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Showing 1 to 20 of 342 for “"Adjoint"”.
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Adjoint Venture: Fast Greeks with Adjoint Algorithmic Differentiation
This dissertation seeks to discuss the adjoint approach to solving affine recursion problems (ARPs) in the context of computing sensitivities of financial instruments. It is shown how, by moving from an intuitive 'forward' approach to solving a recursion to an 'adjoint' approach, one might …
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Abelian algebras and adjoint orbits
Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Mathematics, 1981.
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Adjoint Error Estimation for Elastohydrodynamic Lubrication
In this thesis, adjoint error estimation techniques are applied to complex elastohydrodynamic lubrication (EHL) problems. A functional is introduced, namely the friction, and justification is provided as to why this quantity, and hence its accuracy, is important. An iterative approach has been …
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Adjoint-based optimization for inkjet printing
… with respect to boundary forcing using the adjoint method. Using gradient-based optimization algorithms, optimal waveforms are found that minimize the objective value at various final times and for geometries with increasing complexity. Physical interpretation to the optimal waveforms …
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Adjoint-accelerated Bayesian inference in thermoacoustics
… optimization, with gradients calculated using adjoint methods. We then estimate the posterior uncertainty using Laplace's method, which we evaluate using first and second order adjoint methods. Under the assumptions of Laplace's method, Bayesian model comparison metrics are evaluated through …
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Adjoint-based particle defect yield modeling
… function of photonic devices and circuits. The adjoint method previously used in optimization is modified and implemented to facilitate the simulation of the impact of defects in silicon photonic devices. More specifically, we demonstrate the methodology to build both component-level and …
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Jet Noise Control by Adjoint-Based Optimization
"The adjoint of the perturbed and linearized compressible viscous flow equations is formulated in such a way that its solution can be used to optimize control actuation in order to reduce the noise radiated by a randomly excited two-dimensional mixing layer, which serves as near-nozzle model of a …
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Adjoint-based control of turbulent jet noise
… generally guide noise-reduction efforts so far. Adjoint-based optimization provides a unique and useful tool to pursue jet-noise reduction in a systematic approach. The adjoint of the perturbed and linearized Navier--Stokes equations is crafted to provide the control sensitivity in a direction of …
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Optimalizace difuzoru vodní turbíny s využitím adjoint řešiče
… turbíny. Optimalizace je založena na použití adjoint řešiče v programu ANSYS Fluent. Hlavním cílem bylo potlačení vírového copu v mimooptimálních režimech. Byla vytvořena metodika iterativní optimalizace pro adjungovaný řešič. Cílová funkce pro adjungovaný řešič byla zvolena s cílem …
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Strong Ordering in the Self Adjoint Operator Space
Made available in DSpace on 2014-12-05T21:50:00Z (GMT). No. of bitstreams: 1 0006916.pdf: 2740465 bytes, checksum: cb28ddcdfb5785816f88611e4ef10912 (MD5) Previous issue date: 1953
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Accelerated Adjoint Algorithmic Differentiation with Applications in Finance
Adjoint Differentiation's (AD) ability to calculate Greeks efficiently and to machine precision while scaling in constant time to the number of input variables is attractive for calibration and hedging where frequent calculations are required. Algorithmic adjoint differentiation tools automatically …
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Driving the ocean's overturning : an adjoint sensitivity study
… and mixing on climatological time scales. An adjoint model is used to gain new insights into the spatial characteristics of the sensitivity patterns. Adjoint models provide the sensitivity of a diagnostic, often called cost function, to all model parameters in a single integration. In …
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Self-adjoint extensions to the Dirac Coulomb Hamiltonian
… in this case energy, correspond to self-adjoint operators, in this case the Hamiltonian operator HI, acting on the Hilbert space 7H which describes the system in question. It can easily be shown that self-adjoint operators must have real eigenvalues. The reality of the energy eigenvalues …
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Gradient-Based Optimum Aerodynamic Design Using Adjoint Methods
Continuous adjoint methods and optimal control theory are applied to a pressure-matching inverse design problem of quasi 1-D nozzle flows. Pontryagin’s Minimum Principle is used to derive the adjoint system and the reduced gradient of the cost functional. The properties of adjoint variables at the …
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Self-adjoint Laplacians and Symmetric Diffusions on Hyperbolic Attractors
… in terms of Dirichlet forms. We construct self-adjoint Laplacians and symmetric Markov semigroups on uniformly, partially and generalized hyperbolic attractors, as well as on attractors with nonuniformly hyperbolic structure, endowed with SRB measures or Gibbs u-measures. If the measure has full …
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Adjoint-based optimization of multiphase flows with sharp interfaces
Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2022-11-11 without embargo terms
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Seismic structure beneath Southeast Asia from adjoint waveform tomography
… mantle beneath Southeast Asia obtained from adjoint waveform tomography (often referred to as full-waveform inversion or FWI) is presented. FWI is a non-linear imaging method, where an initial model is updated in order to minimise the difference between observed and predicted waveforms. Based …
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Unsteady adjoint analysis for output sensitivity and mesh adaptation
Adjoint analysis in computational fluid dynamics (CFD) has been applied to design optimization and mesh adaptation, but due to the relative expense of unsteady analysis these applications have predominantly been for steady problems. As the use of adjoint methods continues to becomes more prevalent, …
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Centrifugal compressor return channel shape optimization using adjoint method
… gradient-based optimization process using the adjoint method and its application to centrifugal compressor return channel loss reduction. A proper objective function definition and a generalized geometry parametrization and manipulation algorithm were developed, and the appropriate adjoint …
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Adjoint-based monopole synthesis of sound sources with complex directivities
… the directive sound source. For that purpose, an adjoint-based monopole synthesis method is discretized in a finite differences time domain (FDTD) scheme. Therein, the full non-linear Euler equations are solved by means of computational aeroacoustics (CAA). To efficiently compute reference sound …
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