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 29 for “"null space"”.
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Null -Space Methods for Numerical Solutions of Differential Equations
… we seek to solve, discusses options for finding null bases, explains the explicit null bases we have found, and demonstrates a solution technique for solving the problem referenced above using a null space method.
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Identification of novel properties of metabolic systems through null-space analysis
… based on the invariant properties of the left null-space of the stoichiometry matrix. Although various methods for relating the composition of metabolites exist, this technique has the advantage of not requiring any information apart from the model’s structure and allowed for the development of …
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Workspace Generation for Wire-Actuated Parallel Manipulators
… focuses on the methods and results of the workspace formulation of wire-actuated parallel manipulators. Four methods of workspace generation are studied. The null space method, based on the calculation of wire tensions, is used to formulate the workspaces of example manipulators. The results of …
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A structured reduced sequential quadratic programming and its application to a shape design problem
… structure of the Jacobian in representing the null space basis matrix. By updating the reduced Hessians only of which the dimension is the number of design variables, the storage requirement for Hessians is reduced by a large amount. In addition, the flow part of the Jacobian can be computed …
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Positional control strategies for a modular, long-reach, truss-type manipulator
… be accomplished even in a highly obstructed workspace. The parallel structure of the truss modules enables the manipulator to be withdrawn in the event of a structural failure. Finally, of particular importance to this task, the open framework of the modules provide a passageway for waste …
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Private audio delivery in reverberant spaces
… wireless communication literature, exploits the null space of the multiple-input-multiple-output channel matrix; we refer to it as the Null Space (NS) method. The two methods are evaluated and compared in numerical and real-world experiments. Both methods are shown to achieve sound focusing as …
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Harmonic and Narrowband Disturbance Rejection for Linear Time-Periodic Plants
… and align the zero direction, defined by the null space of the controlled system at the disturbance frequency, with the disturbance. In this research, constraints on controlled system infinity-norms specify nominal performance and robust stability objectives. Periodic controllers are found …
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Biomechanical simulation of virtual physiological humans : modeling of musculoskeletal kinematic and dynamic redundancy using coordinate projection methods
… methods transform the equations of motion into a space of low- or high-dimensionality according to the projection operator. Five different subspaces are studied, namely task, joint, muscle, constraint and null space as well as their relationship. Task space projection simplifies the motion …
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Degree Theory and Nonlinear Boundary Value Problems at Resonance
… the boundary conditions$\}$. Assume the null space of L:BC $\to$ $L\sp1$ (a,b) is one-dimensional and spanned by $\varphi$. This is what is called the problem at resonance.
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Resilient Waveform Design for OFDM-MIMO Communication Systems
… antijam (AJ) MIMO systems, and 4) designing null space projected overlapped-MIMO radar waveform for spectrum sharing between radar and communications system. First, we consider OFDM systems under various jamming attacks. Previous research is focused on jamming OFDM data transmissions. We …
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Analytical SLAM without linearization
… developed for three different use cases use the null space terms of SLAM problem to guarantee that robots starting with unknown initial conditions could converge to a shared consensus coordinate system with estimates reflecting the truth.
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Near aggregation: a time and frequency domain analysis using state trajectories and transfer function residues
… near-unobservability (roughly, an invariant subspace close to the null space of C). Here we establish a relationship between near-unobservability and modal measures of observability as suggested by Selective Modal Analysis. With this result we then obtain an upper bound on the norm of the …
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FastStokes : a fast 3-D fluid simulation program for micro-electro-mechanical systems
… two-step approach that successfully handles the null space of the singular incompressible Stokes BEM operators is developed to avoid numerical errors and solution discontinuities. An analytical flat-panel kernel integration algorithm is implemented in FastStokes and an accurate curved-panel …
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Algorithms for Vertex-Weighted Matching in Graphs
… matrices, to construct sparse bases for the null space or column space of under-determined matrices, and to coarsen graphs in multi-level graph partitioning algorithms. In the first part of this thesis, we develop exact and approximation algorithms for vertex weighted matchings, an …
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Coordinated Control of Robotic Swarms in Unknown Environments
… implementation of the so called \emph{Null Space Behavioral} paradigm. This approach to the problem of merging different subtasks with assigned priority is slightly modified in order to handle critical situations that can be detected when robots are moving through an unknown …
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Fast and strong lightweight robots based on variable gear ratio actuators and control algorithms leveraging the natural dynamics
… architecture and a control scheme using the null space. Second, by developing control algorithms that select optimal gear ratios dynamically based on state feedback, to move with minimal motor torques and to adjust the output impedance appropriately given a task. The proposed approach exploit …
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Constrained control allocation for systems with redundant control effectors
… as a volume in the n-dimensional output space. The allocation schemes which are detailed include traditional allocation methods such as Generalized Inverse solutions as well as more recently developed methods such as Daisy Chaining, Cascading Generalized Inverses, Null-Space Intersection …
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Derivation and application of nonlinear analytical redundancy techniques with applications to robotics
… of interest, analytical redundancy exploits the null-space of the state space control observability matrix to allow the creation of a set of test residuals. These tests use sensor data histories and known control inputs to detect any deviation from the static or dynamic behaviors of the model in …
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Generalizing smoothed aggregation-based algebraic multigrid
… operators approximate the left and right near null-spaces, respectively. As a result, we develop general SA setup algorithms for both the Hermitian positive-definite and the non-Hermitian cases. To realize these algorithms, we develop general prolongation smoothing methods so that restriction …
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Unbounded linear operators in seminormed spaces
… studied in the setting of normed or Banach spaces. However, careful examination of proofs shows that in many cases the Hausdorff property of normed spaces is not used. Even in those cases where explicit use of the Hausdorff property is made, one can often get around this (should one wish to …
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