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 20 of 20 for “"Recovery algorithms"”.
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Recovery algorithms for in-memory OLTP databases
… been the gold standard for relational database recovery. In this thesis, we show that in modern high-throughput transaction processing systems, this is no longer the optimal way to recover a database system. In particular, as transaction throughputs get higher, ARIES-style logging starts to …
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Performance evaluation of checkpoint rollback recovery algorithms in distributed systems
Performance evaluation of checkpoint rollback recovery strategies for distributed systems is a field which has not been studied much. Considerable work has been completed in the performance analysis of checkpoint strategies in centralized systems. The necessity for such a study is clear considering …
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High resolution signal and image recovery: Fast algorithms and analysis
… we address three issues arising in signal recovery problems: developing fast and efficient algorithms for convex set constrained signal recovery, analyzing resolution limits in signal recovery algorithms, and developing new regularization techniques for reducing the ill effects of noise in …
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Sparse Solutions to Structured Underdetermined Systems in the Presence of Small Noise
… bound is very tight and that the two proposed algorithms outperform existing analytical schemes in the literature. Furthermore, we prove, in the case of real-number DFT codes, that if a fixed number of bits is available for the representation of real numbers, then these bits must be allocated …
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Ensuring reliable and secure deployment of emergent workloads on modern microprocessors
… explores the resilience of post-quantum secure algorithms and implementations against physical attacks. The plausible advent of general-purpose quantum computing in the coming decades poses a mounting threat to contemporary public-key cryptography. This threat spurred the development of new …
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Route recovery schemes for link and node failure and link congestion
… interrupted till a new path reestablished. Three recovery algorithms have been proposed that mitigate the changes occur in the network. These changes are link/node failure and link congestion. The algorithms mainly pre-compute a backup next hop for each destination in the network. This path is …
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Development of a guidance, navigation and control architecture and validation process enabling autonomous docking to a tumbling satellite
… the target spacecraft or satellite is tumbling, algorithms and strategies must be implemented to ensure the safety of both docking entities in the event of anomalies. However, difficulties encountered in past docking missions conducted with expensive satellites on orbit have indicated a lack of …
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HARBOR : an integrated approach to recovery and high availability in an updatable, distributed data warehouse
… to build a simple yet efficient crash recovery mechanism that revives a crashed site by querying remote replicas for missing updates. My new integrated approach to recovery and high availability, called HARBOR (High Availability and Replication-Based Online Recovery), targets updatable …
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A spin on compressive sensing imaging : reticle-based single-pixel imaging system
… Optimizing the sensing matrix to improve the recovery quality of the sparse vector uses coherence or cumulative coherence to determine a theoretical bound on the signal sparsity to guarantee successful recovery. SPI imaging systems employing CS techniques typically use a …
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Super Greedy Type Algorithms and Applications In Compressed Sensing
<p>In this manuscript we study greedy-type algorithms such that at a greedy step we pick several dictionary elements contrary to a single dictionary element in standard greedy-type algorithms. We call such greedy algorithms super greedy type algorithms. In the general setting, we propose several …
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Computational time-resolved imaging
… models with computationally tractable signal recovery algorithms leading to image formation. In active optical imaging setups, we use computational time-resolved imaging to experimentally demonstrate: non line-of-sight imaging or looking around corners, in which only diffusely scattered light …
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Efficient analysis of data streams
… to summarise data streams. We present two algorithms which utilise these micro-cluster summaries to enable spectral clustering to be performed on data streams. The methods were tested on simulated data streams, as well as textured images and hand-written digits. Distributed acoustic sensing …
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Channel Comparison Methods and Statistical Problems on Graphs
… Problems we study include (for SBMs) weak recovery, optimal recovery algorithms, mutual information formula, and (for broadcasting on trees) reconstruction, robust reconstruction, uniqueness of belief propagation fixed points, boundary irrelevance, computation of limit information, and so …
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Advances in sparse signal recovery methods
… acquisition, data compression, sub-linear space algorithms, etc. In this thesis we focus on sparse recovery, where the goal is to recover sparse vectors exactly, and to approximately recover nearly-sparse vectors. More precisely, from the short representation of a vector x, we want to recover a …
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Computable Performance Analysis of Recovering Signals with Low-dimensional Structures
… computability of the performance for different recovery algorithms. I present a computational framework for analyzing the recovery performance of signals with low-dimensional structures. I define a family of goodness measures for arbitrary sensing matrices as the optimal values of a set of …
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Unstructured Nodal Discontinuous Galerkin Method for Convection-Diffusion Equations Applied to Neutral Fluids and Plasmas
… in this work to achieve improved efficiency. DG algorithms for hyperbolic terms are well studied. However, an accurate and efficient diffusion solver still constitutes ongoing research, especially for a nodal representation of the discontinuous Galerkin (NDG) method. An affine reconstructed …
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l0 Sparse signal processing and model selection with applications
… To this aim, two efficient sparse signal recovery algorithms are developed in the first part of this thesis. The first method is based on direct minimization of the l0 norm via cyclic descent, which is called the L0LS-CD (l0 penalized least squares via cyclic descent) algorithm. The other …
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Modeling and Analysis of Synchronization Schemes for the TDMA Based Satellite Communication System
… (ICI). Although many synchronization algorithms have been disclosed in literature as the effective recovery methods to reduce detection error in the presence of CFO as well as STE, tradeoffs still have to be made between the estimation accuracy and estimation range (or implementation …
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Inventory estimation from transactions via hidden Markov models
… that under appropriate assumptions, exact stock recovery is possible for all time. To represent the evolution of inventory in a retail store, we use a Hidden Markov Model (HMM), along the lines of [6]. In the latter work, the authors have shown that an HMM-based framework, with Gibbs sampling for …