Data and Reasoning Fabric (DRF)
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Data Reasoning↗
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An Approach to Reasoning Service Migration in Data and Reasoning Fabric (DRF) Implementation
In this paper we consider service migration problem for Data and Reasoning Fabric (DRF) enabled airspace operations assuming a fixed cloud/edge infrastructure with allocated computing, storage and power resources, where cloud/edge servers, and communication stations are in a wired connected network, while vehicles use a wireless network for communication. The objective is to automatically select the best location for the requested service execution, which achieves minimum cost while satisfying the user quality of service (QoS) and available resources constraints. To this end, estimates of the response time, consumed energy and total cost are defined for each potential compute location. A mixed-integer linear program is then formulated and solved to identify optimal compute locations given QoS constraints, network infrastructure limitations, with worst-case vehicle positioning. The approach is applied to trajectory re-planning use case to avoid a collision with an emergency vehicle in real time.
Air mobility↗
HRMA calibration handbook: EKC gravity compensated XRCF models
This document, consisting of hardcopy printout of explanatory text, figures, and tables, represents one incarnation of the AXAF high resolution mirror assembly (HRMA) Calibration Handbook. However, as we have envisioned it, the handbook also consists of electronic versions of this hardcopy printout (in the form of postscript files), the individual scripts which produced the various figures and the associated input data, the model raytrace files, and all scripts, parameter files, and input data necessary to generate the raytraces. These data are all available electronically as either ASCII or FITS files. The handbook is intended to be a living document and will be updated as new information and/or fabrication data on the HRMA are obtained, or when the need for additional results are indicated. The SAO Mission Support Team (MST) is developing a high fidelity HRMA model, consisting of analytical and numerical calculations, computer software, and databases of fundamental physical constants, laboratory measurements, configuration data, finite element models, AXAF assembly data, and so on. This model serves as the basis for the simulations presented in the handbook. The 'core' of the model is the raytrace package OSAC, which we have substantially modified and now refer to as SAOsac. One major structural modification to the software has been to utilize the UNIX binary pipe data transport mechanism for passing rays between program modules. This change has made it possible to simulate rays which are distributed randomly over the entrance aperture of the telescope. It has also resulted in a highly efficient system for tracing large numbers of rays. In one application to date (the analysis of VETA-I ring focus data) we have employed 2 x 10(exp 7) rays, a substantial improvement over the limit of 1 x 10(exp 4) rays in the original OSAC module. A second major modification is the manner in which SAOsac incorporates low spatial frequency surface errors into the geometric raytrace. The original OSAC included the ability to use Legendre-Fourier polynomials to describe deviations from the basic optical prescription. To this we have added bicubic splines to address a deficiency in the handling of the sharper deformations in the areas of mirror support pads. SAO has developed software (TRANS-FIT) to translate the most common finite element analysis models into these forms for incorporation into the raytrace program.
Tananbaum, H. D.↗
An Approach to Reasoning Service Migration in Data and Reasoning Fabric (DRF) Implementation
In this paper we consider service placement problem for Data and Reasoning Fabric (DRF) enabled airspace operations assuming a fixed cloud/edge infrastructure with allocated computing, storage and power resources, where cloud/edge servers, and communication stations are in a wired connected network, while vehicles use a wireless network for communication. The objective is to automatically select the best location for the requested service execution, which achieves minimum cost while satisfying the user quality of service (QoS) and available resources constraints. To this end, we estimate for each potential location the response time, consumed energy and total cost; formulate an optimization problem for cost minimization given the users QoS constraints and network infrastructure limitations; and solve it using nonlinear programming tools. The approach is applied to trajectory re-planning use case to handle a no-fly zone contingency in real time.
Vahram Stepanyan↗
Web-based Visualization and Analytics of Petascale Data: Equity as a Tide that Lifts All Boats
Scientists generate petabytes of data daily to help uncover environmental trends or behaviors that are hard to predict. For example, understanding climate simulations based on the long-term average of temperature, precipitation, and other environmental variables is essential to predicting and establishing root causes of future undesirable scenarios and assessing possible mitigation strategies. While supercomputer centers provide a powerful infrastructure for generating petabytes of simulation output, accessing and analyzing these datasets interactively remains challenging on multiple fronts. This paper presents an approach to managing, visualizing, and analyzing petabytes of data within a browser on equipment ranging from the top NASA supercomputer to commodity hardware like a laptop. Our novel data fabric abstraction layer allows user-friendly querying of scientific information while hid-ing the complexities of dealing with file systems or cloud services.We also optimize network utilization while streaming from petas-cale repositories through state-of-the-art progressive compression algorithms. Based on this abstraction, we provide customizable dashboards that can be accessed from any device with any inter-net connection, enabling interactive visual analysis of vast amounts of data to a wide range of users - from top scientists with access to leadership-class computing environments to undergraduate students of disadvantaged backgrounds from minority-serving institutions. We focus on NASA’s use of petascale climate datasets as an example of particular societal impact and, therefore, a case where achieving equity in science participation is critical. We validate our approach by improving the ability of climate scientists to visually explore their data via two fully interactive dashboards. We further validate our approach by deploying the dashboards and simplified training materials in the classroom at a minority-serving institution.These dashboards, released in simplified form to the general public, contribute significantly to a broader push to democratize the access and use of climate data.
Data visualization↗
Determination of the reliability of Ni-Cd batteries from survival data on cells fabricated 1964 - 1977
The probability of Ni-Cd battery survival was determined by researching survival data on cells fabricated from 1964-1977. A log of cell failure times were plotted against cumulative failure percentage and mean and standard deviation were determined.
Jordan, A. S.↗
HFIR Steady State Heat Transfer Code (HSSHTC) Statistical Uncertainty Analysis
HSSHTC, the safety basis steady state TH code for HFIR, uses a highly conservative approach in which all input and calculation uncertainties are resolved simultaneously at their most limiting setting. This results in excessive conservatism which does not account for the high unlikelihood of such simultaneous worst-case conditions. The present study explores an alternative approach, BEPU, in which reasonable working assumptions for the probability distribution of each input uncertainty are used to determine a relationship between burnout power margin and core fuel failure probability. This was performed under a philosophy of perturbing uncertainty parameters already defined within the HSSHTC methodology while preserving the HSSHTC calculation approach and solution methodology itself. Based on the assumptions employed in this study, the BEPU approach resulted in a 0.29 increase in burnout power ratio (25 MW increase in burnout power) compared to the latest HSSHTC calculations of C-HFIR-2026-004. The study can be refined in the future by employing fuel fabrication data to provide more realistic input distributions. Future changes to the HSSHTC methodology would potentially allow a more comprehensive treatment of uncertainties which may further increase the burnout power ratio.
Wysocki, Aaron [ORNL] (ORCID:0000000222043779)↗
Network Security Challenges and Countermeasures for Software-Defined Smart Grids: A Survey
The rise of grid modernization has been prompted by the escalating demand for power, the deteriorating state of infrastructure, and the growing concern regarding the reliability of electric utilities. The smart grid encompasses recent advancements in electronics, technology, telecommunications, and computer capabilities. Smart grid telecommunication frameworks provide bidirectional communication to facilitate grid operations. Software-defined networking (SDN) is a proposed approach for monitoring and regulating telecommunication networks, which allows for enhanced visibility, control, and security in smart grid systems. Nevertheless, the integration of telecommunications infrastructure exposes smart grid networks to potential cyberattacks. Unauthorized individuals may exploit unauthorized access to intercept communications, introduce fabricated data into system measurements, overwhelm communication channels with false data packets, or attack centralized controllers to disable network control. An ongoing, thorough examination of cyber attacks and protection strategies for smart grid networks is essential due to the ever-changing nature of these threats. Previous surveys on smart grid security lack modern methodologies and, to the best of our knowledge, most, if not all, focus on only one sort of attack or protection. This survey examines the most recent security techniques, simultaneous multi-pronged cyber attacks, and defense utilities in order to address the challenges of future SDN smart grid research. The objective is to identify future research requirements, describe the existing security challenges, and highlight emerging threats and their potential impact on the deployment of software-defined smart grid (SD-SG).
24 POWER TRANSMISSION AND DISTRIBUTION↗
Phenocryst fabric in lunar basalt sample 12052 from the Ocean of Storms.
Pyroxene phenocrysts in Apollo 12 sample 12052, a porphyritic basalt, have a weak, planar preferred orientation and a lineation as determined by crystal-elongation measurements and universal-stage measurements in orthogonal thin sections. The structures are probably the result of laminar flow. Numerous vugs and the flow foliation in sample 12052 suggest crystallization as a surface flow or a near-surface sill. Flowage appears to have ceased by the time of crystallization of the variolitic groundmass of the sample. The fabric data suggest a two-stage crystallization of sample 12052.
Greenwood, W. R.↗
Grain orientation in lunar soil
Orientation of lunar soil particles in a vertical plane, as seen in the radiographs of core tubes was characterized by preparing orientation diagrams for the different stratigraphic units. Radiographs of double-core drive tubes 64001/64002, 60009/60010, and 60013/60014 were used. The orientation results reinforced the stratigraphic differences. Another source of fabric data was the laboratory-deposited sample 14163,148. The artificial deposition results showed that the grain arrangements were dependent upon the method of deposition. These results from lunar soil and other data from a crushed basalt simulant can be a basis for the inference that lunar soil grain orientation and properties are useful in interpreting lunar surface history.
Mahmood, A.↗
Satellite Power Systems (SPS) concept definition study, exhibit C. Volume 6: In-depth element investigation
Computer assisted design of a gallium arsenide solid state dc-to-RF converter with supportive fabrication data was investigated. Specific tasks performed include: computer program checkout; amplifier comparisons; computer design analysis of GaSa solar cells; and GaAs diode evaluation. Results obtained in the design and evaluation of transistors for the microwave space power system are presented.
Hanley, G.↗
Designing with figer-reinforced plastics (planar random composites)
The use of composite mechanics to predict the hygrothermomechanical behavior of planar random composites (PRC) is reviewed and described. These composites are usually made from chopped fiber reinforced resins (thermoplastics or thermosets). The hygrothermomechanical behavior includes mechanical properties, physical properties, thermal properties, fracture toughness, creep and creep rupture. Properties are presented in graphical form with sample calculations to illustrate their use. Concepts such as directional reinforcement and strip hybrids are described. Typical data that can be used for preliminary design for various PRCs are included. Several resins and molding compounds used to make PRCs are described briefly. Pertinent references are cited that cover analysis and design methods, materials, data, fabrication procedures and applications.
Chamis, C. C.↗
Less-Costly Ion Implantation of Solar Cells
Experiments point way toward more relaxed controls over ion-implanation dosage and uniformity in solar-cell fabrication. Data indicate cell performance, measured by output current density at fixed voltage, virtually same whether implant is particular ion species or broad-beam mixture of several species.
Fitzgerald, D. J.↗
Shear Strength at 75 F to 500 F of Fourteen Adhesives Used to Bond a Glass-fabric-reinforced Phenolic Resin Laminate to Steel
Fourteen adhesives used to bond a glass-fabric-reinforced phenolic resin laminate to steel were tested in order to determine their shear strengths at temperatures from 75 F to 500 F. Fabrication methods were varied to evaluate the effect of placing cloth between the facing surfaces to maintain a uniform bond-line thickness. One glass-fabric supported phenolic adhesive was found to have a shear strength of 3,400 psi at 300 F and over 1,000 psi at 500 F. Strength and fabrication data are tabulated for all adhesives tested.
PLASTICS↗
Analyzing Responses of Chemical Sensor Arrays
NASA is developing a third-generation electronic nose (ENose) capable of continuous monitoring of the International Space Station s cabin atmosphere for specific, harmful airborne contaminants. Previous generations of the ENose have been described in prior NASA Tech Briefs issues. Sensor selection is critical in both (prefabrication) sensor material selection and (post-fabrication) data analysis of the ENose, which detects several analytes that are difficult to detect, or that are at very low concentration ranges. Existing sensor selection approaches usually include limited statistical measures, where selectivity is more important but reliability and sensitivity are not of concern. When reliability and sensitivity can be major limiting factors in detecting target compounds reliably, the existing approach is not able to provide meaningful selection that will actually improve data analysis results. The approach and software reported here consider more statistical measures (factors) than existing approaches for a similar purpose. The result is a more balanced and robust sensor selection from a less than ideal sensor array. The software offers quick, flexible, optimal sensor selection and weighting for a variety of purposes without a time-consuming, iterative search by performing sensor calibrations to a known linear or nonlinear model, evaluating the individual sensor s statistics, scoring the individual sensor s overall performance, finding the best sensor array size to maximize class separation, finding optimal weights for the remaining sensor array, estimating limits of detection for the target compounds, evaluating fingerprint distance between group pairs, and finding the best event-detecting sensors.
Zhou, Hanying↗
Reasoning Service Exemplars for NASA’s Data and Reasoning Fabric
Future operations for Urban and Advanced Air Mobility are enabled by a distributed network of reliable and secured data and reasoning services referred to here as a fabric. In the aggregate, such a system must be all encompassing and mission agnostic, but specific use-cases are still needed to improve understanding and drive design paradigms. For this purpose, three reasoning service exemplars for Target Selection and Routing, Trajectory Generation, and Battery Health Management were developed and integrated into a specific NASA proposed data and reasoning fabric. These services were then used to build a mission reasoning application for lightning strike reconnaissance developed in collaboration with the Civil Air Patrol. Autonomous mission execution was then demonstrated using a multivehicle simulation platform with a full envelope 6 Degree-of-Freedom dynamics model for a concept electric Vertical Takeoff and Landing aircraft.
Autonomy↗
Data and Reasoning Fabric (DRF) Close-out
Provides three themes where DRF can support wildfire opportunities.
DRF↗
Long Term Displacement Data of Woven Fabric Webbings Under Constant Load for Inflatable Structures
Inflatable modules for space applications offer weight and launch volume savings relative to current metallic modules. Limited data exist on the creep behavior of the restraint layer of inflatable modules. Long-term displacement and strain data of two high strength woven fabric webbings, Kevlar and Vectran, under constant load is presented. The creep behavior of webbings is required by designers to help determine service life parameters of inflatable modules. Four groups of different webbings with different loads were defined for this study. Group 1 consisted of 4K Kevlar webbings loaded to 33% ultimate tensile strength and 6K Vectran webbings loaded to 27% ultimate tensile strength, group 2 consisted of 6K Kevlar webbings loaded to 40% and 43% ultimate tensile strength, and 6K Vectran webbings loaded to 50% ultimate tensile strength, group 3 consisted of 6K Kevlar webbings loaded to 52% ultimate tensile strength and 6K Vectran webbings loaded to 60% ultimate tensile strength, and group 4 consisted of 12.5K Kevlar webbings loaded to 22% ultimate tensile strength, and 12.5K Vectran webbings loaded to 22% ultimate tensile strength. The uniquely designed test facility, hardware, displacement measuring devices, and test data are presented. Test data indicate that immediately after loading all webbings stretch an inch or more, however as time increases displacement values significantly decrease to fall within a range of several hundredth of an inch over the remainder of test period. Webbings in group 1 exhibit near constant displacements and strains over a 17-month period. Data acquisition was suspended after the 17th month, however webbings continue to sustain load without any local webbing damage as of the 21st month of testing. Webbings in group 2 exhibit a combination of initial constant displacement and subsequent increases in displacement rates over a 16-month period. Webbings in group 3 exhibit steady increases in displacement rates leading to webbing failure over a 3-month period. Five of six webbings experienced local damage and subsequent failure in group 3. Data from group 4 indicates increasing webbing displacements over a 7-month period. All webbings in groups 1, 2, and 4 remain suspended without any local damage as of the writing of this paper. Variations in facility temperatures over test period seem to have had limited effect on long-term webbing displacement data.
Kenner, Winfred S.↗