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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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At least 181 records · Page 10
All sourcesNASA NTRSDOE OSTI
NASA NTRS1983

Establishment of a center of excellence for applied mathematical and statistical research

The state of the art was assessed with regards to efforts in support of the crop production estimation problem and alternative generic proportion estimation techniques were investigated. Topics covered include modeling the greeness profile (Badhwarmos model), parameter estimation using mixture models such as CLASSY, and minimum distance estimation as an alternative to maximum likelihood estimation. Approaches to the problem of obtaining proportion estimates when the underlying distributions are asymmetric are examined including the properties of Weibull distribution.

Woodward, W. A.↗
NASA NTRS1985

Irregularities in the secular variation and geodynamic implications; Proceedings of the Session, Cincinnati, OH, May 17, 1984

Consideration is given to: variations in the Gauss coefficients of the geomagnetic potential over the last several hundred years; eccentric geomagnetic dipole drift; and evidence for geomagnetic jerks from 1931 to 1971. Among other topics discussed are: models of the geomagnetic field in western Europe from 1960 to 1980; the external and internal parts of the geomagnetic jerk of 1970; secular variation of the magnetic mean energy density at the source layer depth; and motions at the core surface in the geostrophic approximation. Consideration is also given to: the unpredictability of geomagnetic secular variation; the use of short-term core-mantle coupling and geomagnetic variation impulses as Lagrangian tracers of core motions; and a comparison of two sequential geomagnetic polarity transitions in the upper Olduvai and the lower Jarmillio in the Southern Hemisphere.

Taylor, P.↗
NASA NTRS1985

Advanced vehicle systems assessment. Volume 4: Supporting analyses

Volume 4 (Supporting Analyses) is part of a five-volume report, Advanced Vehicle Systems Assessment. Thirty-nine individuals, knowledgeable in advanced technology, were interviewed to obtain their preferences. Rankings were calculated for the eight groups they represented, using multiplicative and additive utility models. The four topics for consideration were: (1) preferred range for various battery technologies; (2) preferred battery technology for each of a variety of travel ranges; (3) most promising battery technology, vehicle range combination; and (4) comparison of the most preferred electric vehicle with the methanol-fuled, spark-ignition engine vehicle and with the most preferred of the hybrid vehicles.

Hardy, K.↗
NASA NTRS1985

Books and monographs on finite element technology

The present paper proviees a listing of all of the English books and some of the foreign books on finite element technology, taking into account also a list of the conference proceedings devoted solely to finite elements. The references are divided into categories. Attention is given to fundamentals, mathematical foundations, structural and solid mechanics applications, fluid mechanics applications, other applied science and engineering applications, computer implementation and software systems, computational and modeling aspects, special topics, boundary element methods, proceedings of symmposia and conferences on finite element technology, bibliographies, handbooks, and historical accounts.

Noor, A. K.↗
NASA NTRS1984

Turbine Engine Hot Section Technology, 1984

Presentations were made concerning the hot section environment and behavior of combustion liners, turbine blades, and waves. The presentations were divided into six sessions: instrumentation, combustion, turbine heat transfer, structural analysis, fatigue and fracture, and surface properties. The principal objective of each session was to disseminate research results to date, along with future plans. Topics discussed included modeling of thermal and fluid flow phenomena, structural analysis, fatigue and fracture, surface protective coatings, constitutive behavior, stress-strain response, and life prediction methods.

Source record↗
NASA NTRS1987

Proceedings of the 3rd Annual SCOLE Workshop

Topics addressed include: modeling and controlling the Spacecraft Control Laboratory Experiment (SCOLE) configurations; slewing maneuvers; mathematical models; vibration damping; gravitational effects; structural dynamics; finite element method; distributed parameter system; on-line pulse control; stability augmentation; and stochastic processes.

Taylor, Lawrence W., Jr.↗
NASA NTRS1986

Turbine Engine Hot Section Technology 1986

On October 21 and 22, 1986, the Turbine Engine Hot Section Technology (HOST) Project of the NASA Lewis Research Center sponsored a workshop to discuss current research pertinent to turbine engine durability problems. Presentations were made concerning the hot-section environment and the behavior of combustion liners, turbine blades, and turbine vanes. The presentations were divided Into six sessions: Instrumentation, Combustion, Turbine Heat Transfer, Structural Analysis, Fatigue and Fracture, and Surface Protection. The principal objective of each session was to disseminate research results to date. Topics discussed included modeling of thermal and fluid-flow phenomena, structural analysis, fatigue and fracture, surface protective coatings, constitutive behavior of materials, stress-strain response, and life-prediction methods. Researchers from industry, academia, and government presented results of their work sponsored by the HOST Project. This publication contains extended abstracts and visual material presented during the workshop.

Turbine Engine Hot Section Technology (HOST)↗
NASA NTRS1990

NASA/MSFC FY90 Global Scale Atmospheric Processes Research Program Review

Research supported by the Global Atmospheric Research Program at the Marshall Space Flight Center on atmospheric remote sensing, meteorology, numerical weather forecasting, satellite data analysis, cloud precipitation, atmospheric circulation, atmospheric models and related topics is discussed.

Leslie, Fred W.↗
NASA NTRS1991

Telerobotic ground-remote operations

The Telerobotic Ground-Remote Operations task consists of development of a demonstration local-site operator control station that includes a graphical user interface (GUI) for control of a remote robot, and development of operator-assisted perception algorithms and software that will provide flexible and accurate world modeling capabilities. The topics covered are presented in view graph form and include: (1) local site development configuration; (2) system design; (3) operator control station (local site) software block diagram; (4) operator-assisted perception; and (5) program status.

Bon, Bruce↗
NASA NTRS1993

Design and application of electromechanical actuators for deep space missions

During the period 8/16/92 through 2/15/93, work has been focused on three major topics: (1) screw modeling and testing; (2) motor selection; and (3) health monitoring and fault diagnosis. Detailed theoretical analysis has been performed to specify a full dynamic model for the roller screw. A test stand has been designed for model parameter estimation and screw testing. In addition, the test stand is expected to be used to perform a study on transverse screw loading.

Haskew, Tim A.↗
NASA NTRS1992

Finite element model and identification procedure

Viewgraphs on finite element model and identification procedure are presented. Topics covered include: interferometer finite element model; testbed mode shapes; finite element model update; identification procedure; shaker locations; data analysis; modal frequency and damping comparison; computational procedure; fit comparison; residue analysis; typical residues; identification/FEM residual comparison; and pathlength control using isolation mounts.

How, Jonathan P.↗
NASA NTRS1990

Path planning control

Viewgraphs on path planning control are presented. Topics covered include: model based path planning; sensor based path planning; hybrid path planning; proximity sensor array; and applications for fuzzy logic.

Mcroberts, Malcolm↗
NASA NTRS1992

Studies in turbulence

Various papers on turbulence are presented. Individual topics addressed include: modeling the dissipation rate in rotating turbulent flows, mapping closures for turbulent mixing and reaction, understanding turbulence in vortex dynamics, models for the structure and dynamics of near-wall turbulence, complexity of turbulence near a wall, proper orthogonal decomposition, propagating structures in wall-bounded turbulence flows. Also discussed are: constitutive relation in compressible turbulence, compressible turbulence and shock waves, direct simulation of compressible turbulence in a shear flow, structural genesis in wall-bounded turbulence flows, vortex lattice structure of turbulent shear slows, etiology of shear layer vortices, trilinear coordinates in fluid mechanics.

Gatski, Thomas B.↗
NASA NTRS1994

Workshop on the Analysis of Interplanetary Dust Particles

Great progress has been made in the analysis of interplanetary dust particles (IDP's) over the past few years. This workshop provided a forum for the discussion of the following topics: observation and modeling of dust in the solar system, mineralogy and petrography of IDP's, processing of IDP's in the solar system and terrestrial atmosphere, comparison of IDP's to meteorites and micrometeorites, composition of IDP's, classification, and collection of IDP's.

Zolensky, Michael E.↗
NASA NTRS2009

Integrated System Health Management: Foundational Concepts, Approach, and Implementation.

Implementation of integrated system health management (ISHM) capability is fundamentally linked to the management of data, information, and knowledge (DIaK) with the purposeful objective of determining the health of a system. It is akin to having a team of experts who are all individually and collectively observing and analyzing a complex system, and communicating effectively with each other in order to arrive to an accurate and reliable assessment of its health. We present concepts, procedures, and a specific approach as a foundation for implementing a credible ISHM capability. The capability stresses integration of DIaK from all elements of a system. The intent is also to make possible implementation of on-board ISHM capability, in contrast to a remote capability. The information presented is the result of many years of research, development, and maturation of technologies, and of prototype implementations in operational systems (rocket engine test facilities). The paper will address the following topics: 1. ISHM Model of a system 2. Detection of anomaly indicators. 3. Determination and confirmation of anomalies. 4. Diagnostic of causes and determination of effects. 5. Consistency checking cycle. 6. Management of health information 7. User Interfaces 8. Example implementation ISHM has been defined from many perspectives. We define it as a capability that might be achieved by various approaches. We describe a specific approach that has been matured throughout many years of development, and pilot implementations. ISHM is a capability that is achieved by integrating data, information, and knowledge (DIaK) that might be distributed throughout the system elements (which inherently implies capability to manage DIaK associated with distributed sub-systems). DIaK must be available to any element of a system at the right time and in accordance with a meaningful context. ISHM Functional Capability Level (FCL) is measured by how well a system performs the following functions: (1) detect anomalies, (2) diagnose causes, (3) predict future anomalies/failures, and (4) provide the user with an integrated awareness about the condition of every element in the system and guide user decisions.

Figueroa, Fernando↗
NASA NTRS2010

Ares I-X Launch Vehicle Modal Test Measurements and Data Quality Assessments

The Ares I-X modal test program consisted of three modal tests conducted at the Vehicle Assembly Building at NASA s Kennedy Space Center. The first test was performed on the 71-foot 53,000-pound top segment of the Ares I-X launch vehicle known as Super Stack 5 and the second test was performed on the 66-foot 146,000- pound middle segment known as Super Stack 1. For these tests, two 250 lb-peak electro-dynamic shakers were used to excite bending and shell modes with the test articles resting on the floor. The third modal test was performed on the 327-foot 1,800,000-pound Ares I-X launch vehicle mounted to the Mobile Launcher Platform. The excitation for this test consisted of four 1000+ lb-peak hydraulic shakers arranged to excite the vehicle s cantilevered bending modes. Because the frequencies of interest for these modal tests ranged from 0.02 to 30 Hz, high sensitivity capacitive accelerometers were used. Excitation techniques included impact, burst random, pure random, and force controlled sine sweep. This paper provides the test details for the companion papers covering the Ares I-X finite element model calibration process. Topics to be discussed include test setups, procedures, measurements, data quality assessments, and consistency of modal parameter estimates.

Templeton, Justin D.↗
NASA NTRS2009

Proceedings of the First NASA Formal Methods Symposium

Topics covered include: Model Checking - My 27-Year Quest to Overcome the State Explosion Problem; Applying Formal Methods to NASA Projects: Transition from Research to Practice; TLA+: Whence, Wherefore, and Whither; Formal Methods Applications in Air Transportation; Theorem Proving in Intel Hardware Design; Building a Formal Model of a Human-Interactive System: Insights into the Integration of Formal Methods and Human Factors Engineering; Model Checking for Autonomic Systems Specified with ASSL; A Game-Theoretic Approach to Branching Time Abstract-Check-Refine Process; Software Model Checking Without Source Code; Generalized Abstract Symbolic Summaries; A Comparative Study of Randomized Constraint Solvers for Random-Symbolic Testing; Component-Oriented Behavior Extraction for Autonomic System Design; Automated Verification of Design Patterns with LePUS3; A Module Language for Typing by Contracts; From Goal-Oriented Requirements to Event-B Specifications; Introduction of Virtualization Technology to Multi-Process Model Checking; Comparing Techniques for Certified Static Analysis; Towards a Framework for Generating Tests to Satisfy Complex Code Coverage in Java Pathfinder; jFuzz: A Concolic Whitebox Fuzzer for Java; Machine-Checkable Timed CSP; Stochastic Formal Correctness of Numerical Algorithms; Deductive Verification of Cryptographic Software; Coloured Petri Net Refinement Specification and Correctness Proof with Coq; Modeling Guidelines for Code Generation in the Railway Signaling Context; Tactical Synthesis Of Efficient Global Search Algorithms; Towards Co-Engineering Communicating Autonomous Cyber-Physical Systems; and Formal Methods for Automated Diagnosis of Autosub 6000.

Denney, Ewen↗