248 research outputs found

    Automated visual inspection for the quality control of pad printing

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    Pad printing is used to decorate consumer goods largely because of its unique ability to apply graphics to doubly curved surfaces. The Intelpadrint project was conceived to develop a better understanding of the process and new printing pads, inks and printers. The thesis deals primarily with the research of a printer control system including machine vision. At present printing is manually controlled. Operator knowledge was gathered for use by an expert system to control the process. A novel local corner- matching algorithm was conceived to effect image segmentation, and neuro-fuzzy techniques were used to recognise patterns in printing errors. Non-linear Finite Element Analysis of the rubber printing-pad led to a method for pre-distorting artwork so that it would print undistorted on a curved product. A flexible, more automated printer was developed that achieves a higher printing rate. Ultraviolet-cured inks with improved printability were developed. The image normalisation/ error-signalling stage in inspection was proven in isolation, as was the pattern recognition system

    Predictive Methodology for Quality Assessment in Injection Molding Comparing Linear Regression and Neural Networks

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    The use of recycled polypropylene in industry to reduce environmental impact is increasing. Design for manufacturing and process simulation is a key stage in the development of plastic parts. Traditionally, a trial-and-error methodology is followed to eliminate uncertainties regarding geometry and process. A new proposal is presented, combining simulation with the design of experiments and creating prediction models for seven different process and part quality output features. These models are used to optimize the design without developing additional time-consuming simulations. The study aims to compare the precision and correlation of these models. The methods used are linear regression and artificial neural network (ANN) fitting. A wide range of eight injection parameters and geometry variations are used as inputs. The predictability of nonlinear behavior and compensatory effects due to the complex relationships between this wide set of parameter combinations is analyzed further in the state of the art. Results show that only Back Propagation Neural Networks (BPNN) are suitable for correlating all quality features in a single formula. The use of prediction models accelerates the optimization of part design, applying multiple criteria to support decision-making. The methodology is applied to the design of a plastic support for induction hobs. Furthermore, this methodology has demonstrated that a weight reduction of 27% is feasible. However, it is necessary to combine process parameters that differ from the standard ones with a non-uniform thickness distribution so that the remaining injection parameters, material properties, and dimensions fall within tolerances

    NASA Tech Briefs, March 1995

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    This issue contains articles with a special focus on Computer-Aided design and engineering amd a research report on the Ames Research Center. Other subjects in this issue are: Electronic Components and Circuits, Electronic Systems, Physical Sciences, Materials, Computer Programs, Mechanics, Machinery, Manufacturing/Fabrication, Mathematics and Information Sciences and Life Science

    NASA Tech Briefs, October 1992

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    Topics covered include: Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication technology; Mathematics and Information Sciences; Life Sciences

    Doctor of Philosophy

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    dissertationElectron microscopy can visualize synapses at nanometer resolution, and can thereby capture the fine structure of these contacts. However, this imaging method lacks three key elements: temporal information, protein visualization, and large volume reconstruction. For my dissertation, I developed three methods in electron microscopy that overcame these limitations. First, I developed a method to freeze neurons at any desired time point after a stimulus to study synaptic vesicle cycle. Second, I developed a method to couple super-resolution fluorescence microscopy and electron microscopy to pinpoint the location of proteins in electron micrographs at nanometer resolution. Third, I collaborated with computer scientists to develop methods for semi-automated reconstruction of nervous system. I applied these techniques to answer two fundamental questions in synaptic biology. Which vesicles fuse in response to a stimulus? How are synaptic vesicles recovered at synapses after fusion? Only vesicles that are in direct contact with plasma membrane fuse upon stimulation. The active zone in C. elegans is broad, but primed vesicles are concentrated around the dense projection. Following exocytosis of synaptic vesicles, synaptic vesicle membrane was recovered rapidly at two distinct locations at a synapse: the dense projection and adherens junctions. These studies suggest that there may be a novel form of ultrafast endocytosis

    A research on footwear and foot interaction through anatomy and human engineering

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    Thesis (Master)--Izmir Institute of Technology, Industrial Design, Izmir, 2005Includes bibliographical references (leaves: 144)Text in English; Abstract: Turkish and Englishxix, 155 leavesThe main purpose of this thesis is to examine the footwear design from the human engineering point of view. Traditionally, the concern of the designer has mostly concerned to the form in footwear design field, but user and environment-conscious designer should think about the value and compatibility of the footwear to experience comfort, performance, safety and satisfaction during use. To develop the "Footwear Design" in a human centered way, the designer should be able to synthesis the datum of design that had been analyzed from the "Human Engineering. point of view and able to assess or evaluate which design solution is better and compatible for human mobility.The basic aim of this study is to help designers to comprehend the conceptual infrastructure of footwear and foot interaction such as anatomy, anthropometry, biomechanics, physical characteristics, and ergonomics.One of the main purposes of chapter 2 is to examine the every aspect of industrial product design from the human engineering point of view and in this context, the definition of footwear design elements.In chapter 3, the foot structure is analyzed from the anatomical, morphological and biomechanical point of view with respect to foot-footwear interaction and human engineering and the Failings of modern footwear design and its discordant features and detrimental manner for the foot natural characteristics are examined to attract the attention of the designers for perceiving the responsibility that they have.In chapter 4, there are two main sections which contain fundamental design criteria through foot- footwear interaction and ergonomic considerations. Then the innovative and affirmative characteristic of modern footwear design is analyzed to encourage the designer to design the better products to drive the footwear design to new heights with respect to human nature using appropriate materials and appropriate forms

    Death, survival, and morphological development of hippocampal granule cells born in an inflammatory environment

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    The brain continues to form new neurons throughout life. This process of adult neurogenesis has been thoroughly documented in several species including birds, rodents and humans. Adult neurogenesis is not a global process, but is confined to two subcompartments of the brain; the subventricular zone lining the lateral ventricles, and the subgranular zone (SGZ) in the hippocampal formation. A variety of stimuli such as voluntary exercise, epileptic seizure activity and inflammation can affect the basal level of neurogenesis. In the course of pathological conditions such as Alzheimer’s disease, multiple sclerosis, epilepsy and stroke, an inflammatory response is initiated in the brain. Prolonged epileptic seizure activity, status epilepticus (SE), strongly imposes on the integrity of the delicate brain structure and cell communication. SE not only induces inflammation, but also neuronal death and a transient increase of basal adult neurogenesis in the hippocampal formation. What role inflammation plays in a disease such as epilepsy, and how it affects the neurons born in the aftermath of seizure activity, is largely unknown. The specific aim of the four studies included in this thesis was to investigate the effect inflammation has on the amount of basal and seizure-induced neurogenesis, and if the morphological development or functional characteristics of new neurons is affected when the neuron is born into an inflammatory environment. In brief, the purpose was to investigate the quantity and quality of the neurogenic outcome in inflammation. To comprehend the interplay between neurogenesis and inflammation would provide a valuable insight into disease progression, and could ultimately be part of the treatment or even a cure for pathological conditions involving seizure activity and inflammation

    ESSE 2017. Proceedings of the International Conference on Environmental Science and Sustainable Energy

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    Environmental science is an interdisciplinary academic field that integrates physical-, biological-, and information sciences to study and solve environmental problems. ESSE - The International Conference on Environmental Science and Sustainable Energy provides a platform for experts, professionals, and researchers to share updated information and stimulate the communication with each other. In 2017 it was held in Suzhou, China June 23-25, 2017

    The biomechanics of human locomotion

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    Includes bibliographical references. The thesis on CD-ROM includes Animate, GaitBib, GaitBook and GaitLab, four quick time movies which focus on the functional understanding of human gait. The CD-ROM is available at the Health Sciences Library
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