Search NASA⌕ Search

SEARCH · Search NASA

Results for “tutorials”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,189 records · Page 66

Role of PHM in Autonomous Decision-Making: Aerospace applications

There is an increased need for onboard decision-making capabilities in cyber-physical systems be it in energy, automotive, aviation, space, or other industries as they aim for increased efficiency, resiliency, and mission assurance capabilities. Emerging next-gen technologies such as multi-rover planetary missions, distributed satellites, unmanned ground and aerial vehicle operations and smart grid systems rely on in-time risk assessment and autonomous decision-making. One critical piece of the autonomy puzzle is reliable prediction of system behavior under time-varying and potentially uncertain environmental conditions. Further, if agent states change during operation such as initiation of faults or degradation, reliable diagnostic tools need to be investigated. In this tutorial, we will revise approaches that integrates existing physics-based and data-driven models of agents interacting with probability models of the environment and component operation state. Role of existing PHM methodologies as they feed into decision-making under uncertainty will be studied. Balancing critical trade-offs between high-fidelity prognostic models, prediction time-horizons and the computational requirements for in-time cost-effective decision-making will be discussed through the implementation of surrogate models. Finally, the audience will be introduced to a real-time application of in-time trajectory planning of an unmanned aerial system (UAS) based on its PHM assessments under uncertain and varying wind conditions.

decision-making↗

Pressure-Gain Combustion for Gas Turbines

Pressure Gain Combustion (PGC) is under investigation as a means to improve the thermal efficiency of gas turbines. PGC is a fundamentally unsteady combustion process which, through some means of confinement, raises the total pressure of the working fluid relative to the initial process state. When implemented as a gas turbine combustor it yields a total pressure gain across the device instead of the typical loss seen in a conventional combustor. This pressure gain can significantly improve gas turbine performance. This presentation is a modified and updated version of a 2018 tutorial of the same name. It is tailored to a graduate student audience that is familiar with the PGC concept, but has focused entirely on a specific type of implementation. It will provide a brief review of the concept of PGC and why it's important. The majority of the presentation will describe the various approaches to implementation that are under investigation by the PGC community. Emphasis will be on strategies other than the one that the students are investigating.

Combustion↗

Introduction to Quantum Computing

Quantum computing offers the potential to revolutionize high-performance computing by providing a means to solve certain computational problems asymptotically faster than any classical computer. Quantum computing has advanced recently from merely a theoretical possibility to engineered reality, including commercial entities offering early prototype quantum processors, both special-purpose quantum annealers and general-purpose gate-model processors. The media have been showcasing each new development and implicitly conveying the message that quantum-computing ubiquity is nigh. Here, we will respond to this hype and provide an overview of the exciting but still early state of the field. In this tutorial, we introduce participants to the computational models that give quantum computing its immense computational power. We examine the thought processes that programmers need to map problems to quantum computers. And we discuss hardware and algorithmic challenges that must be overcome before quantum computing becomes a component of every software developer's repertoire. (Update of 2022 slides)

Quantum computing↗

Turbo-Design: Open-Source Radial Equilibrium Turbomachinery Solver: Part I - Turbines

Advances in 3D Geometrical Designs and Cooling have played a significant role in improving the efficiency of turbomachinery. However, these advancements must be effectively translated back to the modeler. Machine learning can facilitate this transition. Specifically, machine learning–based loss models can bridge the gap between 3D and 1D designs, enabling modelers not only to predict velocity triangles but also to extract additional geometric features. Currently, the design tools used at NASA have not been updated to support such integration—until now. TurboDesign is an open-source, Python-based framework that replaces TD2 (LEW-11029-1) and AXOD2 (LEW-16323-1), both of which are radial equilibrium solvers for axial turbines. The goal of this update is to enable the integration of machine learning loss models into radial equilibrium equations. Additionally, TurboDesign is designed to support radial machines. This paper presents the governing equations, the assumptions underlying the code, the integration of legacy loss models, an example of machine learning model integration, and a validation comparison with CFD. All code, tutorials, and documentation are available at: https://www.github.com/nasa/turbo-design

Radial Equilibrium↗

Discharge Physics of High Power Impulse Magnetron Sputtering

High power impulse magnetron sputtering (HIPIMS) is pulsed sputtering where the peak power exceeds the time-averaged power by typically two orders of magnitude. The peak power density, averaged over the target area, can reach or exceed 107 W/m2, leading to plasma conditions that make ionization of the sputtered atoms very likely. A brief review of HIPIMS operation is given in a tutorial manner, illustrated by some original data related to the self-sputtering of niobium in argon and krypton. Emphasis is put on the current-voltage-time relationships near the threshold of self-sputtering runaway. The great variety of current pulse shapes delivers clues on the very strong gas rarefaction, self-sputtering runaway conditions, and the stopping of runaway due to the evolution of atom ionization and ion return probabilities as the gas plasma is replaced by metal plasma. The discussions are completed by considering instabilities and the special case of ?gasless? self-sputtering.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗

Looking Below the Surface with Ultrasonic Phased Array

This article is a brief tutorial on the benefits of volumetric ultrasonic phased array line scanning. The article describes the need, the approach, and the methods/practices used to analyze the data for flaw detection and characterization in the nuclear power plant component arena.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗

Facing Our Energy Challenges in a New Era of Science (2011 EFRC Forum)

Patricia Dehmer, Deputy Director for Science Programs at DOE, opened the May 26, 2011 EFRC Forum session, 'Global Perspectives on Frontiers in Energy Research,' with the talk, 'Facing Our Energy Challenges in a New Era of Science.' In her presentation, Dr. Dehmer gave a tutorial on the energy challenges facing our Nation and showed how the DOE research portfolio addresses those issues. The 2011 EFRC Summit and Forum brought together the EFRC community and science and policy leaders from universities, national laboratories, industry and government to discuss 'Science for our Nation's Energy Future.' In August 2009, the Office of Science established 46 Energy Frontier Research Centers. The EFRCs are collaborative research efforts intended to accelerate high-risk, high-reward fundamental research, the scientific basis for transformative energy technologies of the future. These Centers involve universities, national laboratories, nonprofit organizations, and for-profit firms, singly or in partnerships, selected by scientific peer review. They are funded at $2 to $5 million per year for a total planned DOE commitment of $777 million over the initial five-year award period, pending Congressional appropriations. These integrated, multi-investigator Centers are conducting fundamental research focusing on one or more of several 'grand challenges' and use-inspired 'basic research needs' recently identified in major strategic planning efforts by the scientific community. The purpose of the EFRCs is to integrate the talents and expertise of leading scientists in a setting designed to accelerate research that transforms the future of energy and the environment.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

Flip-chip and backside techniques.

State-of-the-art techniques for failure localization and design modification through bulk silicon are essential for multi-level metallization and new, flip chip packaging methods. The tutorial reviews the transmission of light through silicon, sample preparation, and backside defect localization techniques that are both currently available and under development. The techniques covered include emission microscopy, scanning laser microscope based techniques (electrooptic techniques, LIVA and its derivatives), and other non-IR based tools (FIB, e-beam techniques, etc.).

99 GENERAL AND MISCELLANEOUS↗

Cloud computing security.

Cloud computing is a paradigm rapidly being embraced by government and industry as a solution for cost-savings, scalability, and collaboration. While a multitude of applications and services are available commercially for cloud-based solutions, research in this area has yet to fully embrace the full spectrum of potential challenges facing cloud computing. This tutorial aims to provide researchers with a fundamental understanding of cloud computing, with the goals of identifying a broad range of potential research topics, and inspiring a new surge in research to address current issues. We will also discuss real implementations of research-oriented cloud computing systems for both academia and government, including configuration options, hardware issues, challenges, and solutions.

99 GENERAL AND MISCELLANEOUS↗

Supporting our scientists with Google Earth-based UIs.

Google Earth and Google Maps are incredibly useful for researchers looking for easily-digestible displays of data. This presentation will provide a step-by-step tutorial on how to begin using Google Earth to create tools that further the mission of the DOE national lab complex.

99 GENERAL AND MISCELLANEOUS↗

Chemical Imaging of Catalytic Solids with Synchrotron Radiation

Heterogeneous catalysis is a term normally used to describe a group of catalytic processes, yet it could equally be employed to describe the catalytic solid itself. A better understanding of the chemical and structural variation within such materials is thus a pre-requisite for the rationalising of structure-function relationships and ultimately to the design of new, more sustainable catalytic processes. The past 20 years has witnessed marked improvements in technologies required for analytical measurements at synchrotron sources, including higher photon brightness, nano-focusing, rapid, high resolution data acquisition and in the handling of large volumes of data. It is now possible to image materials using the entire synchrotron radiative profile, thus heralding a new era of in situ/operando measurements of catalytic solids. In this tutorial review we discuss the recent work in this exciting new research area and finally conclude with a future outlook on what will be possible/challenging to measure in the not-too-distant future.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Infrared and Raman Imaging of Heterogeneous Catalysts

The miniaturization of in situ spectroscopic tools has been recognized as a forefront instrumental development for the characterization of heterogeneous catalysts. With the multitude of micro-spectroscopic methods available fundamental insight into the structure-function relationships of catalytic processes can be obtained. Among these techniques vibrational spectroscopy is one of the most versatile methods and capable to shed insight into the molecular structure of reaction intermediates and products, the chemical state of catalyst materials during reaction as well as the nature of interactions between reactants/intermediates/products and the catalyst surface. In this tutorial review we discuss the recent developments in the field of infrared (IR) and Raman micro-spectroscopy and illustrate their potential. Showcase examples include (1) chemical imaging of spatial heterogeneities during catalyst preparation, (2) high-throughput catalyst screening, (3) transport and adsorption phenomena within catalytic solids and (4) reactivity studies of porous oxides, such as zeolites. Finally, new in situ spectroscopy tools based on vibrational spectroscopy and their potential in the catalysis domain are discussed.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

AN AGENT-BASED SIMULATION STUDY OF A COMPLEX ADAPTIVE COLLABORATION NETWORK

One of the most significant problems in organizational scholarship is to discern how social collectives govern, organize, and coordinate the actions of individuals to achieve collective outcomes. The collectives are usually interpreted as complex adaptive systems (CAS). The understanding of CAS is more likely to arise with the help of computer-based simulations. In this tutorial, using agent-based modeling approach, a complex adaptive social communication network model is introduced. The objective is to present the underlying dynamics of the system in a form of computer simulation that enables analyzing the impacts of various mechanisms on network topologies and emergent behaviors. The ultimate goal is to further our understanding of the dynamics in the system and facilitate developing informed policies for decision-makers.

Ozmen, Ozgur↗

Nuclear Fallout Models – An Overview

This presentation is an introduction to a full report, which is a tutorial for individuals using the products of the models reviewed.

nuclear fallout, models, software↗

ISMB Conference Proceedings

This special issue comprises the papers accepted for presentation at the 19th Annual International Conference on Intelligent Systems for Molecular Biology, joint with the 10th European Conference on Computational Biology, an official conference of the International Society for Computational Biology (ISCB; http://www.iscb.org). ISMB/ECCB 2011 (http://www.iscb.org/ismb2011/) will take place in Vienna, Austria, from July 17 through July 19, 2011; preceded during July 14–16 by eight 1- or 2- day Special Interest Group (SIG) meetings, three satellite meetings and nine half-day tutorials; and followed by two additional satellite meetings. The 48 papers in this volume were selected from 258 submitted papers. Submitted papers were assigned to 13 areas. Area Chairs led each topic area by selecting their area's program committee and overseeing the reviewing process. Many Area Chairs were new compared to 2010, and two completely new areas were added in 2011, ‘Data Visualization’ and ‘Mass Spectrometry and Proteomics’. Six papers for which Area Chairs were in conflict were reviewed under a ‘Conflicts Management’ section headed by the Proceedings Chairs; one such paper was accepted in ‘Bioimaging’. Areas, co-chairs and acceptance information are listed in Table 1. Compared to prior years, five mature topic areas had steady submissions, ‘Evolution and Comparative Genomics’, ‘Gene Regulation and Transcriptomics’, ‘Protein Structure and Function’, ‘Sequence Analysis’, ‘Text Mining’. Two areas newer to ISMB were underrepresented this year, ‘Bioimaging’ and ‘Disease Models and Epidemiology’. One area doubled, ‘Applied Bioinformatics’, renamed from last year's ‘Other Bioinformatics Applications’; and one tripled, ‘Protein Interactions and Molecular Networks’. Across the areas, 326 members of the bioinformatics community provided reviews. Most papers received three reviews and several received four or more. There was significant discussion of the merits of the papers first between referees and the Area Chairs, and then between Area Chairs and the proceedings chairs. Initial decisions to accept papers were made during a comprehensive conference call with the Area Chairs, and several papers underwent a further evaluation by additional Area Chairs before acceptance decisions were finalized. We appreciate that in several cases reviewers' opinions might have changed with additional input or further clarifications from the authors; because the ISMB/ECCB 2011 timeline did not allow for a second round of reviews, however, only papers where referees suggested minor revisions could be accepted. For several papers where referee comments might have been unclear to the authors, Area Chairs added additional comments and explanations. In total, 48 papers were conditionally accepted, pending revision. After acceptance notices were sent, the authors had 2 weeks to modify their papers according to the suggestions made by the reviewers and to respond to the reviewers' comments. Modified papers and authors' responses were reexamined during the next week to ensure each paper was modified appropriately in response to the reviewers' comments. We were pleased that all 48 conditionally accepted papers were finally accepted for the conference. The final acceptance rate was 19%, similar to the rates of 20% and 19% in the two prior years. Collectively, the 48 accepted papers had 185 authors from 18 countries across 6 continents, with 82 authors from North America, 54 from Europe, 25 from Asia (excluding Israel), 10 from Israel, 9 from Australia, 4 from South America and 1 author from Africa. We thank the area chairs and reviewers for their hard work and dedication to maintaining a professional review process. We thank all authors of submitted papers and authors of accepted papers for their diligences in responding to reviewer comments within 2 weeks. We thank Steven Leard's team for extensive technical support with the EasyChair submission and reviewing system; Mona Singh and Joel S. Bader for sharing their experience from last year; the team at Oxford University Press for typesetting the papers; Conference Chairs Burkhard Rost, Michal Linial, Peter Schuster and Kurt Zatloukal, as well as the ISMB/ECCB 2011 Steering Committee, for their valuable input; and Steven Leard for helping us oversee the process.

60 APPLIED LIFE SCIENCES↗

Temporal Stability of Visual Search-Driven Biometrics

Previously, we have shown the potential of using an individual s visual search pattern as a possible biometric. That study focused on viewing images displaying dot-patterns with different spatial relationships to determine which pattern can be more effective in establishing the identity of an individual. In this follow-up study we investigated the temporal stability of this biometric. We performed an experiment with 16 individuals asked to search for a predetermined feature of a random-dot pattern as we tracked their eye movements. Each participant completed four testing sessions consisting of two dot patterns repeated twice. One dot pattern displayed concentric circles shifted to the left or right side of the screen overlaid with visual noise, and participants were asked which side the circles were centered on. The second dot-pattern displayed a number of circles (between 0 and 4) scattered on the screen overlaid with visual noise, and participants were asked how many circles they could identify. Each session contained 5 untracked tutorial questions and 50 tracked test questions (200 total tracked questions per participant). To create each participant s "fingerprint", we constructed a Hidden Markov Model (HMM) from the gaze data representing the underlying visual search and cognitive process. The accuracy of the derived HMM models was evaluated using cross-validation for various time-dependent train-test conditions. Subject identification accuracy ranged from 17.6% to 41.8% for all conditions, which is significantly higher than random guessing (1/16 = 6.25%). The results suggest that visual search pattern is a promising, fairly stable personalized fingerprint of perceptual organization.

eye tracking↗

BASTet (Berkeley Analysis and Storage Toolkit)

BASTet is an advanced software library written in Python. BASTet serves as the analysis and storage library for the OpenMSI project. BASTet is an integrate framework for: i) storage of spectral imaging data, ii) storage of derived analysis data, iii) provenance of analyses, iv) integration and execution of analyses via complex workflows. BASTet implements the API for the HDF5 storage format used by OpenMSI. Analyses that are developed using BASTet benefit from direct integration with storage format, automatic tracking of provenance, and direct integration with command-line and workflow execution tools. BASTet also defines interfaces to enable developers to directly integrate their analysis with OpenMSI's web-based viewing infrastruture without having to know OpenMSI. BASTet also provides numerous helper classes and tools to assist with the conversion of data files, ease parallel implementation of analysis algorithms, ease interaction with web-based functions, description methods for data reduction. BASTet also includes detailed developer documentation, user tutorials, iPython notebooks, and other supporting documents.

Bowen, Benjamin↗