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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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A Report that summarizes the potential for evolution of the PGI Fortran front-end source code into a form that offers error/warning messages similar in scope and quality to those provided by CLANG.
El Modelo Estandar describe todas las partculas observadas en el naturaleza hasta el momento as como las caractersticas que gobiernan a las interacciones fundamentales entre ellas. En especial es posible identicar a las interacciones electromagnetica y debil, las cuales bajo determinadas condiciones de temperatura y energa pueden ser descritas a traves de una sola teora que engloba a ambas. A esta teora se le denomina electrodebil y tiene como nalidad caracterizar las propiedades de la interaccion maniesta a partir de la mezcla de las interacciones electromagnetica y debil, la que tambien lleva como nombre interaccion electrodebil. Particularmente, los neutrinos son de especial interes ya que, por un lado, interactuan por medio de la interaccion debil muy raramente en comparacion con otras partculas y, por el otro, no son acertadamente descritos por el Modelo Estandar. Por medio de observaciones experimentales que demostraban que los neutrinos cambian de sabor al propagarse, fenomeno llamado oscilaciones de neutrinos, se pudo llegar a la conclusion de que la implicancia de este fenomeno da como consecuencia que los neutrinos efectivamente s tienen masa, algo que entra en contradiccion con la descripcion inicial del Modelo Estandar, el cual los describe como partculas sin masa. Es de esta manera que las oscilaciones de neutrinos han sido y siguen siendo en la actualidad objeto de interes en la Fsica de Altas Energas tanto teorica como experimental. A n de poder realizar mediciones precisas de oscilaciones de neutrinos, los experimentos encargados de estas mediciones deben tratar de reducir sus incertidumbres en lo posible. Una de estas proviene de la caracterizacion de las secciones de choque de los neutrinos cuando interactuan con la materia, particularmente los nucleones al interior de los nucleos atomicos. El experimento MINERA esta orientado, entre otras cosas, a hacer una correcta caracterizacion de secciones de choque neutrino-nucleon por medio del estudio de un tipo especco de interaccion denominado corriente cargada, cuyas partculas de estado nal incluye hadrones y, principalmente, muones. La precision en los resultados de secciones de choque esta sujeta a que la energa y el momentum estos muones sean, a su vez, correctamente caracterizados, incluyendo sus incertidumbres sistematicas. El objetivo de este trabajo de tesis es precisamente presentar la metodologa usada para medir las energas de los muones producidos por interacciones de neutrinos y sus correspondientes incertidumbres asociadas a dicha medicion.
All analysis was performed using data provided to SNL in June, 2016.
Our motivation was to explore high-dimensional input-output data space; create complex simulation models; respond to a lack of analysis tools; and create a systematic, step-by-step analysis process.
Factors that may affect the precision of Neutron Emission Rate (NER) measurements made in the Canberra 4 neutron counter have been examined and quantified. Measurements of sample NER are corrected for the efficiency of the counter. The efficiency is calculated by measuring a source of known intensity, and taking the ratio of the measured neutrons per second (n/s) to the known output of the source.
The goals of CRADA 350 were achieved in this Phase I SBIR work. Specifically, a software environment was developed which included a nonlinear solver, OASIS. During the Phase I work, we applied the algorithm to a number of nonlinear-solver benchmark problems, including SLAC accelerator problems. By searching over only two optimization-control parameters, this Phase I work has enabled the development of a systematic procedure to facilitate the finding of a “best-guessed” global minimum solution for various types of non-linear problems with different size and complexity. This set of rules was codified and led to a versatile nonlinear program, IMIGO.
In Year 3, MIT was primarily responsible for the effort on Software Characterization, with the following milestones: 1. Completed design of domain-specific language for fault models 2. Completed design of program logic for verification 3. Completed evaluation of relational verification system for jacobi, steepest descent, and conjugate gradient 4. Completed development of relational verification system 5. Completed evaluation of relational verification system
On May 29, 2012 Health Physics Technicians used a hand-held HPI detector to measure the Exposure [mRoentgen/hr] for the Linac beam at 100 MeV and 17 nC/sec miss-steered by ~42° for a B1 current of 154Amps.
A significant problem in quantum computing is the development of physical realizations of algorithms that are robust against noise. One way to examine and mitigate noise would be to simulate large sets of qubits coupling to the external environment on classical computers. This is extremely challenging as quantum information processing is in some sense tied to computing resources that scale exponentially with the number of computing elements (qubits). In this LDRD, we set the foundation for a computational framework potentially allowing simulations of 1000s of qubits vs. 10s now possible. Exact wave-function-based methods demand exponentially increasing resources with system size. The method proposed, entanglement-functional theory (EFT), requires vastly fewer resources. The crucial step is to map the information contained in the wave-functions into a simpler object with associated 1.) auxiliary gate operations and 2.) entanglement functionals of this object. This is similar to the Time-dependent Density Functional Theory (TDDFT) approach that has revolutionized chemistry and materials science. Instead of dealing with the exponentially large wave-function, EFT works with a polynomially large set of projections (the density) that are easily manipulated through unitary operations. For a given set of quantum gates, an isomorphism exists that relates the sequence of events to the time-dependent density. A system of entangled qubits can be simulated at drastically reduced cost relative to existing state-of-the-art vector-state simulation codes.
Abstract not provided.
Summary: Discrete-time fast-slow (DTFS) systems are discrete analogues of fast-slow systems; A slow manifold integrator (SMI) is a DTFS system that approximates a given fast-slow system; Stability of an SMI's slow manifold need not be due to numerical dissipation - can mimic physical mechanisms instead; SMIs are natural tool for capturing high-order slow manifold effects (e.g. drifts).
Uncertainty quantification is recognized as a fundamental task to obtain predictive numerical simulations. However, many realistic engineering applications require complex and computationally expensive high-fidelity numerical simulations for the accurate characterization of the system responses. Moreover, complex physical models and extreme operative conditions can easily lead to hundreds of uncertain parameters that need to be propagated through high-fidelity codes. Under these circumstances, a single fidelity approach, i.e. a workflow that only uses high-fidelity simulations to perform the uncertainty quantification task, is unfeasible due to the prohibitive overall computational cost. In recent years, multifidelity strategies have been introduced to overcome this issue. The core idea of this family of methods is to combine simulations with varying levels of fidelity/accuracy in order to obtain the multifidelity estimators or surrogates with the same accuracy of their single fidelity counterparts at a much lower computational cost. This goal is usually accomplished by defining a prioria sequence of discretization levels or physical modeling assumptions that can be used to decrease the complexity of a numerical realization and thus its computational cost. However ,less attention has been dedicated to low-fidelity models that can be built directly from the small number of high-fidelity simulations available. In this work we focus our attention on Reduced-Order Models that can be considered a particular class of data-driven approaches. Our main goal is to explore the combination of multifidelity uncertainty quantification and reduced-order models to obtain an efficient framework for propagating uncertainties through expensive numerical codes.
Tetrahedral finite element workflows have the potential to drastically reduce time to solution for computational solid mechanics simulations when compared to traditional hexahedral finite element analogues. A recently developed, higher-order composite tetrahedral element has shown promise in the space of incompressible computational plasticity. Mesh adaptivity has the potential to increase solution accuracy and increase solution robustness. In this work, we demonstrate an initial strategy to perform conformal mesh adaptivity for this higher-order composite tetrahedral element using well-established mesh modification operations for linear tetrahedra. We propose potential extensions to improve this initial strategy in terms of robustness and accuracy.
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Last year, we refactored the major components of the SpotSDC visualization platform and added a visualization component for fault tolerance boundary. Also, we designed a new analysis framework to understand an application resiliency with a significantly less amount of samples compared to previous approaches. We evaluated the visualization platform and analysis framework for multiple critical HPC computation kernels and collected evidence for the effectiveness of the method developed.
This document describe multiple-measurement uncertainty analysis that is implemented to the thermophysical properties measurement or dataset of Gen3 CSP materials curated in an online database (http://gen3csp.gatech.edu/). This uncertainty analysis is based on a textbook method, that follows the American National Standard Institute/American Society of Mechanical Engineering (ANSI/ASME) Power Test Codes (PTC) 19.1 Test Uncertainty and NIST Technical Note 1297. It is also consistent with the international guidelines established by the International Organization for Standardization (ISO).
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Abstract not provided.