silkski/ENERAD huggingface dataset:
It is shown that the shapes of acoustic radiation - induced static strain and displacement pulses ( rectified acoustic pulses ) are defined locally by the energy density of the generating waveform . Dispersive properties are introduced analytically by assuming that the rectified pulses are functionally dependent on a phase factor that includes both dispersive and nonlinear terms . The dispersion causes an evolutionary change in the shape of the energy density profile that leads to the generation of solitons experimentally observed in fused silica .
In human space exploration missions ( e.g. a return to the Moon and for future missions to Mars ) , there will be a need to provide voice communications services . In this work we focus on the performance of Voice over IP ( VoIP ) techniques applied to space networks , where long range latencies , simplex links , and significant bit error rates occur . Link layer and network layer overhead issues are examined . Finally , we provide some discussion on issues related to voice conferencing in the space network environment .
Games designed for entertainment have a rich history of providing compelling experiences . From consoles to PCs , games have managed to present intuitive and effective interfaces for a wide range of game styles to successfully allow users to " walk - up - and - play " . Once a user is hooked , successful games artfully present challenging experiences just within reach of a user 's ability , weaving each task and achievement into a compelling and engaging experience . In this paper , engagement is discussed in terms of the psychological theory of Flow . I argue that engagement should be one of the primary goals when developing a serious game and I discuss the best practices and techniques that have emerged from traditional video game development which help foster the creation of engaging , high Flow experiences .
The performance of impulsive , gravity - assist trajectories often improves with the inclusion of one or more maneuvers between flybys . However , grid - based scans over the entire design space can become computationally intractable for even one deep - space maneuver , and few global search routines are capable of an arbitrary number of maneuvers . To address this difficulty a trajectory transcription allowing for any number of maneuvers is developed within a multi - objective , global optimization framework for constrained , multiple gravity - assist trajectories . The formulation exploits a robust shooting scheme and analytic derivatives for computational efficiency . The approach is applied to several complex , interplanetary problems , achieving notable performance without a user - supplied initial guess .
This viewgraph document reviews the use of Radio - frequency identification ( RFID ) for NASA applications . Some of the uses reviewed are : inventory management in space ; potential RFID uses in a remote human outpost ; Ultra - Wideband RFID for tracking ; Passive , wireless sensors in NASA applications such as Micrometeoroid impact detection and Sensor measurements in environmental facilities ; E - textiles for wireless and RFID .
Word frequency effects in dual - task , lexical decision are variously reported to be additive or under - additive across SOA . We replicate and extend earlier lexical decision studies and find word frequency to be additive across SOA . To more directly capture lexical processing , we examine dual - task naming . Once again we find word frequency to be additive across SOA . Lexical processing appears to be constrained by central processing limitations .
NASA s Desert Research and Technology Studies ( D - RATS ) field test is a demonstration that combines operations development , technology advances and science in analog planetary surface conditions . The focus is testing preliminary operational concepts for extravehicular activity ( EVA ) systems by providing hands - on experience with simulated surface operations and EVA hardware and procedures . The DRATS activities also develop technical skills and experience for the engineers , scientists , technicians , and astronauts responsible for realizing the goals of the Lunar Surface Systems Program . The 2009 test is the twelfth for the D - RATS team .
Multiple combustor liner applications , both segmented and fully annular designs , have been configured for exposure in NASA 's High Pressure Burner Rig ( HPBR ) . The segmented liners were attached to the rig structure with SiC / SiC fasteners and exposed to simulated gas turbine conditions for nearly 200 hours . Test conditions included pressures of 6 atm . , gas velocity of 42 m / s , and gas temperatures near 1450 C. The temperatures of both the cooled and combustion flow sides of the liners were measured using optical and contact measurement techniques . Minor weight loss was observed , but the liners remained structural sound , although damage was noted in some fasteners .
In many modern communication applications there is a need for simple circularly polarized antennas for hemispherical coverage with good axial ratio or low value of cross polarization .    We revisited the crooked wire antenna because of its simplicity .   This paper presents results of our investigation on the crooked wire antennas and other elements .
NASA is designing a next generation Extravehicular Activity ( EVA ) Portable Life Support System ( PLSS ) for use in future surface exploration endeavors . To meet the new requirements for ventilation flow at nominal and buddy modes , a fan has been developed and tested . This paper summarizes the results of the performance and life cycle testing efforts conducted at the NASA Johnson Space Center . Additionally , oxygen compatibility assessment results from an evaluation conducted at White Sands Test Facility ( WSTF ) are provided , and lessons learned and future recommendations are outlined .
A summary of existing NASA design criteria monographs for the design of buckling - resistant thin - shell structures is presented . Subsequent improvements in the analysis for nonlinear shell response are reviewed , and current issues in shell stability analysis are discussed . Examples of nonlinear shell responses that are not included in the existing shell design monographs are presented , and an approach for including reliability based analysis procedures in the shell design process is discussed . Suggestions for conducting future shell experiments are presented , and proposed improvements to the NASA shell design criteria monographs are discussed .
In this presentation we investigate a novel framework for the design of autonomous fuzzy intelligent systems . The system integrates the following modules into a single autonomous entity : ( 1 ) a fuzzy expert system ; ( 2 ) artificial neural network ; ( 3 ) genetic algorithm ; and ( 4 ) case - base reasoning . We describe the integration of these units into one intelligent structure and discuss potential applications .
The objective is to develop computational techniques for the design of high - area - ratio nozzles and to validate these models by comparison with experiments and computations using other codes . Performance computations were added to the PARC2D code and the performance of the space shuttle main engine ( SSME ) nozzle was computed for inviscid , laminar and turbulent flow assuming a perfect gas with gamma = 1.2 . The PARC2D code was modified in a non - CASP ( Center for Advanced Space Propulsion ) project to compute equilibrium flow about hypersonic blunt bodies . Progress has been made toward modifying this code to compute equilibrium H2 / O2 flow through the SSME and related nozzles .
The standard treatment of RMS surface roughness data is the application of a Gaussian probability distribution . This handling of surface roughness ignores the skew present in the surface and overestimates the most probable RMS of the surface , the mode . Using experimental data we confirm the Gaussian distribution overestimates the mode and application of an asymmetric distribution provides a better fit . Implementing the proposed asymmetric distribution into the optical manufacturing process would reduce the polishing time required to meet surface roughness specifications .
Accurately predicting fastener preload relaxation in the James Webb Space Telescope ( JWST ) heat strap assemblies is essential to insure adequate thermal performance during its mission lifecycle . The mechanisms for preload relaxation in the strap joints include Al-1100 material creep , indium gasket flow - out , and embedment of the joint faying surfaces . This report documents the results from a bolted joint relaxation test , including analysis and curve fitting of the test data for predicting preloads five years after initial torque application . The report also includes the derivation of a preload uncertainty factor enveloping both torque / preload application scatter and expected preload relaxation at the end of mission life .
Pulse detonation rocket engines ( PDREs ) offer potential performance improvements over conventional designs , but represent a challenging modellng task . A simplified model for an idealized , straight - tube , single - shot PDRE blowdown process and thrust determination is described and implemented . In order to form an assessment of the accuracy of the model , the flowfield time history is compared to experimental data from Stanford University . Parametric Studies of the effect of mixture stoichiometry , initial fill temperature , and blowdown pressure ratio on the performance of a PDRE are performed using the model . PDRE performance is also compared with a conventional steady - state rocket engine over a range of pressure ratios using similar gasdynamic assumptions .
The objective is to develop and demonstrate a fast - acting active clearance control system to improve turbine engine performance , reduce emissions , and increase service life . System studies have shown the benefits of reducing blade tip clearances in modern turbine engines . Minimizing blade tip clearances throughout the engine will contribute materially to meeting NASA 's Ultra - Efficient Engine Technology ( UEET ) turbine engine project goals . NASA GRC is examining two candidate approaches including rub - avoidance and regeneration which are explained in subsequent slides .
The key workshop goal was to explore and document how NASA technologies , such as remote sensing , climate modeling , and high - end computing and visualization along with NASA assets such as Earth Observing Satellites ( EOS ) and Unmanned Aerial Vehicles ( UAVs ) can contribute to creating and managing a sustainable urban environment . The focus was on the greater Bay Area , but many aspects of the workshop were applicable to urban management at the local , regional and global scales . A secondary goal was to help NASA better understand the problems facing urban managers and to make city leaders in the Bay Area more aware of NASA 's capabilities . By bringing members of these two groups together we hope to see the beginnings of new collaborations between NASA and those faced with instituting sustainable urban management in Bay Area cities .
Two Landsat Thematic Mapper ( TM ) images , from July 1984 and July 1992 , were used to identify land use / cover changes in the urban and suburban fringe of the city of Huntsville , Alabama . Image difference was the technique used to quantify the change between the two dates . The eight - year period showed a 16 % change , mainly from agricultural lands to urban areas generated by the settlement of industrial , commercial , and residential areas . Visual analysis of the change map ( i.e. , difference image ) supported this phenomenon by showing that most changes were occurring in the vicinity of the major roads and highways across the city .
This paper presents Propagation Effects of Importance To The NASA / JPL Deep Space Network ( DSN ) . The topics include : 1 ) DSN Antennas ; 2 ) Deep Space Telecom Link Basics ; 3 ) DSN Propagation Region of Interest ; 4 ) Ka - Band Weather Effects Models and Examples ; 5 ) Existing Goldstone Ka - Band Atmosphere Attenuation Model ; 6 ) Existing Goldstone Atmosphere Noise Temperature Model ; and 7 ) Ka - Band delta ( G / T ) Relative to Vacuum Condition . This paper summarizes the topics above .
An intercomparison campaign for Lidar measurements of stratospheric ozone and aerosol has been conducted at the Primary Station of the Network for the Detection of Stratospheric Change ( NDSC ) in Ny - Alesund / Spitsbergen during January - February 1998 . In addition to local instrumentation , the NDSC mobile ozone lidar from NASA / GSFC and the mobile aerosol lidar from Alfred Wegener Institute ( AWI ) participated . The aim is the validation of stratospheric ozone and aerosol profile measurements according to NDSC guidelines . This paper briefly presents the employed instruments and outlines the campaign . Results of the blind intercomparison of ozone profiles are given in a companion paper and temperature measurements are described in this issue .
The Opportunity instruments have provided compelling evidence that the sulfate - rich chemical and siliciclastic sediments at the Meridiani Planum landing site were deposited in shallow water . The local paleo - environment is most often characterized as a broad , shallow sea or large playa , with surface conditions cycling between wet and dry episodes , interbedding evaporates with eolian fine sediments [ e.g. , 1,2 ] . This particular working hypothesis is reasonable , considering the area characterized by the rover s mobility . An alternative , marine origin will be considered here , a working hypothesis that we feel provides a better fit to the local - scale results identified by Opportunity , and the regional - scale characteristics of Meridiani Planum provided by data from orbiting spacecraft , when considered together .
The Virtual Solar Observatory ( VSO ) has survived its infancy and provides metadata search and data identification for measurements from 45 instrument data sets held at 12 online archives , as well as flare and coronal mass ejection ( CME ) event lists . Like any toddler , the VSO is good at getting into anything and everything , and is now extending its grasp to more data sets , new missions , and new access methods using its application programming interface ( API ) . We discuss and demonstrate recent changes , including developments for STEREO and SDO , and an IDL - callable interface for the VSO API . We urge the heliophysics community to help civilize this obstreperous youngster by providing input on ways to make the VSO even more useful for system science research in its role as part of the growing cluster of Heliophysics Virtual Observatories .
To support remote sensing of the outer planets , absorption spectra of H2O broadened by H2 were recorded at room temperature using two Fourier transform spectrometers .   The data from   1300 to 4000 cm-1 were obtained at 0.012 cm-1 resolution with the McMath FTS located at Kitt Peak National Observatory / National Solar Observatory . The remainder of the spectral data   from 55 to 320 cm-1 were taken at 0.0056 cm-1 with the Bruker FTS .
Dr. Jeffrey Jones will be talking about medical issues in space flight secondary to microgravity : fluid shifts , orthostatic changes , muscle and endurance losses , bone mineral losses , radiation exposure , etc . He will discuss the International Space Station ( ISS ) benefits to medicine . He will show the ISS crew video and share the President 's new vision as per the speaker 's bureau direction .
This viewgraph presentation describes the effects of compression , staging and braid angle on braided rope seals . The contents include : 1 ) Test Fixture Schematics ; 2 ) Comparison of Hybrid Seal Braid Architecture ; 3 ) Residual Interference After Compression Cycling ; 4 ) Effect of Compression , Braid , and Staging on Seal Flow ; 5 ) Effect of Staging on Seal Pressure Drop ; 6 ) Three Stag Seal Durability ; 7 ) P&W Turbine Vane Seal Requirements ; and 8) Next Generation Fighter F-22 P&W F119 Engines .
The inevitable transition to parallel programming can be facilitated by appropriate tools , including languages and libraries . After describing the needs of applications developers , this paper presents three specific approaches aimed at development of efficient and reusable parallel software for irregular and dynamic - structured problems . A salient feature of all three approaches in their exploitation of concurrency within a processor . Benefits of individual approaches such as these can be leveraged by an interoperability environment which permits modules written using different approaches to co - exist in single applications .
The evolving role of computational aerothermodynamics ( CA ) within NASA over the past 20 years is reviewed . The presentation highlights contributions to understanding the Space Shuttle pitching moment anomaly observed in the first shuttle flight , prediction of a static instability for Mars Pathfinder , and the use of CA for damage assessment in post - Columbia mission support . In the view forward , several current challenges in computational fluid dynamics and aerothermodynamics for hypersonic vehicle applications are discussed . Example simulations are presented to illustrate capabilities and limitations . Opportunities to advance the state - of - art in algorithms , grid generation and adaptation , and code validation are identified .
Many of NASA ’s direct imaging of exoplanet missions and projects require fabricated coronagraph masks to control scattering and diffraction of light . The designed , patterned mask intended for the coronagraphic testbeds are highly absorptive in the visible range on non - metallic regions . In this work , we employed the cryogenic etching process to fabricate black silicon ( BSi ) to achieve a high aspect ratio ( HAR ) structures with higher etch rate than conventional reactive ion etching ( REI ) . Recent bidirectional reflectance distribution function ( BRDF ) measurements of uniformly etched BSi on silicon wafer show highly diffusive BSi with a specular reflective component in the orders of seven magnitudes lower than the total hemispherical reflectance when the polarized or non - polarized incident beam is used .
This paper deals with the dynamic characterization of a flexible aerospace solar boom . The modeling issues and sine dwell vibration testing to determine natural frequencies and mode shapes of a continuous - longer on deployable ASTROMAST lattice boom are discussed . The details of the proof - of - concept piezoelectric active vibration experiments on a simple cantilever beam to control its vibrations are presented . The control parameters like voltage to the controller crystal and its location are investigated , to determine the effectiveness of control element to suppress selected resonant vibrations of the test specimen . Details of this experiment and plans for its future adaptation to the prototype structure are also discussed .
In 2017 , our team investigated and evaluated the novel concept of operations of astronaut self - scheduling ( rescheduling their own timeline without creating violations ) onboard International Space Station ( ISS ) . Five test sessions were completed for this technology demonstration called Crew Autonomous Scheduling Test ( CAST ) . For the first time in a spaceflight operational environment , an ISS crewmember planned , rescheduled , and executed their activities in real - time on a mobile device while abiding by flight and scheduling constraints . This paper discusses the lessons learned from deployment to execution .
Thermal radiometers such as proposed for the Europa Clipper flyby mission require low noise signal processing for thermal imaging with immunity to Total Ionizing Dose ( TID ) and Single Event Latchup ( SEL ) . Described is a second generation Multi- Channel Digitizer ( MCD2 G ) Application Specific Integrated Circuit ( ASIC ) that accurately digitizes up to 40 thermopile pixels with greater than 50 Mrad ( Si ) immunity TID and 174 MeV - sq cm / mg SEL . The MCD2 G ASIC uses Radiation Hardened By Design ( RHBD ) techniques with a 180 nm CMOS process node .
Next generation space - based robotics systems will be constructed using distributed architectures where electronics capable of working in the extreme environments of the planets of the   solar system are integrated with the sensors and actuators in plug - and - play modules and are connected through common multiple redundant data and power buses .
NASA has a significant maintenance challenge with the agency ’s aging wind tunnel infrastructure . Wind tunnel blades , such as the ones in the National Transonic Facility at NASA Langley Research Center , have been subjected to damage from impacts and fatigue . Accurate analytical models of these blades are necessary to either recertify replacement blades to be built or for redesign of these blades . In this paper a process for generating structural finite element models of these wind tunnel blades is presented . The model developed in this paper was analyzed under loading conditions from tests conducted on the original blades and the results are compared with legacy strain gage data .
Purpose : 1 ) Understand and measure JSC workplace health : a ) levels , sources , indicators & effects of negative , work - related stress ; b ) define leading indicators of emerging issues . 2 Provide linkage to outcomes : a ) Focus application of wellness strategies & HR tools ; b ) Increase quality of work life and productivity . 3 ) Current effort will result in : a ) Online assessment tool ; b ) Assessment of total JSC population ( civil service & contractors ) ; c ) Application of mitigation tools and strategies . 4 ) Product of the JSC Employee Wellness Program . 5 ) Collaboration with Corporate Health Improvement Program / University of Arizona .
Accurate estimates of electron - capture cross sections at energies relevant to ENA modeling ( approx . few MeV per nucleon ) and for multi - electron ions must rely on detailed , but computationally expensive , quantummechanical description of the collision process . Kuang 's semi - classical approach is an elegant and efficient way to arrive at these estimates . Motivated by ENA modeling efforts , we shall briefly present this approach along with sample applications and report on current progress .
As NASA has conducted extensive simulation and testing of the Space Launch System for the Artemis I mission , opportunities were identified for improvements to the Guidance , Navigation and Controls algorithms . These improvements will allow more effective use of the capabilities of the SLS vehicle , and enhance safety of the crew on board . This paper describes several planned updates to the Powered Explicit Guidance algorithm and auxiliary guidance algorithms for Artemis I and subsequent SLS missions .
The results of a system level study done by Hughes Network Systems for NASA are presented . For the supervisory control and data acquisition ( SCADA ) application , use of Ka - band spot beam satellite technology associated with NASA 's Advanced Communication Technology Satellite ( ACTS ) offers a reduction in Earth station antenna size and transmitter power that may translate into lower system costs . The approaches taken to determine commercial potential of the system are described .
The Carbon Dioxide Removal and Compression System ( CRCS ) is designed to perform both the Carbon Dioxide(CO2 ) removal and compress CO2 for further processing . The CRCS was designed as a lower power requirement option to the one currently being used on the International Space Station ( ISS ) . This paper describes the final design , fabrication , assembly , and testing of the integrated CRCS . Initial results indicated that the spiral heaters used did not yield uniform heating within both the adsorption and compression beds . In addition , the heaters for the compression bed were insufficient and an additional HVAC jacket was employed to provide heat to the bed .