Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 15 of 15 for “"Natural Gradient"”.
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Natural gradient methods in statistics and machine learning
… efficiently, drawing heavily on the use of natural gradient methods (Amari, 1998). In the first main contribution chapter of this thesis, we present a novel natural-gradient-based method for optimising the parameters of probability distributions where a direct application of natural …
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Density and recharge effects during the Cape Cod natural-gradient tracer test
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2001.
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Superior to one of Glass: Natural Gradient index Lenses via Patchy Particle Self-Assembly
… suggests that lens proteins may form a gel with gradient density throughout the cellular lens structure, with density mediated by a tightly controlled protein coordination number in each region of the organ. Patchy colloid theory may therefore explain both the graded refractive index lens and the …
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Geometry of Feedback Control and Learning
… directly, viewing control synthesis by policy gradient based algorithms. Adopting such a point of view has been partially inspired by the success of learning algorithms, such as Reinforcement Learning (RL), where using principles of Dynamic Programming (DP), one can devise real-time model-free …
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Developing Sphingosine-1-Phosphate (Spns2) Inhibitors for the Treatment of Multiple Sclerosis
… system. This trafficking is largely due to the natural gradient of S1P which is high levels in blood but low in tissues. Lymphocytes will follow this gradient from areas of low S1P concentration (lymphatic tissue) to areas with higher S1P concentrations. Modulation of S1P levels is the mechanism …
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The effects of urbanisation on bee and wasp communities in Cape Town, South Africa
… nesting guild distribution across an urbanrural/natural gradient. Using pan traps, specimens were collected from 18 sites in the austral spring of 2019 and 2020. A total of 433 bee and 45 wasp specimens, comprising of 45 bee and 27 wasp morphospecies respectively, were collected. Bees from the …
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On Bilevel Optimization without Full Unrolls: Methods and Applications
… (PES), an approach for computing unbiased gradient estimates of parameters that govern a dynamical system, using only partial unrolls of the system. PES estimates the gradient of a Gaussian-smoothed objective, allowing for optimization over chaotic landscapes. 3. Challenge: Most research in …
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Understanding Patterns and Functional Impacts of an Invasive Tree and Its Biological Control in a Riparian System
… <p>Biocontrol defoliation creates a natural gradient of invasive species cover across the landscape. I examined Tamarix dominated sites across a large geographic extent to understand how both the abiotic environment and varied levels of Tamarix influence the functional composition of …
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Probabilistic Continual Learning using Neural Networks
… which maintains a distribution over beliefs, naturally handling continual learning by recursively updating from priors to posteriors. Although previous work has been limited by approximations to this idealised scheme, we scale our probabilistic algorithms to large-data settings and show strong …
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Using seaweed assemblages on intertidal rocky shores to assess the ecological status of Andalusian coasts. Biogeographical implications.
… based indices. Moreover, the existence of a natural gradient along this coast interferes in the final value of the indices. The main objectives of this thesis were: i) the adaptation and comparison of indices based on macroalgae for the assessment of the ecological status in coastal waters of …
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Optimisation Methods For Training Deep Neural Networks in Speech Recognition
… learning difficult via first order stochastic gradient descent (SGD). The task of finding the best procedure to train DNNs continues to be an active area of research and has been made even more challenging by the availability of ever more training data. This thesis focuses on designing better …
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Hydrochemical Dynamics Under Differing Winter Climate Regimes at the Hubbard Brook Experiment Forest
… and hydrology of stream and soil water across a natural gradient of winter climate at the HBEF.</p> <p>Thirty years (1982-2011) of stream and soil water chemistry data were analyzed to assess the trends of overall recovery from acidification, as well as a trends associated with the snowmelt …
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Statistical Model Based Multi-Microphone Speech Processing: Toward Overcoming Mismatch Problem
… component analysis (ICA) implemented with the natural gradient method is extended into the STFT domain with regularized feed-forward ICA (RFFICA) and post-processing based on direction-per-frequency. This method showed up to almost an order of magnitude performance improvement (29 dB in …