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 10 of 10 for “"Nonnegativity"”.
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Matrix Factorization: Nonnegativity, Sparsity and Independence
… factorizations which impose the requirements of nonnegativity, sparsity or independence.
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Computational Tradeoffs and Symmetry in Polynomial Nonnegativity
… mathematics. Although exact conditions for nonnegativity are computationally intractable, there has been a surge of recent work giving sufficient conditions for nonnegativity to address its many practical applications. A major trend in this direction has been the use of convex optimization …
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Power and limitations of convex formulations via linear and semidefinite programming lifts
… and consider the general problem of certifying nonnegativity of functions. We study a class of certificates rooted in convex duality and show that they encompass many existing methods for proving nonnegativity based on convex optimization. In particular we propose a new proof system to certify …
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Estimation of origin-destination flows for dynamic traffic assignment
… vehicles. The framework is extended to allow for nonnegativity and capacity constraints on the OD flows. As OD estimation is intended for use in a real-time setting, computational issues are critical, and several simplifications to increase computational efficiency are propsed and evaluted, called …
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Learning strictly orthogonal p-order nonnegative Laplacian embedding via smoothed iterative reweighted method
… space. Imposing the orthogonality and the nonnegativity constraints can avoid degenerate and negative solutions, respectively. These two attributes are critical yet challenging to achieve simultaneously. Although, in recent years, many attempts have been made to overcome this, this problem …
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Asymptotic Behavior of Homology and Intersection Multiplicity
… sufficient condition for an interesting case of nonnegativity of intersection multiplicity over complete intersections. In the third result, we use the Frobenius endomorphism and the vanishing of Ext to characterize finitely generated modules of finite projective dimension over complete …
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Application and Extension of Weighted Quantile Sum Regression for the Development of a Clinical Risk Prediction Tool
… penalized regression technique that imposes nonnegativity and unit-sum constraints on the coefficients used to weight index components. In this dissertation, we develop a number of extensions to the WQS regression technique and apply them to the construction of the HSM. We introduce a new …
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Quadratic maximization under combinatorial constraints and related applications
… maximization problems subject to sparsity, nonnegativity and other combinatorial constraints. Intuitively, a key technical challenge is determining the support of the optimal solution. We develop a method that can surprisingly solve the maximization exactly when the argument matrix of the …
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Large deviation theory for queueing systems
… by Wentzel. However, mainly due to the nonnegativity constraint, the queue length process, X(t), of our model does not satisfy the assumed conditions. As a detour, we define the “potential process”, Y(t), which allows the negativity in state space in the way that even if a queue is …
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Algorithms and software for efficient tensor decompositions
… extend the optimization framework to support nonnegativity constraints, and develop corresponding sparse tensor kernels that enable CP and Tucker decompositions under general loss functions. The final part of this thesis explores tensor decompositions other than CP and Tucker. Butterfly matrix …