the purchase of B shares COSCO Pacific Ltd.and its affili- ated companies held 4.5 million shares of China International Marine Containers(Grouo)Co.Ltd.(CIMC) as of March 6. Four months ago,the board of direc- tors of COSCO Container Industries Ltd. (COSCO Container)decided to buy more B shares of CIMC through the securities mar- ket.COSCO Container is a shell company registered in the British Virgin Islands with a

  20. Too Much Information Sharing?

    DEFF Research Database (Denmark)

    Ganuza, Juan José; Jansen, Jos

    2013-01-01

    By using general information structures and precision criteria based on the dispersion of conditional expectations, we study how oligopolists’ information acquisition decisions may change the effects of information sharing on the consumer surplus. Sharing information about individual cost...... parameters gives the following trade-off in Cournot oligopoly. On the one hand, it decreases the expected consumer surplus for a given information precision, as the literature shows. On the other hand, information sharing increases the firms’ incentives to acquire information, and the consumer surplus...... increases in the precision of the firms’ information. Interestingly, the latter effect may dominate the former effect....

  1. Chimpanzees Share Forbidden Fruit

    OpenAIRE

    Kimberley J Hockings; Tatyana Humle; Anderson, James R.; Dora Biro; Claudia Sousa; Gaku Ohashi; Tetsuro Matsuzawa

    2007-01-01

    PLoS ONE - www.plosone.org, V.9, e886 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 o...

  2. Knowledge grows when shared

    DEFF Research Database (Denmark)

    Elbæk, Mikael Karstensen

    2010-01-01

    Knowledge is one of the few commodities that don’t devalue when used. Actually knowledge grows when shared and the free online access to peer-reviewed scientific publications is a potent ingredient the process of sharing. The sharing of knowledge is facilitated by the Open Access Movement. However...... infrastructure for Open Access was launched in Ghent, Belgium. This project and initiative is facilitating the success of the Open Access Pilot in FP7 as presented earlier in this journal. In this brief article I will present some of the most interesting issues that were discussed during the first session...

  3. 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

  4. The Audit Logic: Policy Compliance in Distributed Systems

    NARCIS (Netherlands)

    Cederquist, J.G.; Corin, R.; Dekker, M.A.C.; Etalle, S.; Hartog, den J.I.; Lenzini, G.

    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 complia

  5. Multi-domain Information Exchange in a Bandwidth on Demand Tool

    Directory of Open Access Journals (Sweden)

    Giorgos Adam

    2014-05-01

    Full Text Available In this paper we describe the multi-domain information exchange aspects of the AutoBAHN tool, which is used for implementing a Bandwidth on Demand service as part of the GEANT project. This project was driven by the increasing demand for reliable and guaranteed data transportation for scientific purposes. In order to implement the process of information exchange in a multi-domain heterogeneous environment several design decisions have to take place, in order to balance and satisfy by the needs of information security, fast information dissemination, efficient request processing, reliability and robustness. The paper describes how AutoBAHN implements a flexible AAI in a distributed environment, how it exchanges and updates information and how it handles incoming requests in an efficient and timely manner. The multi-domain aspect of this effort stems from the fact that the tool is used in the production environment of several cooperating National Research and Educational Networks (NRENs across Europe. Each NREN may have different underlying technologies, different policies and different use cases, but they all have to coordinate through usage of the AutoBAHN tool in order to produce a multi-domain service of circuit reservation

  6. FACTORS THAT AFFECT DIVIDEND POLICIES

    OpenAIRE

    Ioanaş Corina

    2009-01-01

    In this article we want to know how much should be paid out by a company to its shareholders in the form of dividends. What is the effect of dividend policy on share price? A financial manager’s dividend policy objectives are to maximize owner wealth while providing adequate financing for the company. A company’s dividend policy depends on many variables: company growth rate, profitability, earnings stability, maintenance of control, degree of financial leverage. Different types of dividend p...

  7. Urban sharing culture

    DEFF Research Database (Denmark)

    Fjalland, Emmy Laura Perez

    2015-01-01

    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...... our cities. The sharing economy has the power to democratise access the urban space, resources and raw materials (Steen Nielsen 2008; Harvey 2000); it holds the ability to change the current dominant understandings and structures of economy and growth (Steen Nielsen 2008); solve emerging environmental...... 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...

  8. 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...

  9. 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.

  10. Shared mediated workspaces

    OpenAIRE

    Greef, Tjerk de; Gullström, Charlie; Handberg, Leif; Nefs, H.T.; Parnes, Peter

    2012-01-01

    Shared mediated spaces provide viable alternatives for meetings and interactions. The development of collaborative mediated workspaces and shared negotiation spaces will have a fundamental impact on all human practices. Previous design-led research, has identified spatial design concepts, such as mediated gaze, and spatial montage, which, if unaddressed, may be said to impose friction, and thus impact negatively on the experience of mediated presence. The current paper discusses a set of conc...

  11. The Tradable Shares Puzzle

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A huge number of restricted shares were made tradable in March in the mainland stock market,testing the capability of the fragile capital market Ping An of China has been made the main scapegoat of this year s stock market plunge.A month after its refinancing plan announcement- equivalent to recreating a new Ping An- its 3.12 billion restricted shares were made tradable on March 3,accounting for almost

  12. Researching the Habitus of Global Policy Actors in Education

    Science.gov (United States)

    Lingard, Bob; Sellar, Sam; Baroutsis, Aspa

    2015-01-01

    This paper reprises the argument for the emergence of a global education policy field and then focuses on the shared habitus of global and national policy actors and technicians. It is argued that this shared habitus is constituted as a reflection of and a contribution to the creation of the global education policy field. Bourdieu's approach…

  13. 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.

  14. High resolution, high bandwidth global shutter CMOS area scan sensors

    Science.gov (United States)

    Faramarzpour, Naser; Sonder, Matthias; Li, Binqiao

    2013-10-01

    Global shuttering, sometimes also known as electronic shuttering, enables the use of CMOS sensors in a vast range of applications. Teledyne DALSA Global shutter sensors are able to integrate light synchronously across millions of pixels with microsecond accuracy. Teledyne DALSA offers 5 transistor global shutter pixels in variety of resolutions, pitches and noise and full-well combinations. One of the recent generations of these pixels is implemented in 12 mega pixel area scan device at 6 um pitch and that images up to 70 frames per second with 58 dB dynamic range. These square pixels include microlens and optional color filters. These sensors also offer exposure control, anti-blooming and high dynamic range operation by introduction of a drain and a PPD reset gate to the pixel. The state of the art sense node design of Teledyne DALSA's 5T pixel offers exceptional shutter rejection ratio. The architecture is consistent with the requirements to use stitching to achieve very large area scan devices. Parallel or serial digital output is provided on these sensors using on-chip, column-wise analog to digital converters. Flexible ADC bit depth combined with windowing (adjustable region of interest, ROI) allows these sensors to run with variety of resolution/bandwidth combinations. The low power, state of the art LVDS I/O technology allows for overall power consumptions of less than 2W at full performance conditions.

  15. Automatic Bandwidth Adjustment for Content Distribution in MPLS Networks

    Directory of Open Access Journals (Sweden)

    D. Moltchanov

    2008-04-01

    Full Text Available Aggregates of real-time traffic may experience changes in their statistical characteristics often manifesting non stationary behavior. In multi protocol label switching (MPLS networks this type of the traffic is assigned constant amount of resources. This may result in ineffective usage of resources when the load is below than expected or inappropriate performance when the load is higher. In this paper we propose new algorithm for dynamic resource adaptation to temporarily changing traffic conditions. Assuming that network nodes may reallocate resources on-demand using automatic bandwidth adjustment capability of MPLS framework, the proposed algorithm, implemented at ingress MPLS nodes, dynamically decides which amount of resources is currently sufficient to handle arriving traffic with given performance metrics. This decision is then communicated to interior MPLS nodes along the label switched path. As a basic tool of the algorithm we use change-point statistical test that signals time instants at which statistical characteristics of traffic aggregates change. The major advantage of the proposed approach is that it is fully autonomous, that is, network nodes do not need any support from hosts in terms of resource reservation requests. The proposed algorithm is well suited for traffic patterns experiencing high variability, especially, for non stationary type of the traffic.

  16. Optimizing bandwidth and dynamic range of lumped Josephson parametric amplifiers

    Science.gov (United States)

    Eddins, A.; Vijay, R.; Macklin, C.; Minev, Z.; Siddiqi, I.

    2013-03-01

    Superconducting parametric amplifiers have revolutionized the field of quantum measurement by providing high gain, ultra-low noise amplification. They have been used successfully for high-fidelity qubit state measurements, probing nano-mechanical resonators, quantum feedback, and for microwave quantum optics experiments. Though several designs exist, a simple and robust architecture is the Lumped Josephson Parametric Amplifier (LJPA). This device consists of a capacitively shunted SQUID directly coupled to a transmission line to form a low quality factor (Q) nonlinear resonator. We discuss amplifiers which can be tuned over the full 4-8 GHz band with 20-25 dB of gain and 10 - 50 MHz of signal bandwidth. However, similar to other parametric amplifiers employing a resonant circuit, the LJPA suffers from low dynamic range and has a -1 dB gain compression point of order -130 dBm. We explore new designs comprised of an array of SQUIDs to improve the dynamic range. We will present the results of numerical simulations and preliminary experiments. We will also briefly discuss improvements obtained from different biasing methods and packaging. This research was supported by the Army Research Office under a QCT grant.

  17. QoS routing via multiple paths using bandwidth reservation

    Energy Technology Data Exchange (ETDEWEB)

    Rao, N.S.V.; Batsell, S.G.

    1997-11-01

    The authors address the problem of computing a multipath, consisting of possibly overlapping paths, to transmit data from the source node s to the destination node d over a computer network while ensuring deterministic bounds on end-to-end delay or delivery rate. They consider two generic routing problems within the framework wherein bandwidth can be reserved, and guaranteed, once reserved, on various links of the communication network. The first problem requires that a message of finite length be transmitted from s to d within {tau} units of time. The second problem requires that a sequential message of r units be transmitted at a rate of {eta} such that maximum time difference between two units that are received out of order is no more than q. They propose a polynomial-time algorithm to the first problem based on an adaptation of the classical Ford-Fulkerson`s method. They present simulation results to illustrate the applicability of the proposed algorithm. They show the second problem to be NP-complete and propose a polynomial-time approximate solution.

  18. QoS routing via multiple paths using bandwidth reservation

    Energy Technology Data Exchange (ETDEWEB)

    Rao, N.S.V.; Batsell, S.G.

    1998-01-01

    The authors address the problem of computing a multipath, consisting of possibly overlapping paths, to transmit data from the source node s to the destination node d over a computer network while ensuring deterministic bounds on end-to-end delay or delivery rate.They consider two generic routing problems within the framework wherein bandwidth can be reserved, and guaranteed, once reserved, on various links of the communication network. The first problem requires that a message of finite length be transmitted from s to d within {tau} units of time. The second problem requires that a sequential message of r units be transmitted at a rate of {eta} such that maximum time difference between two units that are received out of order is no more than q. They propose a polynomial-time algorithm to the first problem based on an adaptation of the classical Ford-Fulkerson`s method. They present simulation results to illustrate the applicability of the proposed algorithm. They show the second problem to be NP-complete, and propose a polynomial-time approximately solution.

  19. Extraction of spatial information for low-bandwidth telerehabilitation applications

    Directory of Open Access Journals (Sweden)

    Kok Kiong Tan, PhD

    2014-09-01

    Full Text Available Telemedicine applications, based on two-dimensional (2D video conferencing technology, have been around for the past 15 to 20 yr. They have been demonstrated to be acceptable for face-to-face consultations and useful for visual examination of wounds and abrasions. However, certain telerehabilitation assessments need the use of spatial information in order to accurately assess the patient’s condition and sending three-dimensional video data over low-bandwidth networks is extremely challenging. This article proposes an innovative way of extracting the key spatial information from the patient’s movement during telerehabilitation assessment based on 2D video and then presenting the extracted data by using graph plots alongside the video to help physicians in assessments with minimum burden on existing video data transfer. Some common rehabilitation scenarios are chosen for illustrations, and experiments are conducted based on skeletal tracking and color detection algorithms using the Microsoft Kinect sensor. Extracted data are analyzed in detail and their usability discussed.

  20. Social value of high bandwidth networks: creative performance and education.

    Science.gov (United States)

    Mansell, Robin; Foresta, Don

    2016-03-01

    This paper considers limitations of existing network technologies for distributed theatrical performance in the creative arts and for symmetrical real-time interaction in online learning environments. It examines the experience of a multidisciplinary research consortium that aimed to introduce a solution to latency and other network problems experienced by users in these sectors. The solution builds on the Multicast protocol, Access Grid, an environment supported by very high bandwidth networks. The solution is intended to offer high-quality image and sound, interaction with other network platforms, maximum user control of multipoint transmissions, and open programming tools that are flexible and modifiable for specific uses. A case study is presented drawing upon an extended period of participant observation by the authors. This provides a basis for an examination of the challenges of promoting technological innovation in a multidisciplinary project. We highlight the kinds of technical advances and cultural and organizational changes that would be required to meet demanding quality standards, the way a research consortium planned to engage in experimentation and learning, and factors making it difficult to achieve an open platform that is responsive to the needs of users in the creative arts and education sectors. PMID:26809576

  1. Work-sharing for a sustainable economy

    OpenAIRE

    Klara Zwickl; Franziska Disslbacher; Sigrid Stagl

    2015-01-01

    Achieving low unemployment in an environment of weak growth is a major policy challenge; a more egalitarian distribution of hours worked could be the key to solving it. Whether worksharing actually increases employment, however, has been debated controversially. In this article we present stylized facts on the distribution of hours worked and discuss the role of work-sharing for a sustainable economy. Building on recent developments in labor market theory we review the determin...

  2. 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

  3. Distributed Construction and Maintenance of Bandwidth-Efficient Bluetooth Scatternets

    NARCIS (Netherlands)

    Tekkalmaz, M.; Sözer, H.; Korpeoglu, I.

    2005-01-01

    Bluetooth networks can be constructed as piconets or scatternets depending on the number of nodes in the network. Although piconet construction is a well-defined process specified in Bluetooth standards, scatternet construction policies and algorithms are not well specified. Among many solution prop

  4. 图的循环带宽和%CYCLIC BANDWIDTH SUM OF GRAPHS

    Institute of Scientific and Technical Information of China (English)

    郝建修

    2001-01-01

    Let G be a simple graph. The cyclic bandwidth sum problem is to determine a labeling of graph G in a cycle such that the total length of edges is as small as possible. In this paper, some upper and lower bounds on cyclic bandwidth sum of graphs are studied.

  5. Bandwidth and chirp characterisation of wavelength conversion based on electroabsorption modulators

    DEFF Research Database (Denmark)

    Xu, Lin; Oxenløwe, Leif Katsuo; Chi, Nan;

    2002-01-01

    It is demonstrated experimentally that the frequency chirp of a data modulated signal can be reduced and the modulation bandwidth increased through wavelength conversion in an electroabsorption modulator.......It is demonstrated experimentally that the frequency chirp of a data modulated signal can be reduced and the modulation bandwidth increased through wavelength conversion in an electroabsorption modulator....

  6. 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.

  7. Effects of Signal Spectrum Bandwidth on Different PMD Compensation Feedback Methods

    Institute of Scientific and Technical Information of China (English)

    Na Young Kim; Duckey Lee; Sangin Kim; Namkyoo Park

    2003-01-01

    We compared efficiencies of different PMD compensation feedback methods against transmission signal bandwidth,including NRZ, RZ, CRZ format under various duty cycles. We found that the critical factor determining the efficiency of PMD compensation is not the modulation format, but the spectral bandwidth of the transmission signal.

  8. Effects of Signal Spectrum Bandwidth on Different PMD Compensation Feedback Methods

    Institute of Scientific and Technical Information of China (English)

    Na; Young; Kim; Duckey; Lee; Sangin; Kim; Namkyoo; Park

    2003-01-01

    We compared efficiencies of different PMD compensation feedback methods against transmission signal bandwidth, including NRZ, RZ, CRZ format under various duty cycles. We found that the critical factor determining the efficiency of PMD compensation is not the modulation format, but the spectral bandwidth of the transmission signal.

  9. Task Mapping and Bandwidth Reservation for Mixed Hard/Soft Fault-Tolerant Embedded Systems

    DEFF Research Database (Denmark)

    Saraswat, Prabhat Kumar; Pop, Paul; Madsen, Jan

    2010-01-01

    In this paper we are interested in mixed hard/soft real-time fault-tolerant applications mapped on distributed heterogeneous architectures. We use the Earliest Deadline First (EDF) scheduling for the hard real-time tasks and the Constant Bandwidth Server (CBS) for the soft tasks. The bandwidth re...

  10. 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...

  11. 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.

  12. Gender diversity policies in universities: a multi-perspective framework of policy measures

    NARCIS (Netherlands)

    T.M. Timmers; T.M. Willemsen; K.G. Tijdens

    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 wome

  13. Dynamic Bandwidth Allocation Technique in ATM Networks Based on Fuzzy Neural Networks and Genetic Algorithm

    Institute of Scientific and Technical Information of China (English)

    ZhangLiangjie; LiYanda; 等

    1997-01-01

    In this paper,a dynamic bandwidth allocation technique based on fuzz neural networks(FNNs) and genetic algorithm(GA)is proposed for preventive congestion control in ATM network.The traffic model based on FNN does not need the descriptive traffic parameters in detail,which greatly depend on the user's terminal.Genetic algorithm is used to predict the equivalent bandwidth of the accepted traffic in real-time.Thus,the proposed scheme can estimate the dynamic bandwidth of the network in the time scale from the call arrival to the call admission/rejection due to the fuzzy-tech and GA hardware implementation.Simulation results show that the scheme can perform accurate dynamic bandwidth allocation to DN/OFF bursty traffic in accordance with the required quality of service(QOS),and the bandwidth utilization is improved from the overall point of view.

  14. Dynamic Bit Allocation for Object Tracking in Bandwidth Limited Sensor Networks

    CERN Document Server

    Masazade, Engin; Varshney, Pramod K

    2011-01-01

    In this paper, we study the target tracking problem in wireless sensor networks (WSNs) using quantized sensor measurements under limited bandwidth availability. At each time step of tracking, the available bandwidth $R$ needs to be distributed among the $N$ sensors in the WSN for the next time step. The optimal solution for the bandwidth allocation problem can be obtained by using a combinatorial search which may become computationally prohibitive for large $N$ and $R$. Therefore, we develop two new computationally efficient suboptimal bandwidth distribution algorithms which are based on convex relaxation and approximate dynamic programming (A-DP). We compare the mean squared error (MSE) and computational complexity performances of convex relaxation and A-DP with other existing suboptimal bandwidth distribution schemes based on generalized Breiman, Friedman, Olshen, and Stone (GBFOS) algorithm and greedy search. Simulation results show that, A-DP, convex optimization and GBFOS yield similar MSE performance, w...

  15. Broad-Bandwidth FPGA-Based Digital Polyphase Spectrometer

    Science.gov (United States)

    Jamot, Robert F.; Monroe, Ryan M.

    2012-01-01

    With present concern for ecological sustainability ever increasing, it is desirable to model the composition of Earth s upper atmosphere accurately with regards to certain helpful and harmful chemicals, such as greenhouse gases and ozone. The microwave limb sounder (MLS) is an instrument designed to map the global day-to-day concentrations of key atmospheric constituents continuously. One important component in MLS is the spectrometer, which processes the raw data provided by the receivers into frequency-domain information that cannot only be transmitted more efficiently, but also processed directly once received. The present-generation spectrometer is fully analog. The goal is to include a fully digital spectrometer in the next-generation sensor. In a digital spectrometer, incoming analog data must be converted into a digital format, processed through a Fourier transform, and finally accumulated to reduce the impact of input noise. While the final design will be placed on an application specific integrated circuit (ASIC), the building of these chips is prohibitively expensive. To that end, this design was constructed on a field-programmable gate array (FPGA). A family of state-of-the-art digital Fourier transform spectrometers has been developed, with a combination of high bandwidth and fine resolution. 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 (ADCs). This 6-Gsps (gigasample per second) digital representation of the analog signal is then processed through an FPGA-based streaming fast Fourier transform (FFT). 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.

  16. Shared care and boundaries:

    DEFF Research Database (Denmark)

    Winthereik, Brit Ross

    2008-01-01

    of responsibilities entailed in shared care projects. Rather than seeking to connect all actors in an unbounded space, shared care might instead suggest a space for patients and professionals to experiment with new roles and responsibilities. Practical implications – When designing coordination tools for health care......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...

  17. Bandwidth Resource Dynamic Allocation in Differentiated Services Model%Diffserv中带宽代理BB的实现

    Institute of Scientific and Technical Information of China (English)

    邱瑜; 朱淼良

    2003-01-01

    To employ Differentiated Services, efficient and flexible resource allocation mechanism is needed. Static bandwidth resource allocation Is not suitable for the situations in which traffic varies greatly with times. If customers bought bandwidth according to their highest traffic demands, some resource will be wasted when traffic load is light. On the other hand, the static allocated bandwidth may not satisfy the growing traffic demands. So it is necessary to allocate bandwidth resource in dynamic way. We bring up a prototype of BB, discussing the necessary components to realize the dynamic bandwidth resource allocation and further more, our BB can provides advanced reservation for bandwidth resource. Simulation tests show our design is feasible.

  18. Shared values and normality

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wen-hua; PANG Xue-cheng

    2006-01-01

    This paper investigates the relationship between the normality and the shared values for a meromorphic function on the unit disc △.Based on Marty's normality criterion and through a detailed analysis of the meromorphic functions,it is shown that if for every f∈F,f and f(k) share a and b on △ and the zeros of f(z)-a are of multiplicity k≥3,then F is normal on △,where F is a family of meromorphic functions on the unit disc △,and a and b are distinct values.

  19. Energy Policy. Highlights. 2013 Edition

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-07-01

    Energy Policy Highlights showcases recent developments in energy policies among all 28 IEA member countries. Each contribution underscores the changing nature of both global and domestic energy challenges, as well as the commonality of energy concerns among member countries. The policies highlighted in this publication identify an urgent need to reduce greenhouse gas (GHG) emissions as a clear policy objective. Electricity, enhancing energy efficiency and increasing the share of renewables in the energy mix in a cost effective manner are likewise areas of common focus. On the end-user side, increasing public awareness of domestic energy policies through improved transparency and engagement is an important facet of policy support among IEA member countries. The successful implementation of policies and other initiatives benefitted from efforts to inform the public.

  20. On-time Delivery Model In a ‘N to 1' Assembly System with Inventory Sharing Policy%基于库存分担策略的装配系统准时供货模型研究

    Institute of Scientific and Technical Information of China (English)

    关旭; 马士华; 应丹丰

    2013-01-01

    In a assembly system with uncertain demand time,suppliers' uncoordinated deliver times can heavily bring down the manufacturer's and the supply chain's performances.Under such a circumstance,manufacturer has to use some inventory control policies (e.g.,VMI) to reduce his inventory cost,while the supplier tries to deliver at the most appropriate time.In this paper,the supplier optimal deliver time and the manufacturer's best inventory holding period in an assemble system with uncertain demand time are studied.To this end,two different models are conducted in N-1 setting:the Nash game among the multi-suppliers,and the Stacklberg game between the manufacturer and the suppliers.The manufacturer' s optimal limited inventory holding period under two different conditions is also discussed.One is the manufacturer that sets the same inventory holding period to all the suppliers,and the other is the manufacturer that can choose different inventory holding periods to the different suppliers.The result identifies the suppliers' optimal deliver time and shows that the manufacturer can effectively improve his and the channel's profit by either means.In other words,traditional VMI policy isn't good for neither the manufacturer nor the supply chain.By numerical analysis,the sensitivities of the supplier heterogeneity are identified,and it is shown that the supply chain efficiency increases when the manufacturer is able to choose different inventory holding periods.Moreover,the essential condition for the supply chain coordination is concisely provided.%本文考虑一个由多供应商和单制造商构成的装配系统.当市场的需求时间无法确定时,制造商通过对供应商设定合理的库存分担策略来降低自身成本,供应商则需要自行决定对制造商的补货时间并承担相应的库存持有成本和延迟惩罚成本.文章同时建立了供应商之间的纳什博弈模型和以制造商为主方的主从博弈模型,以找到供应商的最

  1. Policy options

    International Nuclear Information System (INIS)

    The obstacles to bringing about consumer response to environmental dangers are particularly challenging for global problems like ozone depletion and the greenhouse effect. In this situation, there is the danger of what is commonly termed the tragedy of the commons, the ecological destruction that can occur from uncontrolled use of shared resources like the atmosphere. There is probably no country for which reductions in global warming provide an adequate economic incentive to reduce greenhouse gas emissions unilaterally, even though such action could yield substantial global benefits. From any one country's viewpoint, the costs of controlling emissions may exceed the benefits since, without international agreement, reductions achieved by one nation may be offset by another. Therefore, even though the entire world may be better off as a result of efforts to lower emissions, new economic incentives are necessary to lead the market to a socially efficient outcome. This paper describes the range of domestic and international policies that could be adopted to reduce emissions of greenhouse gases, and also discusses the results of modeling analyses of government actions that could reduce or increase such emissions

  2. Shared decision making

    Science.gov (United States)

    ... features on this page, please enable JavaScript. Shared decision making is when health care providers and patients work together to decide ... There many test and treatment options for most health conditions. So your condition may be ... decision making helps you and your provider choose a treatment ...

  3. Quantum Shared Broadcasting

    OpenAIRE

    Giovannetti, V.; Holevo, A. S.

    2007-01-01

    A generalization of quantum broadcasting protocol is presented. Here the goal is to copy an unknown input state into two subsystems which partially overlap. We show that the possibility of implementing these protocols strongly depends upon the overlap among the subsystems. Conditions for approximated shared broadcasting are analyzed.

  4. Share the Fruits

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Procter & Gamble Co,extends its employee stock ownership plan to benefit its Chinese employees The Procter & Gamble Co.(P&G) launched its Chinese employee stock ownership plan(ESOP)on April 1 after five years of preparation.The plan entitles its more than 7,000 employees in China to buy P&G stocks and share its growth benefits.

  5. Promoting teachers’ knowledge sharing

    NARCIS (Netherlands)

    Runhaar, P.R.; Sanders, K.

    2015-01-01

    Teachers’ professional development is nowadays seen as key in efforts to improve education. Knowledge sharing is a learning activity with which teachers not only professionalize themselves, but contribute to the professional development of their colleagues as well. This paper presents two studies, a

  6. 'Smart Power' for' Sharing'

    Institute of Scientific and Technical Information of China (English)

    Wang Ting

    2010-01-01

    @@ As an attitude of life The Interstoff Asia Essential Spring will be held from March 17th to 19th,2010,in Hong Kong Convention & Exhibition Centre.During this exhibition,the Interstoff Asia Directions trend committee will present its apparel fabric trend forecast for next season's wardrobes,unfolding a story of'Smart Power' of 'Sharing'.

  7. 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...

  8. Shared goals and development

    DEFF Research Database (Denmark)

    Blomberg, Olle

    2015-01-01

    In 'Joint Action and Development', Stephen Butterfill argues that if several agents' actions are driven by what he calls a "shared goal" -- a certain pattern of goal-relations and expectations -- then these actions constitute a joint action. This kind of joint action is sufficiently cognitively...

  9. Beyond processor sharing

    NARCIS (Netherlands)

    Aalto, S.; Ayesta, U.; Borst, S.C.; Misra, V.; Núñez Queija, R.

    2007-01-01

    While the (Egalitarian) Processor-Sharing (PS) discipline offers crucial insights in the performance of fair resource allocation mechanisms, it is inherently limited in analyzing and designing differentiated scheduling algorithms such as Weighted Fair Queueing and Weighted Round-Robin. The Discrimin

  10. 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...... potential, yet very real, risks for the system not to meet its intended goals....

  11. Shared Oral Care

    DEFF Research Database (Denmark)

    Hede, Børge; Elmelund Poulsen,, Johan; Christophersen, Rasmus;

    2014-01-01

    Shared Oral Care - Forebyggelse af orale sygdomme på plejecentre Introduktion og formål: Mangelfuld mundhygiejne hos plejekrævende ældre er et alment og veldokumenteret sundhedsproblem, der kan føre til massiv udvikling af tandsygdomme, og som yderligere kan være medvirkende årsag til alvorlige...

  12. Promoting teachers’ knowledge sharing

    NARCIS (Netherlands)

    Runhaar, P.R.; Sanders, K.

    2016-01-01

    Teachers’ professional development is nowadays seen as key in efforts to improve education. Knowledge sharing is a learning activity with which teachers not only professionalize themselves, but contribute to the professional development of their colleagues as well. This paper presents two studies, a

  13. 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...

  14. 77 FR 6549 - Acquisition of Items for Which Federal Prison Industries Has a Significant Market Share

    Science.gov (United States)

    2012-02-08

    ... required DoD to publish a list of product categories for which FPI's share of the DoD market was greater... categories for which FPI has a significant market share is posted at: http://www.acq.osd.mil/dpap/policy/policyvault/USA007288-11-DPAP.pdf .) Accordingly, the updated product categories for which FPI's share of...

  15. Real-Time Virtual Instruments for Remote Sensor Monitoring Using Low Bandwidth Wireless Networks

    Directory of Open Access Journals (Sweden)

    Biruk Gebre

    2008-06-01

    Full Text Available The development of a peer-to-peer virtual instrumentation system for remote acquisition, analysis and transmission of data on low bandwidth networks is described. The objective of this system is to collect high frequency/high bandwidth data from multiple sensors placed at remote locations and adaptively adjust the resolution of this data so that it can be transmitted on bandwidth limited networks to a central monitoring and command center. This is achieved by adaptively re-sampling (decimating the data from the sensors at the remote location before transmission. The decimation is adjusted to the available bandwidth of the communications network which is characterized in real-time. As a result, the system allows users at the remote command center to view high bandwidth data (at a lower resolution with user-aware and minimized latency. This technique is applied to an eight hydrophone data acquisition system that requires a 25.6 Mbps connection for the transmission of the full data set using a wireless connection with 1 – 3.5 Mbps variable bandwidth. This technique can be used for applications that require monitoring of high bandwidth data from remote sensors in research and education fields such as remote scientific instruments and visually driven control applications.

  16. BACH:A Bandwidth-Aware Hybrid Cache Hierarchy Design with Nonvolatile Memories

    Institute of Scientific and Technical Information of China (English)

    Jishen Zhao; Cong Xu; Tao Zhang; Yuan Xie

    2016-01-01

    Limited main memory bandwidth is becoming a fundamental performance bottleneck in chip-multiprocessor (CMP) design. Yet directly increasing the peak memory bandwidth can incur high cost and power consump-tion. In this paper, we address this problem by proposing a memory, a bandwidth-aware reconfigurable cache hierarchy, BACH, with hybrid memory technologies. Components of our BACH design include a hybrid cache hierarchy, a reconfigura-tion mechanism, and a statistical prediction engine. Our hybrid cache hierarchy chooses different memory technologies with various bandwidth characteristics, such as spin-transfer torque memory (STT-MRAM), resistive memory (ReRAM), and embedded DRAM (eDRAM), to configure each level so that the peak bandwidth of the overall cache hierarchy is optimized. Our reconfiguration mechanism can dynamically adjust the cache capacity of each level based on the predicted bandwidth demands of running workloads. The bandwidth prediction is performed by our prediction engine. We evaluate the system performance gain obtained by BACH design with a set of multithreaded and multiprogrammed workloads with and without the limitation of system power budget. Compared with traditional SRAM-based cache design, BACH improves the system throughput by 58%and 14%with multithreaded and multiprogrammed workloads respectively.

  17. An Information-theoretic Model for Knowledge Sharing in Opportunistic Social Networks

    OpenAIRE

    ElSherief, Mai; Elbatt, Tamer; Zahran, Ahmed; Helmy, Ahmed

    2015-01-01

    In this paper we establish fundamental limits on the performance of knowledge sharing in opportunistic social net- works. In particular, we introduce a novel information-theoretic model to characterize the performance limits of knowledge sharing policies. Towards this objective, we first introduce the notions of knowledge gain and its upper bound, knowledge gain limit, per user. Second, we characterize these quantities for a number of network topologies and sharing policies. This work constit...

  18. High-Density, High-Bandwidth, Multilevel Holographic Memory

    Science.gov (United States)

    Chao, Tien-Hsin

    2008-01-01

    A proposed holographic memory system would be capable of storing data at unprecedentedly high density, and its data transfer performance in both reading and writing would be characterized by exceptionally high bandwidth. The capabilities of the proposed system would greatly exceed even those of a state-of-the art memory system, based on binary holograms (in which each pixel value represents 0 or 1), that can hold .1 terabyte of data and can support a reading or writing rate as high as 1 Gb/s. The storage capacity of the state-of-theart system cannot be increased without also increasing the volume and mass of the system. However, in principle, the storage capacity could be increased greatly, without significantly increasing the volume and mass, if multilevel holograms were used instead of binary holograms. For example, a 3-bit (8-level) hologram could store 8 terabytes, or an 8-bit (256-level) hologram could store 256 terabytes, in a system having little or no more size and mass than does the state-of-the-art 1-terabyte binary holographic memory. The proposed system would utilize multilevel holograms. The system would include lasers, imaging lenses and other beam-forming optics, a block photorefractive crystal wherein the holograms would be formed, and two multilevel spatial light modulators in the form of commercially available deformable-mirror-device spatial light modulators (DMDSLMs) made for use in high speed input conversion of data up to 12 bits. For readout, the system would also include two arrays of complementary metal oxide/semiconductor (CMOS) photodetectors matching the spatial light modulators. The system would further include a reference-beam sterring device (equivalent of a scanning mirror), containing no sliding parts, that could be either a liquid-crystal phased-array device or a microscopic mirror actuated by a high-speed microelectromechanical system. Time-multiplexing and the multilevel nature of the DMDSLM would be exploited to enable writing

  19. B3A: Prompting Cooperation Among Rational Participants in P2P Bulk File Sharing Environments

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Peer-to-peer (P2P) file sharing systems assume that their users download files in proportion to their sharing. Unfortunately, users are unlikely to do so without an incentive mechanism. Previous solutions to the problem required some types of centralized control, which strays from the spirit of P2P to provide long-term incentives. This paper presents the balance-based bandwidth allocation, B3A, an incentive framework to inspire participants to share files. In the B3A framework, each peer keeps the differences between the amount of data it has received from each peer and the amount it has sent to that one. When receiving simultaneous requests from various peers, the peer prefers to allocate its limited upload bandwidth to those peers with larger differences. Therefore, the downloading bandwidth perceived by a peer is positively related to its contributions to others, consequently stimulating it to share more files. The B3A framework is fully decentralized, scalable, and secure.

  20. 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.

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

    KAUST Repository

    Majid, M. A.

    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.

  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. Breaking the energy-bandwidth limit of electro-optic modulators: theory and a device proposal

    CERN Document Server

    Lin, Hongtao; Liu, Jifeng; Zhang, Lin; Michel, Jurgen; Hu, Juejun

    2013-01-01

    In this paper, we quantitatively analyzed the trade-off between energy per bit for switching and modulation bandwidth of classical electro-optic modulators. A formally simple energy-bandwidth limit (Eq. 10) is derived for electro-optic modulators based on intra-cavity index modulation. To overcome this limit, we propose a dual cavity modulator device which uses a coupling modulation scheme operating at high bandwidth (> 200 GHz) not limited by cavity photon lifetime and simultaneously features an ultra-low switching energy of 0.26 aJ, representing over three orders of magnitude energy consumption reduction compared to state-of-the-art electro-optic modulators.

  4. A Low Cross-Polarization Smooth-Walled Horn with Improved Bandwidth

    Science.gov (United States)

    Zeng, Lingzhen; Bennett, Charles L.; Chuss, David T.; Wollack, Edward J.

    2009-01-01

    Corrugated feed horns offer excellent beam symmetry, main beam efficiency, and cross-polar response over wide bandwidths, but can be challenging to fabricate. An easier-to-manufacture smooth-walled feed is explored that approximates these properties over a finite bandwidth. The design, optimization and measurement of a monotonically-profiled, smooth-walled scalar feedhorn with a diffraction-limited approximately 7 degrees full width at half maximum (FWHM) is presented. The feed was demonstrated to have low cross polarization (<-30 dB) across the frequency range 33-45 GHz (30% fractional bandwidth). A return loss better than -28 dB was measured across the band.

  5. Cyclic polling-based dynamic wavelength and bandwidth allocation in wavelength division multiplexing passive optical networks

    Institute of Scientific and Technical Information of China (English)

    Zhengcheng Xie; Hui Li; Yuefeng Ji

    2009-01-01

    Cyclic polling-based dynamic wavelength and bandwidth allocation algorithm supporting differentiated classes of services in wavelength division multiplexing (WDM) passive optical networks (PONs) is proposed. In this algorithm, the optical line terminal (OLT) polls for optical network unit (ONU) requests to transmit data in a cyclic manner. Services are categorized into three classes: expedited forward (EF) priority, assured forwarding (AF) priority, and best effort (BE) priority. The OLT assigns bandwidth for different priorities with different strategies. Simulation results show that the proposed algorithm saves a lot of downstream bandwidth under low load and does not show the light-load penalty compared with the simultaneous and interleaved polling schemes.

  6. Increased spectral bandwidths in nonlinear conversion processes by use of multicrystal designs.

    Science.gov (United States)

    Brown, M

    1998-10-15

    The fourth-harmonic generation of broadband 243-nm radiation is reported. The broadband radiation is achieved by implementation of a multicrystal design to overcome spectral bandwidth limitations, and a plane-wave analysis is developed that shows increased spectral bandwidths for these designs. The fourth harmonic of a Cr:LiSAF laser operating at 972 nm is generated in beta-barium borate (BBO). The results demonstrate a spectral bandwidth at 243 nm more than five times broader than that which is expected from a single BBO crystal of equivalent length.

  7. Influences of clock resolution of bandwidth measurement on packet pair algorithm

    Institute of Scientific and Technical Information of China (English)

    Wu Weiguo; Zhang Wenjie; Qian Depei; Liu Yi

    2007-01-01

    Influences of the clock resolution of bandwidth estimator on the accuracy and stability of the packet pair algorithm was analyzed. A mathematic model has been established to reveal the relationship between the result deviation coefficient and the packet size, clock resolution and real bandwidth(value)of the measured route. A bandwidth self-adapting packet pair algorithm was presented based on the mathematic model to reduce the estimation error resulting from the clock resolution and to improve the accuracy and stability of measurement by adjusting the deviation coefficient. Experimental results have verified the validity and stability of the algorithm.

  8. Increased spectral bandwidths in nonlinear conversion processes by use of multicrystal designs.

    Science.gov (United States)

    Brown, M

    1998-10-15

    The fourth-harmonic generation of broadband 243-nm radiation is reported. The broadband radiation is achieved by implementation of a multicrystal design to overcome spectral bandwidth limitations, and a plane-wave analysis is developed that shows increased spectral bandwidths for these designs. The fourth harmonic of a Cr:LiSAF laser operating at 972 nm is generated in beta-barium borate (BBO). The results demonstrate a spectral bandwidth at 243 nm more than five times broader than that which is expected from a single BBO crystal of equivalent length. PMID:18091854

  9. Knowledge Sharing and National Culture

    DEFF Research Database (Denmark)

    Michailova, Snejina; Hutchings, Kate

    2004-01-01

    Much of the knowledge management literature tends to assume a rather universalistunderstanding of knowledge sharing. Yet, attitudes to knowledge sharing as well as actualknowledge-sharing behaviour depend on conditions that vary across institutional and culturalenvironments. This paper contribute...... on knowledge sharing in organisations in thesetwo countries. Research and management implications are also outlined.Keywords: China, knowledge sharing, national culture, Russia...... to the knowledge-sharing literature by specificallydiscussing the interplay between knowledge-sharing and national cultural factors in the context oftransition countries. The paper engages in a comparative examination of two major transitionsocieties, China and Russia, and contributes to understanding...

  10. P2P-based Short Video Sharing System%一种基于P2P的短视频分享系统

    Institute of Scientific and Technical Information of China (English)

    陈卓; 李彦

    2012-01-01

    Online short video sharing is reshaping the way people watching videos, so this paper presents sharing policies mainly adopts the Client/Server architecture, which can result huge bandwidth pressure at streaming server. A P2P based online short video sharing System IShare is proposed, which combines viewing interests of users and social network characteristic of short videos, which can share short videos between users. IShare mainly includes interest based peers clustering and streaming source peers searching. Experimental results show IShare has a high efficient streaming source peers searching ability and can greatly reduce the bandwith consumption of streaming server.%现有在线短视频分享策略通常采用C/S架构,给视频服务器带来较大的带宽压力.为此,提出一种采用点对点方式的在线短视频分享系统IShare,该系统结合用户点播偏好和视频文件之间的社会网络特性实现视频分享.IShare主要包括基于点播兴趣的节点分簇和视频数据源节点的查找2个核心技术.实验结果表明,IShare具备较好的视频数据源节点查找能力,可降低视频服务器带宽资源消耗.

  11. Towards A Shared Mission

    DEFF Research Database (Denmark)

    Staunstrup, Jørgen; Orth Gaarn-Larsen, Carsten

    in the context of universities. Although the economic aspects of value are important and cannot be ignored, we argue for a much richer interpretation of value that captures the many and varied results from universities. A shared mission is a prerequisite for university management and leadership. It makes...... of the universities. The sad result is that the dialog about university development, resources, leadership, governance etc. too often ends up in rather fruitless discussions and sometimes even mutual suspicion. This paper argues for having a dialog involving both internal and external stakeholders agreeing...... 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...

  12. 'An Arena for Sharing'

    DEFF Research Database (Denmark)

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

    2015-01-01

    Background: Despite an increasing focus on cancer rehabilitation programs, there is limited knowledge about the experiences of residential rehabilitation focusing on both the patients and their relatives. Objective: The aim of this study was to explore the experienced benefits of the joint...... involvement of patients and their relatives in a 5-day residential cancer rehabilitation course, provided as part of a larger intervention study in Denmark. Methods: Ethnographic fieldwork, consisting of participant observations and informal conversations, was conducted with 20 individuals (10 patients and 10...... 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...

  13. Shared goals and development

    DEFF Research Database (Denmark)

    Blomberg, Olle

    2015-01-01

    In 'Joint Action and Development', Stephen Butterfill argues that if several agents' actions are driven by what he calls a "shared goal" -- a certain pattern of goal-relations and expectations -- then these actions constitute a joint action. This kind of joint action is sufficiently cognitively...... 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...... a counterexample, I show that the pattern of goal-relations and expectations specified by Butterfill cannot play this role. I then provide an appropriately conceptually and cognitively undemanding amendment with which the account can be saved....

  14. Welding Qualification Sharing

    International Nuclear Information System (INIS)

    ASME Section IX, 'Welding Qualifications', requires that each organization qualify its own welders and welding procedures. Qualification responsibility cannot be subcontracted, and qualifications administered by one organization cannot be transferred to another organization. This requirement has become the subject of close scrutiny as the demand for efficiency, particularly among nuclear plant owners, has increased. Two recent Code Cases change procedure and performance qualification requirements for the better. The first, N-573, enables nuclear plant owners to share welding procedure qualifications. The second, N-600, enables nuclear plant owners to share welder performance qualifications. Several owners have reduced costs using N-573. N-600, because it is relatively new, has not yet been implemented. Its potential for cost savings, though, is equivalent to that afforded by N-573. This paper discusses ASME Section IX's procedure and performance qualification philosophy, assesses that philosophy in light of today's welding environment, and discusses implementation of Code Cases N-573 and N-600. (authors)

  15. Shared Emotions in Music

    OpenAIRE

    Cochrane, Thomas

    2007-01-01

    In this thesis I show that groups can share token emotional states by performing music together. First I argue that emotions are perceptions, representing the self's dynamic relation with the world. This representation is achieved by patterns of bodily changes, functioning independently of conscious feeling. Moreover, emotional expressions should be included in this analysis because they contribute to the pattern of bodily changes. This entails that we can 'think through' our emotions by mani...

  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....

  17. 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...

  18. 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....

  19. Perspectives of risk sharing

    OpenAIRE

    Aase, Knut K.

    2000-01-01

    In this paper we present an overview of the standard risk sharing model of insurance. We discuss and characterize a competitive equilibrium, Pareto optimality, and representative agent pricing, including its implications for insurance premiums. We only touch upon the existence problem of a competitive equilibrium, primarily by presenting several examples. Risk tolerance and aggregation is the subject of one section. Risk adjustment of the probability measure is one topic, as well as the insur...

  20. Does Knowledge Sharing Pay?

    DEFF Research Database (Denmark)

    Mahnke, Volker; Pedersen, Torben; Venzin, Markus

    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....

  1. Sharing Sensor Network Data

    OpenAIRE

    Gong Chen; Nathan Yau; Mark Hansen; Deborah Estrin

    2007-01-01

    Sensor networks generate a variety of data streams in different temporal and spatial resolutions. The data come as numbers text, images, and audio and are dynamically produced periodically and sporadically. How can we organize hundreds of thousands of such data streams? How can we make it easy for scientists and engineers to publish and share such data streams? In this paper, we present our solution, SensorBase.org. It is a web application that not only provides the user with the functionalit...

  2. 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.

  3. 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...

  4. Generation of large-bandwidth x-ray free-electron-laser pulses

    Science.gov (United States)

    Saa Hernandez, Angela; Prat, Eduard; Bettoni, Simona; Beutner, Bolko; Reiche, Sven

    2016-09-01

    X-ray free-electron lasers (XFELs) are modern research tools in disciplines such as biology, material science, chemistry, and physics. Besides the standard operation that aims at minimizing the bandwidth of the produced XFEL radiation, there is a strong scientific demand to produce large-bandwidth XFEL pulses for several applications such as nanocrystallography, stimulated Raman spectroscopy, and multiwavelength anomalous diffraction. We present a self-consistent method that maximizes the XFEL pulse bandwidth by systematically maximizing the energy chirp of the electron beam at the undulator entrance. This is achieved by optimizing the compression scheme and the electron distribution at the source in an iterative back-and-forward tracking. Start-to-end numerical simulations show that a relative bandwidth of 3.25% full-width can be achieved for the hard x-ray pulses in the SwissFEL case.

  5. High-Bandwidth Photon-Counting Detectors with Enhanced Near-Infrared Response Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Laser optical communications offer the potential to dramatically increase the link bandwidth and decrease the emitter power in long-range space communications....

  6. Bandwidth Controllable Tunable Filter for Hyper-/Multi-Spectral Imager Project

    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...

  7. Ultra-low Noise, High Bandwidth, 1550nm HgCdTe APD Project

    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...

  8. A Novel Dynamic Bandwidth Allocation Algorithm with Correction-based the Multiple Traffic Prediction in EPON

    Directory of Open Access Journals (Sweden)

    Ziyi Fu

    2012-10-01

    Full Text Available According to the upstream TDM in the system of Ethernet passive optical network (EPON, this paper proposes a novel dynamic bandwidth allocation algorithm which supports the mechanism with correction-based the multiple services estimation. To improve the real-time performance of the bandwidth allocation, this algorithm forecasts the traffic of high priority services, and then pre-allocate bandwidth for various priority services is corrected according to Gaussian distribution characteristics, which will make traffic prediction closer to the real traffic. The simulation results show that proposed algorithm is better than the existing DBA algorithm. Not only can it meet the delay requirement of high priority services, but also control the delay abnormity of low priority services. In addition, with rectification scheme, it obviously improves the bandwidth utilization.

  9. Transmission Bandwidth Expansion of SI-POF Using WDM-Pulse-Position Modulations

    Institute of Scientific and Technical Information of China (English)

    Katsumi; Takano; Eiji; Matsumoto; Kiyoshi; Nakagawa

    2003-01-01

    WDM-Pulse-position modulation technique in SI-POF transmission is proposed to overcome the limitation from mode dispersion. It can expand the flat transmission bandwidth to 80MHz with 100m-fiber length.

  10. A 750MHz and a 8GHz High Bandwidth Digital FFT Spectrometer Project

    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...

  11. Stimulated Brillouin scattering gain bandwidth reduction and applications in microwave photonics and optical signal processing

    Science.gov (United States)

    Preussler, Stefan; Schneider, Thomas

    2016-03-01

    Stimulated Brillouin scattering (SBS) is one of the most dominant nonlinear effects in standard single-mode fibers and its unique spectral characteristics, especially the narrow bandwidth, enable many different applications. Most of the applications would benefit from a narrower bandwidth. Different methods for the bandwidth reduction of SBS in optical fibers are presented and discussed. A bandwidth reduction down to 17% of the natural gain can be achieved by the superposition of the gain with two losses or the utilization of a multistage system. Furthermore, applications in the field of microwave photonics and optical signal processing like high-resolution spectroscopy of communication signals, the storage of optical data packets as well as the processing of frequency combs including generation of millimeter waves and ideal sinc-shaped Nyquist pulses are presented.

  12. New scintillators for fiber optics: system sensitivity and bandwidth as a function of fiber length

    International Nuclear Information System (INIS)

    Long-wavelength liquid scintillators have been developed for fiber-optic plasma-diagnostic experiments. Relative system sensitivity and bandwidth data as a function of fiber length for several scintillator systems will be presented

  13. 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. PMID:23988981

  14. Spectra power and bandwidth of fiber Bragg grating under influence of gradient strain

    Science.gov (United States)

    Liu, Qinpeng; Qiao, Xueguang; Jia, Zhen'an; Fu, Haiwei

    2016-09-01

    The reflective spectrum power and the bandwidth of the fiber Bragg grating (FBG) under gradient strain are researched and experimentally demonstrated. The gradient strain is applied on the FBG, which can induce FBG bandwidth broadening, resulting in the variation of reflective power. Based on the coupled-mode theory and transfer matrix method, the segmental linear relationship between the gradient strain, the reflective power, and the bandwidth is simulated and analyzed, and the influence of the FBG length on the reflective spectrum is analyzed. In the experiment, the strict gradient stain device is designed; the experimental results indicate that the reflective optic power and the bandwidth of the FBG under gradient stain are concerned with the length of the FBG. Experimental results are well consistent with the theoretical analysis, which have important guiding significance in the FBG dynamic sensing.

  15. A novel weighed cooperative bandwidth spectrum sensing for spectrum occupancy of cognitive radio network

    Institute of Scientific and Technical Information of China (English)

    刘鑫; 陈琨奇; 闫钧华

    2016-01-01

    In cognitive radio network (CRN), a secondary user (SU) may utilize the spectrum resource of the primary user (PU) and avoid causing harmful interference to the primary network (PN) via spectrum sensing. In the traditional time spectrum sensing, the SU cannot detect the PU’s presence during its transmission, thus increasing interference to the PN. In this work, a novel weighed cooperative bandwidth spectrum sensing method is proposed, which allows multiple SUs to use part of the bandwidth to perform cooperative spectrum sensing throughout the whole frame in order to detect the PU’s reappearance in time. The SU’s spectrum efficiency is maximized by jointly optimizing sensing bandwidth proportion, number of cooperative SUs and detection probability, subject to the constraints on the SU’s interference and the false alarm probability. Simulation results show significant decrease on the interference and improvement on the spectrum efficiency using the proposed weighed cooperative bandwidth spectrum sensing method.

  16. Design, Implementation and Evaluation of ICMP-Based Available Network Bandwidth Measurement Based on IMTCP

    Directory of Open Access Journals (Sweden)

    Hiroyuki Hisamatsu

    2014-06-01

    Full Text Available We propose a method to measure available network bandwidth using the Internet Control Message Protocol (ICMP. The recently proposed ImTCP technique uses Transmission Control Protocol (TCP data packets and the corresponding acknowledgement responses to measure the available bandwidth between sender and receiver. Since ImTCP needs to change the sender’s TCP implementation, it needs modifications to sender’s operating system kernel. Moreover, ImTCP cannot measure available bandwidth accurately if the receiver sends delayed acknowledgments. These problems stem from the use of TCP. In this paper, we discuss an ICMP-based method that overcomes these limitations. We evaluate the performance of the proposed method in an experiment al network and show that it generates less measurement traffic and requires less time for band width measurement than PathLoad. We also show that proposed method can measure the available bandwidtheven if the bandwidth changes during measurement.

  17. Continuous-wave non-classical light with GHz squeezing bandwidth

    CERN Document Server

    Ast, Stefan; Mehmet, Moritz; Steinlechner, Sebastian; Eberle, Tobias; Schnabel, Roman

    2012-01-01

    Squeezed states can be employed for entanglement-based continuous-variable quantum key distribution, where the secure key rate is proportional to the bandwidth of the squeezing. We produced a non-classical continuous-wave laser field at the telecommunication wavelength of 1550 nm, which showed squeezing over a bandwidth of more than 2 GHz. The experimental setup used parametric down-conversion via a periodically poled potassium titanyl phosphate crystal (PPKTP). We did not use any resonant enhancement for the funda- mental wavelength, which should in principle allow a production of squeezed light over the full phase-matching bandwidth of several nanometers. We measured the squeezing to be up to 0.3 dB below the vacuum noise from 50 MHz to 2 GHz limited by the measuring bandwidth of the homodyne detector. The squeezing strength was possibly limited by thermal lensing inside the non-linear crystal.

  18. Issues of shared responsibility before the International Court of Justice

    OpenAIRE

    Nollkaemper, Andre

    2012-01-01

    An increasing number of situations where international responsibility of states is engaged, involve wrongful acts committed by two or more states. Examples of such situations of shared responsibility can be found in the context of multinational military operations, extra-territorial migration policies, or acts that contribute to global environmental problems. The principles applicable to cases of shared responsibility are not well developed. In order to lay a foundation for further study on t...

  19. Adaptive High-Bandwidth Digitally Controlled Buck Converter with Improved Line and Load Transient Response

    OpenAIRE

    Lee, ATL; Sin, JKO; Chan, PCH

    2014-01-01

    Digitally controlled switching converter suffers from bandwidth limitation because of the additional phase delay in the digital feedback control loop. In order to overcome the bandwidth limitation without using a high sampling rate, this paper presents an adaptive third-order digital controller for regulating a voltage-mode buck converter with a modest 2x oversampling ratio. The phase lag due to the ADC conversion time delay is virtually compensated by providing an early estimation of the err...

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

    International Nuclear Information System (INIS)

    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.

  1. A Novel Bandwidth Efficient Transmit Diversity Scheme Based on Water-filling

    Institute of Scientific and Technical Information of China (English)

    SHENCong; DAILin; ZHOUShidong; YAOYan

    2004-01-01

    In this paper we propose a novel bandwidth efficient transmit diversity scheme based on layered space-time architecture, in which Channel state information (CSI) is fully utilized to maximize channel capacity according to water-filling principle. It is shown that compared with V-BLAST, this new scheme can maintain the same high bandwidth efficiency, but achieve much better performance thanks to more effective transmission power allocation and diversity gain.

  2. Experimental Demonstration of a Bandwidth Scalable LAN Emulation over EPON Employing OFDMA

    DEFF Research Database (Denmark)

    Deng, Lei; Zhao, Ying; Yu, Xianbin;

    2011-01-01

    We propose a novel EPON system supporting bandwidth scalable local area network emulation by using orthogonal frequency division multiplexing access technology. Added to the EPON traffic, 250Mbps and 500Mbps OFDM LAN traffics are experimentally emulated.......We propose a novel EPON system supporting bandwidth scalable local area network emulation by using orthogonal frequency division multiplexing access technology. Added to the EPON traffic, 250Mbps and 500Mbps OFDM LAN traffics are experimentally emulated....

  3. Optimal bandwidth scheduling of networked control systems (NCSs) in accordance with jitter

    Institute of Scientific and Technical Information of China (English)

    BAI Tao; WU Zhi-ming; YANG Gen-ke

    2005-01-01

    Network-induced delay and jitter are key factors causing performance degradation and instability of NCSs (networked control systems). The relationships between the sampling periods of the control loops, network-induced delay and jitter were studied aimed at token-type networks. A jitter-dependent optimal bandwidth scheduling algorithm for NCSs is proposed, which tries to achieve a tradeoffbetween bandwidth occupancy and system performance. Simulation tests proved the effectiveness of this optimal scheduling algorithm.

  4. Netest: A Tool to Measure the Maximum Burst Size, Available Bandwidth and Achievable Throughput

    OpenAIRE

    Jin, Guojun; Tierney, Brian

    2003-01-01

    Distinguishing available bandwidth and achievable throughput is essential for improving network applications' performance. Achiveable throughput is the throughput considering a number of factors such as network protocol, host speed, network path, and TCP buffer space, where as available bandwidth only considers the network path. Without understanding this difference, trying to improve network applications' performance is like "blind men feeling the elephant" [4]. In this paper, we defin...

  5. Transmission Bandwidth Tunability of a Liquid-Filled Photonic Bandgap Fiber

    Institute of Scientific and Technical Information of China (English)

    ZOU Bing; LIU Yan-Ge; DU Jiang-Sing; WANG Zhi; HAN Ting-Ting; XU Jian-Bo; LI Yuan; LIU Bo

    2009-01-01

    @@ A temperature tunable photonic bandgap tiber (PBGF) is demonstrated by an index-guiding photonic crystal fiber filled with high-index liquid. The temperature tunable characteristics of the fiber axe experimentally and numerically investigated. Compression of transmission bandwidth of the PBGF is demonstrated by changing the temperature of part of the fiber. The tunable transmission bandwidth with a range of 250 nm is achieved by changing the temperature from 30℃ to 90℃.

  6. Bandwidth comparison of photonic crystal fibers and conventional single mode fibers

    DEFF Research Database (Denmark)

    Nielsen, Martin Dybendal; Folkenberg, Jacob Riis; Mortensen, Niels Asger;

    2004-01-01

    We experimentally compare the optical bandwidth of a conventional single-mode fiber (SMF) with 3 different photonic crystal fibers (PCF) all optimized for visible applications. The spectral attenuation, single-turn bend loss, and mode-field diameters (MFD) are measured and the PCF is found to have...... a significantly larger bandwidth than the SMF for an identical MFD. It is shown how this advantage can be utilized for realizing a larger MFD for the PCF while maintaining a bending resistant fiber....

  7. Comparison of steering angle and bandwidth for various phased array antenna concepts

    Science.gov (United States)

    Bonjour, Romain; Singleton, Matthew; Leuchtmann, Pascal; Leuthold, Juerg

    2016-08-01

    In this paper we compare different integratable ultra-fast tunable true-time delay concepts with respect to their performances in a phased array system. The performances of the schemes are assessed with respect to the supported range, i.e. the range within which beam steering for a given fractional bandwidth can be achieved with a gain flatness better than 3 dB. We also compare the array gain as of function of steering angle and fractional bandwidth.

  8. Employee Share Ownership in Australia: Theory, Evidence, Current Practice and Regulation

    OpenAIRE

    Landau, Ingrid; Mitchell, Richard; O'Connell, Ann; Ramsey, Ian

    2007-01-01

    Since at least the 1970s, employee share ownership has enjoyed bipartisan support in Australia. Despite broad and sustained public policy interest in employee share ownership, Australian literature on the subject remains scarce. There has also been very little in the way of comprehensive analysis of the regulatory framework. This paper provides an overview of employee share ownership from an Australian perspective. It begins by reviewing the literature on broad-based employee share ownership ...

  9. Revenue-sharing analysis in the mobile value-added services

    Institute of Scientific and Technical Information of China (English)

    LIU Bing; TANG Shou-lian

    2006-01-01

    This article provides a framework e within which the revenue-sharing in mobile value-added services can be analyzed.It shows that the revenue-sharing ratio between a network operator and a content provider (CP) has no significant effect on prices, market shares or social welfare in the case of nonstandardization. This implies that the revenue-sharing ratio cannot be used as a policy variable.

  10. The Minimum Bandwidth of Narrowband Spikes in Solar Flare Decimetric Radio Waves

    CERN Document Server

    Messmer, P; Messmer, Peter; Benz, Arnold O.

    1999-01-01

    The minimum and the mean bandwidth of individual narrowband spikes in two events in decimetric radio waves is determined by means of multi-resolution analysis. Spikes of a few tens of millisecond duration occur at decimetric/microwave wavelength in the particle acceleration phase of solar flares. A first method determines the dominant spike bandwidth scale based on their scalegram, the mean squared wavelet coefficient at each frequency scale. This allows to measure the scale bandwidth independently of heuristic spike selection criteria, e.g. manual selection. The major drawback is a low resolution in the bandwidth. To overcome this uncertainty, a feature detection algorithm and a criterion for spike shape in the time-frequency plane is applied to locate the spikes. In that case, the bandwidth is measured by fitting an assumed spike profile into the denoised data. The smallest FWHM bandwidth of spikes was found at 0.17 % and 0.41 % of the center frequency in the two events. Knowing the shortest relevant bandwi...

  11. Accounting for filter bandwidth improves the quantitative accuracy of bioluminescence tomography

    Science.gov (United States)

    Taylor, Shelley L.; Mason, Suzannah K. G.; Glinton, Sophie L.; Cobbold, Mark; Dehghani, Hamid

    2015-09-01

    Bioluminescence imaging is a noninvasive technique whereby surface weighted images of luminescent probes within animals are used to characterize cell count and function. Traditionally, data are collected over the entire emission spectrum of the source using no filters and are used to evaluate cell count/function over the entire spectrum. Alternatively, multispectral data over several wavelengths can be incorporated to perform tomographic reconstruction of source location and intensity. However, bandpass filters used for multispectral data acquisition have a specific bandwidth, which is ignored in the reconstruction. In this work, ignoring the bandwidth is shown to introduce a dependence of the recovered source intensity on the bandwidth of the filters. A method of accounting for the bandwidth of filters used during multispectral data acquisition is presented and its efficacy in increasing the quantitative accuracy of bioluminescence tomography is demonstrated through simulation and experiment. It is demonstrated that while using filters with a large bandwidth can dramatically decrease the data acquisition time, if not accounted for, errors of up to 200% in quantitative accuracy are introduced in two-dimensional planar imaging, even after normalization. For tomographic imaging, the use of this method to account for filter bandwidth dramatically improves the quantitative accuracy.

  12. Application of high-bandwidth linear adjustment branch in switching power supply

    International Nuclear Information System (INIS)

    Background: China Spallation Neutron Source (CSNS) is a medium-sized high-flux spallation neutron source under construction with Rapid Cycling Synchrotron (RCS) of 25 Hz as the main accelerator. The RF cavity of RCS requires that the output bandwidth of bias current source is greater than 10 kHz, while the maximum output bandwidth of switching power supply prototype is only 3 kHz, which can't meet the design requirements. Purpose: In order to improve the output bandwidth of the entire system, the linear adjustment branch is added to the switching power supply in a formal bias current source. Methods: This paper introduced the principle of selecting the linear adjustment branch, analyzed the advantages and disadvantages of the different methods and showed the test results of output bandwidth after adding linear adjustment branch. Results: The output bandwidth of the system after adding linear adjustment branch is greater than 10 kHz. Conclusion: Linear adjustment branch can compensate for the output bandwidth of the switching power supply. (authors)

  13. On bandwidth characteristics of tuning fork micro-gyroscope with mechanically coupled sense mode.

    Science.gov (United States)

    Ni, Yunfang; Li, Hongsheng; Huang, Libin; Ding, Xukai; Wang, Haipeng

    2014-01-01

    The bandwidth characteristics of a tuning fork micro-gyroscope with mechanically coupled sense mode were investigated in this paper to provide some references for mechanical bandwidth design. The concept of sense mode mechanical coupling is introduced first. Theoretical frequency response analyses were then carried out on the mechanical part of the gyroscope. Equations representing the relationships between the differential output signal and the frequency of the input angular rate were deduced in full frequency range and further simplified in low frequency range. Based on these equations, bandwidth characteristics under ideal and non-ideal conditions are discussed. Analytical results show that under ideal conditions, the bandwidth characteristics of a tuning fork micro-gyroscope are similar to those of a single mass micro-gyroscope, but under non-ideal conditions, especially when sense mass and/or stiffness are asymmetric, the bandwidth characteristics would be quite different because the in-phase mode would participate in the anti-phase vibration response. Experimental verifications were carried out on two micro-gyroscope prototypes designed in our laboratory. The deduced equations and analytical results can be used in guiding the mechanical bandwidth design of tuning fork micro-gyroscopes with mechanically coupled sense mode.

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

    Science.gov (United States)

    Li, X.; Zheng, C.; Zhou, Y.; Kubota, H.; Yuasa, S.; Pong, Philip W. T.

    2016-06-01

    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.

  16. An improved scheduled traffic model utilizing bandwidth splitting in elastic optical networks

    Science.gov (United States)

    Vyas, Upama; Prakash, Shashi

    2016-07-01

    The surge of traffic in today's networks gave birth to elastic optical networking paradigm. In this paper, first we propose to use the scheduled traffic model (STM) in elastic optical networks (EONs) to ensure guaranteed availability of resources to demands which enter into the network with a predetermined start and end times. In optical networks, such demands are referred to as scheduled lightpath demands (SLDs). To increase the amount of bandwidth accepted in network, next we introduce a time aware routing and spectrum assignment (TA-RSA) approach. We observed that provisioning of bulky SLDs has become more challenging in EONs due to enforcement of RSA constraints. To address this challenge, we improve the proposed STM and designed three heuristics for its implementation in EONs. In this work, we collectively refer to these heuristics as bandwidth segmented RSA (BSRSA). The improved STM (iSTM) allows splitting of SLDs in bandwidth dimension by utilizing the knowledge of attributes viz. demand holding time, overlapping in time and bandwidth requested by SLDs. Our numerical results show that BSRSA consistently outperformed over TA-RSA under all distinctive experimental cases that we considered and achieved fairness in serving heterogeneous bandwidth SLDs. The impact of splitting on the number and capacity of transponders at nodes is also gauged. It is observed that ingenious splitting of demands increases the number of resources (on links and nodes) used, and their utilization, leading to an increase in bandwidth accepted in the network.

  17. On Bandwidth Characteristics of Tuning Fork Micro-Gyroscope with Mechanically Coupled Sense Mode

    Directory of Open Access Journals (Sweden)

    Yunfang Ni

    2014-07-01

    Full Text Available The bandwidth characteristics of a tuning fork micro-gyroscope with mechanically coupled sense mode were investigated in this paper to provide some references for mechanical bandwidth design. The concept of sense mode mechanical coupling is introduced first. Theoretical frequency response analyses were then carried out on the mechanical part of the gyroscope. Equations representing the relationships between the differential output signal and the frequency of the input angular rate were deduced in full frequency range and further simplified in low frequency range. Based on these equations, bandwidth characteristics under ideal and non-ideal conditions are discussed. Analytical results show that under ideal conditions, the bandwidth characteristics of a tuning fork micro-gyroscope are similar to those of a single mass micro-gyroscope, but under non-ideal conditions, especially when sense mass and/or stiffness are asymmetric, the bandwidth characteristics would be quite different because the in-phase mode would participate in the anti-phase vibration response. Experimental verifications were carried out on two micro-gyroscope prototypes designed in our laboratory. The deduced equations and analytical results can be used in guiding the mechanical bandwidth design of tuning fork micro-gyroscopes with mechanically coupled sense mode.

  18. Spectrum Assignment with Non-Deterministic Bandwidth of Spectrum Holein Cognitive Radio Networks

    Directory of Open Access Journals (Sweden)

    Huang Jie

    2016-01-01

    Full Text Available The spectrum allocation for cognitive radio networks (CRNs has received considerable studies under the assumption that the bandwidth of spectrum holes is static. However, in practice, the bandwidth of spectrum holes is time-varied due to primary user/secondary user (PU/SU activity and mobility, which result in non-determinacy. This paper studies the spectrum allocation for CRNs with non-deterministic bandwidth of spectrum holes. We present a novel probability density function (PDF model through order statistic to describe the non-deterministic bandwidth of spectrum holes and provide a bound to approximate it. After that, a statistical spectrum allocation model based on stochastic multiple knapsack problem (MKP is established for spectrum allocation with non-deterministic bandwidth of spectrum holes. To reduce the computational complexity, we transform this stochastic programming probleminto a constant MKP though exploiting the properties of cumulative distribution function (CDF, which can be solved via MTHG algorithm by using auxiliary variable. Simulation results illustrate that the proposed statistical spectrum allocation algorithm can achieve better performances compared to the existing algorithms when the bandwidth of spectrum holes istime-varied.

  19. 48 CFR 1341.201 - Policy.

    Science.gov (United States)

    2010-10-01

    ... CONTRACTING ACQUISITION OF UTILITY SERVICES Acquiring Utility Services 1341.201 Policy. The designee authorized to enter into a contract pursuant to 42 U.S.C. 8287 (regarding shared energy savings,...

  20. Energy conservation. Federal shared energy savings contracting

    International Nuclear Information System (INIS)

    A number of impediments have discouraged federal agencies from using shared energy savings contracts. As of November 30, 1988, only two federal agencies - the U.S. Postal Service (USPS) and the Department of the Army -had awarded such contracts even though they can yield significant energy and cost savings. The three major impediments we identified were uncertainty about the applicability of a particular procurement policy and practice, lack of management incentives, and difficulty in measuring energy and cost savings. To address the first impediment, the Department of Energy (DOE) developed a manual on shared energy savings contracting. The second impediment was addressed when the 100th Congress authorized incentives for federal agencies to enter into shared savings contracts. DOE addressed the third impediment by developing a methodology for calculating energy consumption and cost savings. However, because of differing methodological preferences, this issue will need to be addressed on a contract-by-contract basis. Some state governments and private sector firms are using performance contracts to reduce energy costs in their buildings and facilities. We were able to identify six states that were using performance contracts. Five have established programs, and all six states have projects under contract. The seven energy service companies we contacted indicated interest in federal shared energy savings contracting

  1. Sharing Some Thoughts on Weitzman's The Share Economy

    OpenAIRE

    Russell Cooper

    1985-01-01

    This paper explores the positive and normative aspects of share contracts. In particular, the paper explores the properties of a share system as advanced by Martin Weitzman in The Share Economy.The model employed highlights a "macroeconomic externality" created in a multi-sector economy with imperfect competition. The introduction of share contracts is shown to influence the comparative static properties of the model economy and in some cases to lead to Pareto superior outcomes.

  2. Share the spare : modelling consumer behaviour in the sharing economy

    OpenAIRE

    Østbye, Thea Sørvig

    2015-01-01

    The sharing economy allows consumers to share spare goods and resources through online platforms, using technology to reduce the transaction costs and efficiently match supply with demand on a global scale. Reflecting a change in consumption patterns, the sharing economy is disrupting existing industries, steadily replacing ownership with access. To explain observed consumer behaviour in the sharing economy, we develop an economic model that describes consumers’ choice of providing and rec...

  3. Fixed Access Network Sharing

    Science.gov (United States)

    Cornaglia, Bruno; Young, Gavin; Marchetta, Antonio

    2015-12-01

    Fixed broadband network deployments are moving inexorably to the use of Next Generation Access (NGA) technologies and architectures. These NGA deployments involve building fiber infrastructure increasingly closer to the customer in order to increase the proportion of fiber on the customer's access connection (Fibre-To-The-Home/Building/Door/Cabinet… i.e. FTTx). This increases the speed of services that can be sold and will be increasingly required to meet the demands of new generations of video services as we evolve from HDTV to "Ultra-HD TV" with 4k and 8k lines of video resolution. However, building fiber access networks is a costly endeavor. It requires significant capital in order to cover any significant geographic coverage. Hence many companies are forming partnerships and joint-ventures in order to share the NGA network construction costs. One form of such a partnership involves two companies agreeing to each build to cover a certain geographic area and then "cross-selling" NGA products to each other in order to access customers within their partner's footprint (NGA coverage area). This is tantamount to a bi-lateral wholesale partnership. The concept of Fixed Access Network Sharing (FANS) is to address the possibility of sharing infrastructure with a high degree of flexibility for all network operators involved. By providing greater configuration control over the NGA network infrastructure, the service provider has a greater ability to define the network and hence to define their product capabilities at the active layer. This gives the service provider partners greater product development autonomy plus the ability to differentiate from each other at the active network layer.

  4. Shared clinical decision making

    Science.gov (United States)

    AlHaqwi, Ali I.; AlDrees, Turki M.; AlRumayyan, Ahmad; AlFarhan, Ali I.; Alotaibi, Sultan S.; AlKhashan, Hesham I.; Badri, Motasim

    2015-01-01

    Objectives: To determine preferences of patients regarding their involvement in the clinical decision making process and the related factors in Saudi Arabia. Methods: This cross-sectional study was conducted in a major family practice center in King Abdulaziz Medical City, Riyadh, Saudi Arabia, between March and May 2012. Multivariate multinomial regression models were fitted to identify factors associated with patients preferences. Results: The study included 236 participants. The most preferred decision-making style was shared decision-making (57%), followed by paternalistic (28%), and informed consumerism (14%). The preference for shared clinical decision making was significantly higher among male patients and those with higher level of education, whereas paternalism was significantly higher among older patients and those with chronic health conditions, and consumerism was significantly higher in younger age groups. In multivariate multinomial regression analysis, compared with the shared group, the consumerism group were more likely to be female [adjusted odds ratio (AOR) =2.87, 95% confidence interval [CI] 1.31-6.27, p=0.008] and non-dyslipidemic (AOR=2.90, 95% CI: 1.03-8.09, p=0.04), and the paternalism group were more likely to be older (AOR=1.03, 95% CI: 1.01-1.05, p=0.04), and female (AOR=2.47, 95% CI: 1.32-4.06, p=0.008). Conclusion: Preferences of patients for involvement in the clinical decision-making varied considerably. In our setting, underlying factors that influence these preferences identified in this study should be considered and tailored individually to achieve optimal treatment outcomes. PMID:26620990

  5. Practices in source code sharing in astrophysics

    CERN Document Server

    Shamir, Lior; Allen, Alice; Berriman, Bruce; Teuben, Peter; Nemiroff, Robert J; Mink, Jessica; Hanisch, Robert J; DuPrie, Kimberly

    2013-01-01

    While software and algorithms have become increasingly important in astronomy, the majority of authors who publish computational astronomy research do not share the source code they develop, making it difficult to replicate and reuse the work. In this paper we discuss the importance of sharing scientific source code with the entire astrophysics community, and propose that journals require authors to make their code publicly available when a paper is published. That is, we suggest that a paper that involves a computer program not be accepted for publication unless the source code becomes publicly available. The adoption of such a policy by editors, editorial boards, and reviewers will improve the ability to replicate scientific results, and will also make the computational astronomy methods more available to other researchers who wish to apply them to their data.

  6. The backstage work of data sharing

    Energy Technology Data Exchange (ETDEWEB)

    Kervin, Karina E. [Univ. of Michigan, Ann Arbor, MI (United States); Cook, Robert B. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Michener, William K. [Univ. of New Mexico, Albuquerque, NM (United States)

    2014-11-09

    Conventional wisdom makes the suggestion that there are benefits to the creation of shared repositories of scientific data. Funding agencies require that the data from sponsored projects be shared publicly, but individual researchers often see little personal benefit to offset the work of creating easily sharable data. These conflicting forces have led to the emergence of a new role to support researchers: data managers. This paper identifies key differences between the socio-technical context of data managers and other "human infrastructure" roles articulated previously in Computer Supported Cooperative Work (CSCW) literature and summarizes the challenges that data managers face when accepting data for archival and reuse. Finally, while data managers' work is critical for advancing science and science policy, their work is often invisible and under-appreciated since it takes place behind the scenes.

  7. Game theory and shared water resource management

    Science.gov (United States)

    Najafi, H.; Bagheri, A.

    2011-12-01

    Based on the "New Periodic Table" (NPT) of 2×2 order games by Robinson and Goforth (2005) this study explores all possible game structures, representing a conflict over a shared water resource between two countries. Each game is analyzed to find the possible outcomes (equilibria), Pareto-optimal outcomes, as well as dominant strategies of the players. It is explained why in practice, parties may behave in a way, resulting in Pareto-inferior outcomes and how parties may change their behavior with the structural changes of the game. Further, how parties may develop cooperative solutions through negotiations and involvement of third parties. This work provides useful policy insights into shared water resource problems and identifies the likely structure of such games in the future and the evolution path of the games.

  8. A method for a small web site to add some sharing features

    OpenAIRE

    Madurga Martín-Serrano, Juan Lucas

    2008-01-01

    The aim of this diploma work is to compare and evaluate different methods to enable small web sites to make available videos which will be shared the users. Storage and bandwidth problems of small web sites are taken into account. The requirements of the system were defined as: configurable, feasible, easy use and easy to integrate. Existing solutions and different implementation alternatives are analyzed. With a tool based upon a CMS, using recordings residing on powerful dedicated video pro...

  9. RF/optical shared aperture for high availability wideband communication RF/FSO links

    Energy Technology Data Exchange (ETDEWEB)

    Ruggiero, Anthony J; Pao, Hsueh-yuan; Sargis, Paul

    2014-04-29

    An RF/Optical shared aperture is capable of transmitting and receiving optical signals and RF signals simultaneously. This technology enables compact wide bandwidth communications systems with 100% availability in clear air turbulence, rain and fog. The functions of an optical telescope and an RF reflector antenna are combined into a single compact package by installing an RF feed at either of the focal points of a modified Gregorian telescope.

  10. RF/optical shared aperture for high availability wideband communication RF/FSO links

    Energy Technology Data Exchange (ETDEWEB)

    Ruggiero, Anthony J; Pao, Hsueh-yuan; Sargis, Paul

    2015-03-24

    An RF/Optical shared aperture is capable of transmitting and receiving optical signals and RF signals simultaneously. This technology enables compact wide bandwidth communications systems with 100% availability in clear air turbulence, rain and fog. The functions of an optical telescope and an RF reflector antenna are combined into a single compact package by installing an RF feed at either of the focal points of a modified Gregorian telescope.

  11. A Prognostic Segment-Based Sharing Recovery Mechanism%一种基于分段共享的预测式错误恢复机制

    Institute of Scientific and Technical Information of China (English)

    徐洁; 郭星廷; 夏梦芹

    2003-01-01

    In MPLS/GMPLS networks, a range of restoration schemes will be required to support trade-offs between service interruption time and network resource utilization. Although, the tradition protectionbased and reservation-based recovery schemes exist some merits,but they can not provide a good trade-offs. In this paper,we propose a Prognostic Segment-based Sharing Recovery Mechanism(PSSRM)for restoration of connection over shared bandwidth in a fully distributed GMPLS architecture. PSSRM can use QoS constraints such as bandwidth and recovery time to obtain the good trade-offs of recovery time and resource efficiency.

  12. Sharing Keynote Slideshows

    CERN Document Server

    Clark, Josh

    2010-01-01

    Slideshows have come a long way since overhead projectors were your only option. You can show share your ideas with the world via email, DVD, PDF, YouTube, iPhone, or kiosk. Once your show is polished to perfection, this thorough, accessible guide shows you how to export and deliver it all possible ways-even as a PowerPoint file, QuickTime movie, or web site. As a bonus, you'll find advice on setting up your equipment and delivering an effective presentation.

  13. Anti-Sharing

    OpenAIRE

    Kirstein, Roland; Cooter, Robert

    2005-01-01

    The paper proposes a mechanism that may implement first-best effort in simultaneous teams. Within the framework of this mechanism, each team members is obliged to make a fixed, non-contingent payment, and chooses his individual effort. After the output is produced, each team member receives a gross payment that equals the actual team output. We demonstrate that a Nash equilibrium exists in which each team member chooses first-best effort. We call this mechanism ?Anti-Sharing? since it solves ...

  14. Renewable energy burden sharing. REBUS. Manual for the REBUS model

    International Nuclear Information System (INIS)

    The REBUS model quantifies the effects of implementing renewable electricity targets, and the impact of introducing burden sharing systems within the EU, such as a Tradable Green Certificate (TGC) system. Results are obtained for a range of so-called burden sharing options that reflect differences in economic, social and geographical possibilities to increase the share of renewables in individual geographical regions. The REBUS model furthermore analyses the impact of other supporting mechanisms for renewable electricity on the effects of a burden sharing mechanism. With this, the REBUS model is a framework that can be used for quantifying the most equitable distribution of costs (burden sharing) and compare consequences of different equity criteria. Therewith it aims to support key policy makers, industrial stakeholders and consumers in making decisions on the possibilities to achieve their joint RES-E targets

  15. Shared consultant physician posts.

    LENUS (Irish Health Repository)

    Cooke, J

    2012-01-31

    Our aim was to assess the acceptability and cost-efficiency of shared consultancy posts. Two consultant physicians worked alternate fortnights for a period of twelve months. Questionnaires were distributed to general practitioners, nurses, consultants and junior doctors affected by the arrangement. Patients or their next of kin were contacted by telephone. 1\\/17 of consultants described the experience as negative. 14\\/19 junior doctors reported a positive experience. 11 felt that training had been improved while 2 felt that it had been adversely affected. 17\\/17 GPs were satisfied with the arrangement. 1\\/86 nurses surveyed reported a negative experience. 1\\/48 patients were unhappy with the arrangement. An extra 2.2 (p<0.001) patients were seen per clinic. Length of stay was shortened by 2.49 days (p<0.001). A saving of 69,212 was made due to decreased locum requirements. We present data suggesting structured shared consultancy posts can be broadly acceptable and cost efficient in Ireland.

  16. VHA Data Sharing Agreement Repository

    Data.gov (United States)

    Department of Veterans Affairs — The VHA Data Sharing Agreement Repository serves as a centralized location to collect and report on agreements that share VHA data with entities outside of VA. It...

  17. BOREL'S DIRECTIONS AND SHARED VALUES

    Institute of Scientific and Technical Information of China (English)

    Qingcai ZHANG

    2013-01-01

    In this article,we study the problems of Borel's directions of meromorphic functions concerning shared values and prove that if two meromorphic functions of infinite order share three distinct values,their Borel's directions are same.

  18. Reach on Policy-based Transmition Control Technology in MPLS Communication Network

    OpenAIRE

    Jingyang Wang; Yu Hua; Min Huang; Liwei Guo; Wanzhen Zhou

    2012-01-01

    With the increasing variety of service types supported by the communication network, more and more requirements for bandwidth occurred. Different types of services have different characteristics in the aspects of importance, bandwidth demand, time-sensitive and so on. Customers’s requirements for the controllability and manageability of communication network are more and more demanding. The paper researches on policy-based transmition control technology in MPLS controllable and manageab...

  19. Competition in the sharing economy

    OpenAIRE

    Demary, Vera

    2015-01-01

    Sharing goods, services or knowledge is at the center of the so-called Sharing Economy. Businesses are usually based on online platforms that match demand and supply which is in many cases, but not always provided by individuals. Sharing Economy companies typically compete with traditional companies in many different markets. The main challenge of this type of competition currently is the application of the existing regulation. While incumbent firms adhere to this, Sharing Economy companies o...

  20. Forecasting Dynamic Market Share Relationships

    OpenAIRE

    Terui, Nobuhiko

    1997-01-01

    In market share analysis, it is well recognized that we have often inadmissible predicted marketshare, which means that some of predictors take the values outside the range [0, 1] and the totalsum of predicted shares is not always one, so called "logical inconsistency". In this article, basedon Bayesian VAR model, I propose a dynamic market share model with logical consistency. Theproposed method makes it possible to forecast not only the values of market share by themselves,but also various ...

  1. Transport policy

    OpenAIRE

    1980-01-01

    Transport is a fundamental component of all modern economies. Transport Policy presents a wide ranging collection of previously published articles which aim to provide the reader with an understanding of the main elements of transport policy.

  2. Model Sharing and Collaboration using HydroShare

    Science.gov (United States)

    Goodall, J. L.; Morsy, M. M.; Castronova, A. M.; Miles, B.; Merwade, V.; Tarboton, D. G.

    2015-12-01

    HydroShare is a web-based system funded by the National Science Foundation (NSF) for sharing hydrologic data and models as resources. Resources in HydroShare can either be assigned a generic type, meaning the resource only has Dublin Core metadata properties, or one of a growing number of specific resource types with enhanced metadata profiles defined by the HydroShare development team. Examples of specific resource types in the current release of HydroShare (http://www.hydroshare.org) include time series, geographic raster, Multidimensional (NetCDF), model program, and model instance. Here we describe research and development efforts in HydroShare project for model-related resources types. This work has included efforts to define metadata profiles for common modeling resources, execute models directly through the HydroShare user interface using Docker containers, and interoperate with the 3rd party application SWATShare for model execution and visualization. These examples demonstrate the benefit of HydroShare to support model sharing and address collaborative problems involving modeling. The presentation will conclude with plans for future modeling-related development in HydroShare including supporting the publication of workflow resources, enhanced metadata for additional hydrologic models, and linking model resources with other resources in HydroShare to capture model provenance.

  3. Job-Sharing the Principalship.

    Science.gov (United States)

    Brown, Shelley; Feltham, Wendy

    1997-01-01

    The coprincipals of a California elementary school share their ideas for building a successful job-sharing partnership. They suggest it is important to find the right partner, develop and present a job-sharing proposal, establish systems of communication with each other, evaluate one's progress, focus on the principalship, and provide leadership…

  4. Trade Policy

    OpenAIRE

    Murray Gibbs

    2014-01-01

    In an otherwise insightful and thoughtful article, Sebastian Pfotenhauer (Trade Policy Is Science Policy,” Issues, Fall 2013) might better have entitled his contribution “Trade Policy Needs to Be Reconciled with Science Policy.” The North American Free Trade Agreement (NAFTA) and the agreements administered by the World Trade Organization, particularly the General Agreement on Tariffs and Trade (GATT) and the Technical Barriers to Trade (TBT), were adopted to promote international trade and i...

  5. Sharing Residual Liability

    DEFF Research Database (Denmark)

    Carbonara, Emanuela; Guerra, Alice; Parisi, Francesco

    2016-01-01

    Economic models of tort law evaluate the efficiency of liability rules in terms of care and activity levels. A liability regime is optimal when it creates incentives to maximize the value of risky activities net of accident and precaution costs. The allocation of primary and residual liability...... allows policy makers to induce parties to undertake socially desirable care and activity levels. Traditionally, tort law systems have assigned residual liability either entirely on the tortfeasor or entirely on the victim. In this paper, we unpack the cheapest-cost-avoider principle to consider...

  6. 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

  7. Distributed Secondary Control for DC Microgrid Applications with Enhanced Current Sharing Accuracy

    DEFF Research Database (Denmark)

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

    2013-01-01

    With the consideration of line resistances in a dc microgrid, the current sharing accuracy is lowered down, since the dc output voltage cannot be exactly the same for different interfacing converters. Meanwhile, the dc bus voltage deviation is involved by using droop control. In this paper......, a distributed secondary control method is proposed. Droop control is employed as the primary control method for load current sharing. Meanwhile, the dc output voltage and current in each module is transferred to the others by the low bandwidth communication (LBC) network. Average voltage and current controllers...

  8. Policy Problematization

    Science.gov (United States)

    Webb, P. Taylor

    2014-01-01

    This article places Michel Foucault's concept of "problematization" in relation to educational policy research. My goal is to examine a key assumption of policy related to "solving problems" through such technologies. I discuss the potential problematization has to alter conceptions of policy research; and, through this…

  9. Time to Shift from Macro- to Micro-Policies

    Science.gov (United States)

    Cho, Dongchul; Shin, Sukha

    2012-01-01

    All of the authors seem to share the perception that one can no longer expect much from macroeconomic policies. The authors of this paper share this opinion, but this should not be interpreted as the skeptical view that macroeconomic policies are ineffective on employment. They saw from the Korea's two crises how contrasting outcomes could result…

  10. SHARED TECHNOLOGY TRANSFER PROGRAM

    Energy Technology Data Exchange (ETDEWEB)

    GRIFFIN, JOHN M. HAUT, RICHARD C.

    2008-03-07

    The program established a collaborative process with domestic industries for the purpose of sharing Navy-developed technology. Private sector businesses were educated so as to increase their awareness of the vast amount of technologies that are available, with an initial focus on technology applications that are related to the Hydrogen, Fuel Cells and Infrastructure Technologies (Hydrogen) Program of the U.S. Department of Energy. Specifically, the project worked to increase industry awareness of the vast technology resources available to them that have been developed with taxpayer funding. NAVSEA-Carderock and the Houston Advanced Research Center teamed with Nicholls State University to catalog NAVSEA-Carderock unclassified technologies, rated the level of readiness of the technologies and established a web based catalog of the technologies. In particular, the catalog contains technology descriptions, including testing summaries and overviews of related presentations.

  11. EU BUDGET – THE POLICY OF SHARING THE CAKE

    Directory of Open Access Journals (Sweden)

    Hella GERTH

    2006-06-01

    Full Text Available This paper discusses the EU budget aiming at casting light on the relationship between political and economic matters and on the importance that they function as a mechanism. Somehow the budget could be compared to a barometer showing the political pressure and the level of integration inside the European Union. Discussing the structure of the budget, where the EU money come from and how are the funds distributed afterwards, and also referring to important moments in the historical development of the European Union’s budget, the paper emphasizes the same idea of financial matters strong related to the political choices. It argues also, by describing the complexity of the budgetary procedure and the importance of financial control, that the budget is an important interplay between actors, is an important balance of power trying to reach equilibrium and efficiency. The paper also reviews the main issues of the present budgetary debates, the positions taken by European actors, counting their losses and gains, and to which extent their choices are more a national concern or following the European interest, aiming at presenting the actual state of the European Union taking into account both the economic and the political integration. The budget being one of the key elements forming the structure of the big edifice, the European Union, it is of great importance when discussing budgetary matters to have in mind the present context as a whole, determined by issues like the failure of the summit for setting a new budgetary framework, or the rejection of the European Constitution by the citizens of two of its founding members. Though, it is important when discussing the budget, economical matters to put them in a political context and also to see them in the present context.

  12. Control Structures and Payout Policy

    NARCIS (Netherlands)

    Renneboog, L.D.R.; Trojanowski, G.

    2005-01-01

    This paper examines the payout policies of UK firms listed on the London Stock Exchange during the 1990s.It complements the existing literature by analyzing the trends in both dividends and total payouts (including share repurchases).In a dynamic panel data regression setting, we relate target payou

  13. Exploiting independent filter bandwidth of human factor cepstral coefficients in automatic speech recognition

    Science.gov (United States)

    Skowronski, Mark D.; Harris, John G.

    2004-09-01

    Mel frequency cepstral coefficients (MFCC) are the most widely used speech features in automatic speech recognition systems, primarily because the coefficients fit well with the assumptions used in hidden Markov models and because of the superior noise robustness of MFCC over alternative feature sets such as linear prediction-based coefficients. The authors have recently introduced human factor cepstral coefficients (HFCC), a modification of MFCC that uses the known relationship between center frequency and critical bandwidth from human psychoacoustics to decouple filter bandwidth from filter spacing. In this work, the authors introduce a variation of HFCC called HFCC-E in which filter bandwidth is linearly scaled in order to investigate the effects of wider filter bandwidth on noise robustness. Experimental results show an increase in signal-to-noise ratio of 7 dB over traditional MFCC algorithms when filter bandwidth increases in HFCC-E. An important attribute of both HFCC and HFCC-E is that the algorithms only differ from MFCC in the filter bank coefficients: increased noise robustness using wider filters is achieved with no additional computational cost.

  14. Improvement on Diversity Gain with Filter Bandwidth Enlargement in Fractional Sampling OFDM Receiver

    Science.gov (United States)

    Shinkai, Toshiya; Nishimura, Haruki; Sanada, Yukitoshi

    A diversity scheme with Fractional Sampling (FS) in an OFDM receiver has been investigated recently. Through FS, it is possible to separate multipath components and obtain diversity gain in OFDM systems. Enlargement of the bandwidth of the total frequency response between transmit and receive baseband filters allows the FS scheme to achieve path diversity. However, the transmit filter has to be designed according to the spectrum mask of the wireless standards such as IEEE802.11a/g to avoid interference to the other communication systems and the frequency response of the composite channel including the transmit and receive filters has often been set to minimal bandwidth to eliminate adjacent channel signals. In order to achieve the maximum signal-to-noise ratio (SNR), the same filter is commonly used in the transmitter and the receiver. In this paper, the trade-off among the SNR deterioration, adjacent channel interference, and the diversity gain due to the enlargement of the bandwidth of the receive filter is investigated. Numerical results from computer simulations indicate that the BER performance with wider bandwidth in the receiver shows better performance than that with the minimal bandwidth for maximizing the SNR in certain conditions.

  15. Movie approximation technique for the implementation of fast bandwidth-smoothing algorithms

    Science.gov (United States)

    Feng, Wu-chi; Lam, Chi C.; Liu, Ming

    1997-12-01

    Bandwidth smoothing algorithms can effectively reduce the network resource requirements for the delivery of compressed video streams. For stored video, a large number of bandwidth smoothing algorithms have been introduced that are optimal under certain constraints but require access to all the frame size data in order to achieve their optimal properties. This constraint, however, can be both resource and computationally expensive, especially for moderately priced set-top-boxes. In this paper, we introduce a movie approximation technique for the representation of the frame sizes of a video, reducing the complexity of the bandwidth smoothing algorithms and the amount of frame data that must be transmitted prior to the start of playback. Our results show that the proposed approximation technique can accurately approximate the frame data with a small number of piece-wise linear segments without affecting the performance measures that the bandwidth soothing algorithms are attempting to achieve by more than 1%. In addition, we show that implementations of this technique can speed up execution times by 100 to 400 times, allowing the bandwidth plan calculation times to be reduced to tens of milliseconds. Evaluation using a compressed full-length motion-JPEG video is provided.

  16. Frequency and bandwidth conversion of single photons in a room-temperature diamond quantum memory

    Science.gov (United States)

    Fisher, Kent A. G.; England, Duncan G.; Maclean, Jean-Philippe W.; Bustard, Philip J.; Resch, Kevin J.; Sussman, Benjamin J.

    2016-04-01

    The spectral manipulation of photons is essential for linking components in a quantum network. Large frequency shifts are needed for conversion between optical and telecommunication frequencies, while smaller shifts are useful for frequency-multiplexing quantum systems, in the same way that wavelength division multiplexing is used in classical communications. Here we demonstrate frequency and bandwidth conversion of single photons in a room-temperature diamond quantum memory. Heralded 723.5 nm photons, with 4.1 nm bandwidth, are stored as optical phonons in the diamond via a Raman transition. Upon retrieval from the diamond memory, the spectral shape of the photons is determined by a tunable read pulse through the reverse Raman transition. We report central frequency tunability over 4.2 times the input bandwidth, and bandwidth modulation between 0.5 and 1.9 times the input bandwidth. Our results demonstrate the potential for diamond, and Raman memories in general, as an integrated platform for photon storage and spectral conversion.

  17. SPDC correlated photon source filtered for narrowed bandwidth using volume Bragg grating

    Science.gov (United States)

    Slattery, Oliver; Kuo, Paulina; Kim, Yong-Su; Ma, Lijun; Tang, Xiao

    2012-10-01

    A Volume Bragg Grating (VBG) can be used to efficiently extract a narrow bandwidth, highly collimated beam from an otherwise broad spectrum beam. We use a VBG to extract a narrow bandwidth of signal spectrum from a broadband Spontaneous Parametric Down-Conversion source to optimally match the narrow detection bandwidth of our idler upconversion detector. Improved coincidence count rates and visibility can be achieved when limiting signal-spectrum detection to the narrow signal bandwidth whose photons are correlated with a narrow idler-spectrum bandwidth that has been selected by the up-conversion detector. We compare coincidence count rate and visibility for when the entire signal spectrum is detected and when the spectrum has been filtered by the VBG. We further relax the collection techniques and show that following the VBG, the coincidence count rate improves with minimal loss in visibility compared to when the entire spectrum is detected. We introduce our initial efforts at using the VBG to further narrow the signal spectrum by placing it inside a multipass cavity. Additionally, we further adapt the single photon level up-conversion spectrometer, previously developed for idler spectrum measurement, to indirectly measure the single photon level signal spectrum. We verify its capability for several different wavelength and linewidth selections.

  18. 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.

  19. Bandwidth Allocation for Wireless Data Dissemination in Multi-Cell Environments Using Optimization Techniques

    Directory of Open Access Journals (Sweden)

    K. Madhavi

    2011-11-01

    Full Text Available Effective data management and resource management are vital to the success of emerging mobile data applications. the allocation of resources such as Bandwidth, buffer in mobile cellular networks becomes an increasingly important issue. In addition, varying mobility and various service class requirements of the present multimedia applications makes it a challenging one. It is mostly realized in the present Third generation (3G and beyond 3G (B3G mobile network system. Hence an effective and efficient utilization of resources such as bandwidth in mobile cellular system using better optimization schemes are needed. This paper investigates the problem of bandwidth allocation for data dissemination in a multicell environment. The performance objective is to minimize the overall expected access latency also addresses the critical issues of resource allocation - in particular about optimization of bandwidth with adaptive Quality of Service (QoS requirements. In order to have optimized bandwidth applications, optimization schemes- Linear Programming (LP.LP methods solve optimization problem having linear objective function and constraints.

  20. Optimization of Inter-network Bandwidth Resources for Large-Scale Data Transmission

    Directory of Open Access Journals (Sweden)

    Mu Zhang

    2014-03-01

    Full Text Available In order to solve problems such as low resources utilization of data center backbone bandwidth and expensive daily expenses caused by the tidal effect in the transition of large-scale network data, the new optimization method of bandwidth resource for bulk data transfer is proposed. This method finishes the bulk data transfer by taking full advantage of the idle channel bandwidth. Firstly, the dynamic idle network bandwidth resource was switched into the static flow network; and then the max-min fair multi-commodity flow model is built on the basis of static network; finally, the iterative technique is used to solve the programming model for getting the maximum transport flows and the corresponding transmission path of bulk data transfer. The simulation method was used to test this optimization project. The results show that the optimization method proposed by the paper can significantly improve the utilization of data center backbone bandwidth resource, and the maximum amount of data transmission and the speed of data transfer have been obviously increased