681 research outputs found

    Some inconsistencies in judging problems

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    AbstractSuppose that I individuals are ordered on the basis of the sums of ranks assigned independently by J judges, and that there is a unique winner. If the winner is deleted and the ranks assigned to the remaining individuals are adjusted, then an ordering of the reduced set is obtained. This ordering is said to be consistent with the original ordering if the relative positions of all remaining individuals are unchanged.An examination is made of conditions under which an individual, who was beaten by the winner and at least one other person in the original ranking, emerges as the winner in the reduced ranking. Such an inconsistency is called an interchange

    Grid Databases for Shared Image Analysis in the MammoGrid Project

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    The MammoGrid project aims to prove that Grid infrastructures can be used for collaborative clinical analysis of database-resident but geographically distributed medical images. This requires: a) the provision of a clinician-facing front-end workstation and b) the ability to service real-world clinician queries across a distributed and federated database. The MammoGrid project will prove the viability of the Grid by harnessing its power to enable radiologists from geographically dispersed hospitals to share standardized mammograms, to compare diagnoses (with and without computer aided detection of tumours) and to perform sophisticated epidemiological studies across national boundaries. This paper outlines the approach taken in MammoGrid to seamlessly connect radiologist workstations across a Grid using an "information infrastructure" and a DICOM-compliant object model residing in multiple distributed data stores in Italy and the UKComment: 10 pages, 5 figure

    Prevalence of infraocclusion of primary molars determined using a new 2D image analysis methodology

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    The reported prevalence of infraocclusion varies widely, reflecting differences in definitions and measurement/scoring approaches.This study aimed to quantify the prevalence and extent of infraocclusion in singletons and twins during the late mixed dentition stage of dental development using a new diagnostic imaging method and objective criteria. The study also aimed to determine any associations between infraocclusion and sex, arch type, arch side and tooth type.Two samples were analysed; 1,454 panoramic radiographs of singletons and 270 dental models of twins. Both samples ranged in age from 8-11 years. Adobe Photoshop CS5 was used to measure the extent of infraocclusion. Repeatability tests showed systematic and random errors were small.The prevalence in the maxilla was low (<1%), whereas the prevalence in the mandible was 22% in the singleton sample and 32% in the twin sample. The primary mandibular first molar was affected more often than the second molar. There was no significant difference in the expression between sexes or sides.A new technique for measuring infraocclusion has been developed with high intra- and inter-operator reproducibility. This method should enhance early diagnosis of tooth developmental abnormalities and treatment planning during late mixed dentition stage of development.Ruba Odeh, Suzanna Mihailidis, Grant Townsend, Raija Lähdesmäki, Toby Hughes, and Alan Broo

    Polyvinylbenzyl Tris-Aminodicarboxylate Microspheres for the Optical Sensing of Cu2+ Ions

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    In this work, a tris(2-aminoethyl)aminodicaboxylate functionality was substituted for the chloride of polyvinyl- benzyl chloride (PVBC) which was lightly cross-linked (2%) with divinyl benzene. The resulting derivatized po- lymer microspheres were embedded in a hydrogel matrix of poly vinyl alcohol cross-linked with glutaraldehyde to produce a sensing membrane. The latter responded selectively to Cu2+ solutions of different concentration ranges (1 × 10−4 M to 1 × 10−6 M). The response is based on the interaction between the metal cations and the negatively charged deprotonated dicarboxylate functional group, which led to neutralization of the charges. As a result, an increase in the turbidity of the sensing membrane occurred which is attributed to a change in the re- fractive index of the derivatized polymer microspheres relative to that of the hydrogel. The change in the turbid- ity of the sensing membrane was measured as absorbance using a conventional spectrophotometer. It was found that Cu2+ ions bind to the aminodicarboxylated-polymer with a formation constant, Kf, of 1 × 105 M−1. SEM, Eds and IR analyses were performed on the aminodicarboxylated microspheres and their Cu2+ complex.We are grateful to Professor W. R. Seitz and his research group, at the University of New Hampshire (USA) for their fruitful comments and for supplying us with the polyvinylbenzyl chloride microspheres. We are also grateful to the staff at the department of chemistry of An-Najah National University (PA), for their technical assistance

    Experiences of Engineering Grid-Based Medical Software

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    Objectives: Grid-based technologies are emerging as potential solutions for managing and collaborating distributed resources in the biomedical domain. Few examples exist, however, of successful implementations of Grid-enabled medical systems and even fewer have been deployed for evaluation in practice. The objective of this paper is to evaluate the use in clinical practice of a Grid-based imaging prototype and to establish directions for engineering future medical Grid developments and their subsequent deployment. Method: The MammoGrid project has deployed a prototype system for clinicians using the Grid as its information infrastructure. To assist in the specification of the system requirements (and for the first time in healthgrid applications), use-case modelling has been carried out in close collaboration with clinicians and radiologists who had no prior experience of this modelling technique. A critical qualitative and, where possible, quantitative analysis of the MammoGrid prototype is presented leading to a set of recommendations from the delivery of the first deployed Grid-based medical imaging application. Results: We report critically on the application of software engineering techniques in the specification and implementation of the MammoGrid project and show that use-case modelling is a suitable vehicle for representing medical requirements and for communicating effectively with the clinical community. This paper also discusses the practical advantages and limitations of applying the Grid to real-life clinical applications and presents the consequent lessons learned.Comment: 18 pages, 2 tables, 5 figures. In press International Journal of Medical Informatics. Elsevier publisher

    Part of the D - dimensional Spiked harmonic oscillator spectra

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    The pseudoperturbative shifted - l expansion technique PSLET [5,20] is generalized for states with arbitrary number of nodal zeros. Interdimensional degeneracies, emerging from the isomorphism between angular momentum and dimensionality of the central force Schrodinger equation, are used to construct part of the D - dimensional spiked harmonic oscillator bound - states. PSLET results are found to compare excellenly with those from direct numerical integration and generalized variational methods [1,2].Comment: Latex file, 20 pages, to appear in J. Phys. A: Math. & Ge
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