Estimation of a 3D motion field from a multi-camera array using a multiresolution Gaussian mixture model

The problem of modelling geometry for video based rendering has been much studied in recent years, due to the growing interest in 'free viewpoint' video and similar applications. Common approaches fall into two categories: those which approximate surfaces from dense depth maps obtained by generalisations of stereopsis and those which employ an explicit geometric representation such as a mesh. While the former have generality with respect to geometry, they are limited in terms of viewpoint; the latter, on the other hand, sacrifice generality of geometry for freedom to pick an arbitary viewpoint. The purpose of the work reported here is to bridge this gap in object representation, by employing a stochastic model of object structure: a multiresolution Gaussian mixture. Estimation of the model and tracking it through time from multiple cameras is achieved by a multiresolution stochastic simulation. After a brief outline of the method, its use in modelling human motion using data from local and other sources is presented to illustrate its effectiveness compared to the current state of the art

Unimproved : land observation at the edge of progress

As residents of the United States, all of us have benefited from the resources that this land provides. Some of these resources are responsibly managed, like some logging operations and grazing land. Some are much more harmful, like hydroelectric dams that have drowned Indigenous lands, and block natural habitat. Whether through development or extraction, we as humans have the special ability to drastically change the world around us in a very short amount of time. In a time of rapid environmental change, we need to find ways to better connect, observe, and assess the landscape so that as a society, we can make more informed and compassionate choices on how to manage our shared resources. When we talk about stopping climate change, we have to stop talking about returning to a nostalgic past. We have to start talking about a hopeful but different future with a very rough patch in between. The United States Federal Government has long mapped, and surveyed the land of this country to promote expansion, extraction, and tourism. I am proposing a set of tools, distributed by a new branch of the Department of the Interior, the Civilian Corps of Landscape Reassessment, as a means to give citizens a point of access to the discourse and conversation around land issues and create collaboration between citizens and through active participation, increase personal investment

Study Of Inas/Ga(In)Sb And Inasn/Ga(In)Sb Superlattices By Mbe For Very Long Wavelength Infrared Photodetectors

Infrared (IR) sensors are extremely important in missile defense as well as in satellite-based infrared detection systems. Long-range ballistic missile defense for incoming missile acquisition, tracking, and discrimination requires space-based infrared technology. Hence long wavelength and very long wavelength infrared regimes are extremely important for such applications. The focus of this work is on the investigation of superlattices (SLs) and in particular dilute nitride based SLs for such applications in this infrared region. A comprehensive study of InAs/GaSb, InAs/GaInSb, InAsN/GaSb and InAsN/GaInSb SLs grown by molecular beam epitaxy (MBE) has been carried out using different characterization techniques. Optimization of the structures with growth parameters such as interfacial layers, layer thickness, and material composition will also be discussed. The judicious selection of the above combination of parameters was abetted by theoretical simulation using OPTEL_ZB software. A systematic and detailed study has been made correlating the structural quality, vibrational modes, scanning transmission electron microscope (STEM) micrographs and optical properties of each of the optimized structure of the SL. All the SLs were defect free with sharp interfaces and well defined sublayers as attested by high resolution x-ray diffraction (HRXRD) and asymmetric reciprocal space mapping (RSM) spectra as well as STEM images. The unique feature of this work is the growth of InAsN/GaSb SL which has not been reported elsewhere to the best of our knowledge. This SL shows promise in that thinner layers of InAsN were used for the same strain balancing effect as thicker InAs. Hence the former would improve optical absorption. Since the N in InAsN reduces the overall lattice constant of the material system it added another degree of freedom in strain balancing the structure to the GaSb substrate. A cut off wavelength of ~20 μm was achieved with the InAsN/GaSb SL

Modeling temporal perception

We seem to experience a world abounding with events that exhibit dynamic temporal structure; birds flying, children laughing, rain dripping from an eave, melodies unfolding, etc. Seeing objects in motion, hearing and communicating with sound, and feeling oneself move are such common everyday experiences that one is unlikely to question whether humans are capable of perceiving temporal properties and relations. Despite appearing pre-theoretically uncontroversial, there are longstanding and contentious debates concerning the structure of such experience, how temporal perception works, and even whether the perception of change, motion, and succession is possible. The overarching goal of my project is to develop a comprehensive model of temporal perception that does justice to the apparent phenomenology, explains how perception functions to represent temporally structured targets, and generates empirically-informed hypotheses for how such perception is neuro-cognitively realized. I also defend my model against the challenges of anti-realist competitors whom deny the possibility of perceiving temporal relations between non-simultaneous events (e.g., Reid, Chuard, Le Poidevin). In Chapter 1, I begin with the apparent phenomenology of temporal experience, identifying and lending some plausibility to three claims about the nature and content of temporal experience: i) humans perceive dynamic events that instantiate temporal properties and stand in temporal relations (e.g., change, succession, duration, order), ii) humans perceive events as present, and iii) successive events of brief duration can be experienced together as present within some finite interval. This approach enables me to outline what models of present experience are supposed to represent and explain. I proceed to sketch one family of models that posit an extended perceptual present to explain how non-simultaneous events can be experienced together as present, called “Extensionalist Models” (e.g., James, Broad, Russell, Dainton). I examine two distinct branches of extensionalism (Process vs. Content) and proprietary hypotheses linking those models to the real systems they are intended to explain, and challenge the tenability of process extensionalism. Throughout the dissertation, I advocate for Content Extensionalism, the model that holds we perceive the temporal relations between non-simultaneous events in virtue of targeting and representing temporally extended content. I develop the model by pairing it with a theory of mental representation that distinguishes representation from indication, and explains how representations are source-independent isomorphs of their intended targets. In doing so, I demonstrate its comparative advantages over other extensionalist models, provide a straightforward account of claims (i-iii), and equip the model with the resources to defeat an argument that offers two routes to denying the third and most contentious claim—that successive events occurring within a brief interval are experienced together as present. I conclude the chapter by taking a closer look at the “Intentionalist Models” largely based on Edmund Husserl’s seminal work on time consciousness, rehearse some common objections against it, and argue that content extensionalism is a preferable model. In Chapter 2, I turn my attention to motion perception, arguing that perceptual representations of constant motion are not reducible to mere successions of static perceptions representing what happens at a given time. My position directly opposes temporal atomists (e.g., Chuard, Le Poidevin), whom deny that we perceive motion, claiming that we only perceive what happens at a given time and that putative experiences of motion reduce to a series of static perceptual “snapshots” arranged successively. In the first half of the chapter, I examine and challenge some the motivations for atomism, including its connection to the empiricism of Locke and Reid, and its mereological conception of experience, such that purported experiences of motion supervene on and are reducible to the successive atomic perceptions of which they are composed. In the second half of chapter, I argue that both the apparent phenomenology and neurocognitive research shift the burden upon atomism to provide a compelling an error theory to explain away our putative perceptions as of constant motion and make their anti-realism about extended experiences palatable. I proceed to reconstruct and criticize their standard strategy of appealing to cinematic metaphors to motivate their view that motion perception is entirely reducible to series of static perceptions presented successively. Finally, I draw analogies between Zeno’s puzzle of motion and the temporal perception debate, and argue that the atomist explanation of motion experience is analogous to Zeno’s failed solution to the original puzzle and that content extensionalism provides a preferred explanation consonant with the Russell-Salmon solution. In Chapter 3, I continue to combat skepticism about the perception of temporal properties and relations. Le Poidevin (2007) proposes an epistemological puzzle of time perception, from which he derives the claim that the order and duration of events do not causally contribute to our perceptual beliefs about them. Since his view is motivated by a causal truthmaker principle for grounding knowledge, it also holds that perceptual beliefs about temporal features must be caused by the features themselves in order to count as knowledge. Given these theoretical commitments, there is a puzzle concerning how such perceptual beliefs could constitute knowledge of temporal properties. In response to Le Poidevin, I argue for an account according to which order and duration are objects of perception, causally contribute to our perceptual beliefs about them, and such beliefs are capable of counting as knowledge. I conclude by showing that, on my alternative account, the epistemological puzzle dissolves and his own solution to it fails. In Chapter 4, I specify a target range of temporal phenomena salient to understanding perceptual cognition, and motivate the multi-scale sampling (MSS) hypothesis that sensory subsystems sample information at multiple rates, i.e. shorter and longer sampling periods. I argue that both behavioral and neurophysiological data support the hypothesis that nervous systems process temporal information by sampling stimuli signals at shorter and longer durations, favoring the content extensionalist hypothesis that temporal perception is constituted by multi-scale sampling and integration, over a single-sampling rate hypothesis implied by the atomistic “snapshot” model. In the second half of Chapter 4, I defend a form of constructive realism—the view that scientific theories are best understood as (a) families of models and (b) hypotheses that specify the respects and degrees in which a model represents some real physical system. I conclude the dissertation with a section on philosophy of science, because I engage empirical work throughout the project and employ a model-based approach to theorizing. Furthermore, I suggest that philosophical analysis of the experimental findings may generate new hypotheses and predictions, or offer critical arguments to help rule out the plausibility of particular competing models. To illustrate this interdisciplinary upshot, I briefly make a case for possible philosophical contributions to the fertile domain of temporal processing where there remain many contenders and no consensus on the exact mechanisms that realize temporal perception

Update on Electricity Customer Choice In Ohio: Competition Continues to Outperform Traditional Monopoly Regulation (Executive Summary)

Key Findings at a Glance: Deregulated Markets Save Ohio Electricity Consumers Billions Since 2011, deregulation has saved Ohio consumers $23.9 billion. The Study Team anticipates that savings will continue for the near term to be around$3 billion per year. However, these savings may be lost, in whole or in part, if deregulated energy markets continue to be undermined by cross subsidies. Competition Outperforms Monopoly Regulation Competition has driven down average electricity prices in deregulated Midwestern states while their regulated peers have seen a steady increase in price of generated electricity

Update on Electricity Customer Choice In Ohio: Competition Continues to Outperform Traditional Monopoly Regulation (Executive Summary)

Key Findings at a Glance: Deregulated Markets Save Ohio Electricity Consumers Billions Since 2011, deregulation has saved Ohio consumers $23.9 billion. The Study Team anticipates that savings will continue for the near term to be around$3 billion per year. However, these savings may be lost, in whole or in part, if deregulated energy markets continue to be undermined by cross subsidies. Competition Outperforms Monopoly Regulation Competition has driven down average electricity prices in deregulated Midwestern states while their regulated peers have seen a steady increase in price of generated electricity