33,017 research outputs found
A review of ride comfort studies in the United Kingdom
United Kingdom research which is relevant to the assessment of vehicle ride comfort was reviewed. The findings reported in approximately 80 research papers are outlined, and an index to the areas of application of these studies is provided. The data obtained by different research groups are compared, and it is concluded that, while there are some areas of general agreement, the findings obtained from previous United Kingdom research are insufficient to define a general purpose ride comfort evaluation procedure. The degree to which United Kingdom research supports the vibration evaluation procedure defined in the current International Standard on the evaluation of human exposure to whole-body vibration is discussed
Symmetry sensitivities of Derivative-of-Gaussian filters
We consider the measurement of image structure using linear filters, in particular derivative-of-Gaussian (DtG) filters, which are an important model of V1 simple cells and widely used in computer vision, and whether such measurements can determine local image symmetry. We show that even a single linear filter can be sensitive to a symmetry, in the sense that specific responses of the filter can rule it out. We state and prove a necessary and sufficient, readily computable, criterion for filter symmetry-sensitivity. We use it to show that the six filters in a second order DtG family have patterns of joint sensitivity which are distinct for 12 different classes of symmetry. This rich symmetry-sensitivity adds to the properties that make DtG filters well-suited for probing local image structure, and provides a set of landmark responses suitable to be the foundation of a nonarbitrary system of feature categories
Using basic image features for texture classification
Representing texture images statistically as histograms over a discrete vocabulary of local features has proven widely effective for texture classification tasks. Images are described locally by vectors of, for example, responses to some filter bank; and a visual vocabulary is defined as a partition of this descriptor-response space, typically based on clustering. In this paper, we investigate the performance of an approach which represents textures as histograms over a visual vocabulary which is defined geometrically, based on the Basic Image Features of Griffin and Lillholm (Proc. SPIE 6492(09):1-11, 2007), rather than by clustering. BIFs provide a natural mathematical quantisation of a filter-response space into qualitatively distinct types of local image structure. We also extend our approach to deal with intra-class variations in scale. Our algorithm is simple: there is no need for a pre-training step to learn a visual dictionary, as in methods based on clustering, and no tuning of parameters is required to deal with different datasets. We have tested our implementation on three popular and challenging texture datasets and find that it produces consistently good classification results on each, including what we believe to be the best reported for the KTH-TIPS and equal best reported for the UIUCTex databases
Study and analysis of telemetry systems for the Saturn vehicle Final report
Analyses of telemetry systems used on Saturn launch vehicle
On the relationship between topological and geometric defects
The study of topology in solids is undergoing a renaissance following renewed
interest in the properties of ferroic domain walls as well as recent
discoveries regarding topological insulators and skyrmionic lattices. Each of
these systems possess a property that is `protected' in a symmetry sense, and
is defined rigorously using a branch of mathematics known as topology. In this
article we review the formal definition of topological defects as they are
classified in terms of homotopy theory, and discuss the precise
symmetry-breaking conditions that lead to their formation. We distinguish
topological defects from geometric defects, which arise from the details of the
stacking or structure of the material but are not protected by symmetry. We
provide simple material examples of both topological and geometric defect
types, and discuss the implications of the classification on the resulting
material properties
Tissue transglutaminase in normal and abnormal wound healing: review article
A complex series of events involving inflammation, cell migration and proliferation, ECM stabilisation and remodelling, neovascularisation and apoptosis are crucial to the tissue response to injury. Wound healing involves the dynamic interactions of multiple cells types with components of the extracellular matrix (ECM) and growth factors. Impaired wound healing as a consequence of aging, injury or disease may lead to serious disabilities and poor quality of life. Abnormal wound healing may also lead to inflammatory and fibrotic conditions (such as renal and pulmonary fibrosis). Therefore identification of the molecular events underlying wound repair is essential to develop new effective treatments in support to patients and the wound care sector. Recent advances in the understating of the physiological functions of tissue transglutaminase a multi functional protein cross-linking enzyme which stabilises tissues have demonstrated that its biological activities interrelate with wound healing phases at multiple levels. This review describes our view of the function of tissue trasnglutaminase in wound repair under normal and pathological situations and highlights its potential as a strategic therapeutic target in the development of new treatments to improve wound healing and prevent scarring
Improving the cost effectiveness equation of cascade testing for Familial Hypercholesterolaemia (FH)
Purpose of Review : Many International recommendations for the management of Familial Hypercholesterolaemia (FH) propose the use of Cascade Testing (CT) using the family mutation to unambiguously identify affected relatives. In the current economic climate DNA information is often regarded as too expensive. Here we review the literature and suggest strategies to improve cost effectiveness of CT. Recent findings : Advances in next generation sequencing have both speeded up the time taken for a genetic diagnosis and reduced costs. Also, it is now clear that, in the majority of patients with a clinical diagnosis of FH where no mutation can be found, the most likely cause of their elevated LDL-cholesterol (LDL-C) is because they have inherited a greater number than average of common LDL-C raising variants in many different genes. The major cost driver for CT is not DNA testing but of treatment over the remaining lifetime of the identified relative. With potent statins now off-patent, the overall cost has reduced considerably, and combining these three factors, a FH service based around DNA-CT is now less than 25% of that estimated by NICE in 2009. Summary : While all patients with a clinical diagnosis of FH need to have their LDL-C lowered, CT should be focused on those with the monogenic form and not the polygenic form
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