1,969 research outputs found

    Scalable Audience Reach Estimation in Real-time Online Advertising

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    Online advertising has been introduced as one of the most efficient methods of advertising throughout the recent years. Yet, advertisers are concerned about the efficiency of their online advertising campaigns and consequently, would like to restrict their ad impressions to certain websites and/or certain groups of audience. These restrictions, known as targeting criteria, limit the reachability for better performance. This trade-off between reachability and performance illustrates a need for a forecasting system that can quickly predict/estimate (with good accuracy) this trade-off. Designing such a system is challenging due to (a) the huge amount of data to process, and, (b) the need for fast and accurate estimates. In this paper, we propose a distributed fault tolerant system that can generate such estimates fast with good accuracy. The main idea is to keep a small representative sample in memory across multiple machines and formulate the forecasting problem as queries against the sample. The key challenge is to find the best strata across the past data, perform multivariate stratified sampling while ensuring fuzzy fall-back to cover the small minorities. Our results show a significant improvement over the uniform and simple stratified sampling strategies which are currently widely used in the industry

    Blazes: Coordination Analysis for Distributed Programs

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    Distributed consistency is perhaps the most discussed topic in distributed systems today. Coordination protocols can ensure consistency, but in practice they cause undesirable performance unless used judiciously. Scalable distributed architectures avoid coordination whenever possible, but under-coordinated systems can exhibit behavioral anomalies under fault, which are often extremely difficult to debug. This raises significant challenges for distributed system architects and developers. In this paper we present Blazes, a cross-platform program analysis framework that (a) identifies program locations that require coordination to ensure consistent executions, and (b) automatically synthesizes application-specific coordination code that can significantly outperform general-purpose techniques. We present two case studies, one using annotated programs in the Twitter Storm system, and another using the Bloom declarative language.Comment: Updated to include additional materials from the original technical report: derivation rules, output stream label

    BaseFs - Basically Acailable, Soft State, Eventually Consistent Filesystem for Cluster Management

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    A peer-to-peer distributed filesystem for community cloud management. https://github.com/glic3rinu/basef

    David Mitchell's Ghostwritten and 'The Novel of Globalization': biopower and the Secret History of the Novel

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    David Mitchell's debut novel Ghostwritten (1999) not only depicts a globalized world; its peculiar formal organization also embodies the mode of relatedness that characterizes globalization. This article shows that the invisible, decentralized power that defines globalization can be understood as what Michel Foucault called biopower. As a novel of globalization, Mitchell's novel lays bare the hidden historical and theoretical affinities between the novel genre on the one hand and biopower on the other

    Real-time predictive maintenance for wind turbines using Big Data frameworks

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    This work presents the evolution of a solution for predictive maintenance to a Big Data environment. The proposed adaptation aims for predicting failures on wind turbines using a data-driven solution deployed in the cloud and which is composed by three main modules. (i) A predictive model generator which generates predictive models for each monitored wind turbine by means of Random Forest algorithm. (ii) A monitoring agent that makes predictions every 10 minutes about failures in wind turbines during the next hour. Finally, (iii) a dashboard where given predictions can be visualized. To implement the solution Apache Spark, Apache Kafka, Apache Mesos and HDFS have been used. Therefore, we have improved the previous work in terms of data process speed, scalability and automation. In addition, we have provided fault-tolerant functionality with a centralized access point from where the status of all the wind turbines of a company localized all over the world can be monitored, reducing O&M costs

    The Struggle Itself Toward the Heights Is Enough to Fill a Man\u27s Heart: Calling, Moral Duty, Meaningfulness and Existential Self of Zookeepers

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    Applying Existential Sociology (Douglas & Johnson 1977, Manning 1973, Lyman and Scott 1989, Kotarba and Fontana 1984) as a theoretical foundation, this thesis endeavors to formulate first-order experiential understanding of zookeepers. Utilized is a mixed method approach comprising the survey and interview methods to explore zookeeper sense of calling as a moral duty, meaningfulness of work, and the possible connections formed with animals under their care (Bunderson & Thompson 2009, Spreitzer 1995, Wrzesnesweki et al 1997, and Pratt and Ashforth 2003, Hosey & Melfi 2010). Thirty zookeepers completed questionnaires containing measures of sense of calling, moral duty, work meaningfulness and human-animal bonds. Fifteen zookeepers submitted to semi-structured interviews. Results revealed high sense of calling and moral duty among zookeepers. Quantitative analysis of the study variables revealed a moderate positive association between zookeeper sense of calling and sense of perceived moral duty. Sense of calling for the occupation of zookeeper and work meaningfulness were not statistically related (rs (28) = .541, p\u3c .122). Human-animal bond (Hosey and Melfi 2010) was found among zookeepers. Zookeeper connections made with animals under their care were profound and meaningful. This study helps unravel the complexities of sensing a calling to an occupation and the interrelationship between occupationally-based sense of moral duty and perceived work meaningfulness
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