684 research outputs found
Some inconsistencies in judging problems
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
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
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
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
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
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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