371 research outputs found
Integrating Traditional and Close Range Photogrammetric Bathymetric Reconstructions to Enhance Predictions of Fish Abundance and Distribution on the NSW Coast
The physical structure of marine habitat is a key determinant of the distribution and abundance of marine biota. Photogrammetry is a new method of obtaining bathymetric reconstructions using overlapping imagery. It is associated with several potential improvements over traditional bathymetric reconstruction methods (e.g., hydroacoustic and optical remote sensing), including finer resolutions, 3D mesh surfaces, and novel metrics of structural complexity. However, the greater cost of photogrammetric data collection requires evaluation of its purported benefits to marine research.
This thesis objectively assessed the potential for photogrammetry to improve predictions of marine biota abundance and distribution. Chapter 2 undertook a quantitative review and metanalysis of latest research and the relative performance of metrics. It indicated common metrics, e.g., surface-rugosity, may not always be the best performing. Chapter 3 systematically explored the relationships between metrics derived from common bathymetric reconstructions and reduced a 2,000 predictor dataset to 100 predictors, whilst maximising information captured.
Metric relative performance was assessed in Chapter 4. Photogrammetric metrics contributed to 22 / 35 fish species and 10 / 15 trophic-mobility group best performing abundance models and helped explain a third more variability compared to traditional methods. Chapter 5 extrapolated (‘engineered’) broad-scale photogrammetric metrics from traditional metrics to help alleviate the cost of photogrammetry. Using an independent dataset, the variance 26 / 50 fish species distribution models was explained best when engineered photogrammetric metrics were included.
These findings help confirm the purported benefits to marine research associated with photogrammetric metrics, which would likely improve predictions of the distribution and abundance of fish, and likely other marine biota, across Australia and worldwide. Engineered metrics would allow greater model performance to be translated to broad-extents required by marine spatial prioritisation, conservation and management. Notably, traditional metrics were important for some fish species and groups, and future studies should seek to combine these methods wherever possible
Automated mapping of oblique imagery collected with unmanned vehicles in coastal and marine environments
Recent technological advances in unmanned observational platforms, including remotely operated vehicles (ROVs) and small unmanned aerial systems (sUAS), have made them highly effective tools for research and monitoring within marine and coastal environments. One of the primary types of data collected by these systems is video imagery, which is often captured at an angle oblique to the Earth’s surface, rather than normal to it (e.g., downward looking). This thesis presents a newly developed suite of tools designed to digitally map oblique imagery data collected with ROV and sUAS in coastal and marine environments and quantitatively evaluates the accuracy of the resultant maps. Results indicate that maps generated from oblique imagery collected with unmanned vehicles have highly variable accuracy relative to maps generated with imagery data collected with conventional mapping platforms. These results suggest that resultant maps have the potential to match or even surpass the accuracy of maps generated with imagery data collected with conventional mapping platforms but realizing that potential is largely dependent upon careful survey design
Event-Driven Imaging in Turbid Media: A Confluence of Optoelectronics and Neuromorphic Computation
In this paper a new optical-computational method is introduced to unveil
images of targets whose visibility is severely obscured by light scattering in
dense, turbid media. The targets of interest are taken to be dynamic in that
their optical properties are time-varying whether stationary in space or
moving. The scheme, to our knowledge the first of its kind, is human vision
inspired whereby diffuse photons collected from the turbid medium are first
transformed to spike trains by a dynamic vision sensor as in the retina, and
image reconstruction is then performed by a neuromorphic computing approach
mimicking the brain. We combine benchtop experimental data in both reflection
(backscattering) and transmission geometries with support from physics-based
simulations to develop a neuromorphic computational model and then apply this
for image reconstruction of different MNIST characters and image sets by a
dedicated deep spiking neural network algorithm. Image reconstruction is
achieved under conditions of turbidity where an original image is
unintelligible to the human eye or a digital video camera, yet clearly and
quantifiable identifiable when using the new neuromorphic computational
approach
Synthetic image generation and the use of virtual environments for image enhancement tasks
Deep learning networks are often difficult to train if there are insufficient image samples. Gathering real-world images tailored for a specific job takes a lot of work to perform. This dissertation explores techniques for synthetic image generation and virtual environments for various image enhancement/ correction/restoration tasks, specifically distortion correction, dehazing, shadow removal, and intrinsic image decomposition. First, given various image formation equations, such as those used in distortion correction and dehazing, synthetic image samples can be produced, provided that the equation is well-posed. Second, using virtual environments to train various image models is applicable for simulating real-world effects that are otherwise difficult to gather or replicate, such as dehazing and shadow removal. Given synthetic images, one cannot train a network directly on it as there is a possible gap between the synthetic and real domains. We have devised several techniques for generating synthetic images and formulated domain adaptation methods where our trained deep-learning networks perform competitively in distortion correction, dehazing, and shadow removal. Additional studies and directions are provided for the intrinsic image decomposition problem and the exploration of procedural content generation, where a virtual Philippine city was created as an initial prototype.
Keywords: image generation, image correction, image dehazing, shadow removal, intrinsic image decomposition, computer graphics, rendering, machine learning, neural networks, domain adaptation, procedural content generation
The Fifteenth Marcel Grossmann Meeting
The three volumes of the proceedings of MG15 give a broad view of all aspects of gravitational physics and astrophysics, from mathematical issues to recent observations and experiments. The scientific program of the meeting included 40 morning plenary talks over 6 days, 5 evening popular talks and nearly 100 parallel sessions on 71 topics spread over 4 afternoons. These proceedings are a representative sample of the very many oral and poster presentations made at the meeting.Part A contains plenary and review articles and the contributions from some parallel sessions, while Parts B and C consist of those from the remaining parallel sessions. The contents range from the mathematical foundations of classical and quantum gravitational theories including recent developments in string theory, to precision tests of general relativity including progress towards the detection of gravitational waves, and from supernova cosmology to relativistic astrophysics, including topics such as gamma ray bursts, black hole physics both in our galaxy and in active galactic nuclei in other galaxies, and neutron star, pulsar and white dwarf astrophysics. Parallel sessions touch on dark matter, neutrinos, X-ray sources, astrophysical black holes, neutron stars, white dwarfs, binary systems, radiative transfer, accretion disks, quasars, gamma ray bursts, supernovas, alternative gravitational theories, perturbations of collapsed objects, analog models, black hole thermodynamics, numerical relativity, gravitational lensing, large scale structure, observational cosmology, early universe models and cosmic microwave background anisotropies, inhomogeneous cosmology, inflation, global structure, singularities, chaos, Einstein-Maxwell systems, wormholes, exact solutions of Einstein's equations, gravitational waves, gravitational wave detectors and data analysis, precision gravitational measurements, quantum gravity and loop quantum gravity, quantum cosmology, strings and branes, self-gravitating systems, gamma ray astronomy, cosmic rays and the history of general relativity
Program and Proceedings: The Nebraska Academy of Sciences 1880-2023. 142th Anniversary Year. One Hundred-Thirty-Third Annual Meeting April 21, 2023. Hybrid Meeting: Nebraska Wesleyan University & Online, Lincoln, Nebraska
AERONAUTICS & SPACE SCIENCE Chairperson(s): Dr. Scott Tarry & Michaela Lucas
HUMANS PAST AND PRESENT Chairperson(s): Phil R. Geib & Allegra Ward
APPLIED SCIENCE & TECHNOLOGY SECTION Chairperson(s): Mary Ettel
BIOLOGY Chairpersons: Lauren Gillespie, Steve Heinisch, and Paul Davis
BIOMEDICAL SCIENCES Chairperson(s): Annemarie Shibata, Kimberly Carlson, Joseph Dolence, Alexis Hobbs, James Fletcher, Paul Denton
CHEM Section Chairperson(s): Nathanael Fackler
EARTH SCIENCES Chairpersons: Irina Filina, Jon Schueth, Ross Dixon, Michael Leite
ENVIRONMENTAL SCIENCE Chairperson: Mark Hammer
PHYSICS Chairperson(s): Dr. Adam Davis
SCIENCE EDUCATION Chairperson: Christine Gustafson
2023 Maiben Lecturer: Jason Bartz
2023 FRIEND OF SCIENCE AWARD TO: Ray Ward and Jim Lewi
Walking away from VR as ‘empathy-machine’: peripatetic animations with 360-photogrammetry
My research partakes in an expanded documentary practice that weaves together walking, immersive technologies, and moving image. Two lines of enquiry motivate the research journey: the first responds to the trope of VR as 'empathy-machine' (Milk, 2015), often accompanied by the expression 'walking in someone else's shoes'. Within a research project that begins on foot, the idiom’s significance demands investigation. The second line of enquiry pursues a collaborative artistic practice informed by dialogue and poetry, where the bipedals of walking and the binaries of the digital are entwined by phenomenology, hauntology, performance, and the in-betweens of animation. My practice-as-research methodology involves desk study, experimentation with VR, AR, digital photogrammetry, and CGI animation. Central to my approach is the multifaceted notion of Peripatos ̶ as a school of philosophy, a stroll-like walk, and the path where the stroll takes place ̶ manifested both corporeally and as 'playful curiosity'.
The thread that interweaves practice and theory has my body-moving in the centre; I call it the ‘camera-walk’: a processional shoot that documents a real place and the bodies that make it, while my hand holds high a camera-on-a-stick shooting 360-video. The resulting spherical video feeds into photogrammetric digital processing, and reassembles into digital 3D models that form the starting ground for still images, a site-specific installation, augmented reality (AR) exchanges, and short films. Because 360-video includes the body that carries the camera, the digital meshes produced by the ‘camera-walk’ also reveal the documentarian during the act of documenting. Departing from the pursuit of perfect replicas, my research articulates the iconic lineage of photogrammetry, embracing imperfections as integral.
Despite the planned obsolescence of my digital instruments, I treat my 360-camera as a ‘dangerous tool’, uncovering (and inventing) its hidden virtualities, via Vilém Flusser. Against its formative intentions as an accessory for extreme sports, I focus on everyday life, and become inspired by Harun Farocki’s ‘another kind of empathy’. Within the collaborative projects presented within my thesis, I move away from the colonialist-inspired ideal of ‘walking in someone else’s shoes’, and ‘tread softly’ along the footsteps of my co-walkers
Visual and Camera Sensors
This book includes 13 papers published in Special Issue ("Visual and Camera Sensors") of the journal Sensors. The goal of this Special Issue was to invite high-quality, state-of-the-art research papers dealing with challenging issues in visual and camera sensors
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