1,007 research outputs found

    In situ characterization of two wireless transmission schemes for ingestible capsules

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    We report the experimental in situ characterization of 30-40 MHz and 868 MHz wireless transmission schemes for ingestible capsules, in porcine carcasses. This includes a detailed study of the performance of a magnetically coupled near-field very high-frequency (VHF) transmission scheme that requires only one eighth of the volume and one quarter of the power consumption of existing 868-MHz solutions. Our in situ measurements tested the performance of four different capsules specially constructed for this study (two variants of each transmission scheme), in two scenarios. One mimicked the performance of a body-worn receiving coil, while the other allowed the characterization of the direction-dependent signal attenuation due to losses in the surrounding tissue. We found that the magnetically coupled near-field VHF telemetry scheme presents an attractive option for future, miniturized ingestible capsules for medical applications

    On the road to Enlighten-ment: establishing an institutional repository service for the University of Glasgow

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    Purpose – The purpose of this paper is to chart the development and growth of open access and institutional repositories at the University of Glasgow, Scotland from initial work in 2001 to the University's recently launched service, Enlighten. The University of Glasgow is a signatory to the Scottish Open Access Declaration and recently released a statement on Open Access.<p></p> Design/methodology/approach – The study will focus on the key lessons learned through a twin track approach of advocacy and service development during the DAEDALUS Project (2002-2005) and the transition of that work to a University service called Enlighten. This service includes a repository for published and peer-reviewed papers which has now had over 2 million hits and over 270,000 PDF downloads since it was established in February 2004.<p></p> Findings – The paper reveals the lessons learned by the Library and the project team. It also identifies the range of issues which must be addressed in the successful implementation of a repository and its transition to a production service. These include the development of content policies, copyright clearance and the cultural change necessary to populate a repository service. These challenges have and continue to be addressed by the repository team at the University of Glasgow.<p></p> Originality/value – This paper provides details of the lessons learned in the practical experience of setting up an institutional repository and ensuring its transition to a full and supported University service. It will be of particular interest to institutions implementing a repository or running a pilot service.<p></p&gt

    Finding Largest Empty Circles with Location Constraints

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    Let S be a set of n points in the plane and let CH(S) represent the convex hull of S. The Largest Empty Circle (LEC) problem is the problem of finding the largest circle centered with CH(S) such that no point of S lies within the circle. Shamos and Hoey (SH75) outlined an algorithm for solving this problem in time O(n log n) by first computing the Voronoi diagram, V(S), in time O(n log n), then using V(S) and CH(S) to compute the largest empty circle in time O(n). In a recent paper [Tou83], Toussaint pointed out some problems with the algorithm as outlined by Shamos and presented an algorithm which, given V(S) and CH(S), solves the LEC problem in time O(n log n). In this note we show that Shamos\u27 original claim was correct: given V(S) and CH(S), the LEC problem can be solved in time O(n). More generally, given V(S) and a convex k-gon P, the LEC centered within P can be found in time O(k+n). We also improve on an algorithm given by Toussaint for computing the LEC when the center is constrained to lie within an arbitrary simple polygon. Given a set S of n points and an arbitrary simple k-gon P, the largest empty circle centered within P can be found in time O(kn + n log n). This becomes O(kn) if the Voronoi diagram of S is already given

    Producing Software Using Tools in a Workstation Environment

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    We discuss how we taught students to build and use translation, interpretive, editing and monitoring tools in an undergraduate software engineering course. Students used the tools on low-cost workstations (Macintoshes) to build large, group projects. The students\u27 projects used all available features of workstation environments, including graphics, windows, fonts, mice, networks, and sound generators. We found that 1) the use of tools increased student productivity, 2) a shift in a data structure and algorithm topics is needed to cover material relevant for workstation environments, 3) new topics in system design are required for a workstation environment, 4) traditional material can be easily illustrated with a workstation environment and 5) students enjoyed being able to manipulate the advanced features of workstations in their work, which in turn increased their motivation for and concentration on the course material

    Computing the Largest Empty Rectangle

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    We consider the following problem: Given a rectangle containing N points, find the largest area subrectangle with sides parallel to those of the original rectangle which contains none of the given points. If the rectangle is a piece of fabric or sheet metal and the points are flaws, this problem is finding the largest-area rectangular piece which can be salvaged. A previously known result [13] takes O(N2)O(N^2 ) worst-case and O(Nlog2N)O(N\log ^2 N) expected time. This paper presents an O(Nlog3N)O(N\log ^3 N) time, O(NlogN)O(N\log N) space algorithm to solve this problem. It uses a divide-and-conquer approach similar to the ones used by Bentley [1] and introduces a new notion of Voronoi diagram along with a method for efficient computation of certain functions over paths of a tree

    What is known about the care and support provided for an ageing population with lived experience of chronic viral hepatitis as they near end-of-life: A scoping review

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    Ageing with a chronic hepatitis B (HBV) or hepatitis C (HCV) infection is an emerging public health priority. For people living with chronic viral hepatitis, their disease progression into old age is both underpinned by their existing blood borne virus and the potential emergence of other infectious and non-infectious conditions. These twinned pathways bring additional challenges to the care and support for people as they near end of life. This scoping review sought to examine what is known about the experiences of the end-of-life phase of an increasing population ageing with HBV and HCV in studies conducted in high-income settings and published in peer reviewed literature (2010–2021). In interpreting this literature, we found that challenges in determining the end-of life phase for people with lived experience of HBV or HCV are exacerbated by the conflation of aetiologies into a singular diagnosis of end-stage liver disease. Studies overwhelmingly reported the clinical aspects of end-of-life care (i.e. prognosis assessment and symptom management) with less attention paid to educative aspects (i.e. advance care directives and surrogate decision makers, discussion of treatment options and determining goals of care). Psychosocial interventions (i.e. quality of life beyond symptom management, including emotional/spiritual support and family and bereavement support) received limited attention in the literature, though there was some recognition that psychosocial interventions should be part of end-of-life care provision. Given the focus on the prominent disease presentation of liver cirrhosis and/or end-stage liver disease, the social and cultural dimensions of these infections have received less attention in the literature on end-of-life in the context of chronic viral hepatitis

    Diode-switched thermal-transfer printed antenna on flexible substrate

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    We demonstrate that diode-switching can be used to introduce frequency agility into antennas produced by thermal transfer printing. Our particular example is a triangular Sierpinski fractal pattern with two PIN diodes to switch between operation optimised for the 800 MHz UHF band (diodes on) and the 2400 MHz ISM band (diodes off). Our measured results show an improvement in S11 in the UHF band from -2 dB to -28 dB, and from -7 dB to -30 dB at 2400 MHz, when switching the diodes appropriately. The measured bandwidth is 200 (1000) MHz, and the measured directivity is 3.1dB (5.2dB) while the measured gain is -5.2dB (6.7dB) for the diodes on(off)

    Structural competency in the post-prison period for people who inject drugs: A qualitative case study

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    Introduction: Access to services is key to successful community (re-)integration following release from prison. But many people experience disengagement from services, including people who inject drugs (PWID). We use a case study approach and the notion of structural competency to examine influences on access to services among a group of PWID recently released from prison. Methods: This qualitative study recruited participants from SuperMIX, (a longitudinal cohort study in Victoria, Australia). Inclusion criteria: aged 18+; lifetime history of injecting drug use; incarcerated for > three months and released from custody < 12 months previously. From 48 participants, five case studies were selected as emblematic of the complex and intersecting factors occurring at the time participants missed an appointment at a service. Results: Numerous, concurrent, and interdependent structural influences in participants’ lives coincided with their difficulty accessing and maintaining contact with services and resulted in missed appointments. The key factors involved in the cases presented here include policies around opioid agonist treatment, inadequate, unsuitable and unsafe housing, the management of mental health and side effects of treatment, the lack of social support or estrangement from family, and economic hardship. The support available from service workers to navigate these structural issues was inconsistent. One dissenting case is examined in which missing appointments is anticipated and accommodated. Conclusions: A case study approach enabled a holistic and in-depth examination of upstream structural elements that intersect with limited social and economic resources to exacerbate the challenges of community re-entry. These results highlight structural issues that have a disproportionate impact on the choices and opportunities for PWID. The incorporation of a structural competency framework in design of services and in staff training could support person-centred and coordinated service provision that take into account PWID's experiences post-release to overcome structural barriers to service engagement
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