769 research outputs found

    Practical applications of data mining in plant monitoring and diagnostics

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    Using available expert knowledge in conjunction with a structured process of data mining, characteristics observed in captured condition monitoring data, representing characteristics of plant operation may be understood, explained and quantified. Knowledge and understanding of satisfactory and unsatisfactory plant condition can be gained and made explicit from the analysis of data observations and subsequently used to form the basis of condition assessment and diagnostic rules/models implemented in decision support systems supporting plant maintenance. This paper proposes a data mining method for the analysis of condition monitoring data, and demonstrates this method in its discovery of useful knowledge from trip coil data captured from a population of in-service distribution circuit breakers and empirical UHF data captured from laboratory experiments simulating partial discharge defects typically found in HV transformers. This discovered knowledge then forms the basis of two separate decision support systems for the condition assessment/defect clasification of these respective plant items

    A data analytic approach to automatic fault diagnosis and prognosis for distribution automation

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    Distribution Automation (DA) is deployed to reduce outages and to rapidly reconnect customers following network faults. Recent developments in DA equipment have enabled the logging of load and fault event data, referred to as ‘pick-up activity’. This pick-up activity provides a picture of the underlying circuit activity occurring between successive DA operations over a period of time and has the potential to be accessed remotely for off-line or on-line analysis. The application of data analytics and automated analysis of this data supports reactive fault management and post fault investigation into anomalous network behavior. It also supports predictive capabilities that identify when potential network faults are evolving and offers the opportunity to take action in advance in order to mitigate any outages. This paper details the design of a novel decision support system to achieve fault diagnosis and prognosis for DA schemes. It combines detailed data from a specific DA device with rule-based, data mining and clustering techniques to deliver the diagnostic and prognostic functions. These are applied to 11kV distribution network data captured from Pole Mounted Auto-Reclosers (PMARs) as provided by a leading UK network operator. This novel automated analysis system diagnoses the nature of a circuit’s previous fault activity, identifies underlying anomalous circuit activity, and highlights indications of problematic events gradually evolving into a full scale circuit fault. The novel contributions include the tackling of ‘semi-permanent faults’ and the re-usable methodology and approach for applying data analytics to any DA device data sets in order to provide diagnostic decisions and mitigate potential fault scenarios

    Sustainability evaluation of community-based, solar photovoltaic projects in Malawi

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    Background: A novel project sustainability framework is used to evaluate 65 off-grid solar photovoltaic (PV) energy system projects in Malawi. This study addresses PV projects serving rural public facilities, a solution known to have had historical issues with poor sustainability. A recent countrywide program targeting such facilities was evaluated against existing projects to determine whether this latest iteration offered better results. Method: Sustainability is defined at the project-level with metrics justified under the main themes of technical, economic, social, and organizational. Data captured for each project is based on a custom survey and interview of key stakeholders. Projects are grouped according to age, project implementer, income level, and PV system size to compare relative results. Results: The sustainability outlook for each project is evaluated. We find sustainability for most projects to be low. Social sustainability was weak with many projects due to low local community stakeholder engagement in terms of numbers of stakeholders, meeting frequency, and community contributions. Organizational challenges included a lack of key management positions in place and extremely limited training provisions. Furthermore, the evaluation highlights the economic health of the system to be key to sustainability, with the "healthiest" projects affording only 37% of expected operations and maintenance costs. Relative to expected demand, systems were found to be undersized for both panels (53% of required) and batteries (57%). Users reported achieving only 60% of their desired consumption. Poor sizing standards related to the lack of load profiles for first-time electricity users as well as poor quality components reduced the overall technical sustainability. Conclusion: Rural public facilities with solar PV in Malawi are not well served by isolated community management. Improved sustainability requires the establishment of a robust financial framework prior to project development that includes formal local government support. This paper discusses ideal management frameworks and their ultimate implications for project developers, policy makers, and the research community

    Detection and identification of global maximum power point operation in solar PV applications using a hybrid ELPSO-P&O tracking technique

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    Non-homogeneous irradiation conditions due to environmental changes introduce multiple peaks in non-linear PV characteristics. Hence, to operate PV at the global power point, numerous algorithms have been proposed in the literature. However, due to the insufficient exploitation of control variables, all the MPPT methods presented in literature fail to guarantee Global Maximum Power Point (GMPP) operation. In this paper, a new detection technology to identify global MPP zones using hybrid Enhanced Leader Particle Swarm Optimization (ELPSO) assisted by a conventional Perturb and Observe (P&O) algorithm is proposed. With inherent mutations, ELPSO applied to MPPT excels in exploring global regions at initial stages to determine the global best leader; whilst, P&O is reverted back soon after global solution space is detected. The transition from ELPSO to P&O is mathematically verified and allowed only when ELPSO finds the global optimal zone. Adapting this hybrid strategy, the proposed method has produced interesting results under partial shaded conditions. For further validation, the results of the proposed hybrid ELPSO-P&O are compared with conventional ELPSO and the hybrid PSO-P&O methods. Experimental results along with energy evaluations confirmed the superiority of the ELPSOP&O method in obtaining the maximum available power under all shaded conditions

    'Let's make lots of money': the determinants of performance in the recorded music sector

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    This research analyzes the performance of 467 record labels in eight European countries over a period of 13 years (2003-2015). The main goal is to explain a relative measure of profitability in terms of observed variables, although the nature of the dataset also allows us to include non-observed firm and country effects. To this end alternative models are estimated and three main research questions are tested, namely: (1) the effect of the dual structure of the recorded music market, in which a competitive segment and an oligopoly coexist; (2) the extent and source of the volatility of profits in record labels; and (3) the nonlinear impact of size on performance

    Genome-wide association scan meta-analysis identifies three Loci influencing adiposity and fat distribution.

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    To identify genetic loci influencing central obesity and fat distribution, we performed a meta-analysis of 16 genome-wide association studies (GWAS, N = 38,580) informative for adult waist circumference (WC) and waist-hip ratio (WHR). We selected 26 SNPs for follow-up, for which the evidence of association with measures of central adiposity (WC and/or WHR) was strong and disproportionate to that for overall adiposity or height. Follow-up studies in a maximum of 70,689 individuals identified two loci strongly associated with measures of central adiposity; these map near TFAP2B (WC, P = 1.9x10(-11)) and MSRA (WC, P = 8.9x10(-9)). A third locus, near LYPLAL1, was associated with WHR in women only (P = 2.6x10(-8)). The variants near TFAP2B appear to influence central adiposity through an effect on overall obesity/fat-mass, whereas LYPLAL1 displays a strong female-only association with fat distribution. By focusing on anthropometric measures of central obesity and fat distribution, we have identified three loci implicated in the regulation of human adiposity

    Genome-wide association and HLA fine-mapping studies identify risk loci and genetic pathways underlying allergic rhinitis

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    Allergic rhinitis is the most common clinical presentation of allergy, affecting 400 million people worldwide, with increasing incidence in westernized countries1,2. To elucidate the genetic architecture and understand the underlying disease mechanisms, we carried out a meta-analysis of allergic rhinitis in 59,762 cases and 152,358 controls of European ancestry and identified a total of 41 risk loci for allergic rhinitis, including 20 loci not previously associated with allergic rhinitis, which were confirmed in a replication phase of 60,720 cases and 618,527 controls. Functional annotation implicated genes involved in various immune pathways, and fine mapping of the HLA region suggested amino acid variants important for antigen binding. We further performed genome-wide association study (GWAS) analyses of allergic sensitization against inhalant allergens and nonallergic rhinitis, which suggested shared genetic mechanisms across rhinitis-related traits. Future studies of the identified loci and genes might identify novel targets for treatment and prevention of allergic rhinitis

    Broad utility of an affinity-enrichment strategy for unanchored polyubiquitin chains

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    Protein ubiquitination is a common post-translational modification where selected targets are covalently modified by the ubiquitin protein, often in the form of isopeptide-linked polyubiquitin chains. More recently, unanchored (i.e. non-substrate-linked) polyubiquitin chains have also been described and implicated in a range of biological processes. The development of Tandem-repeated Ubiquitin-Binding Entities (TUBEs), engineered repeats of ubiquitin-binding domains that interact non-covalently with polyubiquitin, has allowed strategies for the affinity-enrichment of ubiquitinmodified proteins to be established, in some cases with linkage specificity. Here, we demonstrate the utility of a Free Ubiquitin-Binding Entity (FUBE), based on an ubiquitin-binding domain with high specificity for the free C-terminus of ubiquitin (the Znf-UBP domain of human USP5). In contrast to TUBEs which do not distinguish conjugated or free polyubiquitin, the FUBE exclusively recognises ubiquitin in its unconjugated form, including endogenous unanchored polyubiquitin chains. Affinity-enrichments using the FUBE demonstrate that unanchored polyubiquitin chains are present in different mammalian cell lines and accumulate when the 26S proteasome is pharmacologically inhibited, being retained on the proteasome. The high conservation of the ubiquitin sequence permits the FUBE to also be applied to the purification of endogenous unanchored polyubiquitin chains from species as diverse as Arabidopsis thaliana and Saccharomyces cerevisiae. The development and refinement of an affinity-enrichment strategy for unanchored polyubiquitin chains opens the way for more complete investigations into their biological significance. © 2013 Strachan J, et al

    Modification of small ubiquitin-related modifier 2 (SUMO2) by phosphoubiquitin in HEK293T cells

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    Additional complexity in the post-translational modification of proteins by ubiquitin is achieved by ubiquitin phosphorylation, for example within PINK1-parkin mediated mitophagy. We performed a preliminary proteomic analysis to identify proteins differentially modified by ubiquitin in HEK293T, compared to phosphomimetic ubiquitin (Ser65Asp), and identified small ubiquitin-related modifier 2 (SUMO2) as a candidate. By transfecting SUMO2 and its C-terminal–GG deletion mutant, along with phosphomimetic ubiquitin, we confirm that ubiquitin modifies SUMO2, rather than vice versa. Further investigations revealed that transfected SUMO2 can also be conjugated by endogenous phospho-Ser65-(poly)ubiquitin in HEK293T cells, pointing to a previously unappreciated level of complexity in SUMO2 modification, and that unanchored (substrate-free) polyubiquitin chains may also be subject to phosphorylation
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