459 research outputs found

    FGC: an efficient constraint-based frequent set miner

    Get PDF
    Despite advances in algorithmic design, association rule mining remains problematic from a performance viewpoint when the size of the underlying transaction database is large. The well-known a priori approach, while reducing the computational effort involved still suffers from the problem of scalability due to its reliance on generating candidate itemsets. In this paper we present a novel approach that combines the power of preprocessing with the application of user-defined constraints to prune the itemset space prior to building a compact FP-tree. Experimentation shows that that our algorithm significantly outperforms the current state of the art algorithm, FP-bonsai

    Cascade effects of load shedding in coupled networks

    Get PDF
    Intricate webs of interlinked critical infrastructures such as electrical grid, telecommunication, and transportation are essential for the minimal functioning of contemporary societies and economies. Advances in Information and Communication Technology (ICT) underpin the increasing interconnectivity of these systems which created new vulnerabilities that can be seriously affected by hardware failure, link cut, human error, natural disaster, physical-attacks and cyber-attacks. Failure of a fraction on nodes may lead to failure of dependent nodes in the other networks. Therefore, the main objective of this paper is to investigate the cascades phenomena caused by load shedding between two interconnected networks using Bak-Tang-Wiesenfeld sandpile modeling. We have found that, large avalanche occurred when node degree and/interconnectivity link become dense. In addition, the coupled random-regular networks have been found to be more robust than the coupled Erdos-Renyi networks. However, coupled random-regular networks are vulnerable to random attack and coupled Erdos-Renyi networks are vulnerable to target attack due to the degree distribution

    Measuring cascade effects in interdependent networks by using effective graph resistance

    Get PDF
    Understanding the correlation between the underlie network structure and overlay cascade effects in the interdependent networks is one of major challenges in complex network studies. There are some existing metrics that can be used to measure the cascades. However, different metrics such as average node degree interpret different characteristic of network topological structure, especially less metrics have been identified to effectively measure the cascading performance in interdependent networks. In this paper, we propose to use a combined Laplacian matrix to model the interdependent networks and their interconnectivity, and then use its effective resistance metric as an indicator to its cascading behavior. Moreover, we have conducted extensive comparative studies among different metrics such as average node degree, and the proposed effective resistance. We have found that the effective resistance metric can describe more accurate and finer characteristics on topological structure of the interdependent networks than average node degree which is widely adapted by the existing research studies for measuring the cascading performance in interdependent networks

    One Pass Concept Change Detection for Data Streams

    Get PDF
    In this research we present a novel approach to the concept change detection problem. Change detection is a fundamental issue with data stream mining as models generated need to be updated when significant changes in the underlying data distribution occur. A number of change detection approaches have been proposed but they all suffer from limitations such as high computational complexity, poor sensitivity to gradual change, or the opposite problem of high false positive rate. Our approach, termed OnePassSampler, has low computational complexity as it avoids multiple scans on its memory buffer by sequentially processing data. Extensive experimentation on a wide variety of datasets reveals that OnePassSampler has a smaller false detection rate and smaller computational overheads while maintaining a competitive true detection rate to ADWIN2

    The reduced cost of providing a nationally recognised service for familial hypercholesterolaemia

    No full text
    OBJECTIVE: Familial hypercholesterolaemia (FH) affects 1 in 500 people in the UK population and is associated with premature morbidity and mortality from coronary heart disease. In 2008, National Institute for Health and Care Excellence (NICE) recommended genetic testing of potential FH index cases and cascade testing of their relatives. Commissioners have been slow to respond although there is strong evidence of cost and clinical effectiveness. Our study quantifies the recent reduced cost of providing a FH service using generic atorvastatin and compares NICE costing estimates with three suggested alternative models of care (a specialist-led service, a dual model service where general practitioners (GPs) can access specialist advice, and a GP-led service).METHODS: Revision of existing 3?year costing template provided by NICE for FH services, and prediction of costs for running a programme over 10?years. Costs were modelled for the first population-based FH service in England which covers Southampton, Hampshire, Isle of Wight and Portsmouth (SHIP). Population 1.95 million.RESULTS: With expiry of the Lipitor (Pfizer atorvastatin) patent the cost of providing a 10-year FH service in SHIP reduces by 42.5% (£4.88 million on patent vs £2.80 million off patent). Further cost reductions are possible as a result of the reduced cost of DNA testing, more management in general practice, and lower referral rates to specialists. For instance a dual-care model with GP management of patients supported by specialist advice when required, costs £1.89 million.CONCLUSIONS: The three alternative models of care are now <50% of the cost of the original estimates undertaken by NICE

    Anthropometric, speed and endurance characteristics of English academy soccer players: Do they influence obtaining a professional contract at 18 years of age

    Get PDF
    This study evaluated the anthropometric, speed and endurance characteristics of English academy soccer players, comparing players who obtained a ‘professional’ contract at 18 years old with those that did not (‘academy’); 443 male academy soccer players from an English professional club undertook anthropometric (height and body mass), speed (10 and 20 m sprint) and endurance (Yo-Yo intermittent endurance test level 2 [Yo-Yo]) assessments between 2005 and 2012. Significant improvements with age were found for speed and endurance at each annual age group up until U18 age category. Significant differences were only observed between ‘professional’ and ‘academy’ players for 10 m (p = 0.003, η2 = 0.01) and 20 m (p = 0.001, η2 = 0.01) speed at U16 and U18 and Yo-Yo performance (p = 0.001, η2 = 0.12) at U18 age category. Practitioners should use speed and endurance assessments for monitoring physical development of players rather than for talent identification purposes

    The topological dimension of type I C*-algebras

    Full text link
    While there is only one natural dimension concept for separable, metric spaces, the theory of dimension in noncommutative topology ramifies into different important concepts. To accommodate this, we introduce the abstract notion of a noncommutative dimension theory by proposing a natural set of axioms. These axioms are inspired by properties of commutative dimension theory, and they are for instance satisfied by the real and stable rank, the decomposition rank and the nuclear dimension. We add another theory to this list by showing that the topological dimension, as introduced by Brown and Pedersen, is a noncommutative dimension theory of type I C*-algebras. We also give estimates of the real and stable rank of a type I C*-algebra in terms of its topological dimension.Comment: 20 pages; minor correction

    'Reclaiming the criminal' : the role and training of prison officers in England, 1877-1914

    Get PDF
    This article examines the role and training of prison officers in England, between 1877 and 1914. It is concerned with the changing penal philosophies and practices of this period and how these were implemented in local prisons, and the duties of the prison officer. More broadly, this article argues that the role of the prison officer and their training (from 1896) reflect wider ambiguities in prison policy and practice during this period

    Procedures for the salvage and necropsy of the Dugong (Dugong Dugon)-second edition 2007

    Get PDF
    This manual provides a detailed guide for dugong (Dugong dugon) carcass handling and necropsy procedures. It is intended to be used as a resource and training guide for anyone involved in dugong incidents including management officers, biologists, parks and wildlife field staff, and veterinarians and pathologists who may lack dugong expertise. Because of the wide range of professionals this book is targeting, information and the use of technical terms is extensive. Section 8.0 provides definitions of various terms used which are italicised throughout the text
    corecore