WorldWideScience

Sample records for bandwidth sharing policy

  1. 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.

  2. 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.

  3. Policy enabled information sharing system

    Science.gov (United States)

    Jorgensen, Craig R.; Nelson, Brian D.; Ratheal, Steve W.

    2014-09-02

    A technique for dynamically sharing information includes executing a sharing policy indicating when to share a data object responsive to the occurrence of an event. The data object is created by formatting a data file to be shared with a receiving entity. The data object includes a file data portion and a sharing metadata portion. The data object is encrypted and then automatically transmitted to the receiving entity upon occurrence of the event. The sharing metadata portion includes metadata characterizing the data file and referenced in connection with the sharing policy to determine when to automatically transmit the data object to the receiving entity.

  4. 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.

  5. 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

  6. 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.

  7. 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...

  8. 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.

  9. 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

  10. 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…

  11. 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.

  12. 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...

  13. 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.

  14. Research Note on "International Consumption Risk Sharing and Monetary Policy"

    OpenAIRE

    Blank, Sven

    2009-01-01

    This model analyzes the impact of monetary policy on international consumption risk sharing. To this end, the setup by Ghironi and Stebunovs (2008) is extended in two dimensions. First, to allow for international portfolio choices, cross-border trade of home and foreign equity is brought in. Second, to assign a non-trivial role to monetary policy, nominal price rigidities are introduced as in Bilbiie, Ghironi, and Melitz (2007). The model features incomplete goods as well as incomplete asset ...

  15. 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

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

    Directory of Open Access Journals (Sweden)

    Hossein Askari

    2014-12-01

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

  17. Research on Scientific Data Sharing and Distribution Policy in Advanced Manufacturing and Automation Fields

    Directory of Open Access Journals (Sweden)

    Liya Li

    2007-12-01

    Full Text Available Scientific data sharing is a long-term and complicated task. The related data sharing and distribution policies are prime concerns. By using both domestic and international experiences in scientific data sharing, the sources, distribution, and classification of scientific data in advanced manufacturing and automation are discussed. A primary data sharing and distribution policy in advanced manufacture and automation is introduced.

  18. Top income shares in Canada: recent trends and policy implications.

    Science.gov (United States)

    Veall, Michael R

    2012-11-01

    According to Canadian taxfiler data, over the last thirty years there has been a surge in the income shares of the top 1%, top 0.1% and top 0.01% of income recipients, even with longitudinal smoothing by individual using three- or five-year moving averages. Top shares fell in 2008 and 2009, but only by a fraction of the overall surge. Alberta, British Columbia, and Ontario have much more pronounced surges than other provinces. Part of the Canadian surge is likely attributable to U.S. factors, but a comprehensive explanation remains elusive. Even so, I draw implications for policies that might achieve some support from across the political spectrum, including the elimination of tax preferences that favour those with high incomes, the promotion of shareholder democracy and, to maintain Canada's relatively high intergenerational mobility, continued wide accessibility to healthcare and education.

  19. 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.

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

    DEFF Research Database (Denmark)

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

    2016-01-01

    In recent years, cross-national collaboration in medical research has gained increased policy attention. Policies are developed to enhance data sharing, ensure open-access, and harmonize international standards and ethics rules in order to promote access to existing resources and increase...... scientific output. In tandem with this promotion of data sharing, numerous ethics policies are developed to control data flows and protect privacy and confidentiality. Both sets of policy making, however, pay limited attention to the moral decisions and social ties enacted in the everyday routines......? We explore what we call the flows, the nonflows, and the overflows of material and information, and we document the work producing the flows of health data and biomaterial. We call this work “ethics work” and argue that it is crucial for data sharing though it is rarely articulated in ethics policies...

  1. Top Income Shares in Canada: Recent Trends and Policy Implications

    OpenAIRE

    Veall, Michael R

    2012-01-01

    According to Canadian taxfiler data, over the last thirty years there has been a surge in the income shares of the top 1%, top 0.1% and top 0.01% of income recipients, even with longitudinal smoothing by individual using three- or five-year moving averages. Top shares fell in 2008 and 2009, but only by a fraction of the overall surge. Alberta, British Columbia and Ontario have much more pronounced surges than other provinces. Part of the Canadian surge is likely attributable to U.S. factors b...

  2. 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

  3. 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.

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

    Science.gov (United States)

    2009-01-01

    KDC then contacts the Attribute Database that manages user attributes and privileges and enviromental attributes (i.e., context). The KDC uses these...highly interconnected where a local disturbance can have impact over a wide area, trust relationships are not always transitive. Third, data is...Krishnamurthi, L.A. Meyerovich, and M.C. Tschantz. Verification and change- impact analysis of access-control policies. Proceedings of the 27th international

  5. 75 FR 2557 - Interim Policy for the Sharing of Information Collected by the Coast Guard Nationwide Automatic...

    Science.gov (United States)

    2010-01-15

    ... SECURITY Coast Guard Interim Policy for the Sharing of Information Collected by the Coast Guard Nationwide.... SUMMARY: The Coast Guard has developed an interim policy for the access and sharing of information... reach the Docket Management Facility by that date. ADDRESSES: This notice and the interim policy...

  6. [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.

  7. 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.

  8. 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…

  9. 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…

  10. 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.

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

    DEFF Research Database (Denmark)

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

    2016-01-01

    of scientific work. This paper takes its point of departure in the practices of a Danish laboratory with great experience in international collaboration regarding genetic research. We focus on a simple query, what makes genetic material and health data flow, and which hopes and concerns travel along with them...... scientific output. In tandem with this promotion of data sharing, numerous ethics policies are developed to control data flows and protect privacy and confidentiality. Both sets of policy making, however, pay limited attention to the moral decisions and social ties enacted in the everyday routines......? We explore what we call the flows, the nonflows, and the overflows of material and information, and we document the work producing the flows of health data and biomaterial. We call this work “ethics work” and argue that it is crucial for data sharing though it is rarely articulated in ethics policies...

  12. 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.

  13. Risk-sharing policies in the context of the French Flood Prevention Action Programmes.

    Science.gov (United States)

    Erdlenbruch, K; Thoyer, S; Grelot, F; Kast, R; Enjolras, G

    2009-01-01

    This article analyzes the consequences for risk distribution of the French Flood Prevention Action Programme (PAPI). By redirecting floods from the most vulnerable to the least vulnerable areas, PAPIs expose farmers to greater flood risks. This has led local water management institutions to introduce compensation payments. The article outlines the results of an exhaustive survey of all PAPIs in France, which examined the way the compensation policies are set up locally. Results of the survey showed that the proposed policies may be financially non-viable. Several more viable risk-sharing solutions are then discussed, involving insurance schemes, state intervention and local institutions.

  14. Research on LTE Carrier Aggregation with Compression Bandwidth and Sharing Frequency Application Between LTE and GSM%LTE压缩带宽载波聚合及与GSM频谱共享方案研究

    Institute of Scientific and Technical Information of China (English)

    王伟; 荣耀; 聂昌

    2016-01-01

    It proposes a scheme on the LTE carrier aggregation with compression bandwidth and sharing frequency between LTE and GSM. It realizes 20+10 MHz LTE carrier aggregation and GSM single frequency network with 12 carriers in 30 MHz bandwidth. The results of field test show that performance of the network is not lost by the compression bandwidth carrier aggregation. Moreover,there is little interference between LTE and GSM when co-location of their sites. LTE BS is interfered by GSM UE when co-existence of their sites. So,it is suggested that the proposed scheme can be implemented in co-location,or avoid using GSM carriers in the LTE bandwidth when co-existence.%提出了一种LTE压缩带宽载波聚合及与GSM频率共享的频率使用方案。在30 MHz带宽内实现20+10 MHz LTE载波聚合以及具有12个GSM频点的单频GSM网络。并通过实测的方式对该方案进行了网络性能验证。结果表明压缩带宽载波聚合在网络性能上基本没有损失。GSM与LTE在共站场景下,相互之间干扰甚微,可实现共存。在不共站场景下GSM终端对LTE基站存在干扰。建议该方案在共站场景下实施或避免在不共站场景下使用LTE带内的频点。

  15. The value of coordination in a two echelon supply chain: Sharing information, policies and parameters.

    OpenAIRE

    Disney, SM; Lambrecht, Marc; Towill, DR; Van de Velde, W.

    2007-01-01

    We study a coordination scheme in a two echelon supply chain. It involves sharing details of replenishment rules, lead-times, demand patterns and tuning the replenishment rules to exploit the supply chain's cost structure. We examine four different coordination strategies; naïve operation, local optimisation, global optimisation and altruistic behaviour on behalf of the retailer. We assume the retailer and the manufacturer use the Order-Up-To policy to determine replenishment orders and end c...

  16. 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.

  17. 'Wrong parents' and 'right parents': shared perspectives about citizen participation in policy implementation.

    Science.gov (United States)

    Potter, Deborah Anne

    2010-06-01

    Government policies, both in Europe and the U.S., increasingly mandate that community-based citizens partner with professionals to plan and implement policy-relevant programs. In the U.S., parents of children with serious emotional disturbances may participate in Community Collaboratives which are charged with implementing children's mental health policy in local communities. This qualitative study examined three Community Collaboratives and identified organizational features associated with how the groups prioritized lay involvement, among other competing goals which they legitimately could pursue. Thirty-four key informants participated in in-depth interviews. Although the overall study identified several factors which permitted greater and lesser degrees of family involvement, this paper reports on one: the symbolic meaning shared by members about lay participation in their shared perspectives about "wrong parents" and "right parents." Furthermore, two alternate types of "right parents" identified a psychologized version of parents as consumers, and a civic vision of parents as partners. Results from this study are applicable to a wide array of lay-professional partnerships. This study suggests that in order to foster lay-professional partnerships in policy initiatives, lay participants must possess additional, civic-based skills, beyond those needed in the service delivery arena. Furthermore, organizational and professional change may be required to address professional dominance. Within mental health, lack of acceptance of nationally touted recovery-based models is a significant barrier. Finally, sociological implications of developing a civic-based framework for lay-professional partnerships are discussed.

  18. 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)

  19. 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.

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

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  1. 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.

  2. Ethics Policies and Ethics Work in Cross-national Genetic Research and Data Sharing: Flows, Nonflows, and Overflows

    DEFF Research Database (Denmark)

    Hoeyer, Klaus; Tupasela, Aaro; Rasmussen, Malene Bøgehus

    2016-01-01

    scientific output. In tandem with this promotion of data sharing, numerous ethics policies are developed to control data flows and protect privacy and confidentiality. Both sets of policymaking, however, pay limited attention to the moral decisions and social ties enacted in the everyday routines......In recent years, cross-national collaboration in medical research has gained increased policy attention. Policies are developed to enhance data sharing, ensure open access, and to harmonize international standards and ethics rules in order to promote access to existing resources and increase......? We explore what we call the flows, the non-flows and the overflows of material and information, and we document the work producing the flows of health data and biomaterial. We call this work “ethics work” and argue that it is crucial for data sharing though it is rarely articulated in ethics policies...

  3. Ethics Policies and Ethics Work in Cross-National Genetic Research and Data Sharing: Flows, Nonflows, and Overflows

    DEFF Research Database (Denmark)

    Hoeyer, Klaus; Tupasela, Aaro; Rasmussen, Malene Bøgehus

    2017-01-01

    scientific output. In tandem with this promotion of data sharing, numerous ethics policies are developed to control data flows and protect privacy and confidentiality. Both sets of policymaking, however, pay limited attention to the moral decisions and social ties enacted in the everyday routines......In recent years, cross-national collaboration in medical research has gained increased policy attention. Policies are developed to enhance data sharing, ensure open access, and to harmonize international standards and ethics rules in order to promote access to existing resources and increase......? We explore what we call the flows, the non-flows and the overflows of material and information, and we document the work producing the flows of health data and biomaterial. We call this work “ethics work” and argue that it is crucial for data sharing though it is rarely articulated in ethics policies...

  4. Climate Change Research. Agencies Have Data-Sharing Policies but Could Do More to Enhance the Availability of Data from Federally Funded Research

    Science.gov (United States)

    2007-09-01

    Data Management for Global Change Research Policy Statements 39 Background 39 Applicability 40 Guidelines and Their Application 40 Suggested Data...the Data Management for Global Change Research Policy Statements, an interagency policy under the Climate Change Science Program (CCSP), provides...Program Source: GAO analysis of survey responses. Note: The CCSP data-sharing policy, Data Management for Global Change Research Policy Statements

  5. 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.

  6. Weak-quasi-bandwidth and forward-bandwidth of graphs

    Institute of Scientific and Technical Information of China (English)

    原晋江

    1996-01-01

    Concepts of weak-quasi-bandwidth and forward-bandwidth of graphs are introduced. They are used to studythe following problems in graph theory: bandwidth, topological bandwidth, fill-in, profile, path-width, tree-width.

  7. 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

  8. Application description and policy model in collaborative environment for sharing of information on epidemiological and clinical research data sets.

    Directory of Open Access Journals (Sweden)

    Elias César Araujo de Carvalho

    Full Text Available BACKGROUND: Sharing of epidemiological and clinical data sets among researchers is poor at best, in detriment of science and community at large. The purpose of this paper is therefore to (1 describe a novel Web application designed to share information on study data sets focusing on epidemiological clinical research in a collaborative environment and (2 create a policy model placing this collaborative environment into the current scientific social context. METHODOLOGY: The Database of Databases application was developed based on feedback from epidemiologists and clinical researchers requiring a Web-based platform that would allow for sharing of information about epidemiological and clinical study data sets in a collaborative environment. This platform should ensure that researchers can modify the information. A Model-based predictions of number of publications and funding resulting from combinations of different policy implementation strategies (for metadata and data sharing were generated using System Dynamics modeling. PRINCIPAL FINDINGS: The application allows researchers to easily upload information about clinical study data sets, which is searchable and modifiable by other users in a wiki environment. All modifications are filtered by the database principal investigator in order to maintain quality control. The application has been extensively tested and currently contains 130 clinical study data sets from the United States, Australia, China and Singapore. Model results indicated that any policy implementation would be better than the current strategy, that metadata sharing is better than data-sharing, and that combined policies achieve the best results in terms of publications. CONCLUSIONS: Based on our empirical observations and resulting model, the social network environment surrounding the application can assist epidemiologists and clinical researchers contribute and search for metadata in a collaborative environment, thus potentially

  9. 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.

  10. Bandwidth efficient coding

    CERN Document Server

    Anderson, John B

    2017-01-01

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

  11. 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.

  12. 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.

  13. 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.

  14. 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...

  15. Immigration Policy Reform in the United States: Reframing the enforcement discourse to fight human trafficking and promote shared prosperity

    Directory of Open Access Journals (Sweden)

    Ana Avendaño

    2013-11-01

    Full Text Available At the time of this writing, the United States Senate has passed the Border Security, Economic Opportunity, and Immigration Modernization Act (S. 744. The bill is the product of countless political compromises and would significantly transform the U.S. immigration system. This paper explores shortcomings in U.S. immigration policy, deconstructs provisions in the bill, and makes policy proposals that would protect and empower migrants who interface with the U.S. immigration system in dangerous and under-regulated environments at the border and in sending communities, in labour recruitment networks, and in the U.S. workforce. Ultimately, the paper seeks to continue an ongoing conversation that challenges the criminalisation of migration which perpetuates vulnerability, and instead forwards rights-based policies that would promote shared prosperity.

  16. 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.

  17. 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…

  18. 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.

  19. Policy Options for Sharing Activities between the Department of Veterans Affairs and the Department of Defense

    Science.gov (United States)

    2007-06-14

    trounced, perhaps a tacit recognition that they have little merit and reflect an organizational resistance to change rather than insurmountable...is the inherent cultural resistance to change of both organizations. The Government Accountability Office has described the DOD as having "a... resistance to change ..." (Pulliam, 2006, para. 5). Clearly, a legislative environment conducive to sharing does exist and has existed since the Sharing Act of

  20. 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.

  1. 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.

  2. 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...

  3. Bandwidth in bolometric interferometry

    Science.gov (United States)

    Charlassier, R.; Bunn, E. F.; Hamilton, J.-Ch.; Kaplan, J.; Malu, S.

    2010-05-01

    Context. Bolometric interferometry is a promising new technology with potential applications to the detection of B-mode polarization fluctuations of the cosmic microwave background (CMB). A bolometric interferometer will have to take advantage of the wide spectral detection band of its bolometers to be competitive with imaging experiments. A crucial concern is that interferometers are assumed to be significantly affected by a spoiling effect known as bandwidth smearing. Aims: We investigate how the bandwidth modifies the work principle of a bolometric interferometer and affects its sensitivity to the CMB angular power spectra. Methods: We obtain analytical expressions for the broadband visibilities measured by broadband heterodyne and bolometric interferometers. We investigate how the visibilities must be reconstructed in a broadband bolometric interferometer and show that this critically depends on hardware properties of the modulation phase shifters. If the phase shifters produce shifts that are constant with respect to frequency, the instrument works like its monochromatic version (the modulation matrix is not modified), while if they vary (linearly or otherwise) with respect to frequency, one has to perform a special reconstruction scheme, which allows the visibilities to be reconstructed in frequency subbands. Using an angular power spectrum estimator that accounts for the bandwidth, we finally calculate the sensitivity of a broadband bolometric interferometer. A numerical simulation is performed that confirms the analytical results. Results: We conclude that (i) broadband bolometric interferometers allow broadband visibilities to be reconstructed regardless of the type of phase shifters used and (ii) for dedicated B-mode bolometric interferometers, the sensitivity loss caused by bandwidth smearing is quite acceptable, even for wideband instruments (a factor of 2 loss for a typical 20% bandwidth experiment).

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

    Science.gov (United States)

    McNeill, Tony

    2012-01-01

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

  5. 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

  6. On the Usability of Shortest Remaining Time First Policy in Shared Hadoop Clusters

    OpenAIRE

    Cheriere, Nathanaël; Donat-Bouillud, Pierre; Ibrahim, Shadi; Simonin, Matthieu

    2016-01-01

    International audience; Hadoop has been recently used to process a diverse variety of applications, sharing the same execution infrastructure. A practical problem facing the Hadoop community is how to reduce job makespans by reducing job waiting times and ex- ecution times. Previous Hadoop schedulers have focused on improving job execution times, by improving data locality but not considering job waiting times. Even worse, enforcing data locality according to the job input sizes can be ineffi...

  7. Bandwidth in bolometric interferometry

    CERN Document Server

    Charlassier, R; Hamilton, J -Ch; Kaplan, J; Malu, S

    2009-01-01

    Bolometric Interferometry is a technology currently under development that will be first dedicated to the detection of B-mode polarization fluctuations in the Cosmic Microwave Background. A bolometric interferometer will have to take advantage of the wide spectral detection band of its bolometers in order to be competitive with imaging experiments. A crucial concern is that interferometers are presumed to be importantly affected by a spoiling effect known as bandwidth smearing. In this paper, we investigate how the bandwidth modifies the work principle of a bolometric interferometer and how it affects its sensitivity to the CMB angular power spectra. We obtain analytical expressions for the broadband visibilities measured by broadband heterodyne and bolometric interferometers. We investigate how the visibilities must be reconstructed in a broadband bolometric interferometer and show that this critically depends on hardware properties of the modulation phase shifters. Using an angular power spectrum estimator ...

  8. Bandwidth Trading as Incentive

    Science.gov (United States)

    Eger, Kolja; Killat, Ulrich

    In P2P networks with multi-source download the file of interest is fragmented into pieces and peers exchange pieces with each other although they did not finish the download of the complete file. Peers can adopt different strategies to trade upload for download bandwidth. These trading schemes should give peers an incentive to contribute bandwidth to the P2P network. This chapter studies different trading schemes analytically and by simulations. A mathematical framework for bandwidth trading is introduced and two distributed algorithms, which are denoted as Resource Pricing and Reciprocal Rate Control, are derived. The algorithms are compared to the tit-for-tat principle in BitTorrent. Nash Equilibria and results from simulations of static and dynamic networks are presented. Additionally, we discuss how trading schemes can be combined with a piece selection algorithm to increase the availability of a full copy of the file. The chapter closes with an extension of the mathematical model which takes also the underlying IP network into account. This results in a TCP variant optimised for P2P content distribution.

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

    Directory of Open Access Journals (Sweden)

    S.Imavathy

    2014-06-01

    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 ac cess policy generated for the file controls the file accesses and policy revocation makes the file permanently inaccessible. The system is built up on 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.

  10. 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.

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

    Directory of Open Access Journals (Sweden)

    Nona TATIASHVILI

    2016-10-01

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

  12. File sharing

    NARCIS (Netherlands)

    van Eijk, N.

    2011-01-01

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

  13. 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

  14. 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

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

    Directory of Open Access Journals (Sweden)

    Stephen M. Mutula

    2013-06-01

    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.

  16. 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.

  17. Involving Research Stakeholders in Developing Policy on Sharing Public Health Research Data in Kenya: Views on Fair Process for Informed Consent, Access Oversight, and Community Engagement.

    Science.gov (United States)

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

    2015-07-01

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

  18. 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.

  19. Ultrahigh bandwidth signal processing

    DEFF Research Database (Denmark)

    Oxenløwe, Leif Katsuo

    2016-01-01

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

  20. Improvement of CBQ for bandwidth reclamation of RPR

    Science.gov (United States)

    Huang, Benxiong; Wang, Xiaoling; Xu, Ming; Shi, Lili

    2004-04-01

    The Resilient Packet Ring (RPR) IEEE 802.17 standard is under development as a new high-speed backbone technology for metropolitan area networks (MAN) [1]. Bandwidth reclamation has been concerned in RPR specifications from draft 0.1 to draft 2.4. According to specifications, allocated bandwidth can be reused, or reclaimed, by a lower priority service class whenever the reclamation does not effect the service guarantees of any equal or higher priority classes on the local station or on any other station on the ring [2]. The class-based queuing (CBQ) algorithm is proposed to implement link-sharing [3]. A hierarchical link-sharing structure can be used to specify guidelines for the distribution of 'excess" bandwidth [4] and it can rate-limit all classes to their allocated bandwidth. There is some sameness between the link-sharing of CBQ and bandwidth reclamation of RPR. The CBQ is a mature technology while RPR is a new technology. Given CBQ improvement and full use so as to make its thought suitable for bandwidth reclamation of RPR is the focus of our work. In this paper, we present the solution that can solve the reclamation problem, which proves to be effective by simulation.

  1. 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.

  2. Theoretical Calculation of MMF's Bandwidth

    Institute of Scientific and Technical Information of China (English)

    LI Xiao-fu; JIANG De-sheng; YU Hai-hu

    2004-01-01

    The difference between over-filled launch bandwidth (OFL BW) and restricted mode launch bandwidth (RML BW) is described. A theoretical model is founded to calculate the OFL BW of grade index multimode fiber (GI-MMF),and the result is useful to guide the modification of the manufacturing method.

  3. Estimating Bottleneck Bandwidth using TCP

    Science.gov (United States)

    Allman, Mark

    1998-01-01

    Various issues associated with estimating bottleneck bandwidth using TCP are presented in viewgraph form. Specific topics include: 1) Why TCP is wanted to estimate the bottleneck bandwidth; 2) Setting ssthresh to an appropriate value to reduce loss; 3) Possible packet-pair solutions; and 4) Preliminary results: ACTS and the Internet.

  4. 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.

  5. Upgrade trigger: Bandwidth strategy proposal

    CERN Document Server

    Fitzpatrick, Conor; Meloni, Simone; Boettcher, Thomas Julian; Whitehead, Mark Peter; Dziurda, Agnieszka; Vesterinen, Mika Anton

    2017-01-01

    This document describes a selection strategy for the upgrade trigger using charm signals as a benchmark. The Upgrade trigger uses a 'Run 2-like' sequence consisting of a first and second stage, in between which the calibration and alignment is performed. The first stage, HLT1, uses an inclusive strategy to select beauty and charm decays, while the second stage uses offline-quality exclusive selections. A novel genetic algorithm-based bandwidth division is performed at the second stage to distribute the output bandwidth among different physics channels, maximising the efficiency for useful physics events. The performance is then studied as a function of the available output bandwidth.

  6. 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...

  7. Black Holes, Bandwidths and Beethoven

    CERN Document Server

    Kempf, A

    2000-01-01

    It is usually believed that a function whose Fourier spectrum is bounded can vary at most as fast as its highest frequency component. This is in fact not the case, as Aharonov, Berry and others drastically demonstrated with explicit counter examples, so-called superoscillations. The claim is that even the recording of an entire Beethoven symphony can occur as part of a signal with 1Hz bandwidth. Superoscillations have been suggested to account e.g. for transplanckian frequencies of black hole radiation. Here, we give an exact proof for generic superoscillations. Namely, we show that for every fixed bandwidth there exist functions which pass through any finite number of arbitrarily prespecified points. Further, we show that the behavior of bandlimited functions can be reliably characterized through an uncertainty relation for the standard deviation of the signals' samples taken at the Nyquist rate. This uncertainty relation generalizes to time-varying bandwidths.

  8. 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.

  9. 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.

  10. Upgrade trigger: Bandwidth strategy proposal

    CERN Document Server

    Boettcher, Thomas Julian; Meloni, Simone; Whitehead, Mark Peter; Williams, Mark Richard James

    2017-01-01

    This document describes a proposed selection strategy for the upgrade trigger using charm signals as a benchmark. The Upgrade trigger uses a 'Run2-like' sequence consisting of a first and second stage, in between which the calibration and alignment is performed. The first stage, HLT1, uses an inclusive strategy to select beauty and charm, while the second stage uses offline-quality exclusive selections. A novel genetic algorithm-based bandwidth division is performed at the second stage to maximise the output of useful physics events, and a range of possible signal efficiencies are presented as a function of the available bandwidth.

  11. Sharing our data—An overview of current (2016) USGS policies and practices for publishing data on ScienceBase and an example interactive mapping application

    Science.gov (United States)

    Chase, Katherine J.; Bock, Andrew R.; Sando, Roy

    2017-01-05

    This report provides an overview of current (2016) U.S. Geological Survey policies and practices related to publishing data on ScienceBase, and an example interactive mapping application to display those data. ScienceBase is an integrated data sharing platform managed by the U.S. Geological Survey. This report describes resources that U.S. Geological Survey Scientists can use for writing data management plans, formatting data, and creating metadata, as well as for data and metadata review, uploading data and metadata to ScienceBase, and sharing metadata through the U.S. Geological Survey Science Data Catalog. Because data publishing policies and practices are evolving, scientists should consult the resources cited in this paper for definitive policy information.An example is provided where, using the content of a published ScienceBase data release that is associated with an interpretive product, a simple user interface is constructed to demonstrate how the open source capabilities of the R programming language and environment can interact with the properties and objects of the ScienceBase item and be used to generate interactive maps.

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

    Science.gov (United States)

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

    2007-04-01

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

  13. Black holes, bandwidths and Beethoven

    Science.gov (United States)

    Kempf, Achim

    2000-04-01

    It is usually believed that a function φ(t) whose Fourier spectrum is bounded can vary at most as fast as its highest frequency component ωmax. This is, in fact, not the case, as Aharonov, Berry, and others drastically demonstrated with explicit counterexamples, so-called superoscillations. It has been claimed that even the recording of an entire Beethoven symphony can occur as part of a signal with a 1 Hz bandwidth. Bandlimited functions also occur as ultraviolet regularized fields. Their superoscillations have been suggested, for example, to resolve the trans-Planckian frequencies problem of black hole radiation. Here, we give an exact proof for generic superoscillations. Namely, we show that for every fixed bandwidth there exist functions that pass through any finite number of arbitrarily prespecified points. Further, we show that, in spite of the presence of superoscillations, the behavior of bandlimited functions can be characterized reliably, namely through an uncertainty relation: The standard deviation ΔT of samples φ(tn) taken at the Nyquist rate obeys ΔT>=1/4ωmax. This uncertainty relation generalizes to variable bandwidths. For ultraviolet regularized fields we identify the bandwidth as the in general spatially variable finite local density of degrees of freedom.

  14. 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.

  15. 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.

  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. 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.

  18. 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

  19. Achieving healthy school siting and planning policies: understanding shared concerns of environmental planners, public health professionals, and educators.

    Science.gov (United States)

    Cohen, Alison

    2010-01-01

    Policy decisions regarding the quality of the physical school environment-both, school siting and school facility planning policies-are often considered through the lens of environmental planning, public health, or education policy, but rarely through all three. Environmental planners consider environmental justice issues on a local level and/or consider the regional impact of a school. Public health professionals focus on toxic exposures and populations particularly vulnerable to negative health outcomes. Educators and education policymakers emphasize investing in human capital of both students and staff. By understanding these respective angles and combining these efforts around the common goals of achieving adequacy and excellence, we can work toward a regulatory system for school facilities that recognizes children as a uniquely vulnerable population and seeks to create healthier school environments in which children can learn and adults can work.

  20. 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…

  1. Black Holes, Bandwidths and Beethoven

    OpenAIRE

    Kempf, A.

    1999-01-01

    It is usually believed that a function whose Fourier spectrum is bounded can vary at most as fast as its highest frequency component. This is in fact not the case, as Aharonov, Berry and others drastically demonstrated with explicit counter examples, so-called superoscillations. It has been claimed that even the recording of an entire Beethoven symphony can occur as part of a signal with 1Hz bandwidth. Bandlimited functions also occur as ultraviolet regularized fields. Their superoscillations...

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

    Directory of Open Access Journals (Sweden)

    Jansen Maria W

    2012-10-01

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

  3. 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...

  4. Raise the Flag for Mountains: Enhancing Policy Dialogue and Knowledge Sharing through the World Mountain Forum Series

    Directory of Open Access Journals (Sweden)

    André Wehrli

    2016-05-01

    Full Text Available As a mountain country, Switzerland has an intrinsic interest and a proven track record in sustainable mountain development (SMD. Many Swiss stakeholders, including the federal and cantonal administrations, universities, and nongovernmental organizations, actively contribute to global SMD in many ways. Switzerland, with its extensive operational experience in mountainous countries around the world, has been one of the driving forces promoting policy dialogue and knowledge management among different actors to support SMD on various levels. This is reflected in its support for the United Nations’ Agenda 21 and the recent Agenda 2030. Still, after close to 25 years of global policy engagement, the voice of the mountains has not yet gained sufficient momentum and needs further strengthening.

  5. Raise the Flag for Mountains: Enhancing Policy Dialogue and Knowledge Sharing through the World Mountain Forum Series

    OpenAIRE

    André Wehrli

    2016-01-01

    As a mountain country, Switzerland has an intrinsic interest and a proven track record in sustainable mountain development (SMD). Many Swiss stakeholders, including the federal and cantonal administrations, universities, and nongovernmental organizations, actively contribute to global SMD in many ways. Switzerland, with its extensive operational experience in mountainous countries around the world, has been one of the driving forces promoting policy dialogue and knowledge management among dif...

  6. 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.

  7. Improving the Bandwidth Selection in Kernel Equating

    Science.gov (United States)

    Andersson, Björn; von Davier, Alina A.

    2014-01-01

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

  8. 47 CFR 2.202 - Bandwidths.

    Science.gov (United States)

    2010-10-01

    ... RULES AND REGULATIONS Emissions § 2.202 Bandwidths. (a) Occupied bandwidth. The frequency bandwidth such.... Facsimile Analogue facsimile by sub-carrier frequency modulation of a single-sideband emission with reduced...: 1980 Hz=1.98 kHz 1K98F3C 5. Composite Emissions (See Table III-B) Radio-relay system,...

  9. A novel approach to implementing digital policy management as an enabler for a dynamic secure information sharing in a cloud environment

    Science.gov (United States)

    Farroha, Bassam S.; Essman, Kristine R.; Farroha, Deborah L.; Cohen, Andy

    2011-06-01

    relevant ESM enterprise services as they impact the ability to share and protect enterprise information. Central to this is the ability to adopt and manage digital policies within the enterprise environment. It describes the management functions that have to be supported, and the challenges that have to be addressed to ensure an effective implementation. Since the adoption of cloud services is becoming an important consideration for the evolution of enterprise architectures, the paper also explores the implications of shifting from traditional to virtual enterprise environments.

  10. 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.

  11. 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

  12. Controlling Laser Plasma Instabilities Using Temporal Bandwidth

    Science.gov (United States)

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

    2016-10-01

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

  13. 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.

  14. 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.

  15. 47 CFR 95.633 - Emission bandwidth.

    Science.gov (United States)

    2010-10-01

    ... SERVICES Technical Regulations Technical Standards § 95.633 Emission bandwidth. (a) The authorized... frequencies 151.820 MHz, 151.880 MHz, and 151.940 MHz are limited to 11.25 kHz. (2) Emissions on frequencies... 47 Telecommunication 5 2010-10-01 2010-10-01 false Emission bandwidth. 95.633 Section...

  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. Tunable-Bandwidth Filter System

    Science.gov (United States)

    Aye, Tin; Yu, Kevin; Dimov, Fedor; Savant, Gajendra

    2006-01-01

    A tunable-bandwidth filter system (TBFS), now undergoing development, is intended to be part of a remote-sensing multispectral imaging system that will operate in the visible and near infrared spectral region (wavelengths from 400 to 900 nm). Attributes of the TBFS include rapid tunability of the pass band over a wide wavelength range and high transmission efficiency. The TBFS is based on a unique integration of two pairs of broadband Raman reflection holographic filters with two rotating spherical lenses. In experiments, a prototype of the TBFS was shown to be capable of spectral sampling of images in the visible range over a 200-nm spectral range with a spectral resolution of .30 nm. The figure depicts the optical layout of a prototype of the TBFS as part of a laboratory multispectral imaging system for the spectral sampling of color test images in two orthogonal polarizations. Each pair of broadband Raman reflection holographic filters is mounted at an equatorial plane between two halves of a spherical lens. The two filters in each pair are characterized by steep spectral slopes (equivalently, narrow spectral edges), no ripple or side lobes in their pass bands, and a few nanometers of non-overlapping wavelength range between their pass bands. Each spherical lens and thus the filter pair within it is rotated in order to rapidly tune its pass band. The rotations of the lenses are effected by electronically controlled, programmable, high-precision rotation stages. The rotations are coordinated by electronic circuits operating under overall supervision of a personal computer in order to obtain the desired variation of the overall pass bands with time. Embedding the filters inside the spherical lenses increases the range of the hologram incidence angles, making it possible to continuously tune the pass and stop bands of the filters over a wider wavelength range. In addition, each spherical lens also serves as part of the imaging optics: The telephoto lens focuses

  18. A System Theoretic Approach to Bandwidth Estimation

    OpenAIRE

    Liebeherr, Jorg; Fidler, Markus; Valaee, Shahrokh

    2008-01-01

    It is shown that bandwidth estimation in packet networks can be viewed in terms of min-plus linear system theory. The available bandwidth of a link or complete path is expressed in terms of a {\\em service curve}, which is a function that appears in the network calculus to express the service available to a traffic flow. The service curve is estimated based on measurements of a sequence of probing packets or passive measurements of a sample path of arrivals. It is shown that existing bandwidth...

  19. Multi-Hop Bandwidth Management Protocol for Mobile Ad Hoc Networks

    CERN Document Server

    Pattanayak, Binod Kumar; Jagadev, Alok Kumar; Nayak, Manojranjan

    2010-01-01

    An admission control scheme should play the role of a coordinator for flows in a data communication network, to provide the guarantees as the medium is shared. The nodes of a wired network can monitor the medium to know the available bandwidth at any point of time. But, in wireless ad hoc networks, a node must consume the bandwidth of neighboring nodes, during a communication. Hence, the consumption of bandwidth by a flow and the availability of resources to any wireless node strictly depend upon the neighboring nodes within its transmission range. We present a scalable and efficient admission control scheme, Multi-hop Bandwidth Management Protocol (MBMP), to support the QoS requirements in multi-hop ad hoc networks. We simulate several options to design MBMP and compare the performances of these options through mathematical analysis and simulation results, and compare its effectiveness with the existing admission control schemes through extensive simulations. KEYWORDS

  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. Shared lives, shared energy

    Energy Technology Data Exchange (ETDEWEB)

    Madsen, P.; Goss, K.

    1982-07-01

    A social experiment in Denmark is described in which 25 families combine private ownership (each family owns its own home) and collectivism (each family owns 1/25 of the grounds, large common house and other facilities). The superinsulated individual homes are small (< 1000 ft/sup 2/) but the common house (7800 ft/sup 2/) provides dining and meeting facilities for all 25 families as well as a central heating plant. Heat may be supplied from solar, wind and/or oil-fired boiler. Adequate hot water storage is provided using solar collectors and a 55 kW Vesta wind generator (surplus power is sold). All south facing roof surfaces are fitted with solar collectors (4455 ft/sup 2/ total). A total of 70% of the energy used is produced on site (solar and wind). The manner of living and sharing (child care, automobiles, cooking, etc.) is described as well as typical floor plans for the units. Other collective housing in Denmark is described and it is postulated that overdrevet may serve as a model. (MJJ)

  4. Exploring the Sharing Economy

    DEFF Research Database (Denmark)

    Netter, Sarah

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

  5. 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...

  6. Ultrawide bandwidth 1.55-um lasers

    Science.gov (United States)

    Morton, Paul A.; Tanbun-Ek, Tawee; Logan, Ralph A.; Ackerman, David A.; Shtengel, Gleb E.; Yadvish, R. D.; Sergent, A. M.; Sciortino, Paul F., Jr.

    1996-04-01

    This paper describes the essential elements for creating a practical wide bandwidth directly modulated laser source. This includes considerations of the intrinsic limitations of the laser structure, due to the resonant frequency and damping of the laser output, together with carrier transport issues to allow carriers in the device active region to be efficiently modulated at high speeds. the use of a P-doped compressively strained multiple-quantum well active region to provide high intrinsic speed and remove transport limitations is described, together with record setting results of 25 GHz modulation bandwidth for a 1.55 micrometer Fabry-Perot laser and 26 GHz bandwidth for a 1.55 micrometer DFB laser. The challenges of providing high bandwidth electrical connections to the laser on a suitable submount, together with fiber attachment and microwave packaging, are discussed. Results of fully packaged 1.55 micrometer DFB lasers with 25 Ghz modulation bandwidth are shown. Digital modulation of the packaged 1.55 micrometer DFB including impedance matching is described, and the transient wavelength chirp is presented. This low chirp is reduced further using an optical filter, to provide a 10 GBit/s source with chirp similar to that of an external electroabsorption modulator.

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

    Directory of Open Access Journals (Sweden)

    Bayu Kanigoro

    2012-05-01

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

  8. 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 analyse...

  9. 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 lin......-free single-mode guidance is found for a large frequency interval covering 60% of the photonic band-gap.......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...

  10. 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.

  11. Improved space bandwidth product in image upconversion

    DEFF Research Database (Denmark)

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

    2012-01-01

    We present a technique increasing the space bandwidth product of a nonlinear image upconversion process used for spectral imaging. The technique exploits the strong dependency of the phase-matching condition in sum frequency generation (SFG) on the angle of propagation of the interacting fields...... with respect to the optical axis. Appropriate scanning of the phase-match condition (Δk=0) while acquiring images, allow us to perform monochromatic image reconstruction with a significantly increased space bandwidth product. We derive the theory for the image reconstruction process and demonstrate acquisition...... of images with >10 fold increase in space bandwidth product, i.e. the number of pixel elements, when compared to upconversion of images using fixed phase-match conditions....

  12. An Adaptive Bandwidth Allocation for Energy Efficient Wireless Communication Systems

    Institute of Scientific and Technical Information of China (English)

    Yung-Fa Huang,Che-Hao Li; Chuan-Bi Lin; Chia-Chi Chang

    2015-01-01

    Abstract―In this paper, an energy efficient bandwidth allocation scheme is proposed for wireless communication systems. An optimal bandwidth expansion (OBE) scheme is proposed to assign the available system bandwidth for users. When the system bandwidth does not reach the full load, the remaining bandwidth can be energy-efficiently assigned to the other users. Simulation results show that the energy efficiency of the proposed OBE scheme outperforms the traditional same bandwidth expansion (SBE) scheme. Thus, the proposed OBE can effectively assign the system bandwidth and improve energy efficiency.

  13. 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.

  14. 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...

  15. A System Theoretic Approach to Bandwidth Estimation

    CERN Document Server

    Liebeherr, Jorg; Valaee, Shahrokh

    2008-01-01

    It is shown that bandwidth estimation in packet networks can be viewed in terms of min-plus linear system theory. The available bandwidth of a link or complete path is expressed in terms of a {\\em service curve}, which is a function that appears in the network calculus to express the service available to a traffic flow. The service curve is estimated based on measurements of a sequence of probing packets or passive measurements of a sample path of arrivals. It is shown that existing bandwidth estimation methods can be derived in the min-plus algebra of the network calculus, thus providing further mathematical justification for these methods. Principal difficulties of estimating available bandwidth from measurement of network probes are related to potential non-linearities of the underlying network. When networks are viewed as systems that operate either in a linear or in a non-linear regime, it is argued that probing schemes extract the most information at a point when the network crosses from a linear to a n...

  16. 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.

  17. Fast Faraday Cup With High Bandwidth

    Science.gov (United States)

    Deibele, Craig E [Knoxville, TN

    2006-03-14

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

  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. 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...

  20. Shared leadership

    DEFF Research Database (Denmark)

    Ulhøi, John Parm; Müller, Sabine

    2012-01-01

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

  1. 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...... the virtues and limits of loss-sharing rules in generating optimal (second-best) incentives and allocations of risk. We find that loss sharing may be optimal in the presence of countervailing policy objectives, homogeneous risk avoiders, and subadditive risk, which potentially offers a valuable tool...

  2. 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.

  3. 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)....

  4. 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...

  5. 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.

  6. Streamlining Policy Creation in Policy Frameworks

    NARCIS (Netherlands)

    Hills, M.A.; Martí-Oliet, N.; Palomino, M.

    2012-01-01

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

  7. 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....

  8. Bandwidth Scale for Frequency Spectrum of Sea Waves

    Institute of Scientific and Technical Information of China (English)

    王伟; 孙孚; 钱成春; 邓拥军

    2000-01-01

    It is well known that energy spectrum bandwidth should be able to reflect the degree of energy concentration. However, the commonly used bandwidth factors defined by Longuet-Higgins could not fit the concept satisfactorily. A new kind of spectrum bandwidth scale factor with a clear physical meaning is given in the present paper and a constant is obtained which reveals the intrinsic characteristics of sea waves. Thereby a universal relationship between significant wave height of sea waves and spectrum bandwidth is established.

  9. Spectrophotometer spectral bandwidth calibration with absorption bands crystal standard.

    Science.gov (United States)

    Soares, O D; Costa, J L

    1999-04-01

    A procedure for calibration of a spectral bandwidth standard for high-resolution spectrophotometers is described. Symmetrical absorption bands for a crystal standard are adopted. The method relies on spectral band shape fitting followed by a convolution with the slit function of the spectrophotometer. A reference spectrophotometer is used to calibrate the spectral bandwidth standard. Bandwidth calibration curves for a minimum spectral transmission factor relative to the spectral bandwidth of the reference spectrophotometer are derived for the absorption bands at the wavelength of the band absorption maximum. The family of these calibration curves characterizes the spectral bandwidth standard. We calibrate the spectral bandwidth of a spectrophotometer with respect to the reference spectrophotometer by determining the spectral transmission factor minimum at every calibrated absorption band of the bandwidth standard for the nominal instrument values of the spectral bandwidth. With reference to the standard spectral bandwidth calibration curves, the relation of the spectral bandwidth to the reference spectrophotometer is determined. We determine the discrepancy in the spectrophotometers' spectral bandwidths by averaging the spectral bandwidth discrepancies relative to the standard calibrated values found at the absorption bands considered. A weighted average of the uncertainties is taken.

  10. 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.

  11. A passive available bandwidth estimation methodology

    OpenAIRE

    Cabellos Aparicio, Alberto; Thompson, John; García, Francisco J.; Domingo Pascual, Jordi

    2009-01-01

    The Available Bandwidth (AB) of an end-to-end path is its remaining capacity and it is an important metric for several applications such as overlay routing and P2P networking. That is why many AB estimation tools have been published recently. Most of these tools use the Probe Rate Model, which requires sending packet trains at a rate matching the AB. Its main issue is that it congests the path under measurement. We present a different approach: a novel passive methodology to estimate the AB ...

  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. 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 ...

  14. 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.

  15. Bandwidth and Noise in Spatiotemporally Modulated Mueller Matrix Polarimeters

    Science.gov (United States)

    Vaughn, Israel Jacob

    Polarimetric systems design has seen recent utilization of linear systems theory for system descriptions. Although noise optimal systems have been shown, bandwidth performance has not been addressed in depth generally and is particularly lacking for Mueller matrix (active) polarimetric systems. Bandwidth must be considered in a systematic way for remote sensing polarimetric systems design. The systematic approach facilitates both understanding of fundamental constraints and design of higher bandwidth polarimetric systems. Fundamental bandwidth constraints result in production of polarimetric "artifacts" due to channel crosstalk upon Mueller matrix reconstruction. This dissertation analyzes bandwidth trade-offs in spatio-temporal channeled Mueller matrix polarimetric systems. Bandwidth is directly related to the geometric positioning of channels in the Fourier (channel) space, however channel positioning for polarimetric systems is constrained both physically and by design parameters like domain separability. We present the physical channel constraints and the constraints imposed when the carriers are separable between space and time. Polarimetric systems are also constrained by noise performance, and there is a trade-off between noise performance and bandwidth. I develop cost functions which account for the trade-off between noise and bandwidth for spatio-temporal polarimetric systems. The cost functions allow a systems designer to jointly optimize systems with good bandwidth and noise performance. Optimization is implemented for a candidate spatio-temporal system design, and high temporal bandwidth systems resulting from the optimization are presented. Systematic errors which impact the bandwidth performance and mitigation strategies for these systematic errors are also presented. Finally, a portable imaging Mueller matrix system is built and analyzed based on the theoretical bandwidth analysis and system bandwidth optimization. Temporal bandwidth performance is

  16. 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.

  17. 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。

  18. 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

    Energy Technology Data Exchange (ETDEWEB)

    Hanekamp, E. [Partners for Innovation, Amsterdam (Netherlands)

    2008-11-15

    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.

  19. Bandwidth Analysis of Smart Meter Network Infrastructure

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  20. Research on Contract Selection Policy after Considering Risk-sharing, Incentive and Execution Costs%考虑风险分担、激励及执行成本的合同选择策略研究

    Institute of Scientific and Technical Information of China (English)

    万欣; 秦旋

    2011-01-01

    The pattern of engineering contract is not only related to the risk sharing manner of engineering project, but also affects the incentive to contractor for continues work hard as well as the easts of contract execution. Taking the contract patterns classified by payment methods as research objects, the policy of selecting contract pattern according to the risk level of engineering project and the risk management capacity of the owner are presented after comprehensively considering the risk sharing, incentive and contract execution costs. The appropriate contract management measures and proposals for the policy are also presented herein to help the owner balancing in variety of factors when selecting contract patterns.%工程合同模式的选择不仅关系到工程项目风险的分担方式,也关系到对承包商持续努力工作的激励程度以及合同执行成本的大小.以按支付方式分类的工程合同模式为研究对象,提出了在综合考虑风险分担、激励及合同执行成本因素基础上,根据工程项目的风险水平及业主的风险管理能力选择合同模式的策略,并给出了相应的治理措施和建议,旨在为业主选择合同模式时权衡多种因素提供帮助.

  1. 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.

  2. Compact antenna arrays with wide bandwidth and low sidelobe levels

    Science.gov (United States)

    Strassner, II, Bernd H.

    2014-09-09

    Highly efficient, low cost, easily manufactured SAR antenna arrays with lightweight low profiles, large instantaneous bandwidths and low SLL are disclosed. The array topology provides all necessary circuitry within the available antenna aperture space and between the layers of material that comprise the aperture. Bandwidths of 15.2 GHz to 18.2 GHz, with 30 dB SLLs azimuthally and elevationally, and radiation efficiencies above 40% may be achieved. Operation over much larger bandwidths is possible as well.

  3. 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.

  4. Optimal resource allocation in random networks with transportation bandwidths

    Science.gov (United States)

    Yeung, C. H.; Wong, K. Y. Michael

    2009-03-01

    We apply statistical physics to study the task of resource allocation in random sparse networks with limited bandwidths for the transportation of resources along the links. Recursive relations from the Bethe approximation are converted into useful algorithms. Bottlenecks emerge when the bandwidths are small, causing an increase in the fraction of idle links. For a given total bandwidth per node, the efficiency of allocation increases with the network connectivity. In the high connectivity limit, we find a phase transition at a critical bandwidth, above which clusters of balanced nodes appear, characterized by a profile of homogenized resource allocation similar to the Maxwell construction.

  5. 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...

  6. Schottky Heterodyne Receivers With Full Waveguide Bandwidth

    Science.gov (United States)

    Hesler, Jeffrey; Crowe, Thomas

    2011-01-01

    Compact THz receivers with broad bandwidth and low noise have been developed for the frequency range from 100 GHz to 1 THz. These receivers meet the requirements for high-resolution spectroscopic studies of planetary atmospheres (including the Earth s) from spacecraft, as well as airborne and balloon platforms. The ongoing research is significant not only for the development of Schottky mixers, but also for the creation of a receiver system, including the LO chain. The new receivers meet the goals of high sensitivity, compact size, low total power requirement, and operation across complete waveguide bands. The exceptional performance makes these receivers ideal for the broader range of scientific and commercial applications. These include the extension of sophisticated test and measurement equipment to 1 THz and the development of low-cost imaging systems for security applications and industrial process monitoring. As a particular example, a WR-1.9SHM (400-600 GHz) has been developed (see Figure 1), with state-of-the-art noise temperature ranging from 1,000-1,800 K (DSB) over the full waveguide band. Also, a Vector Network Analyzer extender has been developed (see Figure 2) for the WR1.5 waveguide band (500 750 GHz) with 100-dB dynamic range.

  7. 加拿大矿产勘查投资抵税股票政策及其启示%Introduction of the Policy concerning Flow-through Shares in Canada and Some Inspirations

    Institute of Scientific and Technical Information of China (English)

    杨宗喜; 唐金荣; 施俊法; 周平

    2013-01-01

    加拿大矿业的繁荣,与其实施的矿产勘查投资抵税股票政策关系密切,该政策通过市场机制,巧妙、简便、有效地调节政府、勘查企业和投资者三者利益,将本该收归国库的个人税收直接用于支持草根勘查,为矿业资本市场注入了新的活力;矿业公司筹得资金,成为勘查活动的主体;投资者税收获得减免,并确定了投资获利的机会。加拿大矿产勘查投资低税股票政策对我们启示有三点:首先,草根勘查是矿产繁荣的基础,国家应制定相关政策鼓励草根勘查;其次,通过市场机制,有效吸引社会资金进入矿产勘查;第三,成功的政策需要在实践中不断调整和完善。%The mining boom in Canada has a close relation to the policy of lfow-through shares. The policy effectively regulates beneifts of government, exploration enterprises and investors in a clever and simple manner; and it also directly uses the personal tax which should have reverted to the Treasury to support grassroots exploration, which bring new vitality into mining capital market. This paper goes on to introduce that mining companies which have raised funds have become the main body in activities of mineral prospecting; while the investors have been granted tax breaks and identiifed the opportunities for proiftable investment. The main inspirations of focus include: grassroots exploration is the basis of the mining boom, so the relevant policies to encourage grassroots exploration should be worked out by the state; we should effectively attract social funds into the mineral exploration by market mechanism; and successful policies needs to be adjusted and perfected continuously in practice.

  8. 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 ...

  9. Avoiding bandwidth collapse in long chains of coupled optical microresonators.

    Science.gov (United States)

    Mookherjea, Shayan; Schneider, Mark A

    2011-12-01

    Coupled photonic oscillators and resonators are sensitive to unavoidable nanoscale disorder, and localization in periodic structures induced by disorder leads eventually to a complete collapse of the bandwidth, which is generally considered problematic for device applications. Here, we investigate the dependence of bandwidth collapse on the interresonator coupling coefficient, a parameter controllable by lithography or device operation.

  10. Optimal Bandwidth Selection in Observed-Score Kernel Equating

    Science.gov (United States)

    Häggström, Jenny; Wiberg, Marie

    2014-01-01

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

  11. 47 CFR 78.104 - Authorized bandwidth and emission designator.

    Science.gov (United States)

    2010-10-01

    ... SERVICES CABLE TELEVISION RELAY SERVICE Technical Regulations § 78.104 Authorized bandwidth and emission... within the frequency limits of the assigned channel. (c) The emission designator shall be specified in... 47 Telecommunication 4 2010-10-01 2010-10-01 false Authorized bandwidth and emission...

  12. 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.

  13. A multiple time-scale model for TCP bandwidth sharing under user heterogeneity

    NARCIS (Netherlands)

    Abendroth, D.; Berg, J.L. van den; Mandjes, M.

    2005-01-01

    Building on the vast body of existing TCP models, we develop a novel versatile model that explicitly captures user heterogeneity, and takes into consideration dynamics at both the packet level and the flow level. It is described how the resulting multiple time-scale model can be numerically evaluate

  14. 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.

  15. 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

  16. Dynamic Bandwidth Allocation Algorithm with Fairness in 1G/10G Coexistence EPON System

    Science.gov (United States)

    Tanaka, Masaki; Takemoto, Michiya; Takahashi, Akira; Shimokasa, Kiyoshi

    Gigabit Ethernet Passive Optical Networks (GE-PON) systems have been deployed widely as a broadband access solution for the optical access network, the so-called FTTx networks. 10 Gigabit EPON (10G-EPON) is about to be standardizing by a task force (802.3av). To provide the next FTTx solution with 10G-EPON systems, one of the key technologies is how to migrate from 1G-based to 10G-based. In this paper, we present Dynamic Bandwidth Allocation (DBA) algorithm which considered a fair policy for 1G/10G coexistence EPON system to achieve a smooth migration.

  17. 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.

  18. Shared decision making

    Science.gov (United States)

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

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

    DEFF Research Database (Denmark)

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

    2016-01-01

    . Secondary controller is realized locally and the communication network is only used to transfer the data of dc currents. Therefore, the secondary controller can regulate the average voltage by only using the data of currents. The proposed approach is verified with simulations based on PLECS.......In this paper, a distributed secondary power sharing approach with low bandwidth communication network is proposed for low voltage direct current (LVDC) microgrids. Conventional droop control causes voltage drop in the grid and also a mismatch on the current of converters in the case...... of consideration of the line resistances. Proposed control system carry out the current value of the other converters to reach the accurate current sharing and suitable voltage regulation as well. Voltage and current controllers locally regulate the voltage and current of converters as a secondary controller...

  20. 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

  1. 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

  2. Arctic Region Policy: Information Sharing Model Options

    Science.gov (United States)

    2010-09-01

    specializations , meaning that expertise is not blended into a process that focuses on one sector over another. Figure 25 highlights APIP’s ability to...8 Figure 5. 2004 Arctic Maritime Activity (From Treadwell, 2009, p. 48) .............. 10 Figure 6. Explorer Stuck in the Antarctic (From New...been a Titanic situation, such as what happened to the cruise ship EXPLORER in the Antarctic in November 2007 as shown in Figure 6 (Browley & 11

  3. Information Sharing Policies for Coalition Systems

    Science.gov (United States)

    2006-10-01

    Le contexte crise(t) paix(t) occurence(e, Terrorisme , t).... Forme générale d’une règle : contexte → règle 1 2 A u t e u r é v é n e...A u t e u r é v é n e m e n t d a t e Un formalisme pour définir une politique de partage Exemples de règles (1) Dans un contexte de terrorisme ...tout observateur a l’obligation de diffuser immédiatement à son chef toute information relative au thème cible- terrorisme . ∀e ∀a ∀b ∀i ∀o∀t ∀t

  4. 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.

  5. 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.

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

    Science.gov (United States)

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

    2017-01-01

    Hybrid quantum networks rely on efficient interfacing of dissimilar quantum nodes, as elements based on parametric downconversion sources, quantum dots, colour centres or atoms are fundamentally different in their frequencies and bandwidths. Although 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 61.5%, 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. PMID:28134242

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. Challenges in Polybinary Modulation for Bandwidth Limited Optical Links

    DEFF Research Database (Denmark)

    Vegas Olmos, Juan José; Tafur Monroy, Idelfonso; Madsen, Peter;

    2016-01-01

    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...... of the current research status of the key building blocks in polybinary systems. The results clearly show how polybinary modulation effectively reduces the bandwidth requirements on optical links while providing high spectral efficiency....

  13. 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.

  14. Bandwidth-Efficient Cooperative Relaying Schemes with Multiantenna Relay

    Directory of Open Access Journals (Sweden)

    Tho Le-Ngoc

    2008-05-01

    Full Text Available We propose coded cooperative relaying schemes in which all successfully decoded signals from multiple sources are forwarded simultaneously by a multiantenna relay to a common multiantenna destination to increase bandwidth efficiency. These schemes facilitate various retransmission strategies at relay and single-user and multiuser iterative decoding techniques at destination, suitable for trade-offs between performance, latency, and complexity. Simulation results show that the proposed schemes significantly outperform direct transmission under the same transmit power and bandwidth efficiency.

  15. Lightweight monitoring of label switched paths for bandwidth management

    OpenAIRE

    Vilà Talleda, Pere; Marzo i Lázaro, Josep Lluís; Calle Ortega, Eusebi; Carrillo, Liliana

    2004-01-01

    The purpose of resource management is the efficient and effective use of network resources, for instance bandwidth. In this article, a connection oriented network scenario is considered, where a certain amount of bandwidth is reserved for each label switch path (LSP), which is a logical path, in a MPLS or GMPLS environment. Assuming there is also some kind of admission control (explicit or implicit), these environments typically provide quality of service (QoS) guarantees. It could happen tha...

  16. On the Bandwidth of High-Impedance Frequency Selective Surfaces

    CERN Document Server

    Costa, Filippo; Monorchio, Agostino; 10.1109/LAWP.2009.2038346

    2010-01-01

    In this letter, the bandwidth of high-impedance surfaces (HISs) is discussed by an equivalent circuit approach. Even if these surfaces have been employed for almost 10 years, it is sometimes unclear how to choose the shape of the frequency selective surface (FSS) on the top of the grounded slab in order to achieve the largest possible bandwidth. Here, we will show that the conventional approach describing the HIS as a parallel connection between the inductance given by the grounded dielectric substrate and the capacitance of the FSS may induce inaccurate results in the determination of the operating bandwidth of the structure. Indeed, in order to derive a more complete model and to provide a more accurate estimate of the operating bandwidth, it is also necessary to introduce the series inductance of the FSS.We will present the explicit expression for defining the bandwidth of a HIS, and we will show that the reduction of the FSS inductance results in the best choice for achieving wide operating bandwidth in c...

  17. 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...

  18. 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.

  19. 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.

  20. 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.

  1. Cascaded passive silicon microrings for large bandwidth slow light device

    Energy Technology Data Exchange (ETDEWEB)

    Li Yuntao; Hu Yingtao; Xiao Xi; Li Zhiyong; Yu Yude; Yu Jinzhong, E-mail: ytli@semi.ac.cn [State Key Laboratory of integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, P. O. Box 912, Beijing 100083 (China)

    2011-02-01

    Slow light devices have important applications in the areas of data buffering, signal processing, and phased array antenna. Cascaded microring resonators structure can obtain large delay and also enhance the bandwidth, which was considered as a potential approach for future on-chip optical buffer. In this paper, we demonstrated a large bandwidth slow light device using cascaded Silicon-on-insulator (SOI) based microring resonators. With carefully designed the gap between the bus and the ring waveguides and the distances between the adjacent rings, a 57 ps group delay was observed and 83 Gbps maximum allowable bit rate is suggested according the measured 3 dB spectral bandwidth in the 8-stage cascaded microrings.

  2. Maximum bandwidth snapshot channeled imaging polarimeter with polarization gratings

    Science.gov (United States)

    LaCasse, Charles F.; Redman, Brian J.; Kudenov, Michael W.; Craven, Julia M.

    2016-05-01

    Compact snapshot imaging polarimeters have been demonstrated in literature to provide Stokes parameter estimations for spatially varying scenes using polarization gratings. However, the demonstrated system does not employ aggressive modulation frequencies to take full advantage of the bandwidth available to the focal plane array. A snapshot imaging Stokes polarimeter is described and demonstrated through results. The simulation studies the challenges of using a maximum bandwidth configuration for a snapshot polarization grating based polarimeter, such as the fringe contrast attenuation that results from higher modulation frequencies. Similar simulation results are generated and compared for a microgrid polarimeter. Microgrid polarimeters are instruments where pixelated polarizers are superimposed onto a focal plan array, and this is another type of spatially modulated polarimeter, and the most common design uses a 2x2 super pixel of polarizers which maximally uses the available bandwidth of the focal plane array.

  3. 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.

  4. A novel dynamic wavelength bandwidth allocation scheme over OFDMA PONs

    Science.gov (United States)

    Yan, Bo; Guo, Wei; Jin, Yaohui; Hu, Weisheng

    2011-12-01

    With rapid growth of Internet applications, supporting differentiated service and enlarging system capacity have been new tasks for next generation access system. In recent years, research in OFDMA Passive Optical Networks (PON) has experienced extraordinary development as for its large capacity and flexibility in scheduling. Although much work has been done to solve hardware layer obstacles for OFDMA PON, scheduling algorithm on OFDMA PON system is still under primary discussion. In order to support QoS service on OFDMA PON system, a novel dynamic wavelength bandwidth allocation (DWBA) algorithm is proposed in this paper. Per-stream QoS service is supported in this algorithm. Through simulation, we proved our bandwidth allocation algorithm performs better in bandwidth utilization and differentiate service support.

  5. Adaptive broadcasting mechanism for bandwidth allocation in mobile services.

    Science.gov (United States)

    Horng, Gwo-Jiun; Wang, Chi-Hsuan; Chou, Chih-Lun

    2014-01-01

    This paper proposes a tree-based adaptive broadcasting (TAB) algorithm for data dissemination to improve data access efficiency. The proposed TAB algorithm first constructs a broadcast tree to determine the broadcast frequency of each data and splits the broadcast tree into some broadcast wood to generate the broadcast program. In addition, this paper develops an analytical model to derive the mean access latency of the generated broadcast program. In light of the derived results, both the index channel's bandwidth and the data channel's bandwidth can be optimally allocated to maximize bandwidth utilization. This paper presents experiments to help evaluate the effectiveness of the proposed strategy. From the experimental results, it can be seen that the proposed mechanism is feasible in practice.

  6. Modeling of Bandwidth Aggregation over Heterogeneous Wireless Access Networks

    DEFF Research Database (Denmark)

    Popovska Avramova, Andrijana; Dittmann, Lars

    2012-01-01

    Motivated by the multihomming capability of the mobile devices and the fact that the heterogeneous wireless access networks overlap in coverage, mobile operators are looking for solutions that will benefit by simultaneous use of the available multiple access interfaces. Multipath or multilink...... 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...

  7. 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.

  8. 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.

  9. 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.

  10. Memory bandwidth efficient two-layer reduced-resolution decoding of high-definition video

    Science.gov (United States)

    Comer, Mary L.

    2000-12-01

    This paper addresses the problem of efficiently decoding high- definition (HD) video for display at a reduced resolution. The decoder presented in this paper is intended for applications that are constrained not only in memory size, but also in peak memory bandwidth. This is the case, for example, during decoding of a high-definition television (HDTV) channel for picture-in-picture (PIP) display, if the reduced resolution PIP-channel decoder is sharing memory with the full-resolution main-channel decoder. The most significant source of video quality degradation in a reduced-resolution decoder is prediction drift, which is caused by the mismatch between the full-resolution reference frames used by the encoder and the subsampled reference frames used by the decoder. to mitigate the visually annoying effects of prediction drift, the decoder described in this paper operates at two different resolutions -- a lower resolution for B pictures, which do not contribute to prediction drift and a higher resolution for I and P pictures. This means that the motion-compensation unit (MCU) essentially operates at the higher resolution, but the peak memory bandwidth is the same as that required to decode at the lower resolution. Storage of additional data, representing the higher resolution for I and P pictures, requires a relatively small amount of additional memory as compared to decoding at the lower resolution. Experimental results will demonstrate the improvement in video quality achieved by the addition of the higher-resolution data in forming predictions for P pictures.

  11. The effect of bandwidth in scale-free network traffic

    CERN Document Server

    Hu, M B; Wang, W X; Wu, Q S; Wu, Y H; Hu, Mao-Bin; Jiang, Rui; Wang, Wen-Xu; Wu, Qing-Song; Wu, Yong-Hong

    2006-01-01

    We model information traffic on scale-free networks by introducing the bandwidth as the delivering ability of links. We focus on the effects of bandwidth on the packet delivering ability of the traffic system to better understand traffic dynamic in real network systems. Such ability can be measured by a phase transition from free flow to congestion. Two cases of node capacity C are considered, i.e., C=constant and C is proportional to the node's degree. We figured out the decrease of the handling ability of the system together with the movement of the optimal local routing coefficient $\\alpha_c$, induced by the restriction of bandwidth. Interestingly, for low bandwidth, the same optimal value of $\\alpha_c$ emerges for both cases of node capacity. We investigate the number of packets of each node in the free flow state and provide analytical explanations for the optimal value of $\\alpha_c$. Average packets traveling time is also studied. Our study may be useful for evaluating the overall efficiency of networke...

  12. 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 and ada...

  13. 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...

  14. 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...

  15. Bandwidth utilization maximization of scientific RF communication systems

    Energy Technology Data Exchange (ETDEWEB)

    Rey, D. [Sandia National Lab., Albuquerque, NM (United States); Ryan, W. [New Mexico State Univ., Las Cruces, NM (United States); Ross, M.

    1997-01-01

    A method for more efficiently utilizing the frequency bandwidth allocated for data transmission is presented. Current space and range communication systems use modulation and coding schemes that transmit 0.5 to 1.0 bits per second per Hertz of radio frequency bandwidth. The goal in this LDRD project is to increase the bandwidth utilization by employing advanced digital communications techniques. This is done with little or no increase in the transmit power which is usually very limited on airborne systems. Teaming with New Mexico State University, an implementation of trellis coded modulation (TCM), a coding and modulation scheme pioneered by Ungerboeck, was developed for this application and simulated on a computer. TCM provides a means for reliably transmitting data while simultaneously increasing bandwidth efficiency. The penalty is increased receiver complexity. In particular, the trellis decoder requires high-speed, application-specific digital signal processing (DSP) chips. A system solution based on the QualComm Viterbi decoder and the Graychip DSP receiver chips is presented.

  16. 47 CFR 74.535 - Emission and bandwidth.

    Science.gov (United States)

    2010-10-01

    ... bandwidth: As specified by the following equation but in no event less than 50 decibels: A = 35 + 0.8(G − 50) + 10 Log10 B. (Attenuation greater than 80 decibels is not required.) Where: A = Attenuation (in decibels) below the mean output power level. G = Percent removed from the carrier frequency. B =...

  17. Characterizing the effective bandwidth of tri-stable energy harvesters

    Science.gov (United States)

    Panyam, Meghashyam; Daqaq, Mohammed F.

    2017-01-01

    Recently, it has been shown that nonlinear vibratory energy harvesters possessing a tri-stable potential function are capable of harvesting energy efficiently over a wider range of frequencies in comparison to harvesters with a double-well potential function. However, the effect of the design parameters of the harvester on the dynamic response and the effective bandwidth of such devices remains uninvestigated. To fill this void, this paper establishes an analytical approach to characterize the effective frequency bandwidth of harvesters that possess a hexic potential energy function. To achieve this goal, the method of multiple scales is utilized to construct analytical solutions describing the amplitude and stability of the intra- and inter-well dynamics of the harvester. Using these solutions, critical bifurcations in the parameter's space are identified and used to define an effective frequency bandwidth of the harvester. The influence of the electric parameters, namely, the time constant ratio (ratio between the period of the mechanical system and the time constant of the harvesting circuit) and the electromechanical coupling, on the effective frequency bandwidth is analyzed. Experimental studies performed on the harvester are presented to validate some of the theoretical findings.

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

    DEFF Research Database (Denmark)

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

    2013-01-01

    Gain-switching of a CW fiber laser is a simple and cost-effective approach to generate pulses using an all-fiber system. We report on the construction of a narrow bandwidth (below 0.1 nm) gain-switched fiber laser and optimize the pulse energy and pulse duration under this constraint. The extracted...

  19. 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

  20. 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.

  1. Assessing Sufficiency and Quality of Bandwidth for Public Libraries

    Directory of Open Access Journals (Sweden)

    John Carlo Bertot

    2007-03-01

    Full Text Available Based on data collected as part of the 2006 Public Libraries and the Internet study, the authors assess the degree to which public libraries provide sufficient and quality bandwidth to support the library’s networked services and resources. The topic is complex due to the arbitrary assignment of a number of kilobytes per second (kbps used to define bandwidth. Such arbitrary definitions to describe bandwidth sufficiency and quality are not useful. Public libraries are indeed connected to the Internet and do provide public-access services and resources. It is, however, time to move beyond connectivity type and speed questions and consider issues of bandwidth sufficiency, quality, and the range of networked services that should be available to the public from public libraries. A secondary, but important issue is the extent to which libraries, particularly in rural areas, have access to broadband telecommunications services.

  2. 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

  3. 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…

  4. A Novel Approach for Core Selection in Shared Tree Multicasting

    Directory of Open Access Journals (Sweden)

    Bidyut Gupta

    2014-03-01

    Full Text Available Multicasting is preferred over multiple unicasts from the viewpoint of better utilization of network bandwidth. Multicasting can be done in two different ways: source based tree approach and shared tree approach. Protocols such as Core Based Tree (CBT, Protocol Independent Multicasting Sparse Mode (PIM-SM use shared treeapproach. Shared tree approach is preferred over source-based tree approach because in the later construction of minimum cost treeper source is needed unlike a single shared tree in the former approach.The work presented in this paper provides an efficient core selection method for shared tree multicasting. In this work, we have used a new concept known as pseudo diameter for core selection. The presented methodselects more than one core to achieve fault tolerance

  5. The Filtering Effect of Sharing Rules

    OpenAIRE

    G. Dari Mattiacci; G.G.A. de Geest

    2004-01-01

    Abstract We provide an explanation for why centralisation of political decision making results in overspending in some policy domains, whereas too low spending persists in others. We study a model in which delegates from jurisdictions bargain over local public goods provision. If all of the costs of public goods are shared through a common budget, policy makers delegate bargaining to `public good lovers', resulting in overprovision of public goods. If a sufficiently large part of the costs ca...

  6. Share your Sweets

    DEFF Research Database (Denmark)

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

    2015-01-01

    as sharing in which group members were allowed to co-feed or remove food from the stock of the food possessor, and the introduction of high-value food resulted in more sharing, not less. Food sharing behavior differed between species in that chimpanzees displayed significantly more begging behavior than......All over the world, humans (Homo sapiens) display resource-sharing behavior, and common patterns of sharing seem to exist across cultures. Humans are not the only primates to share, and observations from the wild have long documented food sharing behavior in our closest phylogenetic relatives......, chimpanzees (Pan troglodytes) and bonobos (Pan paniscus). However, few controlled studies have been made where groups of Pan are introduced to food items that may be shared or monopolized by a first food possessor, and very few studies have examined what happens to these sharing patterns if the food...

  7. 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.

  8. 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.

  9. 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.

  10. GHz bandwidth noise eater hybrid optical amplifier: design guidelines.

    Science.gov (United States)

    Danion, Gwennaël; Bondu, François; Loas, Goulc'hen; Alouini, Mehdi

    2014-07-15

    This Letter describes the design of an optical amplifier system optimized to reduce the relative intensity noise (RIN) of the input signal, and discloses its performance in terms of intensity noise reduction and bandwidth, without phase noise degradation. This polarization-maintaining amplifier is composed of an erbium-doped fiber amplifier (EDFA) cascaded with a semiconductor optical amplifier (SOA). The EDFA is sized to feed the SOA with a constant power corresponding to the optimal saturation level for noise reduction, through coherent population oscillations. When properly optimized, such an amplifier provides, simultaneously, 17 dB optical gain, 5.4 dB noise factor, and 20 dB reduction of the input-RIN across a 3 GHz bandwidth, without any electronics feedback loop.

  11. 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.

  12. Compact silicon multimode waveguide spectrometer with enhanced bandwidth

    Science.gov (United States)

    Piels, Molly; Zibar, Darko

    2017-01-01

    Compact, broadband, and high-resolution spectrometers are appealing for sensing applications, but difficult to fabricate. Here we show using calibration data a spectrometer based on a multimode waveguide with 2 GHz resolution, 250 GHz bandwidth, and a 1.6 mm × 2.1 mm footprint. Typically, such spectrometers have a bandwidth limited by the number of modes supported by the waveguide. In this case, an on-chip mode-exciting element is used to repeatably excite distinct collections of waveguide modes. This increases the number of independent spectral channels from the number of modes to this number squared, resulting in an extension of the usable range. PMID:28290537

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. Ultrawide Bandwidth 180°-Hybrid-Coupler in Planar Technology

    Directory of Open Access Journals (Sweden)

    Steffen Scherr

    2014-01-01

    Full Text Available A new concept of an ultrawide bandwidth 180°-hybrid-coupler is presented. The ultrawideband design approach is based on the excitation of a coplanar waveguide (CPW mode and a coupled slot line (CSL mode in the same double slotted planar waveguide. The coupler is suitable for realization in planar printed circuit board technology. For verification of the new concept a prototype was designed for the frequency range from 3 GHz to 11 GHz, built, and measured. The measurement results presented in this paper show a good agreement between simulation and measurement and demonstrate the very broadband performance of the new device. The demonstrated coupler with a size of 40 mm × 55 mm exhibits a fractional bandwidth of 114% centered at 7 GHz with a maximum amplitude imbalance of 0.8 dB and a maximum phase imbalance of 5°.

  18. Passive Mobile Bandwidth Classification Using Short Lived TCP Connections

    OpenAIRE

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

    2015-01-01

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

  19. Satisfaction and 'comparison sharing'

    DEFF Research Database (Denmark)

    Amilon, Anna

    2009-01-01

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

  20. 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.

  1. DC SQUID RF magnetometer with 200 MHz bandwidth

    Science.gov (United States)

    Talanov, Vladimir; Lettsome, Nesco; Orozco, Antonio; Cawthorne, Alfred; Borzenets, Valery

    2012-02-01

    Because of periodic flux-to-voltage transfer function, Superconducting QUantum Interference Device (SQUID) magnetometers operate in a closed-loop regime [1], which linearizes the response, and increases the dynamic range and sensitivity. However, a transmission line delay between the SQUID and electronics fundamentally limits the closed-loop bandwidth at 20 MHz [1], although the intrinsic bandwidth of SQUIDs is in gigahertz range. We designed a DC SQUID based RF magnetometer capable of wideband sensing coherent magnetic fields up to 200 MHz. To overcome the closed-loop bandwidth limitation, we utilized a low-frequency flux-modulated closed-loop to simultaneously lock the quasi-static magnetic flux and provide AC bias for the RF flux. The SQUID RF voltage is processed by RF electronics based on a double lock-in technique. This yields a signal proportional to the amplitude and phase of the RF magnetic flux, with more than four decades of a linear response. For YBaCuO SQUID on bi-crystal SrTiO substrate at 77 K we achieved a flux noise density of 4 μφ0/Hz at 190 MHz, which is similar to that measured at kHz frequencies with conventional flux-locked loop. [1] D. Drung, et al., Supercond. Sci. Technol. 19, S235 (2006).

  2. 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.

  3. Adaptive bandwidth measurements of importance functions for speech intelligibility prediction.

    Science.gov (United States)

    Whitmal, Nathaniel A; DeRoy, Kristina

    2011-12-01

    The Articulation Index (AI) and Speech Intelligibility Index (SII) predict intelligibility scores from measurements of speech and hearing parameters. One component in the prediction is the "importance function," a weighting function that characterizes contributions of particular spectral regions of speech to speech intelligibility. Previous work with SII predictions for hearing-impaired subjects suggests that prediction accuracy might improve if importance functions for individual subjects were available. Unfortunately, previous importance function measurements have required extensive intelligibility testing with groups of subjects, using speech processed by various fixed-bandwidth low-pass and high-pass filters. A more efficient approach appropriate to individual subjects is desired. The purpose of this study was to evaluate the feasibility of measuring importance functions for individual subjects with adaptive-bandwidth filters. In two experiments, ten subjects with normal-hearing listened to vowel-consonant-vowel (VCV) nonsense words processed by low-pass and high-pass filters whose bandwidths were varied adaptively to produce specified performance levels in accordance with the transformed up-down rules of Levitt [(1971). J. Acoust. Soc. Am. 49, 467-477]. Local linear psychometric functions were fit to resulting data and used to generate an importance function for VCV words. Results indicate that the adaptive method is reliable and efficient, and produces importance function data consistent with that of the corresponding AI/SII importance function.

  4. Ultra-high bandwidth quantum secured data transmission

    Science.gov (United States)

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

    2016-10-01

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

  5. High-bandwidth remote flat panel display interconnect system

    Science.gov (United States)

    Peterson, Darrel G.

    1999-08-01

    High performance electronic displays (CRT, AMLCD, TFEL, plasma, etc.) require wide bandwidth electrical drive signals to produce the desired display images. When the image generation and/or image processing circuitry is located within the same line replaceable unit (LRU) as the display media, the transmission of the display drive signals to the display media presents no unusual design problems. However, many aircraft cockpits are severely constrained for available space behind the instrument panel. This often forces the system designer to specify that only the display media and its immediate support circuitry are to be mounted in the instrument panel. A wide bandwidth interconnect system is then required to transfer image data from the display generation circuitry to the display unit. Image data transfer rates of nearly 1.5 Gbits/second may be required when displaying full motion video at a 60 Hz field rate. In addition to wide bandwidth, this interconnect system must exhibit several additional key characteristics: (1) Lossless transmission of image data; (2) High reliability and high integrity; (3) Ease of installation and field maintenance; (4) High immunity to HIRF and electrical noise; (5) Low EMI emissions; (6) Long term supportability; and (7) Low acquisition and maintenance cost. Rockwell Collins has developed an avionics grade remote display interconnect system based on the American National Standards Institute Fibre Channel standard which meets these requirements. Readily available low cost commercial off the shelf (COTS) components are utilized, and qualification tests have confirmed system performance.

  6. Ultra-high bandwidth quantum secured data transmission

    Science.gov (United States)

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

    2016-01-01

    Quantum key distribution (QKD) provides an attractive means for securing communications in optical fibre networks. However, deployment of the technology has been hampered by the frequent need for dedicated dark fibres to segregate the very weak quantum signals from conventional traffic. Up until now the coexistence of QKD with data has been limited to bandwidths that are orders of magnitude below those commonly employed in fibre optic communication networks. Using an optimised wavelength divisional multiplexing scheme, we transport QKD and the prevalent 100 Gb/s data format in the forward direction over the same fibre for the first time. We show a full quantum encryption system operating with a bandwidth of 200 Gb/s over a 100 km fibre. Exploring the ultimate limits of the technology by experimental measurements of the Raman noise, we demonstrate it is feasible to combine QKD with 10 Tb/s of data over a 50 km link. These results suggest it will be possible to integrate QKD and other quantum photonic technologies into high bandwidth data communication infrastructures, thereby allowing their widespread deployment. PMID:27734921

  7. Quantum gates with optimal bandwidth in noisy environments

    Science.gov (United States)

    Low, Guang Hao; Theodore, Yoder; Chuang, Isaac

    The traditional approach of open-loop quantum error correction suppresses certain systematic imperfections ɛ in quantum control to higher orders ɛ  (L) by a well-designed sequence of L imperfect quantum gates. However, this philosophy of maximal flatness leads to an ɛ-bandwidth that scales poorly with length and a residual that is easily overwhelmed by unaccounted sources of noise. We advance the paradigm of equiripple compensated gates that directly optimize for bandwidth given the limitations imposed by noise of magnitude δ, leading to dramatically improved performance. Where ɛ represent amplitude errors, we provide a formalism that generalizes both approaches and is effective at finding such gates. With it, we provide in closed-form the phase angles for an optimal family of population inversion gates with an ɛ -bandwidth of  (logδ-1/L) - a quadratic improvement over optimal maximally flat variants. We also construct optimal NOT gates and discuss extensions to other gates and error models.

  8. 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.

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

    Science.gov (United States)

    2016-11-15

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

  10. 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.

  11. 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.

  12. 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....

  13. 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....

  14. 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.

  15. 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...

  16. 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.

  17. Facilitating Knowledge Sharing

    DEFF Research Database (Denmark)

    Holdt Christensen, Peter

    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...... 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...

  18. 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...

  19. 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+.

  20. Space bandwidth-efficient realizations of linear systems.

    Science.gov (United States)

    Kutay, M A; Erden, M F; Ozaktas, H M; Arkan, O; Güleryüz, O; Candan, C A

    1998-07-15

    One can obtain either exact realizations or useful approximations of linear systems or matrix-vector products that arise in many different applications by implementing them in the form of multistage or multichannel fractional Fourier-domain filters, resulting in space-bandwidth-efficient systems with acceptable decreases in accuracy. Varying the number and the configuration of filters enables one to trade off between accuracy and efficiency in a flexible manner. The proposed scheme constitutes a systematic way of exploiting the regularity or structure of a given linear system or matrix, even when that structure is not readily apparent.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-10-25

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

  2. 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

  3. Tunable polarization plasma channel undulator for narrow bandwidth photon emission

    Science.gov (United States)

    Rykovanov, S. G.; Wang, J. W.; Kharin, V. Yu.; Lei, B.; Schroeder, C. B.; Geddes, C. G. R.; Esarey, E.; Leemans, W. P.

    2016-09-01

    The theory of a plasma undulator excited by a short intense laser pulse in a parabolic plasma channel is presented. The undulator fields are generated either by the laser pulse incident off-axis and/or under the angle with respect to the channel axis. Linear plasma theory is used to derive the wakefield structure. It is shown that the electrons injected into the plasma wakefields experience betatron motion and undulator oscillations. Optimal electron beam injection conditions are derived for minimizing the amplitude of the betatron motion, producing narrow-bandwidth undulator radiation. Polarization control is readily achieved by varying the laser pulse injection conditions.

  4. 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...

  5. 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.

  6. 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.

  7. 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 overlooked in current debates. This approach highlights specific experiential interrelations taking place among individuals who are jointly engaged and located in a common environment, and situates this type of sharing within a broader and richer spectrum of sharing phe- nomena. Whereas Schutz’ route...

  8. 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...

  9. 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…

  10. 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.

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

    Directory of Open Access Journals (Sweden)

    Muhammad Nugraha

    2016-09-01

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

  12. 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

  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. An Exponential Time 2-Approximation Algorithm for Bandwidth

    CERN Document Server

    Fürer, Martin; Kasiviswanathan, Shiva Prasad

    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 O(1.9797^n) time and uses polynomial space. This improves both the previous best 2- and 3-approximation algorithms of Cygan et al. which have an O(3^n) and O(2^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.

  17. Bandwidth Improvement of UWB Microstrip Antenna Using Finite Ground Plane

    Directory of Open Access Journals (Sweden)

    Priyanka Mishra

    2015-06-01

    Full Text Available Microstrip antennas play a vital role in communication system. It is required in high performance wireless applications. But due to its resonant nature microstrip antennas have some considerable drawbacks like narrowband performance. Extensive study has been carried out on microstrip patch antennas in the recent past, but it still have large scope for improvement in the near future. To overcome narrow bandwidth problem, number of methods and techniques have been suggested and investigated, keeping in mind that the basic advantages of microstrip antenna should not be altered such as low profile, light weight, low cost and simple printed circuit structure. The area of investigation includes modification in geometrical shape of the antenna, use of resonators, use of dipole, and many other parameters. This paper presents a comparison between conventional microstrip antenna and microstip antenna with finite ground plane at ultra wideband. HFSS simulation tool is used here for antenna simulation. For feeding purpose microstrip feed line is used (50Ω. Optimized result provides impedance bandwidth of 7.2GHz with VSWR<2, operating frequency range is from 6.5GHz to 13.7GHz. Proposed antenna is useful for many ultra wideband applications.

  18. Unmanned Aircraft System Control and ATC Communications Bandwidth Requirements

    Science.gov (United States)

    Henriksen, Steve

    2008-01-01

    There are significant activities taking place to establish the procedures and requirements for safe and routine operation of unmanned aircraft systems (UAS) in the National Airspace System (NAS). Among the barriers to overcome in achieving this goal is the lack of sufficient frequency spectrum necessary for the UAS control and air traffic control (ATC) communications links. This shortcoming is compounded by the fact that the UAS control communications links will likely be required to operate in protected frequency spectrum, just as ATC communications links are, because they relate to "safety and regularity of flight." To support future International Telecommunications Union (ITU) World Radio Conference (WRC) agenda items concerning new frequency allocations for UAS communications links, and to augment the Future Communications Study (FCS) Technology Evaluation Group efforts, NASA Glenn Research Center has sponsored a task to estimate the UAS control and ATC communications bandwidth requirements for safe, reliable, and routine operation of UAS in the NAS. This report describes the process and results of that task. The study focused on long-term bandwidth requirements for UAS approximately through 2030.

  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. Improving microwave antenna gain and bandwidth with phase compensation metasurface

    Science.gov (United States)

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

    2015-06-01

    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 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.

  2. 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.

  3. The establishment of the High Level Panel of Experts on food security and nutrition (HLPE). Shared, independent and comprehensive knowledge for international policy coherence in food security and nutrition

    OpenAIRE

    2011-01-01

    Following the 2007-2008 food crisis, improvements of world food governance was at the centre of international discussions, leaning towards a new Global Partnership for Agriculture, Food Security and Nutrition. In this process, the issue of the management of various streams of knowledge appeared a central element to allow for better policy coordination, and led to the creation of the High Level Panel of Experts on food security and nutrition (HLPE). Here we describe the genesis and unveil the ...

  4. 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...

  5. 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.

  6. 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 kn...

  7. 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.

  8. 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…

  9. An Enhanced Power Sharing Scheme for Voltage unbalance and harmonics compensation in an islanded AC microgrid

    DEFF Research Database (Denmark)

    Han, Yang; Shen, Pan; Zhao, Xin

    2016-01-01

    compensation (UHC), the auxiliary control, and the virtual positive/negative-sequence impedance (VPI/VNI) loops at fundamental frequency, and the virtual variable harmonic impedance (VVHI) loop at harmonic frequencies, an accurate power sharing is achieved. Moreover, the low bandwidth communication (LBC...

  10. 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.

  11. 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

  12. 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.

  13. 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…

  14. 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.

  15. 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....

  16. 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

  17. 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...

  18. 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

  19. 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.

  20. 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.

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

    Science.gov (United States)

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

    2016-11-01

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

  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. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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...

  8. 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.

  9. 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.

  10. 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.

  11. 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.

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

    NARCIS (Netherlands)

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

    2009-01-01

    Are policies to increase women’s share among university professors effective? The importance of gender equality on the labor market has been well established, but our understanding of what kind of policy is effective to increase the share of women is still unclear. Three sets of factors explain wome

  13. Urban sharing culture

    DEFF Research Database (Denmark)

    Fjalland, Emmy Laura Perez

    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...... problems and side effects from concentration of consumption and contamination; and due to the shift from ownership to access it change our basic social cultural norms (Sayer 2005; Sayer 2011) about the ‘good’ life and social status (Freudendal-Pedersen 2007), commons and individuality, responsibility...

  14. 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.

  15. Financial Impact of Liver Sharing and Organ Procurement Organizations' Experience With Share 35: Implications for National Broader Sharing.

    Science.gov (United States)

    Fernandez, H; Weber, J; Barnes, K; Wright, L; Levy, M

    2016-01-01

    The Share 35 policy for organ allocation, which was adopted in June 2013, allocates livers regionally for candidates with Model for End-Stage Liver Disease scores of 35 or greater. The authors analyzed the costs resulting from the increased movement of allografts related to this new policy. Using a sample of nine organ procurement organizations, representing 17% of the US population and 19% of the deceased donors in 2013, data were obtained on import and export costs before Share 35 implementation (June 15, 2012, to June 14, 2013) and after Share 35 implementation (June 15, 2013, to June 14, 2014). Results showed that liver import rates increased 42%, with an increased cost of 51%, while export rates increased 112%, with an increased cost of 127%. When the costs of importing and exporting allografts were combined, the total change in costs for all nine organ procurement organizations was $11 011 321 after Share 35 implementation. Extrapolating these costs nationally resulted in an increased yearly cost of $68 820 756 by population or $55 056 605 by number of organ donors. Any alternative allocation proposal needs to account for the financial implications to the transplant infrastructure.

  16. 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

  17. 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.

  18. 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

  19. A variable bandwidth assignment scheme for the Land Mobile Satellite experiment

    Science.gov (United States)

    Yan, T.-Y.; Li, V. O. K.

    The Mobile Satellite Experiment is a proposed experimental satellite-based communications network which provides data and voice communications to mobile terminals dispersed in geographically dispersed areas. In this paper, an analytical model is developed to calculate the performance of a Variable Bandwidth Assignment (VBA) Scheme. Under this scheme, the satellite channel bandwidth is dynamically reassigned so that a message may be transmitted in the shortest possible time. To transmit a long message, message channels will be reconfigured to have more bandwidth such that the transmission time is reduced, while to transmit a short message, the channel bandwidth will be shrunk such that the released bandwidth can be used to serve other messages. The model is illustrated with numerical examples. It is shown that a VBA scheme can achieve considerable improvement in transmission delays over a Fixed Bandwidth Assignment Scheme.

  20. 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

  1. 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).

  2. 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...

  3. 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.

  4. 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.

  5. 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

  6. 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.

  7. Labia Majora Share

    Science.gov (United States)

    Lee, Hanjing; Yap, Yan Lin; Low, Jeffrey Jen Hui

    2017-01-01

    Defects involving specialised areas with characteristic anatomical features, such as the nipple, upper eyelid, and lip, benefit greatly from the use of sharing procedures. The vulva, a complex 3-dimensional structure, can also be reconstructed through a sharing procedure drawing upon the contralateral vulva. In this report, we present the interesting case of a patient with chronic, massive, localised lymphedema of her left labia majora that was resected in 2011. Five years later, she presented with squamous cell carcinoma over the left vulva region, which is rarely associated with chronic lymphedema. To the best of our knowledge, our management of the radical vulvectomy defect with a labia majora sharing procedure is novel and has not been previously described. The labia major flap presented in this report is a shared flap; that is, a transposition flap based on the dorsal clitoral artery, which has consistent vascular anatomy, making this flap durable and reliable. This procedure epitomises the principle of replacing like with like, does not interfere with leg movement or patient positioning, has minimal donor site morbidity, and preserves other locoregional flap options for future reconstruction. One limitation is the need for a lax contralateral vulva. This labia majora sharing procedure is a viable option in carefully selected patients. PMID:28194353

  8. Towards A Shared Mission

    DEFF Research Database (Denmark)

    Staunstrup, Jørgen; Orth Gaarn-Larsen, Carsten

    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...... 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......A mission shared by stakeholders, management and employees is a prerequisite for an engaging dialog about the many and substantial changes and challenges currently facing universities. Too often this essen-tial dialog reveals mistrust and misunderstandings about the role and outcome...

  9. 47 CFR 27.1178 - Administration of the Cost-Sharing Plan.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Administration of the Cost-Sharing Plan. 27... Cost-Sharing Policies Governing Broadband Radio Service Relocation from the 2150-2160/62 Mhz Band § 27.1178 Administration of the Cost-Sharing Plan. The Wireless Telecommunications Bureau, under...

  10. 47 CFR 27.1162 - Administration of the Cost-Sharing Plan.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Administration of the Cost-Sharing Plan. 27... Cost-Sharing Policies Governing Microwave Relocation from the 2110-2150 Mhz and 2160-2200 Mhz Bands § 27.1162 Administration of the Cost-Sharing Plan. The Wireless Telecommunications Bureau,...

  11. Partnership or placation? The role of trust and justice in the shared ownership of renewable energy projects

    NARCIS (Netherlands)

    Goedkoop, Fleur; Devine-Wright, Patrick

    2016-01-01

    Governments in several European countries have developed policies that encourage companies to share ownership of renewable energy projects with local communities. Shared ownership presumes that company and community actors have common goals, can form effective partnerships and negotiate fair outcome

  12. 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

  13. 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.

  14. Sharing the dance -

    DEFF Research Database (Denmark)

    He, Jing; Ravn, Susanne

    2017-01-01

    to the highly specialized field of elite sports dance, we aim at exploring the way in which reciprocity unfolds in intensive deliberate practices of movement. In our analysis, we specifically argue that the ongoing dynamics of two separate flows of movement constitute a shared experience of dancing together....... In this sense, moving together, in sports dance, is a practical way of understanding each other. In agreement with Zahavi, our analysis emphasizes the bi-directed nature of sharing. However, at the same time, we contribute to Zahavi’s ongoing endeavour as the special case of sports dance reveals how reciprocity...

  15. Constant-bandwidth constant-temperature hot-wire anemometer.

    Science.gov (United States)

    Ligeza, P

    2007-07-01

    A constant-temperature anemometer (CTA) enables the measurement of fast-changing velocity fluctuations. In the classical solution of CTA, the transmission band is a function of flow velocity. This is a minor drawback when the mean flow velocity does not significantly change, though it might lead to dynamic errors when flow velocity varies over a considerable range. A modification is outlined, whereby an adaptive controller is incorporated in the CTA system such that the anemometer's transmission band remains constant in the function of flow velocity. For that purpose, a second feedback loop is provided, and the output signal from the anemometer will regulate the controller's parameters such that the transmission bandwidth remains constant. The mathematical model of a CTA that has been developed and model testing data allow a through evaluation of the proposed solution. A modified anemometer can be used in measurements of high-frequency variable flows in a wide range of velocities. The proposed modification allows the minimization of dynamic measurement errors.

  16. Wide bandwidth nanowire electromechanics on insulating substrates at room temperature

    Science.gov (United States)

    Sebastian, Abhilash; Mathew, John; Sengupta, Shamashis; Gokhale, Maheshwar; Bhattacharya, Arnab; Deshmukh, Mandar

    2013-03-01

    We present a simple fabrication scheme for nano-scale devices on insulating substrates. Doubly clamped InAs nanowire resonators with local gate configuration are fabricated on sapphire substrates. Parasitic capacitance is reduced on insulating substrates thus enabling measurements at all temperatures and particularly above room temperature, an essential requirement for NEMS sensors. Mechanical motion of the nanowire is capacitively actuated and detected using a network analyser. This technique provides wide bandwidth radio frequency transduction and allows the nanowire oscillations to be probed at a much faster rate compared to mixing techniques. Both in-plane and out-of-plane vibrational modes of the nanowire are observed and the non-linear response of the resonators is studied. Quality factor of the resonator increases at low temperatures. We also study the relation between mechanical motion and thermal strains in the nanowire. This opens up a new approach in studying thermal properties of nanostructures. Our method of fabrication can be extended to NEMS devices on flexible substrates and other nanostructures.

  17. 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.

  18. High Bandwidth Short Stroke Rotary Fast Tool Servo

    Energy Technology Data Exchange (ETDEWEB)

    Montesanti, R C; Trumper, D L

    2003-08-22

    This paper presents the design and performance of a new rotary fast tool servo (FTS) capable of developing the 40 g's tool tip acceleration required to follow a 5 micron PV sinusoidal surface at 2 kHz with a planned accuracy of 50 nm, and having a full stroke of 50 micron PV at lower frequencies. Tests with de-rated power supplies have demonstrated a closed-loop unity-gain bandwidth of 2 kHz with 20 g's tool acceleration, and we expect to achieve 40 g's with supplies providing {+-} 16 Amp to the Lorentz force actuator. The use of a fast tool servo with a diamond turning machine for producing non-axisymmetric or textured surfaces on a workpiece is well known. Our new rotary FTS was designed to specifically accommodate fabricating prescription textured surfaces on 5 mm diameter spherical target components for High Energy Density Physics experiments on the National Ignition Facility Laser (NIF).

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

    Science.gov (United States)

    Dumont, Joey; Fillion-Gourdeau, François; Lefebvre, Catherine; Gagnon, Denis; MacLean, Steve

    2017-02-01

    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. This method has the advantage that its input is the unfocused field coming from the laser chain, which is experimentally known with high accuracy. We use our method to show that the reflection of a linearly polarized Gaussian beam of femtosecond duration off a high numerical aperture parabolic mirror induces ellipticity in the dominant field components and generates strong longitudinal components. We also estimate that future high-power laser facilities may reach intensities of {10}24 {{W}} {{cm}}-2.

  20. 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.

  1. 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.

  2. Octave Bandwidth Orthomode Transducers for the Expanded Very Large Array

    Science.gov (United States)

    Coutts, Gordon M.

    2011-06-01

    Quadruple-ridge orthomode transducers (OMTs) have been designed to operate over a full octave bandwidth for the expanded very large array (EVLA) project. The OMT separates linearly polarized signal components by matching a circular waveguide input to two orthogonal coaxial outputs. The OMT is used in conjunction with a quadrature hybrid to detect circularly polarized signal components. This paper focuses on the 1 GHz-2 GHz L-Band OMT design, which has better than 18.8 dB measured return loss across the band, with no evidence of trapped-mode resonances. The OMT is designed with an emphasis on performance, ease of tuning and manufacturability since a large number of units are needed for the array application. Extensive parametric analyses were carried out, and nominal dimensions have been set to ensure the devices exceed RF specifications provided the parts are machined to within specified tolerances. With excellent wideband performance and a simplified manufacturing process, the proposed OMT would be amenable to much larger future array projects.

  3. 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.

  4. 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...

  5. 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...

  6. 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

  7. 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...

  8. 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...

  9. 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

  10. 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...

  11. 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...

  12. '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'.

  13. The Sharing Economy

    DEFF Research Database (Denmark)

    Hamari, Juho; Sjöklint, Mimmi; Ukkonen, Antti

    2016-01-01

    Information and communications technologies (ICTs) have enabled the rise of so-called “Collaborative Consumption” (CC): the peer-to-peer-based activity of obtaining, giving, or sharing the access to goods and services, coordinated through community-based online services. CC has been expected to a...

  14. 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...

  15. 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

    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...

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. Agent based Bandwidth Reservation Routing Technique in Mobile Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    Vishnu Kumar Sharma,

    2011-12-01

    Full Text Available In mobile ad hoc networks (MANETs, inefficient resource allocation causes heavy losses to the service providers and results in inadequate user proficiency. For improving and automating the quality of service of MANETs, efficient resource allocation techniques are required. In this paper, we propose an agent based bandwidth reservation technique for MANET. The mobile agent from the source starts forwarding the data packets through the path which has minimum cost, congestion and bandwidth. The status of every node is collected which includes the bottleneck bandwidth field and the intermediate node computes the available bandwidth on the link. At the destination, after updating the new bottleneck bandwidth field, the data packet is feedback to the source. In resource reservation technique, if the available bandwidth is greater than bottleneck bandwidth, then bandwidth reservation for the flow is done. Using rate monitoring and adjustment methodologies, rate control is performed for the congested flows. By simulation results, we show that the resource allocation technique reduces the losses and improves the network performance.

  1. Construction and experimental testing of the constant-bandwidth constant-temperature anemometer.

    Science.gov (United States)

    Ligeza, P

    2008-09-01

    A classical constant-temperature hot-wire anemometer enables the measurement of fast-changing flow velocity fluctuations, although its transmission bandwidth is a function of measured velocity. This may be a source of significant dynamic errors. Incorporation of an adaptive controller into the constant-temperature system results in hot-wire anemometer operating with a constant transmission bandwidth. The construction together with the results of experimental testing of a constant-bandwidth hot-wire anemometer prototype are presented in this article. During the testing, an approximately constant transmission bandwidth of the anemometer was achieved. The constant-bandwidth hot-wire anemometer can be used in measurements of high-frequency variable flows characterized by a wide range of velocity changes.

  2. 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.

  3. Promises and pitfalls of data sharing in qualitative research.

    Science.gov (United States)

    Tsai, Alexander C; Kohrt, Brandon A; Matthews, Lynn T; Betancourt, Theresa S; Lee, Jooyoung K; Papachristos, Andrew V; Weiser, Sheri D; Dworkin, Shari L

    2016-11-01

    The movement for research transparency has gained irresistible momentum over the past decade. Although qualitative research is rarely published in the high-impact journals that have adopted, or are most likely to adopt, data sharing policies, qualitative researchers who publish work in these and similar venues will likely encounter questions about data sharing within the next few years. The fundamental ways in which qualitative and quantitative data differ should be considered when assessing the extent to which qualitative and mixed methods researchers should be expected to adhere to data sharing policies developed with quantitative studies in mind. We outline several of the most critical concerns below, while also suggesting possible modifications that may help to reduce the probability of unintended adverse consequences and to ensure that the sharing of qualitative data is consistent with ethical standards in research.

  4. Extravehicular Activity Operations Concepts Under Communication Latency and Bandwidth Constraints

    Science.gov (United States)

    Beaton, Kara H.; Chappell, Steven P.; Abercromby, Andrew F. J.; Miller, Matthew J.; Nawotniak, Shannon Kobs; Hughes, Scott; Brady, Allyson; Lim, Darlene S. S.

    2017-01-01

    The Biologic Analog Science Associated with Lava Terrains (BASALT) project is a multi-year program dedicated to iteratively develop, implement, and evaluate concepts of operations (ConOps) and supporting capabilities intended to enable and enhance human scientific exploration of Mars. This pa-per describes the planning, execution, and initial results from the first field deployment, referred to as BASALT-1, which consisted of a series of 10 simulated extravehicular activities (EVAs) on volcanic flows in Idaho's Craters of the Moon (COTM) National Monument. The ConOps and capabilities deployed and tested during BASALT-1 were based on previous NASA trade studies and analog testing. Our primary research question was whether those ConOps and capabilities work acceptably when performing real (non-simulated) biological and geological scientific exploration under 4 different Mars-to-Earth communication conditions: 5 and 15 min one-way light time (OWLT) communication latencies and low (0.512 Mb/s uplink, 1.54 Mb/s downlink) and high (5.0 Mb/s uplink, 10.0 Mb/s downlink) bandwidth conditions representing the lower and higher limits of technical communication capabilities currently proposed for future human exploration missions. The synthesized results of BASALT-1 with respect to the ConOps and capabilities assessment were derived from a variety of sources, including EVA task timing data, network analytic data, and subjective ratings and comments regarding the scientific and operational acceptability of the ConOp and the extent to which specific capabilities were enabling and enhancing, and are presented here. BASALT-1 established preliminary findings that baseline ConOp, software systems, and communication protocols were scientifically and operationally acceptable with minor improvements desired by the "Mars" extravehicular (EV) and intravehicular (IV) crewmembers, but unacceptable with improvements required by the "Earth" Mission Support Center. These data will provide a

  5. 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.

  6. 货币政策、会计稳健性与企业R & D投资--基于沪深A股上市公司的经验证据%Monetary policy,Accounting Conservatism and Corporate R & D Investment-Based on the Empirical Evidence of Shanghai and Shenzhen A-share Listed Companies

    Institute of Scientific and Technical Information of China (English)

    刘胜强; 常武斌

    2016-01-01

    文章以2007-2014年已披露R&D支出的沪深A股上市公司为样本,实证检验了货币政策、会计稳健性与企业R&D投资之间的关系。结果发现:我国上市公司会计信息总体较为稳健,并且在货币政策紧缩阶段会计稳健性更高;会计稳健性与企业R&D投资显著负相关,这种负相关关系在民营企业中更为明显;进一步研究发现,紧缩的货币政策可以通过会计稳健性来间接影响微观企业R&D投资行为,与国有企业相比,货币政策的这种作用在民营企业中更显著。%Based on the panel data of R&D investment of Shanghai and Shenzhen A-shares listed companies revealed in their financial statements from 2007 to 2014,this paper empirically tests the relationship between monetary policy,accounting con⁃servatism and corporate R&D investment. The results show that the overall accounting information of Chinese listed companies is relatively robust and more stable in the stage of tight monetary policy. There is a significant negative relationship between ac⁃counting conservatism and corporate R&D investment and this negative relationship between them in private enterprises is more obvious. The further study finds that,tight monetary policy can indirectly affect the microscopic corporate R&D invest⁃ment behavior through the accounting conservatism. Compared with the state-owned enterprises,the effect of monetary policy is more significant in the private enterprises.

  7. 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.

  8. 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.

  9. 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.

  10. 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....

  11. Shared care and boundaries:

    DEFF Research Database (Denmark)

    Winthereik, Brit Ross

    2008-01-01

    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...... of healthcare in relation to IT design. Originality/value – The paper shows that “unshared” care does not exist; care is always shared among human and nonhuman actors. It also points to the value of studying how boundaries are enacted in projects that seek to create continuity across boundaries. Udgivelsesdato......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...

  12. Analysis and Design of I/Q Charge-Sharing Band-Pass-Filter for Superheterodyne Receivers

    NARCIS (Netherlands)

    Madadi, I.; Tohidian, M.; Staszewski, R.B.

    2015-01-01

    A complex quadrature charge-sharing (CS) technique is proposed to implement a discrete-time band-pass filter (BPF) with a programmable bandwidth of 20–100 MHz. The BPF is part of a cellular superheterodyne receiver and completely determines the receiver frequency selectivity. It operates at the full

  13. 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.

  14. Fishers sharing real-time information about “bad” fishing locations

    DEFF Research Database (Denmark)

    Eliasen, Søren Qvist; Bichel, Nikolaj

    2016-01-01

    use of time-place regulation, risks/benefits of sharing knowledge and experiences from a previous real-time information sharing system as basis for developing the four models for fisher's sharing of information. The models differ with regard to data and information collection methods, who owns...... to specific local conditions, and a recommendation for policy support of development of information sharing systems is outlined....

  15. 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...

  16. Intelligence Sharing in Counterproliferation

    Science.gov (United States)

    2007-09-01

    Routledge, 2004), 75. 3 Dieter Mahncke, Wyn Rees , and Wayne C. Thompson, Redefining transatlantic security relations: The Challenge of Change...Redefining Transatlantic Security Relations, by Dieter Mahncke, Wyn Rees , and Wayne C. Thompson, it is argued that these differences coupled with...Regarding Weapons of Mass Destruction” by U.S. Senators Laurence Silbermann and Charles Robb, “the information sharing problem manifested itself in

  17. 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...

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. DEVELOPMENT OF AN S-BAND KLYSTRON WITH BANDWIDTH OF 11%

    Institute of Scientific and Technical Information of China (English)

    Wang Yong; Ding Yaogen; Zhang Jian; Wang Shuguo; Xu Miaoling; Jiang Zhenbo; Lu Xi

    2004-01-01

    This letter introduces the design ideas, simulation and test results of an S-band klystron with bandwidth of 11%, which was developed by the Institute of Electronics, Chinese Academy of Sciences (IECAS). On the peak power level of 800 kW, the efficiency of klystron is more than 30%; the gain is more than 41 dB; the equal-driving relative instantaneous bandwidth is over 11%; the average power is larger than 8 kW, and the power fluctuation within bandwidth is less than 1.5 dB.

  5. Error-resilient video communications over CDMA networks with a bandwidth constraint.

    Science.gov (United States)

    Shen, Yushi; Cosman, Pamela C; Milstein, Laurence B

    2006-11-01

    We present an adaptive video transmission scheme for use in a code-division multiple-access network, which incorporates efficient bandwidth allocation among source coding, channel coding, and spreading under a fixed total bandwidth constraint. We derive the statistics of the received signal, as well as a theoretical bound on the packet drop rate at the receiver. Based on these results, a bandwidth allocation algorithm is proposed at the packet level, which incorporates the effects of both the changing channel conditions and the dynamics of the source content. Detailed simulations are done to evaluate the performance of the system, and the sensitivity of the system to estimation error is presented.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. Bandwidth and Offset Launch Investigations on a 1.4 m Multimode Polymer Spiral Waveguide

    CERN Document Server

    Chen, Jian; Penty, Richard V; White, Ian H; Westbergh, Petter; Larsson, Anders

    2016-01-01

    Bandwidth measurements are conducted on a 1.4 m long spiral polymer multimode waveguide for a SMF and 50/125 um MMF launch and for different input offsets. The waveguide exhibits a bandwidth of at least 30 GHz for all input types, yielding a bandwidth-length product of at least 42 GHzxm, while no impact is observed on the waveguide performance due to the different spatial input offsets. The results indicate that data transmission at data rates even higher than 25 Gb/s can be achieved over such structures, thereby demonstrating the potential of multimode polymer waveguide technologies in short-reach board-level datacommunication links.

  11. 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.

  12. 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.

  13. 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…

  14. Sharing Space Situational Awareness Data

    Science.gov (United States)

    Bird, D.

    2010-09-01

    The Commander, United States Strategic Command (CDRUSSTRATCOM) accepted responsibility for sharing space situational awareness (SSA) information/services with commercial & foreign entities from the US Air Force on 22 Dec 09 (formerly the Commercial & Foreign Entities Pilot Program). The requirement to share SSA services with non-US Government (USG) entities is derived from Title 10, United States Code, Section 2274 (2010) and is consistent with the new National Space Policy. US Strategic Command’s (USSTRATCOM’s) sharing of SSA services consists of basic services (Two-Line Elements, decay data and satellite catalog details) available on www.space-track.org and advanced services (conjunction assessment, launch support, etc) available with a signed agreement. USSTRATCOM has requested USG permission to enter into international agreements to enable SSA data exchange with our foreign partners. USSTRATCOM recently authorized Joint Functional Component Command for Space (JFCC SPACE) to share Conjunction Summary Messages (CSMs) with satellite owner/operators whose satellites have been identified as closely approaching another space object. CSMs contain vector and covariance data computed using Special Perturbations theory. To facilitate the utility of the CSMs, USSTRATCOM has and is hosting CSM Workshops to ensure satellite operators fully understand the data contained in the CSM in order to provide an informed recommendation to their leadership. As JFCC SPACE matures its ability to accept ephemeris data from a satellite operator, it will be necessary to automatically transfer that data from one security level to another. USSTRATCOM and Air Force Space Command are coordinating the integration of a cross domain solution that will allow JFCC SPACE to do just that. Finally, USSTRATCOM is also working with commercial and governmental organizations to develop an internationally-accepted conjunction assessment message. The United States Government (USG), specifically the

  15. 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.

  16. 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

  17. 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.

  18. Mobile energy sharing futures

    DEFF Research Database (Denmark)

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

    2016-01-01

    We foresee a future where energy in our mobile devices can be shared and redistributed to suit our current task needs. Many of us are beginning to carry multiple mobile devices and we seek to re-evaluate the traditional view of a mobile device as only accepting energy. In our vision, we can...... leverage the energy stored in our devices to wirelessly distribute energy between our friends, family, colleagues and strangers devices. In this paper we explore the opportunities and interactions presented by such spontaneous energy transfer interactions and present some envisaged collaborative energy...

  19. 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…

  20. 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.

  1. Vaccines, our shared responsibility.

    Science.gov (United States)

    Pagliusi, Sonia; Jain, Rishabh; Suri, Rajinder Kumar

    2015-05-05

    The Developing Countries Vaccine Manufacturers' Network (DCVMN) held its fifteenth annual meeting from October 27-29, 2014, New Delhi, India. The DCVMN, together with the co-organizing institution Panacea Biotec, welcomed over 240 delegates representing high-profile governmental and nongovernmental global health organizations from 36 countries. Over the three-day meeting, attendees exchanged information about their efforts to achieve their shared goal of preventing death and disability from known and emerging infectious diseases. Special praise was extended to all stakeholders involved in the success of polio eradication in South East Asia and highlighted challenges in vaccine supply for measles-rubella immunization over the coming decades. Innovative vaccines and vaccine delivery technologies indicated creative solutions for achieving global immunization goals. Discussions were focused on three major themes including regulatory challenges for developing countries that may be overcome with better communication; global collaborations and partnerships for leveraging investments and enable uninterrupted supply of affordable and suitable vaccines; and leading innovation in vaccines difficult to develop, such as dengue, Chikungunya, typhoid-conjugated and EV71, and needle-free technologies that may speed up vaccine delivery. Moving further into the Decade of Vaccines, participants renewed their commitment to shared responsibility toward a world free of vaccine-preventable diseases.

  2. 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.

  3. 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.

  4. 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.

  5. MedlinePlus: Privacy Policy

    Science.gov (United States)

    ... Español You Are Here: Home → NLM Privacy Policy URL of this page: https://medlineplus.gov/privacy.html ... uses the Go.USA.gov and Bit.ly URL shortening services. The shorter URLs are shared in ...

  6. Secure public cloud platform for medical images sharing.

    Science.gov (United States)

    Pan, Wei; Coatrieux, Gouenou; Bouslimi, Dalel; Prigent, Nicolas

    2015-01-01

    Cloud computing promises medical imaging services offering large storage and computing capabilities for limited costs. In this data outsourcing framework, one of the greatest issues to deal with is data security. To do so, we propose to secure a public cloud platform devoted to medical image sharing by defining and deploying a security policy so as to control various security mechanisms. This policy stands on a risk assessment we conducted so as to identify security objectives with a special interest for digital content protection. These objectives are addressed by means of different security mechanisms like access and usage control policy, partial-encryption and watermarking.

  7. Study on Dielectric Resonator Antenna with Annular Patch for High Gain and Large Bandwidth

    Institute of Scientific and Technical Information of China (English)

    FENG Kuisheng; LI Na; MENG Qingwei; WANG Yongfeng; ZHANG Jingwei

    2015-01-01

    A new high-gain cylindrical Dielectric res-onator antenna (DRA) with a large bandwidth is proposed. A cylindrical Dielectric resonator (DR), a double-annular patch and a metallic cylinder are used to obtain a large bandwidth and a high gain. The mode TM12 excited in the patch is used to enhance the gain of the DRA, and the cavity formed by the metallic cylinder provides a further higher gain and a larger bandwidth. The measured results demonstrate that the proposed DRA achieves a large band-width of 23%from 5.3 to 6.8GHz with VSWR less than two and a high gain around 11 dBi.

  8. 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

    2016-12-01

    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.

  9. 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.

  10. 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.

  11. 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...

  12. Photonic MPLS Network Technologies to Create Bandwidth-Abundant IP Networks

    Institute of Scientific and Technical Information of China (English)

    Atsushi; Watanabe

    2003-01-01

    This paper describes the prototypes of the Photonic MPLS router that can create bandwidth-abundant IP networks in a cost-effective manner. The characteristics of and recent advances in these prototypes are also described.

  13. A wide bandwidth analog front-end circuit for 60-GHz wireless communication receiver

    Science.gov (United States)

    Furuta, M.; Okuni, H.; Hosoya, M.; Sai, A.; Matsuno, J.; Saigusa, S.; Itakura, T.

    2014-03-01

    This paper presents an analog front-end circuit for a 60-GHz wireless communication receiver. The feature of the proposed analog front-end circuit is a bandwidth more than 1-GHz wide. To expand the bandwidth of a low-pass filter and a voltage gain amplifier, a technique to reduce the parasitic capacitance of a transconductance amplifier is proposed. Since the bandwidth is also limited by on-resistance of the ADC sampling switch, a switch separation technique for reduction of the on-resistance is also proposed. In a high-speed ADC, the SNDR is limited by the sampling jitter. The developed high resolution VCO auto tuning effectively reduces the jitter of PLL. The prototype is fabricated in 65nm CMOS. The analog front-end circuit achieves over 1-GHz bandwidth and 27.2-dB SNDR with 224 mW Power consumption.

  14. 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....

  15. A memory cost improved bandwidth request algorithm in DVB-RCS

    Science.gov (United States)

    He, Jian; Wang, Zulin

    2007-11-01

    The Bandwidth request algorithm which intervenes in the bandwidth-on-demand (BoD) access mechanism plays an important role in DVB-RCS satellite systems to optimize bandwidth utilization. In this paper, a memory cost improved bandwidth request algorithm (MCI-BRA) is proposed. The MCI-BRA deals mainly with the memory cost which is measured as the queue size at the terminal while offers a controllable trade-off between delay and efficiency. A traffic plane model for a satellite system using DVB-RCS is also described. Several assumptions are discussed, followed by detailed description of the MCI-BRA. Comparisons between the proposed algorithm and existing ones are also presented and analyzed. The simulating results show that MCI-BRA proposed in this work performs better than existing algorithms on controlling memory cost while handles the delay and efficiency issues as well as the existing ones.

  16. 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.

  17. 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...

  18. 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....

  19. Bandwidth Estimation Problem & Solutions in IEEE 802.11 based Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    Neeraj Gupta

    2012-11-01

    Full Text Available With the rise in multimedia applications in ad hoc networks it is necessary to ensure the quality of service support from network. The routers which may be mobile nodes in ad hoc networks should be able to evaluate the resources available in the network, prior to offering guarantees on delay, bandwidth or any other metric. Estimating the available bandwidth is often required before performing admission control, flows management, congestion control or routing based on bandwidth constraints so that before any new flow is admitted the existing flow does not degrade. Lot of work in terms of various tools and techniques has been proposed to evaluate the available bandwidth in last decade; no consensus has yet been arrived. We present a comprehensive review on the various state of art work proposed carried out in this area

  20. 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.

  1. 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 the...

  2. 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.

  3. 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.

  4. 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...

  5. Shared Consumption : A Technological Analysis

    OpenAIRE

    John A. Weymark

    2004-01-01

    James Buchanan (Economica, [1966]) has argued that Alfred Marshall's theory of jointly-supplied goods can be extended to analyze the allocation of impure public goods. This article introduces a way of modelling sharing technologies for jointly-supplied goods that captures the essential features of Buchanan's proposal. Public and private goods are special cases of shared goods obtained by appropriately specifying the sharing technology. Necessary conditions for an allocation in a shared goods ...

  6. 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.

  7. 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...

  8. Fractions: How to Fair Share

    Science.gov (United States)

    Wilson, P. Holt; Edgington, Cynthia P.; Nguyen, Kenny H.; Pescosolido, Ryan S.; Confrey, Jere

    2011-01-01

    Children learn from a very early age what it means to get their "fair share." Whether it is candy or birthday cake, many children successfully create equal-size groups or parts of a collection or whole but later struggle to create fair shares of multiple wholes, such as fairly sharing four pies among a family of seven. Recent research suggests…

  9. 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.

  10. Available Bandwidth Estimation in Network-Aware Applications for Wireless Campus e-Learning System

    OpenAIRE

    Mohd Faisal Ibrahim; Masita Jamal; Saadiah Yahya; Mohd Nasir Taib

    2012-01-01

    The constraint of a wireless network has motivated many researchers to develop network-aware applications that can dynamically adjust the users' demand based on network resources. For this to happen, applications need to have some mechanism that can estimate the network bandwidth by simply adjusting their behavior based on the collected network characteristics information. In the past, there have been several proposals that provide passive and active bandwidth estimation approaches for wired ...

  11. 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....

  12. 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℃.

  13. Cost Sharing in Zambia's Public Universities: Prospects and Challenges

    Science.gov (United States)

    Masaiti, Gift; Shen, Hong

    2013-01-01

    This research paper explores the concept of "cost sharing" which became more prominent in Zambia education with the advent of democratic form of governance in 1991. As a way of responding to the ever diminishing tax revenues, government through the education policy of 1996, allowed higher education institutions including public…

  14. Legal, economic and cultural aspects of file sharing

    NARCIS (Netherlands)

    van Eijk, N.; Poort, J.P.; Rutten, P.

    2010-01-01

    This contribution seeks to identify the short and long-term economic and cultural effects of file sharing on music, films and games, while taking into account the legal context and policy developments. The short-term implications examined concern direct costs and benefits to society, whereas the lon

  15. 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.

  16. 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.

  17. Varactor-tuned superconducting filter with constant absolute bandwidth at VHF-band

    Energy Technology Data Exchange (ETDEWEB)

    Li, Bo [Department of Physics, Tsinghua University, Beijing 100084 (China); Cao, Bisong, E-mail: bscao@tsinghua.edu.cn [Department of Physics, Tsinghua University, Beijing 100084 (China); Guo, Xubo; Zhang, Xiaoping [Department of Physics, Tsinghua University, Beijing 100084 (China); Chen, Yidong [Superconductor Technology Co., Ltd, Beijing 100085 (China); Wei, Bin; Jiang, Linan [Department of Physics, Tsinghua University, Beijing 100084 (China)

    2015-09-15

    Highlights: • A four-pole superconducting tunable filter at VHF-band with constant absolute bandwidth is proposed. • The novel resonator consists of a spiral-in-spiral-out (SISO) microstrip line with one end shorted to ground and the other loaded with a varactor diode. • Both combline and interdigital constructions for coupling are introduced, and tuned to meet the constant bandwidth requirements. • The measurements show bandwidth variation is less than 1.3% while tuning from 247.28 to 266.58 MHz, and a high Q{sub u} of 1600–5500 is archived. - Abstract: A four-pole superconducting tunable filter at VHF-band with constant absolute bandwidth is proposed. The resonator consists of a spiral-in-spiral-out (SISO) resonator with one end shorted to ground and the other end loaded with a varactor diode. Both combline and interdigital constructions for coupling are introduced, and tuned to meet the constant bandwidth requirement. The fabricated device has a compact size, a tuning range of 7.3% from 247.28 to 266.58, a 3-dB bandwidth of 2.32 ± 0.03 MHz. The insertion loss ranges from 0.5 to 1.6 dB, yielding a high unloaded Q of 1600–5500. The simulated and measured results show an excellent agreement.

  18. 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.

  19. 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.

  20. 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.

  1. Bandwidth turbulence control based on flow community structure in the Internet

    Science.gov (United States)

    Wu, Xiaoyu; Gu, Rentao; Ji, Yuefeng

    2016-10-01

    Bursty flows vary rapidly in short period of time, and cause fierce bandwidth turbulence in the Internet. In this letter, we model the flow bandwidth turbulence process by constructing a flow interaction network (FIN network), with nodes representing flows and edges denoting bandwidth interactions among them. To restrain the bandwidth turbulence in FIN networks, an immune control strategy based on flow community structure is proposed. Flows in community boundary positions are immunized to cut off the inter-community turbulence spreading. By applying this control strategy in the first- and the second-level flow communities separately, 97.2% flows can effectively avoid bandwidth variations by immunizing 21% flows, and the average bandwidth variation degree reaches near zero. To achieve a similar result, about 70%-90% immune flows are needed with targeted control strategy based on flow degrees and random control strategy. Moreover, simulation results showed that the control effect of the proposed strategy improves significantly if the immune flow number is relatively smaller in each control step.

  2. Using the Sirocco File System for high-bandwidth checkpoints.

    Energy Technology Data Exchange (ETDEWEB)

    Klundt, Ruth Ann; Curry, Matthew L.; Ward, H. Lee

    2012-02-01

    The Sirocco File System, a file system for exascale under active development, is designed to allow the storage software to maximize quality of service through increased flexibility and local decision-making. By allowing the storage system to manage a range of storage targets that have varying speeds and capacities, the system can increase the speed and surety of storage to the application. We instrument CTH to use a group of RAM-based Sirocco storage servers allocated within the job as a high-performance storage tier to accept checkpoints, allowing computation to potentially continue asynchronously of checkpoint migration to slower, more permanent storage. The result is a 10-60x speedup in constructing and moving checkpoint data from the compute nodes. This demonstration of early Sirocco functionality shows a significant benefit for a real I/O workload, checkpointing, in a real application, CTH. By running Sirocco storage servers within a job as RAM-only stores, CTH was able to store checkpoints 10-60x faster than storing to PanFS, allowing the job to continue computing sooner. While this prototype did not include automatic data migration, the checkpoint was available to be pushed or pulled to disk-based storage as needed after the compute nodes continued computing. Future developments include the ability to dynamically spawn Sirocco nodes to absorb checkpoints, expanding this mechanism to other fast tiers of storage like flash memory, and sharing of dynamic Sirocco nodes between multiple jobs as needed.

  3. 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.

  4. Borrowing brainpower - sharing insecurities

    DEFF Research Database (Denmark)

    Wegener, Charlotte; Meier, Ninna; Ingerslev, Karen

    2016-01-01

    Academic writing is a vital, yet complex skill that must be developed within a doctoral training process. In addition, becoming an academic researcher is a journey of changing sense of self and identity. Through analysis of a group session, we show how the feedback of peers addresses questions...... of structure and writing style along with wider issues of researcher identity. Thus, peer learning is demonstrated as a process of simultaneously building a text and an identity as scholarly researcher. The paper advocates ‘borrowing brainpower’ from peers in order to write better texts and, at the same time......, ‘share insecurities’ during the development of the researcher identity. Based on a distributed notion of peer learning and identity, we point to the need for further research into the everyday activities of doctoral writing groups in order to understand the dynamic relationship between production of text...

  5. 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.

  6. 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

    are used locally as the distributed secondary controllers in each converter to enhance the current sharing accuracy and restore the dc bus voltage simultaneously. All the controllers are realized locally and the LBC system is only used for changing the data of dc voltage and current. Thus, a decentralized......, 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...

  7. Biomedical Data Sharing, Security and Standards

    Directory of Open Access Journals (Sweden)

    Belinda Seto

    2007-06-01

    Full Text Available The National Institutes of Health (NIH implemented a policy on data sharing in 2003. The policy reaffirmed the principle that data should be made as widely and freely available as possible while safeguarding the privacy of research participants, and protecting confidential and proprietary data. Restricted availability of unique resources upon which further studies are dependent can impede the advancement of research and the delivery of medical care. Therefore, research data supported with NIH funds should be made readily available for research purposes to qualified individuals within the scientific community.  One approach to sharing data is to establish a network of databases. However, there are a number of barriers to creating successful networks, which can include fundamental differences in informatics infrastructure and communication tools used at various research sites. Solutions will entail standards for data collection, processing, and archiving to allow interoperability among the databases and the ability to query data across databases. Open architectures for data collection as well as software to facilitate communication across different databases are needed.

  8. Secret Sharing and Proactive Renewal of Shares in Hierarchical Groups

    CERN Document Server

    Naskar, Ruchira; 10.5121/ijcsit.2010.2312

    2010-01-01

    Secret sharing in user hierarchy represents a challenging area for research. Although a lot of work has already been done in this direc- tion, this paper presents a novel approach to share a secret among a hierarchy of users while overcoming the limitations of the already exist- ing mechanisms. Our work is based on traditional (k +1; n)-threshold secret sharing, which is secure as long as an adversary can compromise not more than k secret shares. But in real life it is often feasible for an adversary to obtain more than k shares over a long period of time. So, in our work we also present a way to overcome this vulnerability, while implementing our hierarchical secret sharing scheme. The use of Elliptic Curve Cryptography makes the computations easier and faster in our work.

  9. Fostering EMA's transparency policy

    DEFF Research Database (Denmark)

    Banzi, Rita; Bertele', Vittorio; Demotes-Mainard, Jacques

    2014-01-01

    The European Medicines Agency has opened a window to access clinical trial data. This is an important step forward which deserves attention, support, and advice from all the stakeholders. Regulatory agencies are the most comprehensive repositories of clinical trial data on drugs and can also...... promote and develop standard practices for data sharing. The release of the EMA draft policy on publication and access to clinical trial data in 2013 has fueled a lively debate among academia, industry, and the public in general that is still ongoing. As clinical researchers and producers and users...... of clinical trial data, we endorse the European Medicines Agency's opening and offer a few suggestions for complete, safe, and effective data sharing....

  10. 产业政策、信息披露与分析师行为--来自深圳A股市场的经验证据%Industrial Policy,Information Disclosure and Analysts’ Behavior:The Empirical Evidence from Shenzhen A-Share Market

    Institute of Scientific and Technical Information of China (English)

    潘亮

    2015-01-01

    信息性质是影响分析师行为的重要因素。信息来源越广,信息质量越高,分析师的跟进数量越多,预测准确度越高,分歧度越小。以2003~2010年深圳A股市场的行业为样本,研究发现,分析师对受到产业政策影响且整体信息披露质量较高的行业兴趣更大,预测准确度较高,但预测分歧度并未因此减小。对处于国家调控行业内的公司,将相应的产业政策与公司公开披露的信息结合分析,才能更加全面地观察到信息性质对分析师行为的影响。%The information property is an important factor which affects analysts ’ behavior.The wider the sources of information,the higher the quality of information,the larger the number of analysts following, the higher the forecast accuracy and the smaller the forecast dispersion.We choose a sample of industries in Shenzhen A-share market for the year 2003 ~2010, the research indicates that analysts have more interest in the industries which are influenced by the industrial policies and whose overall information disclosure quality are higher,and ana-lyst’ s forecast accuracy is higher, but the forecast dispersion does not reduce.To the certain companies within the very industries which are regulated by the country,we should analyze them with the combination of the industrial policy and company public information,only then can we fully observe the influence of information property on ana-lysts’ behavior.

  11. Summation bandwidths at threshold in normal and hearing-impaired listeners.

    Science.gov (United States)

    Higgins, M B; Turner, C W

    1990-12-01

    The bandwidths for summation at threshold were measured for subjects with normal hearing and subjects with sensorineural hearing loss. Thresholds in quiet and in the presence of a masking noise were measured for complex stimuli consisting of 1 to 40 pure-tone components spaced 20 Hz apart. The single component condition consisted of a single pure tone at 1100 Hz; additional components were added below this frequency, in a replication of the Gässler [Acustica 4, 408-414 (1954)] procedure. For the normal subjects, thresholds increased approximately 3 dB per doubling of bandwidth for signal bandwidths exceeding the critical bandwidth. This slope was less for the hearing-impaired subjects. Summation bandwidths, as estimated from two-line fits, were wider for the hearing-impaired than for the normal subjects. These findings provide evidence that hearing-impaired subjects integrate sound energy over a wider-than-normal frequency range for the detection of complex signals. A second experiment used stimuli similar to those of Spiegel [J. Acoust. Soc. Am. 66, 1356-1363 (1979)], and added components both above and below the frequency of the initial component. Using these stimuli, the slope of the threshold increase beyond the critical bandwidth was approximately 1.5 dB per doubling of bandwidth, thus replicating the Spiegel (1979) experiment. It is concluded that the differences between the Gässler (1954) and Spiegel (1979) studies were due to the different frequency content of the stimuli used in each study. Based upon the present results, it would appear that the slope of threshold increase is dependent upon the direction of signal expansion, and the size of the critical bands into which the signal is expanded.

  12. Data sharing in neuroimaging research

    Directory of Open Access Journals (Sweden)

    Jean-Baptiste ePoline

    2012-04-01

    Full Text Available Significant resources around the world have been invested in neuroimaging studies of brain function and disease. Easier access to this large body of work should have profound impact on research in cognitive neuroscience and psychiatry, leading to advances in the diagnosis and treatment of psychiatric and neurological disease. A trend toward increased sharing of neuroimaging data has emerged in recent years. Nevertheless, a number of barriers continue to impede momentum. Many researchers and institutions remain uncertain about how to share data or lack the tools and expertise to participate in data sharing. The use of electronic data capture methods for neuroimaging greatly simplifies the task of data collection and has the potential to help standardize many aspects of data sharing. We review here the motivations for sharing neuroimaging data, the current data sharing landscape, and the sociological or technical barriers that still need to be addressed. The INCF Task Force on Neuroimaging Datasharing, in conjunction with several collaborative groups around the world, has started work on several tools to ease and eventually automate the practice of data sharing. It is hoped that such tools will allow researchers to easily share raw, processed, and derived neuroimaging data, with appropriate metadata and provenance records, and will improve the reproducibility of neuroimaging studies. By providing seamless integration of data sharing and analysis tools within a commodity research environment, the Task Force seeks to identify and minimize barriers to data sharing in the field of neuroimaging.

  13. 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

  14. Alluring Ideas: Cherry Picking Policy from around the World

    Science.gov (United States)

    Winstanley, Carrie

    2012-01-01

    A common feature of contemporary policymaking is the sharing and adaptation of policies from other countries. As neo-liberal globalisation continues to impact on the development of policy, such practices are increasingly commonplace. This article considers the current phenomenon of "policy borrowing" with reference to the use of data…

  15. Democracy in Education through Community-Based Policy Dialogues

    Science.gov (United States)

    Winton, Sue

    2010-01-01

    In 2008, People for Education, an Ontario-based parent-led organization, hosted eight policy dialogues with citizens about possibilities for the province's public schools. Policy dialogues are conversations about policy issues, ideas, processes, and outcomes where participants share their knowledge, perspectives, and experiences. In small groups…

  16. Nordic Energy Policy Cooperation

    DEFF Research Database (Denmark)

    Jørgensen, Birte Holst

    2016-01-01

    the borders long before the politicians supported and pushed for further cooperation. Energy efficiency was addressed by a portfolio of activities ranging from knowledge-sharing, public campaigns, labelling and standardisation of products. The need to address environmental degradation was inspired by the UN...... officials. With the consolidation of Nordic Energy Research in 1999, the cooperation benefitted from having an institution that exclusively could focus on Nordic energy policy issues and deliver research-based decision support to decision makers in the Nordic energy sector....

  17. Globalisation and social policy.

    Science.gov (United States)

    Langmore, J

    2001-01-01

    This paper discusses six major themes: that economic and social issues are closely interdependent and that the appropriate stance is to work on both together, simultaneously; that though the threats from globalisation have been exaggerated, there can be substantial costs as well as considerable benefits; that constraints on national policy are significant but are less severe than is commonly considered; that the vitality-the vigour-of national and international political processes must be increased to cope effectively with the changes which are underway; that the private sector, unions and civil society have crucial roles in the provision of services and in advocating socially responsible values, standards and policies; and that one of the most effective means of addressing the erosion of national autonomy from globalisation is for countries to cooperate in setting and implementing shared objectives and international standards and establishing more global public goods.

  18. Energy policy in Denmark

    Energy Technology Data Exchange (ETDEWEB)

    Lidegaard, M.

    2012-12-15

    Denmark has a long tradition of active energy policy, initiated by the first oil crisis in 1973. Over the years, numerous actions have been taken on the basis of a broad consensus in the Danish Parliament - both in order to reduce the energy consumption and in order to increase the share of renewable energy. Now, the cornerstones for the Danish energy future have also been laid. The Danish Government has set the long-term goal to abandon fossil fuels by 2050. An important milestone was reached in March 2012 with an Energy Agreement for the period 2012-2020 - again based on a broad consensus in the Danish Parliament. This Agreement contains a wide range of ambitious initiatives, bringing Denmark a good step closer to the target of 100% renewable energy. In the present publication, a selection of past and present Danish energy policies is presented, together with the results achieved in terms of energy savings, use of renewables etc. (LN)

  19. 2013 Information Sharing Environment Performance Data

    Data.gov (United States)

    Information Sharing Environment — This is a survey of federal departments and agencies who share terrorism information and are therefore considered part of the Information Sharing Environment. The...

  20. 2012 Information Sharing Environment Performance Data

    Data.gov (United States)

    Information Sharing Environment — This is a survey of federal departments and agencies who share terrorism information and are therefore considered part of the Information Sharing Environment. The...

  1. Monetary Policy and Economic Policy

    Directory of Open Access Journals (Sweden)

    Iordachioaia Adelina-Geanina

    2011-02-01

    Full Text Available There is widespread agreement that monetary policy matters,but there is disagreement about how it should be conducted. Behind this disagreement lie differences in theoretical understandings. The paper contrasts the New Classical, Neo-Keynesian, and Post-Keynesian frameworks, there by surfacing the differences. The New Classical model has policy only affecting long run inflation. The Neo-Keynesian has policy impacting inflation, unemployment, and real wages. The Post-Keynesian model also impacts growth, so policy implicitly picks a quadruple. Inflation targeting is a sub-optimal policy frame because it biases decisions toward low inflation by obscuring the fact that policy also affects unemployment, real wages, and growth.

  2. Challenges in sharing information effectively

    DEFF Research Database (Denmark)

    Sonnenwald, Diane H.

    2006-01-01

    were not recognized; implications of relevant information were not shared; differences in the role and expression of emotions when sharing information was not understood; and, the need to reestablish trust was not recognized. Conclusion. The challenges in information sharing identified here may extend...... to other high stress, unique and complex situations, such as natural disasters. Recommendations for more effective information behaviour techniques in dynamic group work situations are presented....

  3. SharePoint User's Guide

    CERN Document Server

    Corporation, Infusion Development

    2009-01-01

    This straightforward guide shows SharePoint users how to create and use web sites for sharing and collaboration. Learn to use the document and picture libraries for adding and editing content, add discussion boards and surveys, receive alerts when documents and information have been added or changed, and enhance security. Designed to help you find answers quickly, the book shows how to make the most of SharePoint for productivity and collaboration.

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

    Science.gov (United States)

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

    2012-10-01

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

  5. 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.

  6. 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.

  7. Modeling Shared Variables in VHDL

    DEFF Research Database (Denmark)

    Madsen, Jan; Brage, Jens P.

    1994-01-01

    A set of concurrent processes communicating through shared variables is an often used model for hardware systems. This paper presents three modeling techniques for representing such shared variables in VHDL, depending on the acceptable constraints on accesses to the variables. Also a set of guide......A set of concurrent processes communicating through shared variables is an often used model for hardware systems. This paper presents three modeling techniques for representing such shared variables in VHDL, depending on the acceptable constraints on accesses to the variables. Also a set...

  8. Technology Mediated Information Sharing (Monitor Sharing) in Primary Care Encounters

    Science.gov (United States)

    Asan, Onur

    2013-01-01

    The aim of this dissertation study was to identify and describe the use of electronic health records (EHRs) for information sharing between patients and clinicians in primary-care encounters and to understand work system factors influencing information sharing. Ultimately, this will promote better design of EHR technologies and effective training…

  9. Processor-sharing queues and resource sharing in wireless LANs

    NARCIS (Netherlands)

    Cheung, Sing Kwong

    2007-01-01

    In the past few decades, the processor-sharing (PS) model has received considerable attention in the queueing theory community and in the field of performance evaluation of computer and communication systems. The scarce resource is simultaneously shared among all users in these systems. PS models ar

  10. Data Sharing & Publishing at Nature Publishing Group

    Science.gov (United States)

    VanDecar, J. C.; Hrynaszkiewicz, I.; Hufton, A. L.

    2015-12-01

    In recent years, the research community has come to recognize that upon-request data sharing has important limitations1,2. The Nature-titled journals feel that researchers have a duty to share data without undue qualifications, in a manner that allows others to replicate and build upon their published findings. Historically, the Nature journals have been strong supporters of data deposition in communities with existing data mandates, and have required data sharing upon request in all other cases. To help address some of the limitations of upon-request data sharing, the Nature titles have strengthened their existing data policies and forged a new partnership with Scientific Data, to promote wider data sharing in discoverable, citeable and reusable forms, and to ensure that scientists get appropriate credit for sharing3. Scientific Data is a new peer-reviewed journal for descriptions of research datasets, which works with a wide of range of public data repositories4. Articles at Scientific Data may either expand on research publications at other journals or may be used to publish new datasets. The Nature Publishing Group has also signed the Joint Declaration of Data Citation Principles5, and Scientific Data is our first journal to include formal data citations. We are currently in the process of adding data citation support to our various journals. 1 Wicherts, J. M., Borsboom, D., Kats, J. & Molenaar, D. The poor availability of psychological research data for reanalysis. Am. Psychol. 61, 726-728, doi:10.1037/0003-066x.61.7.726 (2006). 2 Vines, T. H. et al. Mandated data archiving greatly improves access to research data. FASEB J. 27, 1304-1308, doi:10.1096/fj.12-218164 (2013). 3 Data-access practices strengthened. Nature 515, 312, doi:10.1038/515312a (2014). 4 More bang for your byte. Sci. Data 1, 140010, doi:10.1038/sdata.2014.10 (2014). 5 Data Citation Synthesis Group: Joint Declaration of Data Citation Principles. (FORCE11, San Diego, CA, 2014).

  11. Payments and Central Bank Policy

    DEFF Research Database (Denmark)

    Korsgaard, Søren

    This thesis consists of three chapters. The rst, "Paying for Payments", examines the role of interchange fees in payment card networks. The second, "Bank Liquidity and the Interbank Market" (co-authored with Mikael Reimer Jensen), investigates how banks' liquidity holdings at the central bank a ect...... outcomes in the money market. The third, "Collateralized Lending and Central Bank Collateral Policy", considers the emergence of credit constraints under collateralized lending, and how central banks use collateral policy to mitigate these constraints. While the chapters can be read independently......, they share common themes. Each chapter is concerned with payments in one way or another, each is concerned with the e ciency of market outcomes, and, to the extent that there is scope for improving these outcomes, each discusses the appropriate role for policy, in particular central bank policy....

  12. Optimization of Single-Sensor Two-State Hot-Wire Anemometer Transmission Bandwidth.

    Science.gov (United States)

    Ligęza, Paweł

    2008-10-28

    Hot-wire anemometric measurements of non-isothermal flows require the use of thermal compensation or correction circuitry. One possible solution is a two-state hot-wire anemometer that uses the cyclically changing heating level of a single sensor. The area in which flow velocity and fluid temperature can be measured is limited by the dimensions of the sensor's active element. The system is designed to measure flows characterized by high velocity and temperature gradients, although its transmission bandwidth is very limited. In this study, we propose a method to optimize the two-state hot-wire anemometer transmission bandwidth. The method is based on the use of a specialized constanttemperature system together with variable dynamic parameters. It is also based on a suitable measurement cycle paradigm. Analysis of the method was undertaken using model testing. Our results reveal a possible significant broadening of the two-state hot-wire anemometer's transmission bandwidth.

  13. 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...... reserved for the servers determines the quality of service (QoS) for soft tasks. CBS enforces temporal isolation, such that soft task overruns do not affect the timing guarantees of hard tasks. Transient faults in hard tasks are tolerated using checkpointing with rollback recovery. We have proposed a Tabu...... Search-based approach for task mapping and CBS bandwidth reservation, such that the deadlines for the hard tasks are satisfied, even in the case of transient faults, and the QoS for the soft tasks is maximized. Researchers have used fixed execution time models, such as the worst-case execution times...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-05-15

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-06-01

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

  16. Wide Bandwidth Microwave Absorbers of Ferrite-Rubber Composites with Square-Rod Structure

    Directory of Open Access Journals (Sweden)

    Kim Sung-Soo

    2016-01-01

    Full Text Available As one way of shape control for the wide bandwidth in microwave absorbers, a square-rod structure of ferrite composite is proposed. Microwave absorbance of the square-rod absorber is analyzed by the transmission line approximation which provides the reflection loss as a function of material parameters and dimension of the structure. In particular, the absorption bandwidth is greatly dependent upon the size of the square rod, which has been identified in both composites of Ni-Zn ferrite and Co2Z hexagonal ferrites. With a controlled geometry of square rod in those composites, a wide bandwidth (about 6 GHz with respect to – 20 dB reflection loss has been predicted.

  17. Three-Dimensional Single-Port Labyrinthine Acoustic Metamaterial: Perfect Absorption with Large Bandwidth and Tunability

    Science.gov (United States)

    Zhang, Chi; Hu, Xinhua

    2016-12-01

    Metamaterials are engineered materials which exhibit fascinating properties unreachable by traditional materials. Here, we report on the design, fabrication, and experimental characterization of a three-dimensional single-port labyrinthine acoustic metamaterial. By using curled perforations with one end closed and with appropriate loss inside, the metamaterial can perfectly absorb airborne sounds in a low-frequency band. Both the position and the relative width of the band can be tuned flexibly. A trade-off is uncovered between the relative absorption bandwidth and thickness of the metamaterial. When the relative absorption bandwidth is as high as 51%, the requirement of deep-subwavelength thickness (0.07 λ ) can still be satisfied. We emphasize that the perfect absorption with large tunability in relative bandwidth (from 9% to >180 % ) was not attainable previously and may find applications ranging from noise reduction to sound imaging.

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

    Institute of Scientific and Technical Information of China (English)

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

    2012-01-01

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

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

    Science.gov (United States)

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

    2015-10-01

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

  20. Global path and bandwidth scheduling in inter-data-center IP/optical transport network

    Science.gov (United States)

    Zhao, Yang; Wang, Lei; Chen, Xue; Yang, Futao; Shi, Sheping; Wang, Huitao

    2016-07-01

    We propose a flow-oriented global path and bandwidth scheduling scheme for inter-data-center IP/optical network. To improve the throughput of network and reduce the mutual impact between flows, we allow each flow to be carried by a multi-path optical channel data unit (ODU) channel. In addition bandwidth is allocated to flows fairly according to weight. Simulation results reveal that compared to high-priority-first mechanism, the method proposed improves average bandwidth allocation ratio by about 15% and allocation fairness between flows by 30%. Furthermore, compared to pure IP network, router ports are significantly saved and network cost can be reduced by up to 40% with scheme proposed in unified controlled IP/optical network.

  1. A Distributed Cluster Scheme For Bandwidth Management In Multi-hop MANETs

    CERN Document Server

    Pattanayak, Binod Kumar; Mishra, Manoj Kumar; Nayak, Manoj Ranjan

    2010-01-01

    Electronic collaboration among devices in a geographically localized environment is made possible with the implementation of IEEE 802.11 based wireless ad hoc networks. Dynamic nature of mobile ad hoc networks(MANETs) may lead to unpredictable intervention of attacks or fault occurrence, which consequently may partition the network, degrade its performance, violate the QoS requirements and most importantly, affect bandwidth allocation to mobile nodes in the network. In this paper, we propose a new distributed cluster scheme for MANETs, especially in harsh environments, based on the concept of survivability to support QoS requirements and to protect bandwidth efficiently. With the incorporation of clustering algorithms in survivability technology, we employ a simple network configuration and expect to reduce occurrences of faults in MANETs. At the same time, we address the scalability problem, which represents a great challenge to network configuration. We do expect a simplification of accessing bandwidth allo...

  2. Practical security of continuous-variable quantum key distribution with finite sampling bandwidth effects

    Science.gov (United States)

    Wang, Chao; Huang, Peng; Huang, Duan; Lin, Dakai; Zeng, Guihua

    2016-02-01

    Practical security of the continuous-variable quantum key distribution (CVQKD) system with finite sampling bandwidth of analog-to-digital converter (ADC) at the receiver's side is investigated. We find that the finite sampling bandwidth effects may decrease the lower bound of secret key rate without awareness of the legitimate communicators. This leaves security loopholes for Eve to attack the system. In addition, this effect may restrains the linear relationship of secret key bit rate with repetition rate of the system; subsequently, there is a saturation value for the secret key bit rate with the repetition rate. To resist such kind of effects, we propose a dual sampling detection approach in which two ADCs are employed so that the finite sampling bandwidth effects are removed.

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

    CERN Document Server

    Zagorodnov, I; Limberg, T

    2016-01-01

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

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

    Science.gov (United States)

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

    2016-11-01

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

  5. Bandwidth and Gain Enhancement of Patch Antenna with Stacked Parasitic Strips Based on LTCC Technology

    Directory of Open Access Journals (Sweden)

    Li Li

    2014-01-01

    Full Text Available A compact patch antenna with stacked parasitic strips (SPSs based on low temperature cofired ceramic (LTCC technology is presented. By adding three pairs of SPSs above the traditional patch antenna, multiple resonant modes are excited to broaden the bandwidth. At the same time, the SPSs act as directors to guide the antenna radiation toward broadside direction to enhance the gain. The measured results show that the prototype antenna achieves an impedance bandwidth of 16% for S11<-10 dB (32.1–37.9 GHz and a maximum gain of about 8 dBi at 35 GHz. Furthermore, the radiation patterns and gain are relatively stable within the operating bandwidth. The total volume of the antenna is only 8 × 8 × 1.1 mm3.

  6. Robust Design of Virtual Topology for WDM Networks under Bandwidth Demand Uncertainties

    Institute of Scientific and Technical Information of China (English)

    YANG Fei; LI Le-min; WANG Sheng; GUO Lei; ZHANG Yan-ni

    2007-01-01

    In this paper, a novel method is proposed to address the problem of designing virtual topology over wavelength division multiplexing (WDM) networks under bandwidth demand uncertainties. And a bandwidth demand model under uncertainties is presented. The optimization goal of virtual topology design is defimed as minimizing the maximum value among p percentiles of the bandwidth demand distribution on all light-paths. Correspondingly, we propose a heuristic algorithm called an improved decreasing multi-hop logical topology design algorithm(ID-MLTDA) that involves with a degree of uncertainties to design virtual topology. The proposed algorithm yields better performance than previous algorithms. Additionally, the simplicity and efficiency of the proposed algorithm can be in favor of the feasibility for topology design of large networks.

  7. Fully Controllable Pancharatnam-Berry Metasurface Array with High Conversion Efficiency and Broad Bandwidth

    Science.gov (United States)

    Liu, Chuanbao; Bai, Yang; Zhao, Qian; Yang, Yihao; Chen, Hongsheng; Zhou, Ji; Qiao, Lijie

    2016-01-01

    Metasurfaces have powerful abilities to manipulate the properties of electromagnetic waves flexibly, especially the modulation of polarization state for both linearly polarized (LP) and circularly polarized (CP) waves. However, the transmission efficiency of cross-polarization conversion by a single-layer metasurface has a low theoretical upper limit of 25% and the bandwidth is usually narrow, which cannot be resolved by their simple additions. Here, we efficiently manipulate polarization coupling in multilayer metasurface to promote the transmission of cross-polarization by Fabry-Perot resonance, so that a high conversion coefficient of 80–90% of CP wave is achieved within a broad bandwidth in the metasurface with C-shaped scatters by theoretical calculation, numerical simulation and experiments. Further, fully controlling Pancharatnam-Berry phase enables to realize polarized beam splitter, which is demonstrated to produce abnormal transmission with high conversion efficiency and broad bandwidth. PMID:27703254

  8. Dynamic Online Bandwidth Adjustment Scheme Based on Kalai-Smorodinsky Bargaining Solution

    Science.gov (United States)

    Kim, Sungwook

    Virtual Private Network (VPN) is a cost effective method to provide integrated multimedia services. Usually heterogeneous multimedia data can be categorized into different types according to the required Quality of Service (QoS). Therefore, VPN should support the prioritization among different services. In order to support multiple types of services with different QoS requirements, efficient bandwidth management algorithms are important issues. In this paper, I employ the Kalai-Smorodinsky Bargaining Solution (KSBS) for the development of an adaptive bandwidth adjustment algorithm. In addition, to effectively manage the bandwidth in VPNs, the proposed control paradigm is realized in a dynamic online approach, which is practical for real network operations. The simulations show that the proposed scheme can significantly improve the system performances.

  9. Narrow Bandwidth 850-nm Fiber Bragg Gratings in Few-Mode Polymer Optical Fibers

    DEFF Research Database (Denmark)

    Stefani, Alessio; Yuan, Wu; Markos, Christos;

    2011-01-01

    We report on the inscription and characterization of narrow bandwidth fiber Bragg gratings (FBGs) with 850-nm resonance wavelength in polymer optical fibers (POFs). We use two fibers: an in-house fabricated microstructured POF (mPOF) with relative hole size of 0.5 and a commercial step-index POF......, which supports six modes at 850 nm. The gratings have been written with the phase-mask technique and a 325-nm HeCd laser. The mPOF grating has a full-width at half-maximum (FWHM) bandwidth of 0.29 nm and the step-index POF has a bandwidth of 0.17 nm. For both fibers, the static tensile strain...

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

    Directory of Open Access Journals (Sweden)

    Xibin Zhang

    2016-04-01

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

  11. Measurement of Coherence Bandwidth in UHF Radio Channels for Narrowband Networks

    Directory of Open Access Journals (Sweden)

    Jaroslaw Sadowski

    2015-01-01

    Full Text Available This paper presents results of investigation on the coherence bandwidth of narrowband radio channels in 430 MHz band. The coherence bandwidth values were estimated from a power delay profile obtained by recording CDMA2000 forward channel signals during real-field measurements in various environments: medium city, flat terrain, and hilly terrain in northern Poland. The results of measurements are compared with characteristic parameters of UHF radio channel models defined for exemplary narrowband digital system from the TETRA standard. In all of the tested environments, the coherence bandwidth values during most of an observation time were much higher than 25 kHz. Therefore, the fading in tested UHF narrowband channels should be classified as flat fading.

  12. Narrowing the filter-cavity bandwidth in gravitational-wave detectors via optomechanical interaction.

    Science.gov (United States)

    Ma, Yiqiu; Danilishin, Shtefan L; Zhao, Chunnong; Miao, Haixing; Korth, W Zach; Chen, Yanbei; Ward, Robert L; Blair, D G

    2014-10-10

    We propose using optomechanical interaction to narrow the bandwidth of filter cavities for achieving frequency-dependent squeezing in advanced gravitational-wave detectors, inspired by the idea of optomechanically induced transparency. This can allow us to achieve a cavity bandwidth on the order of 100 Hz using small-scale cavities. Additionally, in contrast to a passive Fabry-Pérot cavity, the resulting cavity bandwidth can be dynamically tuned, which is useful for adaptively optimizing the detector sensitivity when switching amongst different operational modes. The experimental challenge for its implementation is a stringent requirement for very low thermal noise of the mechanical oscillator, which would need a superb mechanical quality factor and a very low temperature. We consider one possible setup to relieve this requirement by using optical dilution to enhance the mechanical quality factor.

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

    Science.gov (United States)

    Li, Mingfu

    2014-01-01

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

  14. Attitudes to Sharing Personal Health Information in Living Kidney Donation

    Science.gov (United States)

    Hizo-Abes, Patricia; Young, Ann; Reese, Peter P.; McFarlane, Phil; Wright, Linda; Cuerden, Meaghan

    2010-01-01

    Background and objectives: In living kidney donation, transplant professionals consider the rights of a living kidney donor and recipient to keep their personal health information confidential and the need to disclose this information to the other for informed consent. In incompatible kidney exchange, personal health information from multiple living donors and recipients may affect decision making and outcomes. Design, setting, participants, & measurements: We conducted a survey to understand and compare the preferences of potential donors (n = 43), potential recipients (n = 73), and health professionals (n = 41) toward sharing personal health information (in total 157 individuals). Results: When considering traditional live-donor transplantation, donors and recipients generally agreed that a recipient's health information should be shared with the donor (86 and 80%, respectively) and that a donor's information should be shared with the recipient (97 and 89%, respectively). When considering incompatible kidney exchange, donors and recipients generally agreed that a recipient's information should be shared with all donors and recipients involved in the transplant (85 and 85%, respectively) and that a donor's information should also be shared with all involved (95 and 90%, respectively). These results were contrary to attitudes expressed by transplant professionals, who frequently disagreed about whether such information should be shared. Conclusions: Future policies and practice could facilitate greater sharing of personal health information in living kidney donation. This requires a consideration of which information is relevant, how to put it in context, and a plan to obtain consent from all concerned. PMID:20299371

  15. Removal of eye blink artifacts in wireless EEG sensor networks using reduced-bandwidth canonical correlation analysis

    Science.gov (United States)

    Somers, Ben; Bertrand, Alexander

    2016-12-01

    Objective. Chronic, 24/7 EEG monitoring requires the use of highly miniaturized EEG modules, which only measure a few EEG channels over a small area. For improved spatial coverage, a wireless EEG sensor network (WESN) can be deployed, consisting of multiple EEG modules, which interact through short-distance wireless communication. In this paper, we aim to remove eye blink artifacts in each EEG channel of a WESN by optimally exploiting the correlation between EEG signals from different modules, under stringent communication bandwidth constraints. Approach. We apply a distributed canonical correlation analysis (CCA-)based algorithm, in which each module only transmits an optimal linear combination of its local EEG channels to the other modules. The method is validated on both synthetic and real EEG data sets, with emulated wireless transmissions. Main results. While strongly reducing the amount of data that is shared between nodes, we demonstrate that the algorithm achieves the same eye blink artifact removal performance as the equivalent centralized CCA algorithm, which is at least as good as other state-of-the-art multi-channel algorithms that require a transmission of all channels. Significance. Due to their potential for extreme miniaturization, WESNs are viewed as an enabling technology for chronic EEG monitoring. However, multi-channel analysis is hampered in WESNs due to the high energy cost for wireless communication. This paper shows that multi-channel eye blink artifact removal is possible with a significantly reduced wireless communication between EEG modules.

  16. Power and Efficiency Optimized in Traveling-Wave Tubes Over a Broad Frequency Bandwidth

    Science.gov (United States)

    Wilson, Jeffrey D.

    2001-01-01

    A traveling-wave tube (TWT) is an electron beam device that is used to amplify electromagnetic communication waves at radio and microwave frequencies. TWT's are critical components in deep space probes, communication satellites, and high-power radar systems. Power conversion efficiency is of paramount importance for TWT's employed in deep space probes and communication satellites. A previous effort was very successful in increasing efficiency and power at a single frequency (ref. 1). Such an algorithm is sufficient for narrow bandwidth designs, but for optimal designs in applications that require high radiofrequency power over a wide bandwidth, such as high-density communications or high-resolution radar, the variation of the circuit response with respect to frequency must be considered. This work at the NASA Glenn Research Center is the first to develop techniques for optimizing TWT efficiency and output power over a broad frequency bandwidth (ref. 2). The techniques are based on simulated annealing, which has the advantage over conventional optimization techniques in that it enables the best possible solution to be obtained (ref. 3). Two new broadband simulated annealing algorithms were developed that optimize (1) minimum saturated power efficiency over a frequency bandwidth and (2) simultaneous bandwidth and minimum power efficiency over the frequency band with constant input power. The algorithms were incorporated into the NASA coupled-cavity TWT computer model (ref. 4) and used to design optimal phase velocity tapers using the 59- to 64-GHz Hughes 961HA coupled-cavity TWT as a baseline model. In comparison to the baseline design, the computational results of the first broad-band design algorithm show an improvement of 73.9 percent in minimum saturated efficiency (see the top graph). The second broadband design algorithm (see the bottom graph) improves minimum radiofrequency efficiency with constant input power drive by a factor of 2.7 at the high band edge (64

  17. Food Sharing: An Evolutionary Perspective.

    Science.gov (United States)

    Feinman, Saul

    Food altruism and the consumption of food are examined from a sociological perspective which assumes that humans share food as inclusive fitness actors. Inclusive fitness implies the representation of an individual's genes in future generations through his own or others' offspring. The discussion includes characteristics of food sharing among kin…

  18. Unveiling the Knowledge Sharing Culture

    NARCIS (Netherlands)

    Hendriks, P.H.J.

    2009-01-01

    It is generally acknowledged that organisation culture affects how knowledge processes such as knowledge-sharing evolve. Despite the growing attention to the aspects of culture, the knowledge management debate has not paid systematic attention to the assessment or measurement of a knowledge-sharing

  19. SECTORAL SHARES AND ECONOMIC GROWTH

    DEFF Research Database (Denmark)

    Ahmad, Nisar; Naveed, Amjad; Naz, Amber

    2013-01-01

    In developed countries, the share of services and industrial sector has increased in the past few decades and at the same time the share of agriculture sector went down considerably. In the literature, there exists a debate about structural change in the developed countries. Neoclassical economists...

  20. Knowledge Sharing: Developing from within

    Science.gov (United States)

    Patrick, Keith; Dotsika, Fefie

    2007-01-01

    Purpose: If collaboration and knowledge sharing lie at the core of providing added-value to either services or products can we improve this process? The purpose of this paper is to suggest that it can be improved and this lies in how we develop the systems that support collaboration and knowledge sharing. This can be achieved within the…