14,397 research outputs found

    Event Analysis of Pulse-reclosers in Distribution Systems Through Sparse Representation

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    The pulse-recloser uses pulse testing technology to verify that the line is clear of faults before initiating a reclose operation, which significantly reduces stress on the system components (e.g. substation transformers) and voltage sags on adjacent feeders. Online event analysis of pulse-reclosers are essential to increases the overall utility of the devices, especially when there are numerous devices installed throughout the distribution system. In this paper, field data recorded from several devices were analyzed to identify specific activity and fault locations. An algorithm is developed to screen the data to identify the status of each pole and to tag time windows with a possible pulse event. In the next step, selected time windows are further analyzed and classified using a sparse representation technique by solving an l1-regularized least-square problem. This classification is obtained by comparing the pulse signature with the reference dictionary to find a set that most closely matches the pulse features. This work also sheds additional light on the possibility of fault classification based on the pulse signature. Field data collected from a distribution system are used to verify the effectiveness and reliability of the proposed method.Comment: Accepted in: 19th International Conference on Intelligent System Application to Power Systems (ISAP), San Antonio, TX, 201

    Model For The Dynamics Of A Bubble Undergoing Small Shape Oscillations Between Elastic Layers

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    A model is presented for a pulsating and translating gas bubble in a channel formed by two soft elastic parallel layers. The bubble is free to undergo small shape deformations. Coupled nonlinear second-order differential equations are obtained for the shape and position of the bubble, and numerical integration of an expression for the liquid velocity at the layer interfaces yields an estimate of their displacement. Simulations reveal behavior consistent with laboratory observations.Applied Research Laboratorie

    A Tale of Two Cities: From Davids Holdings to Metcash

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    In 1994, the Full Federal Court upheld the decision of the trial judge to prevent the acquisition of QIW by Davids, on the grounds that, Davids would become the only supplier of groceries to independent retailers in the geographic market. While the independent retailers faced significant competition in the downstream (retail) business from the integrated retail chains, the Court found that such competition would not be sufficient to prevent the exercise of monopoly power in the upstream (wholesale) business. In 2011, the Full Federal Court upheld the decision of the trial judge not to prevent the acquisition by Metcash of Franklins. The acquisition had been opposed by the ACCC on the grounds that it would leave Metcash as effectively the only wholesale supplier of packaged groceries to independent retailers in New South Wales. The Court rejected the Commission’s claim, finding that the merged firm would not be able to exercise market power due to the constraining presence downstream of the integrated retail chains. Two cases with apparently similar facts. What explains the different outcomes? In this article, we try to identify a critical analytical difference in the way that the cases were presented to the Court and will suggest that this difference may have had a significant influence on the outcomes

    A Tale of Two Cities: From Davids Holdings to Metcash

    Get PDF
    In 1994, the Full Federal Court upheld the decision of the trial judge to prevent the acquisition of QIW by Davids, on the grounds that, Davids would become the only supplier of groceries to independent retailers in the geographic market. While the independent retailers faced significant competition in the downstream (retail) business from the integrated retail chains, the Court found that such competition would not be sufficient to prevent the exercise of monopoly power in the upstream (wholesale) business. In 2011, the Full Federal Court upheld the decision of the trial judge not to prevent the acquisition by Metcash of Franklins. The acquisition had been opposed by the ACCC on the grounds that it would leave Metcash as effectively the only wholesale supplier of packaged groceries to independent retailers in New South Wales. The Court rejected the Commission’s claim, finding that the merged firm would not be able to exercise market power due to the constraining presence downstream of the integrated retail chains. Two cases with apparently similar facts. What explains the different outcomes? In this article, we try to identify a critical analytical difference in the way that the cases were presented to the Court and will suggest that this difference may have had a significant influence on the outcomes

    Agricultural interpretation technique development

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    There are no author-identified significant results in this report

    Cell death regulation in Drosophila: Conservation of mechanism and unique insights

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    Programmed cell death, or apoptosis, is a genetically encoded form of cell suicide that results in the orderly death and phagocytic removal of excess, damaged, or dangerous cells during normal development and in the adult. The cellular machinery required to carry out apoptosis is present in most, if not all cells, but is only activated in cells instructed to die (for review see Jacobson et al. 1997). Here, we review cell death regulation in the fly in the context of a first pass look at the complete Drosophila genome and what is known about death regulation in other organisms, particularly worms and vertebrates

    A pathway of signals regulating effector and initiator caspases in the developing Drosophila eye

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    Regulated cell death and survival play important roles in neural development. Extracellular signals are presumed to regulate seven apparent caspases to determine the final structure of the nervous system. In the eye, the EGF receptor, Notch, and intact primary pigment and cone cells have been implicated in survival or death signals. An antibody raised against a peptide from human caspase 3 was used to investigate how extracellular signals controlled spatial patterning of cell death. The antibody crossreacted specifically with dying Drosophila cells and labelled the activated effector caspase Drice. It was found that the initiator caspase Dronc and the proapoptotic gene head involution defective were important for activation in vivo. Dronc may play roles in dying cells in addition to activating downstream effector caspases. Epistasis experiments ordered EGF receptor, Notch, and primary pigment and cone cells into a single pathway that affected caspase activity in pupal retina through hid and Inhibitor of Apoptosis Proteins. None of these extracellular signals appeared to act by initiating caspase activation independently of hid. Taken together, these findings indicate that in eye development spatial regulation of cell death and survival is integrated through a single intracellular pathway

    Incontinence-specific quality of life measures used in trials of treatments for female urinary incontinence: a systematic review.

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    This systematic review examined the use of incontinence-specific QOL measures in clinical trials of female incontinence treatments, and systematically evaluated their quality using a standard checklist. Of 61 trials included in the review, 58 (95.1%) used an incontinence-specific QOL measure. The most commonly used were IIQ (19 papers), I-QoL (12 papers) and UDI (9 papers). Eleven papers (18.0%) used measures which were not referenced or were developed specifically for the study. The eight QOL measures identified had good clinical face validity and measurement properties. We advise researchers to evaluate carefully the needs of their specific study, and select the QOL measure that is most appropriate in terms of validity, utility and relevance, and discourage the development of new measures. Until better evidence is available on the validity and comparability of measures, we recommend that researchers consider using IIQ or I-QOL with or without UDI in trials of incontinence treatments

    Multi-parameter analysis in eddy current inspection of aircraft engine components

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    One of the major problems limiting the life of critical aircraft engine components, such as compressor discs and spacers, is the formation of low cycle fatigue (LCF) cracks in the fastener bolt holes. Such cracks are often initiated from corners and their surfaces are oxidized during the engine operation. Eddy current techniques using rotating probes are considered to be the most appropriate for detecting bolt hole cracks. Inspection according to damage tolerance criteria requires repeatable detection (90% probability of detection with 95% confidence) of cracks of the order of 0.125 mm (0.005″). If only threshold setting methods are used by a human analyst or implemented by means of electronic instrumentation, detectability can be low since it is difficult to distinguish between the actual flaw signal and noise in the eddy current signal as both are of similar amplitude. However, in certain cases, searching for structure in the noisy waveform can provide indications of defects that escape detection by threshold setting techniques. One way of achieving this is by using multi-parameter signal analysis and pattern recognition methods
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