64 research outputs found
Cut-off rate calculations for the outer channel in a concatenated cooling system
Concatenated codes were long used as a practical means of achieving long block or constraint lengths for combating errors on very noisy channels. The inner and outer encoders are normally separated by an interleaver, so that decoded error bursts coming from the inner decoder are randomized before entering the outer decoder. The effectiveness of this interleaver is examined by calculating the cut-off rate of the outer channel seen by the outer decoder with and without interleaving. Interleaving never hurts the performance of a concatenated code, and when the inner code rate is near the cut-off rate of the inner channel, interleaving significantly improves code performance
Practical assessment on the run – iPads as an effective mobile and paperless tool in physical education and teaching
This paper investigates the use of iPads in the assessment of predominantly second year Bachelor of Education (Primary/Early Childhood) pre-service teachers undertaking a physical education and health unit. Within this unit, practical assessment tasks are graded by tutors in a variety of indoor and outdoor settings. The main barriers for the lecturer or tutor for effective assessment in these contexts include limited time to assess and the provision of explicit feedback for large numbers of students, complex assessment procedures, overwhelming record-keeping and assessing students without distracting from the performance being presented. The purpose of this pilot study was to investigate whether incorporating mobile technologies such as iPads to access online rubrics within the Blackboard environment would enhance and simplify the assessment process. Results from the findings indicate that using iPads to access online rubrics was successful in streamlining the assessment process because it provided pre-service teachers with immediate and explicit feedback. In addition, tutors experienced a reduction in the amount of time required for the same workload by allowing quicker forms of feedback via the iPad dictation function. These outcomes have future implications and potential for mobile paperless assessment in other disciplines such as health, environmental science and engineering
The ethics of entrepreneurial philanthropy
A salient if under researched feature of the new age of global inequalities is the rise to prominence of entrepreneurial philanthropy, the pursuit of transformational social goals through philanthropic investment in projects animated by entrepreneurial principles. Super-wealthy entrepreneurs in this way extend their suzerainty from the domain of the economic to the domains of the social and political. We explore the ethics and ethical implications of entrepreneurialphilanthropy through systematic comparison with what we call customaryphilanthropy, which preferences support for established institutions and social practices. We analyse the ethical statements made at interview by 24 elite UK philanthropists, 12 customary and 12 entrepreneurial, to reveal the co-existence of two ethically charged narratives of elite philanthropic motivations, each instrumental in maintaining the established socio-economic order. We conclude that entrepreneurial philanthropy, as an ostensibly efficacious instrument of social justice, is ethically flawed by its unremitting impulse toward ideological purity
Alzheimer's Disease: a Review of its Visual System Neuropathology. Optical Coherence Tomography-a Potential Role As a Study Tool in Vivo
Alzheimer's disease (AD) is a prevalent, long-term progressive degenerative disorder with great social impact. It is currently thought that, in addition to neurodegeneration, vascular changes also play a role in the pathophysiology of the disease. Visual symptoms are frequent and are an early clinical manifestation; a number of psychophysiologic changes occur in visual function, including visual field defects, abnormal contrast sensitivity, abnormalities in color vision, depth perception deficits, and motion detection abnormalities. These visual changes were initially believed to be solely due to neurodegeneration in the posterior visual pathway. However, evidence from pathology studies in both animal models of AD and humans has demonstrated that neurodegeneration also takes place in the anterior visual pathway, with involvement of the retinal ganglion cells' (RGCs) dendrites, somata, and axons in the optic nerve. These studies additionally showed that patients with AD have changes in retinal and choroidal microvasculature. Pathology findings have been corroborated in in-vivo assessment of the retina and optic nerve head (ONH), as well as the retinal and choroidal vasculature. Optical coherence tomography (OCT) in particular has shown great utility in the assessment of these changes, and it may become a useful tool for early detection and monitoring disease progression in AD. The authors make a review of the current understanding of retinal and choroidal pathological changes in patients with AD, with particular focus on in-vivo evidence of retinal and choroidal neurodegenerative and microvascular changes using OCT technology.info:eu-repo/semantics/publishedVersio
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Convolutional Coding Techniques for Certain Quadratic Residual Codes
International Telemetering Conference Proceedings / October 14-16, 1975 / Sheraton Inn, Silver Spring, MarylandThe encoding and decoding of the extended Golay code and the (32, 16) quadratic residue code by convolutional coding techniques is discussed. The generation of the extended Golay code is described in detail. A modified version of the Viterbi algorithm for hard and soft decision decoding was implemented, and the simulation results are presented.International Foundation for TelemeteringProceedings from the International Telemetering Conference are made available by the International Foundation for Telemetering and the University of Arizona Libraries. Visit http://www.telemetry.org/index.php/contact-us if you have questions about items in this collection
An Analysis of Motor System Optimization Options- A Question of Diminishing Return on Investment
This paper presents the verified results of a pump system optimization project at a major midwestern brewery. A 150-horsepower "sweet water" pump circulates a glycol/water solution to cool tanks of beer during fermentation. To keep the pump from overloading the motor, the discharge throttling valve was kept mostly closed, reducing flow and increasing pressure drop. The result was inadequate cooling and energy waste. A systems analysis showed that trimming the impeller would cut the required pumping energy by more than half. The impeller was trimmed and the energy savings paid for the entire project including the systems analysis in only six months. Further optimization efforts are currently under way on this system
Tracing Learning Across, Within, and Between Real and Virtual Worlds: A Discussion of Methods, Ethics, and Findings
There is a renewed recognition that we must study people across different spaces in their lives to better understand situated learning. Since most studies across spaces have been published in the last five years, it is time to step back and share what we know about cross-spatial learning. Further, developing methods to study people across these cross-disciplinary, multi-world spaces is challenging to say the least and involves pragmatic as well as ethical challenges. This symposium brings together researchers from different disciplines in education who have engaged in multi-year studies across informal/formal/virtual/real worlds. The object is to share diverse solutions to methodological and ethical challenges and synthesize major findings concerning learning in these cross-space studies for future directions in research
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