SEARCH · Engineering Papers

Results for “Peer to Peer”

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.

SourceResearch connectionFrom yearThrough year

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

At least 973 records · Page 54

All sources NASA NTRS DOE OSTI

NASA NTRS2007

Online Remote Sensing Interface

BasinTools Module 1 processes remotely sensed raster data, including multi- and hyper-spectral data products, via a Web site with no downloads and no plug-ins required. The interface provides standardized algorithms designed so that a user with little or no remote-sensing experience can use the site. This Web-based approach reduces the amount of software, hardware, and computing power necessary to perform the specified analyses. Access to imagery and derived products is enterprise-level and controlled. Because the user never takes possession of the imagery, the licensing of the data is greatly simplified. BasinTools takes the "just-in-time" inventory control model from commercial manufacturing and applies it to remotely-sensed data. Products are created and delivered on-the-fly with no human intervention, even for casual users. Well-defined procedures can be combined in different ways to extend verified and validated methods in order to derive new remote-sensing products, which improves efficiency in any well-defined geospatial domain. Remote-sensing products produced in BasinTools are self-documenting, allowing procedures to be independently verified or peer-reviewed. The software can be used enterprise-wide to conduct low-level remote sensing, viewing, sharing, and manipulating of image data without the need for desktop applications.

Lawhead, Joel↗

NASA NTRS2007

Algorithm-Based Fault Tolerance for Numerical Subroutines

A software library implements a new methodology of detecting faults in numerical subroutines, thus enabling application programs that contain the subroutines to recover transparently from single-event upsets. The software library in question is fault-detecting middleware that is wrapped around the numericalsubroutines. Conventional serial versions (based on LAPACK and FFTW) and a parallel version (based on ScaLAPACK) exist. The source code of the application program that contains the numerical subroutines is not modified, and the middleware is transparent to the user. The methodology used is a type of algorithm- based fault tolerance (ABFT). In ABFT, a checksum is computed before a computation and compared with the checksum of the computational result; an error is declared if the difference between the checksums exceeds some threshold. Novel normalization methods are used in the checksum comparison to ensure correct fault detections independent of algorithm inputs. In tests of this software reported in the peer-reviewed literature, this library was shown to enable detection of 99.9 percent of significant faults while generating no false alarms.

Tumon, Michael↗

NASA NTRS2009

From Research to Flight: Surviving the TRL Valley of Death for Robotic and Human Exploration

Fundamental research is critical to taking the next giant leap in the scientific exploration of space. NASA should be pushing the envelope and asking "what if?" .. Technology push enables new capabilities. When NASA began, everything was enabling. .. Technology pull is often required to meet current mission requirements. Technology management requires more than issuing NRAs and overseeing contracts. Continuous assessment, peer review, and system systems studies are vital to credible TRL advancement. A strategy for taking technology R&D to new heights will lead to discoveries at far-reaching destinations..

Johnson, Les↗

NASA NTRS2010

Selected Papers Presented at MODSIM World 2009 Conference and Expo

Selected papers from MODSIM World 2009 Conference and Expo are contained in this NASA Conference Publication (CP). MODSIM World 2009 was held in Virginia Beach, Virginia, October 14-16, 2009, at the Virginia Beach Convention Center. The theme of the 2009 conference and expo was "21st Century Decision-Making: The Art of Modeling & Simulation." The 79 submitted papers were peer-reviewed and 64 were accepted for presentation at MODSIM World 2009. As a condition of acceptance, the first author was responsible for securing/obtaining all permissions associated with the general release and public availability of the paper. Further, the first authors also had to grant NASA the right to include their papers in the NASA CP. There are 53 papers in this NASA CP.

Thomas E Pinelli↗

NASA NTRS2010

DigitalHuman (DH): An Integrative Mathematical Model ofHuman Physiology

Mathematical models and simulation are important tools in discovering the key causal relationships governing physiological processes and improving medical intervention when physiological complexity is a central issue. We have developed a model of integrative human physiology called DigitalHuman (DH) consisting of -5000 variables modeling human physiology describing cardiovascular, renal, respiratory, endocrine, neural and metabolic physiology. Users can view time-dependent solutions and interactively introduce perturbations by altering numerical parameters to investigate new hypotheses. The variables, parameters and quantitative relationships as well as all other model details are described in XML text files. All aspects of the model, including the mathematical equations describing the physiological processes are written in XML open source, text-readable files. Model structure is based upon empirical data of physiological responses documented within the peer-reviewed literature. The model can be used to understand proposed physiological mechanisms and physiological interactions that may not be otherwise intUitively evident. Some of the current uses of this model include the analyses of renal control of blood pressure, the central role of the liver in creating and maintaining insulin resistance, and the mechanisms causing orthostatic hypotension in astronauts. Additionally the open source aspect of the modeling environment allows any investigator to add detailed descriptions of human physiology to test new concepts. The model accurately predicts both qualitative and more importantly quantitative changes in clinically and experimentally observed responses. DigitalHuman provides scientists a modeling environment to understand the complex interactions of integrative physiology. This research was supported by.NIH HL 51971, NSF EPSCoR, and NASA

Hester, Robert L.↗

NASA NTRS2010

The James Webb Space Telescope Mission

The James Webb Space Telescope (JWST) is a large aperture, cryogenic, infrared-optimized space observatory under development by NASA for launch in 2014. The European and Canadian Space Agencies are mission partners. JWST will find and study the first galaxies that formed in the early universe, peer through dusty clouds to see AGN environments and stars forming planetary systems at high spatial resolution. The breakthrough capabilities of JWST will enable new studies of star formation and evolution in the Milky Way, including the Galactic Center, nearby galaxies, and the early universe. JWST's instruments are designed to work primarily in the infrared range of 1 - 28 microns, with some capability in the visible. JWST will have a segmented primary mirror, approximately 6.5 meters in diameter, and will be diffraction-limited at wavelength of 2 microns (0.1 arcsec resolution). The JWST observatory will be placed in a L2 orbit by an Ariane 5 launch vehicle provided by ESA. The observatory is designed for a 5-year prime science mission, with propellant for 10 years of science operations. The instruments will provide broad- and narrow-band imaging, coronography, and multi-object and integral-field spectroscopy (spectral resolution of 100 to 3,000) across the 1 - 28 micron wavelength range. Science and mission operations will be conducted from the Space Telescope Science Institute in Baltimore, Maryland.

Sonneborn, George↗

NASA NTRS2010

Treadmill Exercise Within LBNP as an Integrated Coutermeasure to Microgravity

An integrated exercise countermeasure for microgravity is needed to protect multiple physiologic systems and save crew time. Such a countermeasure should protect orthostatic tolerance, upright ambulatory capability (including sprinting), aerobic capacity, muscle strength/endurance, and other physiologic parameters relevant to human performance. We developed a novel physiologic countermeasure, treadmill exercise within LBNP, for preventing cardiovascular and musculoskeletal deconditioning associated with prolonged bed rest and spaceflight. We evaluated 40 min of daily LBNP treadmill exercise by a battery of physiologic parameters relevant to maintaining exercise performance and health of both women and men during bed-rest (simulated microgravity) studies lasting from 5 to 60 days. For 30 day studies, we employed identical twins with one twin as the control and the other twin as the exerciser to improve comparative power. During the WISE 60-day HDT study, the treadmill exercise within LBNP was performed 3-4 days each week and resistive exercise was performed 2-3 days each week. Our treadmill within LBNP protocol maintained plasma volume and sprint speed (30 day HDT bed-rest studies of identical twins), orthostatic tolerance to a degree, upright exercise capacity, muscle strength and endurance, and some bone parameters during 30 day (twin studies) and 60 day (WISE-2005) bed-rest simulations of microgravity. When combining treadmill exercise within LBNP and resistive exercise (WISE), cardiac mass increased significantly in the exercise (EX) group during bed rest relative to controls (CON). Upright peak VO2, and knee extensor strength and endurance decreased significantly in CON subjects; but these parameters were preserved in the EX group. In the 60 day WISE study, each LBNP exercise session was followed immediately by 10 minutes of static LBNP, and the last such session occurred three days before the end of bed rest. Still, orthostatic tolerance was better maintained in the EX group than in the CON group. Therefore, these collective peer-reviewed results document that our treadmill exercise within LBNP countermeasure safely and efficiently protects multiple physiologic systems in women and men during bed-rest studies of up to 60 days. Supported by NASA grants NNJ04HF71G and NAG 9-1425, NIH grant GCRC M01 RR00827 and by WISE support from ESA, NASA, CSA, and CNES.

Lee, Stuart↗

NASA NTRS2010

A Scientific Revolution: The Hubble and James Webb Space Telescopes

Astronomy is going through a scientific revolution, responding to a flood of data from the Hubble Space Telescope, other space missions, and large telescopes on the ground. In this talk, I will discuss some of the important discoveries of the last decade, from dwarf planets in the outer Solar System to the mysterious dark energy that overcomes gravity to accelerate the expansion of the Universe. The next decade will be equally bright with the newly refurbished Hubble and the promise of its successor, the James Webb Space Telescope. An infrared-optimized 6.5m space telescope, Webb is designed to find the first galaxies that formed in the early universe and to peer into the dusty gas clouds where stars and planets are born. With MEMS technology, a deployed primary mirror and a tennis-court sized sunshield, the mission presents many technical challenges. I will describe Webb's scientific goals, its design and recent progress in constructing the observatory. Webb is scheduled for launch in 2014.

Gardner, Jonathan P.↗

NASA NTRS2010

James Webb Space Telescope Project Overview and Status for the SPIE

Often described as the successor to the Hubble Space Telescope, the JWST will serve astronomers world-wide in much the same way: Science & mission operations managed by the Space Telescope Science Institute The science investigations performed by the JWST will be determined by the General Observer community. Observing time allocated through annual peer-reviewed proposal cycles Four science themes have been defined by a succession of international community working groups to guide engineering development of the JWST: a) Identify the first bright objects that formed in the early Universe, and follow the ionization history. b) Determine how galaxies and dark matter, including gas, stars, metals, overall morphology and active nuclei evolved to the present day. c) Observe the birth and early development of stars and the formation of planets. d) Study the physical and chemical properties of solar systems (including our own) and where the building blocks of life may be present.

Sabelhaus, Phillip A.↗

NASA NTRS2010

Aeronautics Research Mission Directorate Integrated Systems Research Program (ISRP) and UAS Integration in the NAS Project

Program Goal: Conduct research at an integrated system-level on promising concepts and technologies and explore, assess, or demonstrate the benefits in a relevant environment.Criteria for selection of projects for Integrated Systems Research: a) Technology has attained enough maturity in the foundational research program that they merit more in-depth evaluation at an integrated system level in a relevant environment. b) Technologies which systems analysis indicates have the most potential for contributing to the simultaneous attainment of goals. c) Technologies identified through stakeholder input as having potential for simultaneous attainment of goals. d) Research not being done by other government agencies and appropriate for NASA to conduct. e) Budget augmentation. Environmentally Responsible Aviation (ERA) Project Explore and assess new vehicle concepts and enabling technologies through system-level experimentation to simultaneously reduce fuel burn, noise, and emissions Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project Contribute capabilities that reduce technical barriers related to the safety and operational challenges associated with enabling routine UAS access to the NAS Innovative Concepts for Green Aviation (ICGA) Project Spur innovation by offering research opportunities to the broader aeronautics community through peer-reviewed proposals, with a focus on making aviation more eco-friendly. Establish incentive prizes similar to the Centennial Challenges and sponsor innovation demonstrations of selected technologies that show promise of reducing aviation s impact on the environment

Wolfe, Jean↗

NASA NTRS2010

Aligning for Innovation - Alignment Strategy to Drive Innovation

With the sudden need for innovation that will help the country achieve its long-term space exploration objectives, the question of whether NASA is aligned effectively to drive the innovation that it so desperately needs to take space exploration to the next level should be entertained. Authors such as Robert Kaplan and David North have noted that companies that use a formal system for implementing strategy consistently outperform their peers. They have outlined a six-stage management systems model for implementing strategy, which includes the aligning of the organization towards its objectives. This involves the alignment of the organization from the top down. This presentation will explore the impacts of existing U.S. industrial policy on technological innovation; assess the current NASA organizational alignment and its impacts on driving technological innovation; and finally suggest an alternative approach that may drive the innovation needed to take the world to the next level of space exploration, with NASA truly leading the way.

Johnson, Hurel↗

NASA NTRS2010

Workload: Measurement and Management

Poster: The workload research project has as its task to survey the available literature on: (1) workload measurement techniques; and (2) the effects of workload on operator performance. The first set of findings provides practitioners with a collection of simple-to-use workload measurement techniques along with characterizations of the kinds of tasks each technique has been shown reliably address. This allows design practitioners to select and use the most appropriate techniques for the task(s) at hand. The second set of findings provides practitioners with the guidance they need to design for appropriate kinds and amounts of workload across all tasks for which the operator is responsible. This guidance helps practitioners design systems and procedures that ensure appropriate levels of engagement across all tasks, and avoid designs and procedures that result in operator boredom, complacency, loss of awareness, undue levels of stress, or skill atrophy that can result from workload that distracts operators from the tasks they perform and monitor, workload levels that are too low, too high, or too consistent or predictable. Only those articles that were peer reviewed, long standing and generally accepted in the field, and applicable to a relevant range of conditions in a select domain of interest, in analogous "extreme" environments to those in space were included. In addition, all articles were reviewed and evaluated on uni-dimensional and multi-dimensional considerations. Casner & Gore also examined the notion of thresholds and the conditions that may benefit mostly from the various methodological approaches. Other considerations included whether the tools would be suitable for guiding a requirement-related and design-related question. An initial review of over 225 articles was conducted and entered into an EndNote database. The reference list included a range of conditions in the domain of interest (subjective/objective measures), the seminal works in workload, as well as summary works

Gore, Brian Francis↗

NASA NTRS2010

Volcanism on Io: Results from Global Geologic Mapping

We have completed a new 1:15,000,000 global geologic map of Jupiter's volcanic moon, Io, based on a set of 1 km/pixel combined Galileo- Voyager mosaics produced by the U.S. Geological Survey. The map was produced over the last three years using ArcGIS(TM) software, and has undergone peer-review. Here we report some of the key results from our global mapping efforts, and how these results relate to questions regarding the volcano-tectonic evolution of Io.

Williams, David A.↗

NASA NTRS2010

Geologic Map of the Olympia Cavi Region of Mars (MTM 85200): A Summary of Tactical Approaches

The 1:500K-scale geologic map of MTM 85200 - the Olympia Cavi region of Mars - has been submitted for peer review [1]. Physiographically, the quadrangle includes portions of Olympia Rupes, a set of sinuous scarps which elevate Planum Boreum ~800 meters above Olympia Planum. The region includes the high-standing, spiral troughs of Boreales Scopuli, the rugged and deep depressions of Olympia Cavi, and the vast dune fields of Olympia Undae. Geologically, the mapped units and landforms reflect the recent history of repeated accumulation and degradation. The widespread occurrence of both weakly and strongly stratified units implicates the drape-like accumulation of ice, dust, and sand through climatic variations. Similarly, the occurrence of layer truncations, particularly at unit boundaries, implicates punctuated periods of both localized and regional erosion and surface deflation whereby underlying units were exhumed and their material transported and re-deposited. Herein, we focus on the iterative mapping approaches that allowed not only the accommodation of the burgeoning variety and volume of data sets, but also facilitated the efficient presentation of map information. Unit characteristics and their geologic history are detailed in past abstracts [2-3].

Skinner, J. A., Jr.↗

NASA NTRS2011

Space Shuttle Program (SSP) Orbiter Main Propulsion System (MPS) Gaseous Hydrogen (GH2) Flow Control Valve (FCV) Poppet Eddy Current (EC) Inspection Probability of Detection (POD) Study

The Director of the NASA Engineering and Safety Center (NESC), requested an independent assessment of the anomalous gaseous hydrogen (GH2) flow incident on the Space Shuttle Program (SSP) Orbiter Vehicle (OV)-105 during the Space Transportation System (STS)-126 mission. The main propulsion system (MPS) engine #2 GH2 flow control valve (FCV) LV-57 transition from low towards high flow position without being commanded. Post-flight examination revealed that the FCV LV-57 poppet had experienced a fatigue failure that liberated a section of the poppet flange. The NESC assessment provided a peer review of the computational fluid dynamics (CFD), stress analysis, and impact testing. A probability of detection (POD) study was requested by the SSP Orbiter Project for the eddy current (EC) nondestructive evaluation (NDE) techniques that were developed to inspect the flight FCV poppets. This report contains the findings and recommendations from the NESC assessment.

Piascik, Robert S.↗

NASA NTRS2010

Tropical Cyclones, Hurricanes, and Climate: NASA's Global Cloud-Scale Simulations and New Observations that Characterize the Lifecycle of Hurricanes

One of the primary interests of Global Change research is the impact of climate changes and climate variability on extreme weather events, such as intense tropical storms and hurricanes. Atmospheric climate models run at resolutions of global weather models have been used to study the impact of climate variability, as seen in sea surface temperatures, on the frequency and intensity of tropical cyclones. NASA's Goddard Earth Observing System Model, version 5 (GEOS-5) in ensembles run at 50 km resolution has been able to reproduce the interannual variations of tropical cyclone frequency seen in nature. This, and other global models, have found it much more difficult to reproduce the interannual changes in intensity, a result that reflects the inability of the models to simulate the intensities of the most extreme storms. Better representation of the structures of cyclones requires much higher resolution models. Such improved representation is also fundamental to making best use of satellite observations. In collaboration with NOAA's Geophysical Fluid Dynamics Laboratory, GEOS-5 now has the capability of running at much higher resolution to better represent cloud-scale resolutions. Global simulations at cloud-permitting resolutions (10- to 3.5-km) allows for the development of realistic tropical cyclones from tropical storm 119 km/hr winds) to category 5 (>249km1hr winds) intensities. GEOS-5 has produced realistic rain-band and eye-wall structures in tropical cyclones that can be directly analyzed against satellite observations. For the first time a global climate model is capable of representing realistic intensity and track variability on a seasonal scale across basins. GEOS-5 is also used in assimilation mode to test the impact of NASA's observations on tropical cyclone forecasts. One such test, for tropical cyclone Nargis in the Indian Ocean in May 2008, showed that observations from Atmospheric Infrared Sounder (AIRS) and the Advanced Microwave Sounding Unit (AMSU-A) on Aqua substantially reduced forecast track errors. Tropical cyclones in the northern Indian Ocean pose serious challenges to operational weather forecasting systems, partly due to their shorter lifespan and more erratic track, compared to those in the Atlantic and the Pacific. SA is also bringing several state of the art instruments in recent field campaigns to peer under the clouds and study the inner workings of the tropical storms. With the Genesis and Rapid Intensification Processes (GRIP) experiment, a NASA Earth science field experiment in 2010 that includes the Global Hawk Unmanned Airborne System (UAS) configured with a suite of in situ and remote sensing instruments that are observing and characterizing the lifecycle of hurricanes, we expect significant improvement in our understanding of the track and intensification processes with the assimilation of the satellite and field campaign observations of meteorological parameters in the numerical prediction models.

Putman, William M.↗

NASA NTRS2011

Space Shuttle Program (SSP) Orbiter Main Propulsion System (MPS) Gaseous Hydrogen (GH2) Flow Control Valve (FCV) Poppet Eddy Current (EC) Inspection Probability of Detection (POD) Study: Appendices - Volume 2

Piascik, Robert S.↗

NASA NTRS2010

Quality Control and Calibration of the Dual-Polarization Radar at Kwajalein, RMI

Weather radars, recording information about precipitation around the globe, will soon be significantly upgraded. Most of today s weather radars transmit and receive microwave energy with horizontal orientation only, but upgraded systems have the capability to send and receive both horizontally and vertically oriented waves. These enhanced "dual-polarimetric" (DP) radars peer into precipitation and provide information on the size, shape, phase (liquid / frozen), and concentration of the falling particles (termed hydrometeors). This information is valuable for improved rain rate estimates, and for providing data on the release and absorption of heat in the atmosphere from condensation and evaporation (phase changes). The heating profiles in the atmosphere influence global circulation, and are a vital component in studies of Earth s changing climate. However, to provide the most accurate interpretation of radar data, the radar must be properly calibrated and data must be quality controlled (cleaned) to remove non-precipitation artifacts; both of which are challenging tasks for today s weather radar. The DP capability maximizes performance of these procedures using properties of the observed precipitation. In a notable paper published in 2005, scientists from the Cooperative Institute for Mesoscale Meteorological Studies (CIMMS) at the University of Oklahoma developed a method to calibrate radars using statistically averaged DP measurements within light rain. An additional publication by one of the same scientists at the National Severe Storms Laboratory (NSSL) in Norman, Oklahoma introduced several techniques to perform quality control of radar data using DP measurements. Following their lead, the Topical Rainfall Measuring Mission (TRMM) Satellite Validation Office at NASA s Goddard Space Flight Center has fine-tuned these methods for specific application to the weather radar at Kwajalein Island in the Republic of the Marshall Islands, approximately 2100 miles southwest of Hawaii and 1400 miles east of Guam in the tropical North Pacific Ocean. This tropical oceanic location is important because the majority of rain, and therefore the majority of atmospheric heating, occurs in the tropics where limited ground-based radar data are available.

Marks, David A.↗