silkski/ENERAD huggingface dataset:
Advanced mobile satellite communication experiments in the Ka - band and the mm - wave will be carried out using the COMETS satellite , which is scheduled for launch in 1997 . Mobile antennas will play a much more key role in high frequency systems such as COMETS than in conventional L - band mobile systems . This paper describes three types of antennas which are now being developed by the Communications Research Laboratory ( CRL ) for the COMETS mobile experiments . One is a mechanically steered waveguide slot array antenna , another is an electronically steered active phased array antenna , and the third is a mechanically steered torus reflector antenna . The first two antennas will be used in the Ka - band , while the latter will be used in the mm - wave .
In a Psychological Refractory Period paradigm where the first task requires one of several possible responses on some trials ( the go trials ) , but no response on other ( no - go ) trials , response modality modulates the amount of interference on Task 2 processing . This is true even when Task 1 is no - go trial . Differences in the cost of switching response sets between processing for Task 1 and Task 2 may provide an account of this surprising phenomenon .
Two state of the art technologies have been developed for External Fuel Tank foam inspections . Results of POD tests have shown Backscatter Radiography and Terahertz imaging detect critical defects with no false positive issue . These techniques are currently in use on the External Tank program as one component in the foam quality assurance program .
Resting conventional ECG is notoriously insensitive for detecting coronary artery disease ( CAD ) and only nominally useful in screening for cardiomyopathy ( CM ) . Similarly , conventional exercise stress test ECG is both time- and labor - consuming and its accuracy in identifying CAD is suboptimal for use in population screening . We retrospectively investigated the accuracy of several advanced resting electrocardiographic ( ECG ) parameters , both alone and in combination , for detecting CAD and cardiomyopathy ( CM ) .
The GEMnet(TM ) ( Global Electronics Message network ) will provide global digital data communications anywhere in the world at any time for minimum cost . GEMnet(TM ) is an end - to - end Non - Voice Non - Geostationary Mobile Satellite ( NVNG ) ( sometimes dubbed ' Little LEO ' ) System which consists of a constellation of 38 low Earth orbiting small satellites and a ground segment . The GEMnet(TM ) ground segment will consist of subscriber user terminals , gateway stations , a Network Operational Center(NOC ) , and a backbone network interconnecting the NOC and gateways . This paper will describe the GEMnet(TM ) system concept including ground and space segments , system heritage , data communication services , and protocols .
Congestion and uncertainty on the airport surface are major constraints to the available capacity of the air transport system . This project is to study the problem of planning and scheduling airport surface movement at large airports . Specifically , we focus on the departure time scheduling and taxiway path planning of multiple aircraft under uncertainty . We also developed a simulation tool that is capable of simulating aircraft movement along the taxiway and possible uncertainty during the movement .
The S2 VLBI system synthesizes wide IF bandwidths by rapidly switching the local oscillator ( LO ) frequency in a small ( 1 - 4 ) number of baseband converters ( BBC 's ) . Data are recorded on video cassettes using an array of 8 VHS transports . Characteristics of the S2 Data Acquisition System ( DAS ) , the S2 Record and Playback Terminals ( RT and PT ) and the S2 Correlator are summarized . The bandwidth synthesis ( BWS ) frequency switching sequence used in a series of system validation experiments is presented .
The Ultra - Compact Imaging Spectrometer ( UCIS ) is a miniature telescope and spectrometer system intended for mapping terrain mineralogy over distances from 1.5 m to infinity with spatial sampling of 1.35 mrad over a 33 deg field , and spectral sampling of 10 nm in the 600 - 2500 nm range . The core of the system has been designed for operation in a Martian environment , but can also be used in a terrestrial environment when placed inside a vacuum vessel . We report the laboratory and field calibration data that include spatial and spectral calibration , and demonstrate the use of the system .
In the light of strong indications that a majority of critical defects formed in bismuth silicon oxide ( BSO ) during growth from the melt is related directly or indirectly to gravitational interference , it is suggested to use the reduced gravity environment of outer space for experimentation directed at the identification and control of these defects . The results of these experiments are expected to lead to advances in our understanding of crystal growth related defect formation in general and will establish a basis for effective defect engineering , the approach to efficient achievement of defect related , application specific properties in opto - electronic materials
While machine learning and spacecraft autonomy continue to gain research interest , significant work remains to be done in efficiently applying modern machine learning techniques to problems in space ight . This study presents a framework for deriving a discrete neural spacecraft attitude controller using reinforcement learning , a paradigm of machine learning , without the need for high - performance computing . The developed attitude controller is an approximately time - optimal solution to a highly constrained control problem , able to achieve well above industry - standard pointing accuracies . Control examples are also presented of the agent performing large - angle spacecraft slews in the developed simulation environment and future extensions of this work are discussed .
A compact Hg ion trap package that was vacuum - sealed since 9 years has been demonstrated to be successfully operational showing excellent ion - trap lifetime exceeding 400 days . In addition to the vacuum package , the same 9 - year old optical and detection packages are utilized to obtain these results . Charge transfer relaxation effects between neutral Hg and trapped Hg ion are studied . This work shows the reliability of such units in view of next - generation ground and space - borne trapped ion clocks .
In this paper , we propose a saturation control scheme for linear parameter - varying ( LPV ) systems from an antiwindup control perspective . The proposed control approach is advantageous because it can be thought of as an augmented control algorithm from the existing control system . Moreover , the synthesis condition for an antiwindup compensator is formulated as a linear matrix inequality ( LMI ) optimization problem and can be solved efficiently . We have applied the LPV antiwindup controller to an F-16 longitudinal autopilot control system design to enhance aircraft safety and improve flight quality in a high angle of attack region .
This paper presents an application of robust gain - scheduled control concepts using a linear parameter - varying ( LPV ) control synthesis method to design fault tolerant controllers for a civil transport aircraft . To apply the robust LPV control synthesis method , the nonlinear dynamics must be represented by an LPV model , which is developed using the function substitution method over the entire flight envelope . The developed LPV model associated with the aerodynamic coefficient uncertainties represents nonlinear dynamics including those outside the equilibrium manifold . Passive and active fault tolerant controllers ( FTC ) are designed for the longitudinal dynamics of the Boeing 747 - 100/200 aircraft in the presence of elevator failure . Both FTC laws are evaluated in the full nonlinear aircraft simulation in the presence of the elevator fault and the results are compared to show pros and cons of each control law .
The NASA White Sands Test Facility ( WSTF ) routinely operates hypergolic propulsion systems . Some of the onsite activities include performing long duration studies on the operational life of these systems . A few of them have been in use for over twenty years . During this span of time contamination has built up in the propellant and some of the distribution infrastructure . This study investigated the nature of this contamination , the pathology of its generation , and developed a process for removal of the contamination that was cost efficient with minimal waste generation .
This paper is a tribute to Dr Fred Munpton , the founder of the International Committee on Natural Zeolites ( ICNZ ) , by one of his students , who later succeed him as president of the ICNZ . The tribute reflects on Dr. Mumpton 's skills as an editor and his zeal for the study of natural zeolites .
The Alpha Jet Atmospheric eXperiment ( AJAX ) is a research project based at Moffett Field , CA , which collects airborne measurements of ozone , carbon dioxide , methane , water vapor , and formaldehyde , as well as 3 - D winds , temperature , pressure , and location . Since its first science flight in 2011 , AJAX has developed a wide a variety of mission types , combining vertical profiles ( from approx . 8 km to near surface),boundary layer legs , and plume sampling as needed . With an ongoing five - year data set , the team has sampled over 160 vertical profiles , a dozen wildfires , and numerous stratospheric ozone intrusions . This talk will present an overview of our flights flown to date , with particular focus on methane observations in the San Francisco Bay Area , Sacramento , and the delta region .
Differences in rain rate between TMI and PR vary systematically with PR Z - profile statistics , whose frequency of occurrence is modified to create seasonal biases in the sub - tropical Southeastern U.S. ( and almost certainly elsewhere ) . Tropical ( non - tropical ) DSDs in N. Alabama exhibit larger ( smaller ) D(sub 0 ) , and larger ( smaller ) N(sub 0 ) and mu . The formulation process for empirical retrievals of DSD using dual - pol radar is sensitive to D(sub max ) assumptions used in the scattering model stage . 4 . DSD retrievals from Parsivel disdrometers compare favorably to those of the 2DVD unless rain rates exceed 25 mm / hr and D(sub m ) exceeds 2 mm ( at which point the Parsivels overestimate D(sub m ) and rain rate ) .
The " Unmanned Aircraft System ( UAS ) Integration into the National Airspace System ( NAS ) " Project conducted flight test program , referred to as Flight Test 3 , at Armstrong Flight Research Center from June - August 2015 . Four flight test days were dedicated to the NASA Ames - developed Detect and Avoid ( DAA ) System referred to as Autoresolver . The encounter scenarios , which involved NASA 's Ikhana UAS and a manned intruder aircraft , were designed to collect data on DAA system performance in real - world conditions and uncertainties with four different surveillance sensor systems . Resulting flight test data and analysis results will be used to evaluate the DAA system performance ( e.g. , trajectory prediction accuracy , threat detection ) and to add fidelity to simulation models used to inform Minimum Operating Performance Standards ( MOPS ) for integrating UAS into routine NAS operations .
The Kennedy Space Center Network Documentation System ( KSC NDS ) is being designed and implemented by NASA and the KSC contractor organizations to provide a means of network tracking , configuration , and control . Currently , a variety of host and client platforms are in use as a result of each organization having established its own network documentation system . The solution is to incorporate as many existing ' systems ' as possible in the effort to consolidate and standardize KSC - wide documentation .
The space dust ( SPADUS ) experiment , to be launched into a sun - synchronous polar orbit at an altitude of 833 km onboard the USAF ARGOS P91 - 1 mission , will provide time - resolved measurements of the intensity , size spectrum and geocentric trajectories of dust particles encountered during the nominal three year mission . The experiment uses polyvinylidene fluoride dust sensors with a total detector area of 576 sq cm . The SPADUS will measure particle sizes between 2 and 200 microns , particle velocities between 1 and 10 km / s to better than 4 percent , and the direction of incidence with a mean error of 7 percent . These data will identify the particles as being debris or of natural origin .
The scope of the work in this presentation focuses on the development of algorithms for the integration of rate dependent constitutive equations . In view of their robustness ; i.e. , their superior stability and convergence properties for isotropic and anisotropic coupled viscoplastic - damage models , implicit integration schemes have been selected . This is the simplest in its class and is one of the most widely used implicit integrators at present .
The design methodologies of using sequence diagrams , multi - process functional flow diagrams , and hierarchical state machines were successfully applied in designing three MSL ( Mars Science Laboratory ) flight software modules responsible for handling actuator motions of the CHIMRA ( Collection and Handling for In Situ Martian Rock Analysis ) , IC ( Inlet Covers ) , and DRT ( Dust Removal Tool ) mechanisms . The methodologies were essential to specify complex interactions with other modules , support concurrent foreground and background motions , and handle various fault protections . Studying task scenarios with multi - process functional flow diagrams yielded great insight to overall design perspectives . Since the three modules require three different levels of background motion support , the methodologies presented in this paper provide an excellent comparison . All three modules are fully operational in flight .
Silicon - oxide - nitride - oxide - silicon ( SONOS ) nonvolatile memory is gaining favor over conventional EEPROM FLASH memory technology . This paper characterizes the SONOS write operation using a nonquasi - static MOSFET model . This includes floating gate charge and voltage characteristics as well as tunneling current , voltage threshold and drain current characterization . The characterization of the SONOS memory cell predicted by the model closely agrees with experimental data obtained from actual SONOS memory cells . The tunnel current , drain current , threshold voltage and read drain current all closely agreed with empirical data .
Introduction :   During the 2018 Atacama Rover Astrobiology Drilling Studies ( ARADS ) field activities , we conducted a survey of surface and subsurface sediment radioactivity . Our objective was to characterize the radiation environment of various near - surface sampling locations , as well as along the entire profile of a 2.60 m deep pit that had been dug near one of the ARADS rover drill site locations . This pit was used to collect samples that have been well characterized [ 2 ] for comparison to samples collected and analyzed by the rover .
Minimum display requirements for Detect - and - Avoid ( DAA ) systems are being developed in order to support the expansion of Unmanned Aircraft Systems ( UAS ) into the National Airspace System ( NAS ) . The present study examines UAS pilots ' subjective assessments of four DAA display configurations with varying forms of maneuver guidance . For each configuration , pilots rated the intuitiveness of the display and how well it supported their ability to perform the DAA task . Responses revealed a clear preference for the DAA displays that presented suggestive maneuver guidance in the form of " banding " compared to an Information Only display , which lacked any maneuver guidance . Implications on DAA display requirements , as well as the relation between the subjective evaluations and the objective performance data from previous studies are discussed .
Excessive vibration of turbomachinery blades causes high cycle fatigue ( HCF ) problems requiring damping treatments to mitigate vibration levels . Based on the technical challenges and requirements learned from previous turbomachinery blade research , a feasibility study of resonant damping control using shunted piezoelectric patches with passive and active control techniques has been conducted on cantilever beam specimens . Test results for the passive damping circuit show that the optimum resistive shunt circuit reduces the third bending resonant vibration by almost 50 % , and the optimum inductive circuit reduces the vibration by 90 % . In a separate test , active control reduced vibration by approximately 98 % .
A subsystem architecture derived from the International Space Station 's ( ISS ) Atmosphere Revitalization Subsystem ( ARS ) has been functionally demonstrated . This ISS - derived architecture features re - arranged unit operations for trace contaminant control and carbon dioxide removal functions , a methane purification component as a precursor to enhance resource recovery over ISS capability , operational modifications to a water electrolysis - based oxygen generation assembly , and an alternative major atmospheric constituent monitoring concept . Results from this functional demonstration are summarized and compared to the performance observed during ground - based testing conducted on an ISS - like subsystem architecture . Considerations for further subsystem architecture and process technology development are discussed .
This paper describes a point - mass model of a multirotor electric vertical takeoff and landing aircraft designed to carry up to five passengers and a pilot . The model employs thrust , thrust vector angle and bank angle as controls , which are computed in part using the acceleration , heading - angle rate , and flight - path - angle rate generated by control systems in response to speed , heading angle , and flight - path angle commands . The equations of motion are integrated forward in time using the controls needed for following the desired vertical climb / descent and speed profiles , and horizontal path and cruise speed in the presence of wind to generate the flight trajectory .
We have developed as web - based database containing spectra of diatomic moiecuies . All data is computed from first principles , and if a user requests data for a molecule / ion that is not in the database , new calculations are automatically carried out on that species . Rotational , vibrational , and electronic transitions are included . Different levels of accuracy can be selected from qualitatively correct to the best calculations that can be carried out . The user can view and modify spectroscopic constants , view potential energy curves , download detailed high temperature linelists , or view synthetic spectra .
This paper describes Project Management at NASA 's Kennedy Space Center ( KSC ) from a strategic perspective . It develops the historical context of the agency and center 's strategic planning process and illustrates how now is the time for KSC to become a center which has excellence in project management . The author describes project management activities at the center and details observations on those efforts . Finally the author describes the Strategic Project Management Process Model as a conceptual model which could assist KSC in defining an appropriate project management process system at the center .
Methods exist to define the logistics support requirements for new aircraft concepts but are not directly applicable to new launch vehicle concepts . In order to define the support requirements and to discriminate among new technologies and processing choices for these systems , NASA Langley Research Center ( LaRC ) is developing new analysis methods . This paper describes several methods under development , gives their current status , and discusses the benefits and limitations associated with their use .
A hybrid transition trip - dot sizing and placement test technique was developed in support of recent experimental research on a hybrid wing - body configuration under study for the NASA Environmentally Responsible Aviation project . The approach combines traditional methods with Computational Fluid Dynamics . The application had three - dimensional boundary layers that were simulated with either fully turbulent or transitional flow models using established Reynolds - Averaged Navier - Stokes methods . Trip strip effectiveness was verified experimentally using infrared thermography during a low - speed wind tunnel test . Although the work was performed on one specific configuration , the process was based on fundamental flow physics and could be applicable to other configurations .
The learning objectives of this viewgraph presentation are to : ( 1 ) Understand the biomedical effects of spaceflight and their associated health risks . ( 2 ) Understand how the " Factor of Risk " for fracture can be calculated in the adult skeleton for space travel . and ( 3 ) Understand how various countermeasures [ CMs ] influence the Factor of Risk .
Combining multiple engineering workstations into a network - based heterogeneous parallel computer allows application of aerodynamic optimization with advance computational fluid dynamics codes , which is computationally expensive in mainframe supercomputer . This paper introduces a nonlinear quasi - Newton optimizer designed for this network - based heterogeneous parallel computer on a software called Parallel Virtual Machine . This paper will introduce the methodology behind coupling a Parabolized Navier - Stokes flow solver to the nonlinear optimizer . This parallel optimization package has been applied to reduce the wave drag of a body of revolution and a wing / body configuration with results of 5 % to 6 % drag reduction .
The properties of accretion disk corona in a parameter regime suitable for Galactic black hole candidates are considered and the results of an analysis of these properties using a self - consistent Monte Carlo code are presented . Examples of the coronal temperature structure , the shape and angular dependency of the spectrum and the maximum temperature allowed for each optical depth of the corona are presented . It is shown that the observed spectrum of the Galactic black hole candidate Cygnus X-1 can not be explained by accreting disk corona models with a slab geometry , where the accretion disk is sandwiched by the comptonizing medium .
For over 30 years , the NASA Airborne Science Program has provided airborne platforms for space bound instrument development , for calibrating new and existing satellite systems , and for making in situ and remote sensing measurements that can only be made from aircraft . New technologies have expanded the capabilities of aircraft that are operated for these missions . Over the last several years a new technology investment portfolio has yielded improvements that produce better measurements for the airborne science communities . These new technologies include unmanned vehicles , precision trajectory control and advanced telecommunications capabilities . We will discuss some of the benefits of these new technologies and systems which aim to provide users with more precision , lower operational costs , quicker access to data , and better management of multi aircraft and multi sensor campaigns .