459 research outputs found
FGC: an efficient constraint-based frequent set miner
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
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
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
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
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
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
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
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
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
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Human platelet protein ubiquitylation and changes following GPVI activation
Platelet activators stimulate post-translational modification of signalling proteins to change their
activity or their molecular interactions leading to signal propagation. One covalent modification is attachment of the small protein ubiquitin to lysine residues in target proteins. Modification by ubiquitin can either target proteins for degradation by the proteasome or act as a scaffold for other proteins. Pharmacological inhibition of deubiquitylases or the proteasome inhibits platelet
activation by collagen, demonstrating a role for ubiquitylation, but relatively few substrates for
ubiquitin have been identified and the molecular basis of inhibition is not established. Here we report the ubiquitome of human platelets and changes in ubiquitylated proteins following stimulation by collagen related peptide (CRP-XL). Using platelets from six individuals over three
independent experiments, we identified 1634 ubiquitylated peptides derived from 691 proteins, revealing extensive ubiquitylation in resting platelets. 925 of these peptides show an increase of more than 2-fold following stimulation with CRP-XL. Multiple sites of ubiquitylation were 16 identified on a number of proteins including Syk, filamin and integrin heterodimer subunits. This work reveals extensive protein ubiquitylation during activation of human platelets and opens the possibility of novel therapeutic interventions targeting the ubiquitin machinery
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