9,402 research outputs found

    A review of research into the development of radiologic expertise: Implications for computer-based training

    Get PDF
    Rationale and Objectives. Studies of radiologic error reveal high levels of variation between radiologists. Although it is known that experts outperform novices, we have only limited knowledge about radiologic expertise and how it is acquired.Materials and Methods. This review identifies three areas of research: studies of the impact of experience and related factors on the accuracy of decision-making; studies of the organization of expert knowledge; and studies of radiologists' perceptual processes.Results and Conclusion. Interpreting evidence from these three paradigms in the light of recent research into perceptual learning and studies of the visual pathway has a number of conclusions for the training of radiologists, particularly for the design of computer-based learning programs that are able to illustrate the similarities and differences between diagnoses, to give access to large numbers of cases and to help identify weaknesses in the way trainees build up a global representation from fixated regions

    Performance evaluation of MPLS-enabled communications infrastructure for wide area monitoring systems

    Get PDF
    In order to obtain the transient power system measurement information, Wide Area Monitoring Systems (WAMS) should be able to collect Phasor Measurement Unit (PMU) data in a timely manner. Therefore along with the continual deployment of PMUs in Great Britain (GB) transmission system substations, a high performance communications infrastructure is becoming essential with regard to the establishment of reliable WAMS. This paper focuses mainly on evaluating the performance of the real-time WAMS communication infrastructure when Multi-Protocol Label Switching (MPLS) capability is added to a conventional IP network. Furthermore, PMU communications from geographically distributed substations to a Phasor Data Concentrator (PDC) are investigated over different transport protocols. Using OPNET Modeler, simulations are performed based on the existing WAMS infrastructure as installed on the GB transmission system. The simulation results are analyzed in detail in order to fully determine the different characteristics of communication delays between PMUs and PDC

    Computer aided detection

    Get PDF

    Parallel detrended fluctuation analysis for fast event detection on massive PMU data

    Get PDF
    ("(c) 2015 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.")Phasor measurement units (PMUs) are being rapidly deployed in power grids due to their high sampling rates and synchronized measurements. The devices high data reporting rates present major computational challenges in the requirement to process potentially massive volumes of data, in addition to new issues surrounding data storage. Fast algorithms capable of processing massive volumes of data are now required in the field of power systems. This paper presents a novel parallel detrended fluctuation analysis (PDFA) approach for fast event detection on massive volumes of PMU data, taking advantage of a cluster computing platform. The PDFA algorithm is evaluated using data from installed PMUs on the transmission system of Great Britain from the aspects of speedup, scalability, and accuracy. The speedup of the PDFA in computation is initially analyzed through Amdahl's Law. A revision to the law is then proposed, suggesting enhancements to its capability to analyze the performance gain in computation when parallelizing data intensive applications in a cluster computing environment

    Parallel detrended fluctuation analysis for fast event detection on massive PMU data

    Get PDF
    ("(c) 2015 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.")Phasor measurement units (PMUs) are being rapidly deployed in power grids due to their high sampling rates and synchronized measurements. The devices high data reporting rates present major computational challenges in the requirement to process potentially massive volumes of data, in addition to new issues surrounding data storage. Fast algorithms capable of processing massive volumes of data are now required in the field of power systems. This paper presents a novel parallel detrended fluctuation analysis (PDFA) approach for fast event detection on massive volumes of PMU data, taking advantage of a cluster computing platform. The PDFA algorithm is evaluated using data from installed PMUs on the transmission system of Great Britain from the aspects of speedup, scalability, and accuracy. The speedup of the PDFA in computation is initially analyzed through Amdahl's Law. A revision to the law is then proposed, suggesting enhancements to its capability to analyze the performance gain in computation when parallelizing data intensive applications in a cluster computing environment

    The Concept of Cat Face

    Get PDF
    Over the course of a week in March, Lee Sedol, the world’s best player of Go, played a series of five games against a computer program. The series, which the program AlphaGo won 4-1, took place in Seoul, while tens of millions watched live on internet feeds. Go, usually considered the most intellectually demanding of board games, originated in China but developed into its current form in Japan, enjoying a long golden age from the 17th to the 19th century. Famous contests from the period include the Blood Vomiting game, in which three moves of great subtlety were allegedly revealed to Honinbo Jowa by ghosts, enabling him to defeat his young protégé Intetsu Akaboshi, who after four days of continuous play collapsed and coughed up blood, dying of TB shortly afterwards. Another, the Ear Reddening game, turned on a move of such strength that it caused a discernible flow of blood to the ears of the master Inoue Genan Inseki. That move was, until 13 March this year, probably the most talked about move in the history of Go. That accolade probably now belongs to move 78 in the fourth game between Sedol and AlphaGo, a moment of apparently inexplicable intuition which gave Sedol his only victory in the series. The move, quickly named the Touch of God, has captured the attention not just of fans of Go but of anyone with an interest in what differentiates human from artificial intelligence

    Knowledge and information needs of informal caregivers in palliative care : a qualitative systematic review

    Get PDF
    Objectives: To review current understanding of the knowledge and information needs of informal caregivers in palliative settings. Data sources: Seven electronic databases were searched for the period January 1994–November 2006: Medline, CINAHL, PsychINFO, Embase, Ovid, Zetoc and Pubmed using a meta-search engine (Metalib®). Key journals and reference lists of selected papers were hand searched. Review methods: Included studies were peer-reviewed journal articles presenting original research. Given a variety of approaches to palliative care research, a validated systematic review methodology for assessing disparate evidence was used in order to assign scores to different aspects of each study (introduction and aims, method and data, sampling, data analysis, ethics and bias, findings/results, transferability/generalizability, implications and usefulness). Analysis was assisted by abstraction of key details of study into a table. Results: Thirty-four studies were included from eight different countries. The evidence was strongest in relation to pain management, where inadequacies in caregiver knowledge and the importance of education were emphasized. The significance of effective communication and information sharing between patient, caregiver and service provider was also emphasized. The evidence for other caregiver knowledge and information needs, for example in relation to welfare and social support was weaker. There was limited literature on non-cancer conditions and the care-giving information needs of black and minority ethnic populations. Overall, the evidence base was predominantly descriptive and dominated by small-scale studies, limiting generalizability. Conclusions: As palliative care shifts into patients’ homes, a more rigorously researched evidence base devoted to understanding caregivers knowledge and information needs is required. Research design needs to move beyond the current focus on dyads to incorporate the complex, three-way interactions between patients, service providers and caregivers in end-of-life care setting

    A physical model for low-frequency electromagnetic induction in the near field based on direct interaction between transmitter and receiver electrons

    Get PDF
    A physical model of electromagnetic induction is developed which relates directly the forces between electrons in the transmitter and receiver windings of concentric coaxial finite coils in the near-field region. By applying the principle of superposition, the contributions from accelerating electrons in successive current loops are summed, allowing the peak-induced voltage in the receiver to be accurately predicted. Results show good agreement between theory and experiment for various receivers of different radii up to five times that of the transmitter. The limitations of the linear theory of electromagnetic induction are discussed in terms of the non-uniform current distribution caused by the skin effect. In particular, the explanation in terms of electromagnetic energy and Poynting’s theorem is contrasted with a more direct explanation based on variable filament induction across the conductor cross section. As the direct physical model developed herein deals only with forces between discrete current elements, it can be readily adapted to suit different coil geometries and is widely applicable in various fields of research such as near-field communications, antenna design, wireless power transfer, sensor applications and beyond

    Antimicrobial properties of mucus from the brown garden snail Helix aspersa

    Get PDF
    Research into naturally occurring antimicrobial substances has yielded effective treatments. One area of interest is peptides and proteins produced by invertebrates as part of their defence system, including the contents of mollusc mucus. Mucus produced by the African giant land snail, Achatina fulica has been reported to contain two proteins with broad-spectrum antibacterial activity. Mucus from the brown garden snail, Helix aspersa, appears to have skin regeneration properties. This study sought to investigate the antimicrobial properties of H. aspersa mucus. Mucus was collected from H. aspersa snails, diluted in phosphatebuffered saline (PBS), with the supernatant tested against a wide range of organisms in a disc-diffusion antimicrobial assay. This was followed with comparative experiments involving A. fulica, including bacteriophage assays. Mucus from both species of snail was passed through a series of protein size separation columns in order to determine the approximate size of the antimicrobial substance. Electrophoresis was also carried out on the H. aspersa mucus. Results indicated that H. aspersa mucus had a strong antibacterial effect against several strains of Pseudomonas aeruginosa and a weak effect against Staphylococcus aureus. Mucus from A. fulica also inhibited the growth of S. aureus, but the broad spectrum of activity reported by other workers was not observed. Antimicrobial activity was not caused by bacteriophage. Size separation experiments indicated that the antimicrobial substance(s) in H. aspersa were between 30 and 100 kDa. Electrophoresis revealed two proteins in this region (30–40 kDa and 50–60 kDa). These do not correspond with antimicrobial proteins previously reported in A. fulica. This study found one or more novel antimicrobial agents in H. aspersa mucus, with a strong effect against P. aeruginosa
    corecore