6,833 research outputs found

    More-than-words: Reconceptualising Two-year-old Children’s Onto-epistemologies Through Improvisation and the Temporal Arts

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    This thesis project takes place at a time of increasing focus upon two-year-old children and the words they speak. On the one hand there is a mounting pressure, driven by the school readiness agenda, to make children talk as early as possible. On the other hand, there is an increased interest in understanding children’s communication in order to create effective pedagogies. More-than-words (MTW) examines an improvised art-education practice that combines heterogenous elements: sound, movement and materials (such as silk, string, light) to create encounters for young children, educators and practitioners from diverse backgrounds. During these encounters, adults adopt a practice of stripping back their words in order to tune into the polyphonic ways that children are becoming-with the world. For this research-creation, two MTW sessions for two-year-old children and their carers took place in a specially created installation. These sessions were filmed on a 360˚ camera, nursery school iPad and on a specially made child-friendly Toddler-cam (Tcam) that rolled around in the installation-event with the children. Through using the frameless technology of 360˚ film, I hoped to make tangible the relation and movement of an emergent and improvised happening and the way in which young children operate fluidly through multiple modes. Travelling with posthuman, Deleuzio-Guattarian and feminist vital material philosophy, I wander and wonder speculatively through practice, memory, and film data as a bag lady, a Haraway-ian writer/artist/researcher-creator who resists the story of the wordless child as lacking and tragic; the story that positions the word as heroic. Instead, through returning to the uncertainty of improvisation, I attempt to tune into the savage, untamed and wild music of young children’s animistic onto-epistemologies

    The development of liquid crystal lasers for application in fluorescence microscopy

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    Lasers can be found in many areas of optical medical imaging and their properties have enabled the rapid advancement of many imaging techniques and modalities. Their narrow linewidth, relative brightness and coherence are advantageous in obtaining high quality images of biological samples. This is particularly beneficial in fluorescence microscopy. However, commercial imaging systems depend on the combination of multiple independent laser sources or use tuneable sources, both of which are expensive and have large footprints. This thesis demonstrates the use of liquid crystal (LC) laser technology, a compact and portable alternative, as an exciting candidate to provide a tailorable light source for fluorescence microscopy. Firstly, to improve the laser performance parameters such that high power and high specification lasers could be realised; device fabrication improvements were presented. Studies exploring the effect of alignment layer rubbing depth and the device cell gap spacing on laser performance were conducted. The results were the first of their kind and produced advances in fabrication that were critical to repeatedly realising stable, single-mode LC laser outputs with sufficient power to conduct microscopy. These investigations also aided with the realisation of laser diode pumping of LC lasers. Secondly, the identification of optimum dye concentrations for single and multi-dye systems were used to optimise the LC laser mixtures for optimal performance. These investigations resulted in novel results relating to the gain media in LC laser systems. Collectively, these advancements yielded lasers of extremely low threshold, comparable to the lowest reported thresholds in the literature. A portable LC laser system was integrated into a microscope and used to perform fluorescence microscopy. Successful two-colour imaging and multi-wavelength switching ability of LC lasers were exhibited for the first time. The wavelength selectivity of LC lasers was shown to allow lower incident average powers to be used for comparable image quality. Lastly, wavelength selectivity enabled the LC laser fluorescence microscope to achieve high enough sensitivity to conduct quantitative fluorescence measurements. The development of LC lasers and their suitability to fluorescence microscopy demonstrated in this thesis is hoped to push towards the realisation of commercialisation and application for the technology

    Neural Microfacet Fields for Inverse Rendering

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    We present Neural Microfacet Fields, a method for recovering materials, geometry, and environment illumination from images of a scene. Our method uses a microfacet reflectance model within a volumetric setting by treating each sample along the ray as a (potentially non-opaque) surface. Using surface-based Monte Carlo rendering in a volumetric setting enables our method to perform inverse rendering efficiently by combining decades of research in surface-based light transport with recent advances in volume rendering for view synthesis. Our approach outperforms prior work in inverse rendering, capturing high fidelity geometry and high frequency illumination details; its novel view synthesis results are on par with state-of-the-art methods that do not recover illumination or materials.Comment: Project page: https://half-potato.gitlab.io/posts/nmf

    2023-2024 Catalog

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    The 2023-2024 Governors State University Undergraduate and Graduate Catalog is a comprehensive listing of current information regarding:Degree RequirementsCourse OfferingsUndergraduate and Graduate Rules and Regulation

    An Investigation into Radiative Property Variations across Pre-Annealed Advanced High Strength Steel Coils

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    In recent years, increasingly stringent crashworthiness and emissions regulations have driven automakers to consider novel materials for automotive lightweighting. Advanced high-strength steels (AHSS) used in automotive chassis construction has increased considerably. The most widely used grades of AHSS are dual-phase (DP) ferrite-martensite (α + α') grades. Advanced high strength steel coils must be annealed with a precise heating schedule to achieve the required mechanical properties. However, temperature excursions during intercritical annealing cause erratic changes in the steel's microstructure, resulting in variations in post-annealed mechanical properties across coils. These variations lead to high scrap rates and cost manufacturers millions of dollars annually. Past research has attributed these temperature excursions to non-uniform thermal irradiation. The present work shows variations in radiative properties across a single AHSS coil may cause temperature excursions through pyrometer errors and nonuniform heating. Radiative property variations across a coil may also arise before annealing due to non-homogeneities in surface topography, influencing how the radiative properties subsequently evolve during annealing. This thesis documents experimental and theoretical work characterising radiative property variations across a single AHSS coil processed on an industrial cold-rolling line. The ex-situ radiative properties of samples extracted from various coil locations are analysed using a Fourier Transform Infra-Red (FTIR) spectrometer equipped with an integrating sphere, revealing large swings in radiative properties along its length and width. The effect of these variations on pyrometric temperature measurements, strip temperature evolution, and in turn, the as-formed mechanical properties are discussed. Radiative property variations are strongly correlated to differences in surface topography (particularly surface cavities) through optical profilometry, optical microscopy, and scanning electron microscopy (SEM). The work uses 3D depth mapping of optical imagery to generate surface height maps and theoretically models the radiative properties using a geometric optics approximation (GOA) ray-tracing algorithm. The GOA approach provides accurate spectral emissivity predictions within its validity regime. The study then explores reasons for surface cavity formation, hypothesising that cavities form due to the dissolution of selective grain boundary oxides (formed during hot rolling) during acid pickling, which leads to micro-topographical changes to the strip surface. Furthermore, non-homogeneous cold-rolling parameters subsequently lead to non-uniform cavity flattening. The thesis then explores the combined effect of acid pickling time and cold-rolling reduction percentage by studying different AHSS alloys, cold-rolled and acid-pickled to different extents, through a factorial design-of-experiments procedure. An artificial neural network (ANN) regression model for near-instantaneous spectral emissivity predictions of AHSS was developed using surface roughness parameters and optical imagery as inputs. Manufacturers can implement this model with emerging in-situ strip imaging technologies to provide real-time spectral emissivity predictions before a coil section enters an annealing furnace. Galvanisers can also use these on-line spectral emissivity predictions to update pyrometry and furnace temperature control algorithms in real time. This thesis expands our knowledge base on the possible causes for temperature excursions across an AHSS coil during annealing. Findings of this research will benefit steel manufacturers in identifying and reducing non-homogeneities in mechanical properties across AHSS coils, reducing high scrap rates in the industry

    Realistic Volume Rendering with Environment-Synced Illumination in Mixed Reality

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    Interactive volume visualization using a mixed reality (MR) system helps provide users with an intuitive spatial perception of volumetric data. Due to sophisticated requirements of user interaction and vision when using MR head-mounted display (HMD) devices, the conflict between the realisticness and efficiency of direct volume rendering (DVR) is yet to be resolved. In this paper, a new MR visualization framework that supports interactive realistic DVR is proposed. An efficient illumination estimation method is used to identify the high dynamic range (HDR) environment illumination captured using a panorama camera. To improve the visual quality of Monte Carlo-based DVR, a new spatio-temporal denoising algorithm is designed. Based on a reprojection strategy, it makes full use of temporal coherence between adjacent frames and spatial coherence between the two screens of an HMD to optimize MR rendering quality. Several MR development modules are also developed for related devices to efficiently and stably display the DVR results in an MR HMD. Experimental results demonstrate that our framework can better support immersive and intuitive user perception during MR viewing than existing MR solutions.Comment: 6 pages, 6 figure

    Стан та перспективи подальших досліджень сфери обчислення глобального освітлення у реальному часі

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    Currently, computer graphics is a very important part of computer science. Graphics-related developments have been used in many different situations, for example, in animated and cinema movie productions, in computer graphics applications, modeling, and simulation systems, for different visualizations in medicine, mathematics, physics, etc. One of the main problems of computer graphics is the task of transforming the information of some imaginary scene and its observer into a photorealistic image of this scene for them. Solving this problem is very important, but right now obtaining a good quality result is possible only in a non-interactive scenario (for example, in animated films), while in real-time (for example, in computer modeling or simulations, in computer games) it is usually necessary to use some approximate algorithms. Although these algorithms are often able to provide a natural-looking result, they still have plenty of very noticeable inaccuracies. However, this topic is gaining more and more development recently due to the improvement of graphics processors. In addition to a significant increase in computation speed and the number of cores, the appearance of ray tracing hardware acceleration plays a large role. Global illumination computation is an inseparable part of photorealistic image generation. This paper is focused on solving this problem in real-time, which means developing a system capable of generating such images at a speed sufficient for the resulting sequence to be perceived by a person as a smooth animation. We give the theoretical information required for understanding this problem and describe existing methods and algorithms for solving it with their advantages and disadvantages. Also based on an overview of the topic's current state, we analyze further research prospects and directions for improving existing and developing new methods of real-time global illumination calculation, while considering compute power and technologies of the latest graphics hardware. Pages of the article in the issue: 72 - 79 Language of the article: UkrainianУ статті розглядається така проблема сучасної комп’ютерної графіки як обчислення глобального освітлення в реальному часі. Глобальне освітлення є невід’ємною частиною фотореалістичного рендерінгу, але його підрахунок потребує доволі об’ємних обчислень. Через це на даний момент якісне глобальне освітлення існує лише у неінтерактивних рендерах (наприклад, у мультиплікаційних фільмах), а у реальному часі (наприклад, комп’ютерному моделюванні або симуляціях, комп’ютерних іграх) зазвичай використовуються певні наближення, які хоч і надають зображенню певну природність, але все одно мають вкрай помітні неточності. Але останнім часом дана тема набуває все більшого розвитку за рахунок удосконалення відеопроцессорів. Крім значного підвищення їх швидкодії та збільшення кількості ядер досить велику роль грає поява апаратного прискорення трасування променів. В даній роботі проводиться теоретичне дослідження проблеми глобального освітлення, наводяться існуючи підходи та розробки для вирішення даної проблеми та аналізуються перспективи подальших досліджень та розробки нових методів обчислення глобального освітлення в реальному часі з урахуванням новітніх апаратних можливостей обчислювальної техніки

    Development of a sensor for microvibrations measurement in the AlbaSat CubeSat mission

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    openMicrovibrations on spacecraft represent an issue for payloads requiring high pointing accuracy and/or stability over time, and they might represent a particular concern for CubeSats and small satellites that, usually, are not equipped with very-high performance attitude control systems. Hence, collecting reliable measures of the vibration spectra during the operations of a CubeSat represents a significant research activity. This thesis presents the development of a sensor, configured as a payload within the AlbaSat mission, capable of accurately measuring the microvibrations in space, with particular focus on those produced by the Momentum Exchange Devices (MED), i.e., Reaction or Momentum Wheels, that represent one of the most important microvibrations sources. The thesis takes place in the framework of the AlbaSat mission. AlbaSat is a 2U CubeSat developed by a student team of the University of Padova under the “Fly Your Satellite! – Design Booster” programme promoted by the European Space Agency (ESA). The mission has four different objectives: (1) to collect measurements of the space debris environment in-situ, (2) to measure the microvibrations on board the CubeSat, (3) to precisely determine the position of the satellite through laser ranging and (4) to investigate alternative systems for possible Satellite Quantum Communication applications on nanosatellites. The requirements for the correct sizing of the sensor and the chosen physical and functional architecture are defined and presented in the thesis. A meticulous schedule for functional tests is finally outlined, aimed at verifying the correct functionality of the microvibration sensor. These tests serve as a starting point for the future development of the payload.Microvibrations on spacecraft represent an issue for payloads requiring high pointing accuracy and/or stability over time, and they might represent a particular concern for CubeSats and small satellites that, usually, are not equipped with very-high performance attitude control systems. Hence, collecting reliable measures of the vibration spectra during the operations of a CubeSat represents a significant research activity. This thesis presents the development of a sensor, configured as a payload within the AlbaSat mission, capable of accurately measuring the microvibrations in space, with particular focus on those produced by the Momentum Exchange Devices (MED), i.e., Reaction or Momentum Wheels, that represent one of the most important microvibrations sources. The thesis takes place in the framework of the AlbaSat mission. AlbaSat is a 2U CubeSat developed by a student team of the University of Padova under the “Fly Your Satellite! – Design Booster” programme promoted by the European Space Agency (ESA). The mission has four different objectives: (1) to collect measurements of the space debris environment in-situ, (2) to measure the microvibrations on board the CubeSat, (3) to precisely determine the position of the satellite through laser ranging and (4) to investigate alternative systems for possible Satellite Quantum Communication applications on nanosatellites. The requirements for the correct sizing of the sensor and the chosen physical and functional architecture are defined and presented in the thesis. A meticulous schedule for functional tests is finally outlined, aimed at verifying the correct functionality of the microvibration sensor. These tests serve as a starting point for the future development of the payload
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