117,356 research outputs found

    Arbitrary boolean advertisements: the final step in supporting the boolean publish/subscribe model

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    Publish/subscribe systems allow for an efficient filtering of incoming information. This filtering is based on the specifications of subscriber interests, which are registered with the system as subscriptions. Publishers conversely specify advertisements, describing the messages they will send later on. What is missing so far is the support of arbitrary Boolean advertisements in publish/subscribe systems. Introducing the opportunity to specify these richer Boolean advertisements increases the accuracy of publishers to state their future messages compared to currently supported conjunctive advertisements. Thus, the amount of subscriptions forwarded in the network is reduced. Additionally, the system can more time efficiently decide whether a subscription needs to be forwarded and more space efficiently store and index advertisements. In this paper, we introduce a publish/subscribe system that supports arbitrary Boolean advertisements and, symmetrically, arbitrary Boolean subscriptions. We show the advantages of supporting arbitrary Boolean advertisements and present an algorithm to calculate the practically required overlapping relationship among subscriptions and advertisements. Additionally, we develop the first optimization approach for arbitrary Boolean advertisements, advertisement pruning. Advertisement pruning is tailored to optimize advertisements, which is a strong contrast to current optimizations for conjunctive advertisements. These recent proposals mainly apply subscription-based optimization ideas, which is leading to the same disadvantages. In the second part of this paper, our evaluation of practical experiments, we analyze the efficiency properties of our approach to determine the overlapping relationship. We also compare conjunctive solutions for the overlapping problem to our calculation algorithm to show its benefits. Finally, we present a detailed evaluation of the optimization potential of advertisement pruning. This includes the analysis of the effects of additionally optimizing subscriptions on the advertisement pruning optimization

    Statistics for evidence-based policy in the Church of England : predicting diocesan performance

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    This study computed the percentage changes recorded on six separate performance indicators between 1991 and 2000 in order to calculate the effect of the Decade of Evangelism on the mainland dioceses of the Church of England. The performance indicators were usual Sunday attendance, Easter Sunday communicants, Christmas communicants, electoral roll membership, total baptism figures, and total confirmation figures. Statistical procedures (including cluster analysis, analysis of variance, canonical correlation analysis, and multiple regression) were then employed in order to identify from the range of variables routinely collected by the central church authorities policy-related factors associated with church growth (or at least reduced decline) over this period. These analyses identified four areas, concerned with expanding non-stipendiary ministry, with encouraging the ordination of women, with resisting church closure, and with promoting a financial policy that includes planned subscriptions and charitable giving. These conclusions are offered as an applied example of using statistics as a tool for mission and as the basis for evidence-based policy

    Dimension-Based Subscription Pruning for Publish/Subscribe Systems

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    Subscription pruning has been proven as valuable routing optimization for Boolean subscriptions in publish/ subscribe systems. It aims at optimizing subscriptions independently of each other and is thus applicable for all kinds of subscriptions regardless of their individual and collective structures. The original subscription pruning approach tries to optimize the event routing process based on the expected increase in network load. However, a closer look at pruning-based routing reveals its further applicability to optimizations in respect to other dimensions. In this paper, we introduce and investigate subscription pruning based on three dimensions of optimization: network load, memory usage, and system throughput. We present the algorithms to perform prunings based on these dimensions and discuss the results of a series of practical experiments. Our analysis reveals the advantages and disadvantages of the different dimensions of optimization and allows conclusions about the suitability of dimension-based pruning for different application requirements

    Transformations to achieve the Sustainable Development Goals Includes the SDG Index and Dashboards. Sustainable Development Report 2019

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    The Sustainable Development Report 2019 presents an updated SDG Index and Dashboards with a refined assessment of countries’ distance to SDG targets. The report has been successfully audited for the first time by the European Commission Joint Research Centre. New indicators have been included, primarily to refine the indicator selection on agriculture, diets, gender equality and freedom of speech. We have also added more metrics for international spillovers, including on fatal work accidents. A new website and data visualization tools are available (http://sustainabledevelopment.report). Once again, Nordic countries – Denmark, Sweden and Finland – top the SDG Index. Yet, even these countries face major challenges in implementing one or several SDGs. No country is on track for achieving all 17 goals with major performance gaps even in the top countries on SDG 12 (Responsible Consumption and Production), SDG 13 (Climate Action), SDG 14 (Life Below Water) and SDG 15 (Life on Land). Income and wealth inequalities, as well as gaps in health and education outcomes by population groups also remain important policy challenges in developing and developed countries alike. The Sustainable Development Report 2019 generates seven major findings: 1. High-level political commitment to the SDGs is falling short of historic promises In September 2019, heads-of-states and governments will convene for the first time in person at the UN in New York to review progress on their promises made four years after the adoption of the 2030 Agenda. Yet, our in-depth analyses show that many have not taken the critical steps to implement the SDGs. Out of 43 countries surveyed on SDG implementation efforts, including all G20 countries and countries with a population greater than 100 million, 33 countries have endorsed the SDGs in official statements since January 1st, 2018. Yet in only 18 of them do central budget documents mention the SDGs. This gap between rhetoric and action must be closed. 2. The SDGs can be operationalized through six SDG Transformations SDG implementation can be organized along the following Transformations: 1. Education, Gender, and Inequality; 2. Health, Wellbeing, and Demography; 3. Energy Decarbonization and Sustainable Industry; 4. Sustainable Food, Land, Water, Oceans; 5. Sustainable Cities and Communities; and 6. Digital Revolution for Sustainable Development. The transformations respect strong interdependencies across the SDGs and can be operationalized by well-defined parts of governments in collaboration with civil society, business, and other stakeholders. They must be underpinned and guided by the principles of Leave No One Behind and Circularity and Decoupling of resource use from human wellbeing. 3. Trends on climate (SDG 13) and biodiversity (SDG 14 and SDG 15) are alarming On average, countries obtain their worst scores on SDG 13 (Climate Action), SDG 14 (Life Below Water) and SDG 15 (Life on Land). No country obtains a “green rating” (synonym of SDG achieved) on SDG 14 (Life Below Water). Trends on greenhouse gas emissions and, even more so, on threatened species are moving in the wrong direction. These findings are in line with the recent reports from the IPCC and IPBES on climate change mitigation and biodiversity protection, respectively. 4. Sustainable land-use and healthy diets require integrated agriculture, climate and health policy interventions Land use and food production are not meeting people’s needs. Agriculture destroys forests and biodiversity, squanders water and releases one-quarter of global greenhouse-gas emissions. In total, 78% of world nations for which data are available obtain a “red rating” (synonym of major SDG challenge) on sustainable nitrogen management; the highest number of “red” rating across all indicators included in the report. At the same time, one-third of food is wasted, 800 million people remain undernourished, 2 billion are deficient in micronutrients, and obesity is on the rise. New indicators on nations’ trophic level and yield gap closure highlight the depth of the challenge. Transformations towards sustainable landuse and food systems are required to balance efficient and resilient agriculture and forestry with biodiversity conservation and restoration as well as healthy diets

    Vitis: A Gossip-based Hybrid Overlay for Internet-scale Publish/Subscribe

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    Peer-to-peer overlay networks are attractive solutions for building Internet-scale publish/subscribe systems. However, scalability comes with a cost: a message published on a certain topic often needs to traverse a large number of uninterested (unsubscribed) nodes before reaching all its subscribers. This might sharply increase resource consumption for such relay nodes (in terms of bandwidth transmission cost, CPU, etc) and could ultimately lead to rapid deterioration of the system’s performance once the relay nodes start dropping the messages or choose to permanently abandon the system. In this paper, we introduce Vitis, a gossip-based publish/subscribe system that significantly decreases the number of relay messages, and scales to an unbounded number of nodes and topics. This is achieved by the novel approach of enabling rendezvous routing on unstructured overlays. We construct a hybrid system by injecting structure into an otherwise unstructured network. The resulting structure resembles a navigable small-world network, which spans along clusters of nodes that have similar subscriptions. The properties of such an overlay make it an ideal platform for efficient data dissemination in large-scale systems. We perform extensive simulations and evaluate Vitis by comparing its performance against two base-line publish/subscribe systems: one that is oblivious to node subscriptions, and another that exploits the subscription similarities. Our measurements show that Vitis significantly outperforms the base-line solutions on various subscription and churn scenarios, from both synthetic models and real-world traces

    Improving access: is there any hope?

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    World-wide calls for improvements in access to journal literature are being answered by a plethora of projects and services. Consortial purchasing, national licences and "big deals" dominate changes in collection development. Moves to set up affordable easy-to-use electronic document delivery services offer an alternative model based on single-article purchase. More radical barrier-free access models are moving the economic emphasis away from purchasing to input-payments. Are all these projects and services making a difference or will access to journal literature be no better in years to come than it is now? It is arguable that only those initiatives which are developing new models through collaboration between the stakeholders will succeed in making a major break-through in access

    The impact of consortia purchasing of periodical publications on the document supply service

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    Purpose – This paper aims to show the impact of consortia purchased periodical publications on document supply services. These services have undergone considerable changes over the last five years, first decreasing but now recovering. Design/methodology/approach – First, this paper reviews the most recent specialised literature, focusing mainly on the impact of electronic journals in libraries, their effects, and proposed actions. Second, as an example of this new behaviour, presents the document supply service data, as collected in one hospital’s health-science library in the last four years. Findings – As evidenced by the literature, the users’ acceptance of electronic journals has undoubtedly been excellent. Consortia purchasing projects have become a basic tool that expand collections, support cooperative technological development, and require negotiating skills from librarians. But these mass purchases do not seem to be the ideal solution for libraries, they entail losing freedom when choosing the collection and often make library collections homogeneous by publisher. Originality/value – Reflects on what possible causes have led to the current situation and the current way to manage the collection.Publicad

    The IRS and Nonprofit Media: A Step Forward Toward Creating a More Informed Public

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    This is a follow up to the 2013 report, The IRS and Nonprofit Media: Toward Creating an More Informed Public and reviews the current state of IRS determinations and rules surrounding nonprofit media organizations. Nonprofit media organizations are making vital contributions to society by providing coverage on important public topics that are being abandoned by commercial organizations, such as investigative and in-depth pieces on the state of health careand schools or stories that explore the experiences of minority, ethnic, or low-income communities. Although nonprofit media organizations are providing news and information that is useful to individuals and beneficial to communities, the field would continue to benefit from updated IRS guidance on the standards for their exemption as well as a checklist to help them prepare exemption applications
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