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 62 for “"Quaternion"”.
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Nonlinear Control for Dual Quaternion Systems
… <p>A novel mathematical system known as dual quaternions provide an efficient method for mathematically modeling rigid body transformations, expressing both rotation and translation. Dual quaternions can be viewed as a representation of the special Euclidean group <em>SE</em> (3). An eight …
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Adaptive Quaternion Control for a Miniature Tailsitter UAV
… with a computationally efficient adaptive quaternion control algorithm. A backstepping method for model cancellation and consistent tracking of reference model attitude dynamics is derived. This is used in conjunction with two different algorithms designed for the identification of system …
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The quaternion Bingham Distribution, 3D object detection, and dynamic manipulation
… space of 3-D orientations. This is given by the quaternion Bingham distribution-a maximum entropy probability distribution on the 4-D unit quaternion hypersphere. In this thesis, we apply the quaternion Bingham to two applications: 3-D object instance detection from RGB-D images, and robot ping …
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Quaternion-Based Human Gesture Recognition System Using Multiple Body-Worn Intertial Sensors
In this study, we designed a multi-sensor gesture recognition system that can classify among six different human gestures. Data was collected from eleven participants using five gyroscopic motion sensors tied to their upper body. A total of 1080 samples were collected, which contain almost 6000 …
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Assessing self-similarity in redundant complex and quaternion wavelet domains: Theory and applications
… informative descriptors. Next, we step into the quaternion domain and propose a matrix-formulation for non-decimated quaternion wavelet transforms and define spectral tools for use in machine learning tasks. We define non-decimated quaternion wavelet spectra based on the modulus and three …
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A Quaternion-Based Motion Tracking and Gesture Recognition System Using Wireless Inertial Sensors
… of a total of ten sensors and uses their quaternion output to map the player's motions to an onscreen character. To demonstrate the system's capabilities, a simple virtual reality game was created. A hierarchical skeletal model was implemented that allows players to navigate the virtual …
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The Locally Free Cancellation Property of The Group Ring Zg (Eichler Condition, Quaternion Group, Kernel Group)
It is of the utmost importance to know whether ZG has locally free cancellation in many applications where ZG is the integral group ring of a finite group G over Z. Jacobinski's cancellation theorem implies that cancellation holds unless some quotient G/N is a binary poly- hedral group. Swan's …
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Evolved neural network approximation of discontinuous vector fields in unit quaternion space (S3) for anatomical joint constraint
… This culminated in the creation corrective quaternion constraints represented by discontinuous vector fields, learned by topologically evolved neural networks and trained via the resilient back propagation algorithm. Quaternion constraints are difficult to implement and although alternative …
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Graphs on which dihedral, quaternion, and abelian groups act vertex and/or edge transitively and applications to tensor products
"The graphs on which dihedral, quaternion, and abelian groups act vertex and/or edge transitivity are completely characterized. The vertex transitive graphs belong to one of three families--the well known circulant graphs, the metacirculant graphs constructured by Alspach and Parsons, and a family …
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Development of the kinematic model for an ultrasound scanning machine by means of dual quaternion transformations of screw coordinates
Thesis (B.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1989.
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Dual Quaternions for Gravity Recovery Missions
<p>A dual quaternion-based modeling, state estimation and control approach is introduced as a better alternative to the traditional methods which are currently utilized for gravity recovery missions. The proposed modeling and control approach was verified against and compared to the tangent bundle …
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Optimized Thruster Allocation Utilizing Dual Quaternions for the Asteroid Sample Return Mission (OSIRIS-REx)
… asteroid Bennu, with a focus on utilizing dual quaternion dynamics and a newly developed thruster allocation method. The dual quaternion based dynamics are chosen in order to demonstrate its feasibility in real-time applications. Contrary to typical plant dynamics, which decouple the spacecraft …
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Linear Colour Image Processing in Hypercomplex Algebra guided by Genetic Algorithms
… into a canonic convolution based on linear quaternion system (LQS) since LQS is a canonic form of a general linear quaternion function of the first degree. The proposed mathematical frameworks are specific for linear filtering since the convolution operations are carried out in projective 4D …
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Sliding Mode Control with Chattering Reduction
… experiencing constant disturbances using quaternion kinematics and Euler’s equations of rotational motion. Furthermore, a Conventional Sliding Mode Controller and an Adaptive Controller are also designed using Lyapunov analysis. The error quaternion and angular velocities are driven …
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Lunar Surface Navigation Using Gravity and Star Tracker Measurements
… attitude error vector, a, between the estimated quaternion—found using Shuster's Quaternion Estimator (QUEST) algorithm—and the reference quaternion, the longitude (λ) and latitude (ϕ) positions, and the dynamic accelerometer bias. The MEKF assumes constant state propagation between time steps …
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Anti-self-dual fields and manifolds
… Riemannian holonomy, among these hyper–Kähler, Quaternion–Kähler and Spin(7)–manifolds. We first consider the octonionic anti–self–duality equations on manifolds with holonomy Spin(7). We construct explicit solutions to their symmetry reductions, the non–abelian Seiberg–Witten equations, with …
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Improving attitude determination and control of resource-constrained CubeSats using unscented Kalman filtering
… (already implemented on some CubeSats). The quaternion estimates were converted to Euler angles to improve ease of interpretation. For the majority of the missions, the mean total Euler angle estimation error improvement ranged from 83% - 98% with error variance decreased by as much as 98%. …
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Eigenvalue statistics for beta-ensembles
… for certain matrices with real, complex, or quaternion entries. In random matrix jargon, these are the cases β = 1, 2 and 4 respectively. This thesis explores the general P > 0 case mathematically and with symbolic software. We focus on generalizations of the Hermite distributions originating …
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Hypercomplex scaling and wavelet filters: their discovery and their application to colour vector image processing
… new discrete scaling and wavelet filters with quaternion coefficients and the first with Clifford Cl(1,1) and Cl(2,0) coefficients; and then to demonstrate the use of these filters by finding hypercomplex wavelet transforms of colour vector images. We solve certain symbolic matrix equations …
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