Science.gov

Sample records for augmented space approach

  1. Magnetism on rough surfaces of Fe, Co and Ni : An augmented space approach

    NASA Astrophysics Data System (ADS)

    Parida, Priyadarshini; Ganguli, Biplab; Mookerjee, Abhijit

    2015-10-01

    The augmented space formalism coupled with the recursion method and a tight-binding linear Muffin-tin orbitals basis has been applied to study the effects of roughness on the properties of (001) surfaces of body-centered cubic Fe and face-centered cubic Co and Ni. The formalism is also proposed for the study of smooth surface. Comparisons have been made for three types of surfaces: a smooth surface, the surface with a rough top layer, and a more realistic model with several rough top layers converging into a crystalline bulk. Comparisons have been made between the magnetic moments, work function and electronic density of states in the three models described above.

  2. Navigation for space shuttle approach and landing using an inertial navigation system augmented by data from a precision ranging system or a microwave scan beam landing guidance system

    NASA Technical Reports Server (NTRS)

    Mcgee, L. A.; Smith, G. L.; Hegarty, D. M.; Merrick, R. B.; Carson, T. M.; Schmidt, S. F.

    1970-01-01

    A preliminary study has been made of the navigation performance which might be achieved for the high cross-range space shuttle orbiter during final approach and landing by using an optimally augmented inertial navigation system. Computed navigation accuracies are presented for an on-board inertial navigation system augmented (by means of an optimal filter algorithm) with data from two different ground navigation aids; a precision ranging system and a microwave scanning beam landing guidance system. These results show that augmentation with either type of ground navigation aid is capable of providing a navigation performance at touchdown which should be adequate for the space shuttle. In addition, adequate navigation performance for space shuttle landing is obtainable from the precision ranging system even with a complete dropout of precision range measurements as much as 100 seconds before touchdown.

  3. Electronic and magnetic properties at rough and sharp transition metal-metal interfaces: An augmented space approach

    NASA Astrophysics Data System (ADS)

    Parida, Priyadarshini; Ganguli, Biplab; Mookerjee, Abhijit

    2015-05-01

    The augmented space formalism (ASF) coupled with recursion method and a tight binding linear muffin-tin orbital basis has been applied to study the layerwise electronic and magnetic properties of (0 0 1) interfaces of body-centered cubic Fe/Ag and face centered cubic Co/Ag, Fe/Cu and Co/Cu. Three different thickness of interfaces are considered: mono, two and three layers of transition metals with metal substrates. Layers of an interface are considered disordered alloys with different degree of disorderedness due to interdiffusion of transition metal layer atoms and substrate atoms during growth process. We show that ASF is applicable to sharp interface also. Result of three layers of transition metal rough interface agrees well with available experimental result.

  4. Space-based augmentation for global navigation satellite systems.

    PubMed

    Grewal, Mohinder S

    2012-03-01

    This paper describes space-based augmentation for global navigation satellite systems (GNSS). Space-based augmentations increase the accuracy and integrity of the GNSS, thereby enhancing users' safety. The corrections for ephemeris, ionospheric delay, and clocks are calculated from reference station measurements of GNSS data in wide-area master stations and broadcast via geostationary earth orbit (GEO) satellites. This paper discusses the clock models, satellite orbit determination, ionospheric delay estimation, multipath mitigation, and GEO uplink subsystem (GUS) as used in the Wide Area Augmentation System developed by the FAA.

  5. Removal of the intestinal mucosa: photochemical approach in bladder augmentation

    NASA Astrophysics Data System (ADS)

    Haselhuhn, Gregory D.; Kropp, Kenneth A.; Keck, Rick W.; Selman, Steven H.

    1995-03-01

    Experiments were undertaken to determine whether 5-aminoleuvinic acid in combination with light could be used as an adjunct to intestinal bladder augmentation with the aim of removing intestinal mucosa with subsequent re-epithelialization of the treated segment with urothelium. Histopathologic studies of so-treated intestinal segments used in bladder augmentation demonstrate the feasibility of this approach.

  6. Melatonin enhances vertical bone augmentation in rat calvaria secluded spaces

    PubMed Central

    Shino, Hiromichi; Hasuike, Akira; Arai, Yoshinori; Honda, Masaki; Isokawa, Keitaro

    2016-01-01

    Background Melatonin has many roles, including bone remodeling and osseointegration of dental implants. The topical application of melatonin facilitated bone regeneration in bone defects. We evaluated the effects of topical application of melatonin on vertical bone augmentation in rat calvaria secluded spaces. Material and Methods In total, 12 male Fischer rats were used and two plastic caps were fixed in the calvarium. One plastic cap was filled with melatonin powder and the other was left empty. Results Newly generated bone at bone defects and within the plastic caps was evaluated using micro-CT and histological sections. New bone regeneration within the plastic cap was increased significantly in the melatonin versus the control group. Conclusions Melatonin promoted vertical bone regeneration in rat calvaria in the secluded space within the plastic cap. Key words:Melatonin, bone regeneration, bone defects, secluded space, rat calvarium. PMID:26595835

  7. Space Launch System Implementation of Adaptive Augmenting Control

    NASA Technical Reports Server (NTRS)

    Wall, John H.; Orr, Jeb S.; VanZwieten, Tannen S.

    2014-01-01

    Given the complex structural dynamics, challenging ascent performance requirements, and rigorous flight certification constraints owing to its manned capability, the NASA Space Launch System (SLS) launch vehicle requires a proven thrust vector control algorithm design with highly optimized parameters to provide stable and high-performance flight. On its development path to Preliminary Design Review (PDR), the SLS flight control system has been challenged by significant vehicle flexibility, aerodynamics, and sloshing propellant. While the design has been able to meet all robust stability criteria, it has done so with little excess margin. Through significant development work, an Adaptive Augmenting Control (AAC) algorithm has been shown to extend the envelope of failures and flight anomalies the SLS control system can accommodate while maintaining a direct link to flight control stability criteria such as classical gain and phase margin. In this paper, the work performed to mature the AAC algorithm as a baseline component of the SLS flight control system is presented. The progress to date has brought the algorithm design to the PDR level of maturity. The algorithm has been extended to augment the full SLS digital 3-axis autopilot, including existing load-relief elements, and the necessary steps for integration with the production flight software prototype have been implemented. Several updates which have been made to the adaptive algorithm to increase its performance, decrease its sensitivity to expected external commands, and safeguard against limitations in the digital implementation are discussed with illustrating results. Monte Carlo simulations and selected stressing case results are also shown to demonstrate the algorithm's ability to increase the robustness of the integrated SLS flight control system.

  8. Space Launch System Implementation of Adaptive Augmenting Control

    NASA Technical Reports Server (NTRS)

    VanZwieten, Tannen S.; Wall, John H.; Orr, Jeb S.

    2014-01-01

    Given the complex structural dynamics, challenging ascent performance requirements, and rigorous flight certification constraints owing to its manned capability, the NASA Space Launch System (SLS) launch vehicle requires a proven thrust vector control algorithm design with highly optimized parameters to robustly demonstrate stable and high performance flight. On its development path to preliminary design review (PDR), the stability of the SLS flight control system has been challenged by significant vehicle flexibility, aerodynamics, and sloshing propellant dynamics. While the design has been able to meet all robust stability criteria, it has done so with little excess margin. Through significant development work, an adaptive augmenting control (AAC) algorithm previously presented by Orr and VanZwieten, has been shown to extend the envelope of failures and flight anomalies for which the SLS control system can accommodate while maintaining a direct link to flight control stability criteria (e.g. gain & phase margin). In this paper, the work performed to mature the AAC algorithm as a baseline component of the SLS flight control system is presented. The progress to date has brought the algorithm design to the PDR level of maturity. The algorithm has been extended to augment the SLS digital 3-axis autopilot, including existing load-relief elements, and necessary steps for integration with the production flight software prototype have been implemented. Several updates to the adaptive algorithm to increase its performance, decrease its sensitivity to expected external commands, and safeguard against limitations in the digital implementation are discussed with illustrating results. Monte Carlo simulations and selected stressing case results are shown to demonstrate the algorithm's ability to increase the robustness of the integrated SLS flight control system.

  9. Utilization of the Space Vision System as an Augmented Reality System For Mission Operations

    NASA Technical Reports Server (NTRS)

    Maida, James C.; Bowen, Charles

    2003-01-01

    Augmented reality is a technique whereby computer generated images are superimposed on live images for visual enhancement. Augmented reality can also be characterized as dynamic overlays when computer generated images are registered with moving objects in a live image. This technique has been successfully implemented, with low to medium levels of registration precision, in an NRA funded project entitled, "Improving Human Task Performance with Luminance Images and Dynamic Overlays". Future research is already being planned to also utilize a laboratory-based system where more extensive subject testing can be performed. However successful this might be, the problem will still be whether such a technology can be used with flight hardware. To answer this question, the Canadian Space Vision System (SVS) will be tested as an augmented reality system capable of improving human performance where the operation requires indirect viewing. This system has already been certified for flight and is currently flown on each shuttle mission for station assembly. Successful development and utilization of this system in a ground-based experiment will expand its utilization for on-orbit mission operations. Current research and development regarding the use of augmented reality technology is being simulated using ground-based equipment. This is an appropriate approach for development of symbology (graphics and annotation) optimal for human performance and for development of optimal image registration techniques. It is anticipated that this technology will become more pervasive as it matures. Because we know what and where almost everything is on ISS, this reduces the registration problem and improves the computer model of that reality, making augmented reality an attractive tool, provided we know how to use it. This is the basis for current research in this area. However, there is a missing element to this process. It is the link from this research to the current ISS video system and to

  10. Hands in space: gesture interaction with augmented-reality interfaces.

    PubMed

    Billinghurst, Mark; Piumsomboon, Tham; Huidong Bai

    2014-01-01

    Researchers at the Human Interface Technology Laboratory New Zealand (HIT Lab NZ) are investigating free-hand gestures for natural interaction with augmented-reality interfaces. They've applied the results to systems for desktop computers and mobile devices.

  11. An activity systemic approach to augmentative and alternative communication.

    PubMed

    Hedvall, Per-Olof; Rydeman, Bitte

    2010-12-01

    The purpose of this paper is to discuss and highlight how Cultural-Historical Activity Theory (CHAT) can contribute to the understanding of the different factors at play when a person is using augmentative and alternative communication (AAC). It is based on data from a 3-year project concerning activity-based vocabulary design of voice output communication aids (VOCAs). Four persons who used AAC and their assistants were interviewed about shopping activities and their views about a vocabulary that included pre-stored phrases. A CHAT model, the Activity Diamond, was applied in an analysis of the data. The result was a multiplicity of human, artifactual, and natural factors, in which six themes were identified: Attitude/Preference, Expectation/Trust, Goal/Power, Place/Space, Time/Learning, and Usability/Accessibility. The themes are exemplified and discussed in relation to AAC.

  12. Extinction of drug seeking: Neural circuits and approaches to augmentation.

    PubMed

    McNally, Gavan P

    2014-01-01

    Extinction training can reduce drug seeking behavior. This article reviews the neural circuits that contribute to extinction and approaches to enhancing the efficacy of extinction. Extinction of drug seeking depends on cortical-striatal-hypothalamic and cortical-hypothalamic-thalamic pathways. These pathways interface, in the hypothalamus and thalamus respectively, with the neural circuits controlling reinstatement of drug seeking. The actions of these pathways at lateral hypothalamic orexin neurons, and of perifornical/dorsomedial hypothalamic derived opioid peptides at kappa opioid receptors in the paraventricular thalamus, are important for inhibiting drug seeking. Despite effectively reducing or inhibiting drug seeking in the short term, extinguished drug seeking is prone to relapse. Three different strategies to augment extinction learning or retrieval are reviewed: pharmacological augmentation, retrieval - extinction training, and provision of extinction memory retrieval cues. These strategies have been used in animal models and with human drug users to enhance extinction or cue exposure treatments. They hold promise as novel strategies to promote abstinence from drug seeking. This article is part of a Special Issue entitled 'NIDA 40th Anniversary Issue'.

  13. Augmenting the Funding Sources for Space Science and the ASTRO-1 Space Telescope

    NASA Astrophysics Data System (ADS)

    Morse, Jon

    2015-08-01

    The BoldlyGo Institute was formed in 2013 to augment the planned space science portfolio through philanthropically funded robotic space missions, similar to how some U.S. medical institutes and ground-based telescopes are funded. I introduce BoldlyGo's two current projects: the SCIM mission to Mars and the ASTRO-1 space telescope. In particular, ASTRO-1 is a 1.8-meter off-axis (unobscured) ultraviolet-visible space observatory to be located in a Lagrange point or heliocentric orbit with a wide-field panchromatic camera, medium- and high-resolution spectrograph, and high-contrast imaging coronagraph and/or an accompanying starshade/occulter. It is intended for the post-Hubble Space Telescope era in the 2020s, enabling unique measurements of a broad range of celestial targets, while providing vital complementary capabilities to other ground- and space-based facilities such as the JWST, ALMA, WFIRST-AFTA, LSST, TESS, Euclid, and PLATO. The ASTRO-1 architecture simultaneously wields great scientific power while being technically viable and affordable. A wide variety of scientific programs can be accomplished, addressing topics across space astronomy, astrophysics, fundamental physics, and solar system science, as well as being technologically informative to future large-aperture programs. ASTRO-1 is intended to be a new-generation research facility serving a broad national and international community, as well as a vessel for impactful public engagement. Traditional institutional partnerships and consortia, such as are common with private ground-based observatories, may play a role in the support and governance of ASTRO-1; we are currently engaging interested international organizations. In addition to our planned open guest observer program and accessible data archive, we intend to provide a mechanism whereby individual scientists can buy in to a fraction of the gauranteed observing time. Our next step in ASTRO-1 development is to form the ASTRO-1 Requirements Team

  14. Space augmentation of military high-level waste disposal

    NASA Technical Reports Server (NTRS)

    English, T.; Lees, L.; Divita, E.

    1979-01-01

    Space disposal of selected components of military high-level waste (HLW) is considered. This disposal option offers the promise of eliminating the long-lived radionuclides in military HLW from the earth. A space mission which meets the dual requirements of long-term orbital stability and a maximum of one space shuttle launch per week over a period of 20-40 years, is a heliocentric orbit about halfway between the orbits of earth and Venus. Space disposal of high-level radioactive waste is characterized by long-term predictability and short-term uncertainties which must be reduced to acceptably low levels. For example, failure of either the Orbit Transfer Vehicle after leaving low earth orbit, or the storable propellant stage failure at perihelion would leave the nuclear waste package in an unplanned and potentially unstable orbit. Since potential earth reencounter and subsequent burn-up in the earth's atmosphere is unacceptable, a deep space rendezvous, docking, and retrieval capability must be developed.

  15. The Demand for Medical Education: An Augmented Human Capital Approach.

    ERIC Educational Resources Information Center

    Quinn, Robert; Price, Jamie

    1998-01-01

    Examines investment and consumption features of the demand for medical education, using medical application data over the 1948 to 1994 time period. Examines a variant of a pure human capital (investment) model and a model augmented by consumption and demographic variables, using medical education data. A static human capital model best forecasts…

  16. A Rational Approach to Sinus Augmentation: The Low Window Sinus Lift

    PubMed Central

    Zaniol, Alex

    2017-01-01

    Sinus augmentation is a well-known approach to treating alveolar bone ridge atrophy in the posterior maxilla. The preparation of the lateral window is crucial. Its size, design, and position in the vestibular sinus wall may affect the intra- and postsurgical complication rates and affect the intrasurgical activity of both surgeons and assistants. The present paper describes a rational technique that also exploits the guided surgery approach for design and preparation of a lateral window for sinus augmentation, the Low Window Sinus Lift. To illustrate the use of this approach, a case is presented in which the 50-year-old patient had the left maxillary first molar extracted, followed two months later by sinus augmentation and placement of three implants. One year after delivery of the definitive prosthesis, all three implants were successful, and the prosthesis was fully functional. Controlled studies should be undertaken to assess whether this technique provides significant advantages compared to other sinus augmentation approaches. PMID:28337349

  17. Plant nanobionics approach to augment photosynthesis and biochemical sensing

    NASA Astrophysics Data System (ADS)

    Giraldo, Juan Pablo; Landry, Markita P.; Faltermeier, Sean M.; McNicholas, Thomas P.; Iverson, Nicole M.; Boghossian, Ardemis A.; Reuel, Nigel F.; Hilmer, Andrew J.; Sen, Fatih; Brew, Jacqueline A.; Strano, Michael S.

    2014-04-01

    The interface between plant organelles and non-biological nanostructures has the potential to impart organelles with new and enhanced functions. Here, we show that single-walled carbon nanotubes (SWNTs) passively transport and irreversibly localize within the lipid envelope of extracted plant chloroplasts, promote over three times higher photosynthetic activity than that of controls, and enhance maximum electron transport rates. The SWNT-chloroplast assemblies also enable higher rates of leaf electron transport in vivo through a mechanism consistent with augmented photoabsorption. Concentrations of reactive oxygen species inside extracted chloroplasts are significantly suppressed by delivering poly(acrylic acid)-nanoceria or SWNT-nanoceria complexes. Moreover, we show that SWNTs enable near-infrared fluorescence monitoring of nitric oxide both ex vivo and in vivo, thus demonstrating that a plant can be augmented to function as a photonic chemical sensor. Nanobionics engineering of plant function may contribute to the development of biomimetic materials for light-harvesting and biochemical detection with regenerative properties and enhanced efficiency.

  18. On augmented superfield approach to vector Schwinger model

    NASA Astrophysics Data System (ADS)

    Gupta, Saurabh; Kumar, R.

    2016-11-01

    We exploit the techniques of Bonora-Tonin superfield formalism to derive the off-shell nilpotent and absolutely anticommuting (anti-)BRST as well as (anti-)co-BRST symmetry transformations for the (1+1)-dimensional (2D) bosonized vector Schwinger model. In the derivation of above symmetries, we invoke the (dual)-horizontality conditions as well as gauge and (anti-)co-BRST invariant restrictions on the superfields that are defined onto the (2,2)-dimensional supermanifold. We provide geometrical interpretation of the above nilpotent symmetries (and their corresponding charges). We also express the nilpotency and absolute anticommutativity of the (anti-)BRST and (anti-)co-BRST charges within the framework of augmented superfield formalism.

  19. Nilpotent Symmetries in Jackiw-Pi Model: Augmented Superfield Approach

    NASA Astrophysics Data System (ADS)

    Gupta, Saurabh; Kumar, R.

    2016-02-01

    We derive the complete set of off-shell nilpotent (s2_{(a)b} = 0) and absolutely anticommuting ( s b s a b + s a b s b =0) Becchi-Rouet-Stora-Tyutin (BRST) ( s b ) as well as anti-BRST symmetry transformations ( s a b ) corresponding to the combined Yang-Mills and non-Yang-Mills symmetries of the (2+1)-dimensional Jackiw-Pi model within the framework of augmented superfield formalism. The absolute anticommutativity of the (anti-)BRST symmetries is ensured by the existence of two sets of Curci-Ferrari (CF) type of conditions which emerge naturally in this formalism. The presence of CF conditions enables us to derive the coupled but equivalent Lagrangian densities. We also capture the (anti-)BRST invariance of the coupled Lagrangian densities in the superfield formalism. The derivation of the (anti-)BRST transformations of the auxiliary field ρ is one of the key findings which can neither be generated by the nilpotent (anti-)BRST charges nor by the requirements of the nilpotency and/or absolute anticommutativity of the (anti-)BRST transformations. Finally, we provide a bird's-eye view on the role of auxiliary field for various massive models and point out few striking similarities and some glaring differences among them.

  20. Augmenting LTP-Like Plasticity in Human Motor Cortex by Spaced Paired Associative Stimulation.

    PubMed

    Müller-Dahlhaus, Florian; Lücke, Caroline; Lu, Ming-Kuei; Arai, Noritoshi; Fuhl, Anna; Herrmann, Eva; Ziemann, Ulf

    2015-01-01

    Paired associative stimulation (PASLTP) of the human primary motor cortex (M1) can induce LTP-like plasticity by increasing corticospinal excitability beyond the stimulation period. Previous studies showed that two consecutive PASLTP protocols interact by homeostatic metaplasticity, but animal experiments provided evidence that LTP can be augmented by repeated stimulation protocols spaced by ~30 min. Here we tested in twelve healthy selected PASLTP responders the possibility that LTP-like plasticity can be augmented in the human M1 by systematically varying the interval between two consecutive PASLTP protocols. The first PASLTP protocol (PAS1) induced strong LTP-like plasticity lasting for 30-60 min. The effect of a second identical PASLTP protocol (PAS2) critically depended on the time between PAS1 and PAS2. At 10 min, PAS2 prolonged the PAS1-induced LTP-like plasticity. At 30 min, PAS2 augmented the LTP-like plasticity induced by PAS1, by increasing both magnitude and duration. At 60 min and 180 min, PAS2 had no effect on corticospinal excitability. The cumulative LTP-like plasticity after PAS1 and PAS2 at 30 min exceeded significantly the effect of PAS1 alone, and the cumulative PAS1 and PAS2 effects at 60 min and 180 min. In summary, consecutive PASLTP protocols interact in human M1 in a time-dependent manner. If spaced by 30 min, two consecutive PASLTP sessions can augment LTP-like plasticity in human M1. Findings may inspire further research on optimized therapeutic applications of non-invasive brain stimulation in neurological and psychiatric diseases.

  1. Study of phase stability of MnCr using the augmented space recursion based orbital peeling technique

    NASA Astrophysics Data System (ADS)

    Banerjee, Rudra; Mookerjee, Abhijit

    2009-07-01

    In an earlier communication we have developed a recursion based approach to the study of phase stability and transition of binary alloys [K. Tarafder, M. Rahaman, D. Paudyal, B. Sanyal, O. Eriksson, A. Mookerjee, Physica B 403 (2000) 4111]. We had combined the recursion method introduced by Haydock et al. [J. Phys. C Solid State Phys. 5 (1972) 2485] and the our augmented space approach [A. Mookerjee, J. Phys. C Solid State Phys. 6 (1973) 1340] with the orbital peeling technique proposed by Burke [Surf. Sci. 58 (1976) 349] to determine the small energy differences involved in the discussion of phase stability. We extend that methodology for the study of MnCr alloys.

  2. An approach to space power

    NASA Technical Reports Server (NTRS)

    Miley, G. H.; Nadler, J. H.; Hochberg, T.; Barnouin, O.; Gu, Y. B.

    1990-01-01

    Fusion offers the potential for a very high specific power, providing a large specific impulse that can be traded-off with thrust for mission optimization. Thus fusion is a leading candidate for missions beyond the moon. A new approach is discussed for space fusion power, namely Inertial Electrostatic Confinement (IEC). This method offers a high power density in a relatively small, simple device. It appears capable of burning aneutronic fuels which are most desirable for space applications and is well suited for direct conversion. An experimental device to test the concept is described.

  3. Space Shuttle Main Engine fuel preburner augmented spark igniter shutdown detonations

    NASA Technical Reports Server (NTRS)

    Dexter, C. E.; Mccay, T. D.

    1986-01-01

    Detonations were experienced in the Space Shuttle Main Engine fuel preburner (FPB) augmented spark igniter (ASI) during engine cutoff. Several of these resulted in over pressures sufficient to damage the FPB ASI oxidizer system. The detonations initiated in the FPB ASI oxidizer line when residual oxidizer (oxygen) in the line mixed with backflowing fuel (hydrogen) and detonated. This paper reviews the damage history to the FPB ASI oxidizer system, an engineering assessment of the problem cause, a verification of the mechanisms, the hazards associated with the detonations, and the solution implemented.

  4. Mechanism of augmented exercise hyperpnea in chronic heart failure and dead space loading

    PubMed Central

    Poon, Chi-Sang; Tin, Chung

    2013-01-01

    Patients with chronic heart failure (CHF) suffer increased alveolar VD/VT (dead-space-to-tidal-volume ratio), yet they demonstrate augmented pulmonary ventilation such that arterial PCO2 (PaCO2) remains remarkably normal from rest to moderate exercise. This paradoxical effect suggests that the control law governing exercise hyperpnea is not merely determined by metabolic CO2 production (V̇CO2) per se but is responsive to an apparent (real-feel) metabolic CO2 load (V˙CO2o) that also incorporates the adverse effect of physiological VD/VT on pulmonary CO2 elimination. By contrast, healthy individuals subjected to dead space loading also experience augmented ventilation at rest and during exercise as with increased alveolar VD/VT in CHF, but the resultant response is hypercapnic instead of eucapnic, as with CO2 breathing. The ventilatory effects of dead space loading are therefore similar to those of increased alveolar VD/VT and CO2 breathing combined. These observations are consistent with the hypothesis that the increased series VD/VT in dead space loading adds to V˙CO2o as with increased alveolar VD/VT in CHF, but this is through rebreathing of CO2 in dead space gas thus creating a virtual (illusory) airway CO2 load within each inspiration, as opposed to a true airway CO2 load during CO2 breathing that clogs the mechanism for CO2 elimination through pulmonary ventilation. Thus, the chemosensing mechanism at the respiratory controller may be responsive to putative drive signals mediated by within-breath PaCO2 oscillations independent of breath-to-breath fluctuations of the mean PaCO2 level. Skeletal muscle afferents feedback, while important for early-phase exercise cardioventilatory dynamics, appears inconsequential for late-phase exercise hyperpnea. PMID:23274121

  5. Maintaining space in localized ridge augmentation using guided bone regeneration with tenting screw technology.

    PubMed

    Chasioti, Evdokia; Chiang, Tat Fai; Drew, Howard J

    2013-01-01

    Prosthetic guided implant surgery requires adequate ridge dimensions for proper implant placement. Various surgical procedures can be used to augment deficient alveolar ridges. Studies have examined new bone formation on deficient ridges, utilizing numerous surgical techniques and biomaterials. The goal is to develop time efficient techniques, which have low morbidity. A crucial factor for successful bone grafting procedures is space maintenance. The article discusses space maintenance tenting screws, used in conjunction with bone allografts and resorbable barrier membranes, to ensure uneventful guided bone regeneration (GBR) enabling optimal implant positioning. The technique utilized has been described in the literature to treat severely resorbed alveolar ridges and additionally can be considered in restoring the vertical and horizontal component of deficient extraction sites. Three cases are presented to illustrate the utilization and effectiveness of tenting screw technology in the treatment of atrophic extraction sockets and for deficient ridges.

  6. A new approach for vibration control in large space structures

    NASA Technical Reports Server (NTRS)

    Kumar, K.; Cochran, J. E., Jr.

    1987-01-01

    An approach for augmenting vibration damping characteristics in space structures with large panels is presented. It is based on generation of bending moments rather than forces. The moments are generated using bimetallic strips, suitably mounted at selected stations on both sides of the large panels, under the influence of differential solar heating, giving rise to thermal gradients and stresses. The collocated angular velocity sensors are utilized in conjunction with mini-servos to regulate the control moments by flipping the bimetallic strips. A simple computation of the rate of dissipation of vibrational energy is undertaken to assess the effectiveness of the proposed approach.

  7. Cortical lamina technique: A therapeutic approach for lateral ridge augmentation using guided bone regeneration

    PubMed Central

    Thomas, Raison; Baron, Tarun-Kumar; Shah, Rucha; Mehta, Dhoom-Singh

    2017-01-01

    Background The present study aimed at evaluating the efficacy of a novel technique, the bone lamina technique, in horizontal ridge augmentation clinically & radiographically using a combination of allogenic cortical shell, particulate xenograft and resorbable collagen membrane. Material and Methods Localized horizontal ridge defects, in ten patients (6 male, 4 female), with bucco-palatal ridge width less than 5 mm were included in this study. Localised ridge augmentation was performed using bone lamina technique with mineralised allogenic shell of 1 mm thickness trimmed to the appropriate size using stereo-lithographic models and fixed to the recipient site with stainless steel micro-screws of 1 mm diameter. The space between the shell & host bone was filled with particulate xenograft followed by placement of collagen membrane and primary closure of the site. Clinical parameters including ridge width before & after flap reflection & radiographic (CBCT) ridge width measurements were recorded pre-operatively,and six months after the augmentation procedure. Results obtained were analysed statistically. Results The mean clinical ridge width before flap reflection (BFR), after flap reflection (AFR) & radiographically was 3.7 ± 0.74 mm, 2 ± 0.70 mm & 1.77 ± 0.71 mm respectively at baseline which increased to 6.8 ± 0.95 mm, 5.15 ± 0.98 mm & 4.90 ± 0.90 mm with a mean gain in ridge width of 3.1 ± 0.63 mm (p< 0.005), 3.15 ± 0.63 mm (p<0.005) & 3.13 ± 0.70 mm (p< 0.005) respectively. Conclusions The present study demonstrates that bone lamina technique can be effective means of horizontal ridge augmentation and the use of mineralized allograft in combination with xenograft and collagen membrane leads to good amount of bone regeneration for subsequent implant placement. Key words:Dental implant, guided bone regeneration, horizontal ridge defect, ridge augmentation. PMID:28149458

  8. A revolutionary lunar space transportation system architecture using extraterrestrial LOX-augmented NTR propulsion

    NASA Astrophysics Data System (ADS)

    Borowski, Stanley K.; Corban, Robert R.; Culver, Donald W.; Bulman, Melvin J.; McIlwain, Mel C.

    1994-08-01

    The concept of a liquid oxygen (LOX)-augmented nuclear thermal rocket (NTR) engine is introduced, and its potential for revolutionizing lunar space transportation system (LTS) performance using extraterrestrial 'lunar-derived' liquid oxygen (LUNOX) is outlined. The LOX-augmented NTR (LANTR) represents the marriage of conventional liquid hydrogen (LH2)-cooled NTR and airbreathing engine technologies. The large divergent section of the NTR nozzle functions as an 'afterburner' into which oxygen is injected and supersonically combusted with nuclear preheated hydrogen emerging from the NTR's choked sonic throat: 'scramjet propulsion in reverse.' By varying the oxygen-to-fuel mixture ratio (MR), the LANTR concept can provide variable thrust and specific impulse (Isp) capability with a LH2-cooled NTR operating at relatively constant power output. For example, at a MR = 3, the thrust per engine can be increased by a factor of 2.75 while the Isp decreases by only 30 percent. With this thrust augmentation option, smaller, 'easier to develop' NTR's become more acceptable from a mission performance standpoint (e.g., earth escape gravity losses are reduced and perigee propulsion requirements are eliminated). Hydrogen mass and volume is also reduced resulting in smaller space vehicles. An evolutionary NTR-based lunar architecture requiring only Shuttle C and/or 'in-line' shuttle-derived launch vehicles (SDV's) would operate initially in an 'expandable mode' with NTR lunar transfer vehicles (LTV's) delivering 80 percent more payload on piloted missions than their LOX/LH2 chemical propulsion counterparts. With the establishment of LUNOX production facilities on the lunar surface and 'fuel/oxidizer' depot in low lunar orbit (LLO), monopropellant NTR's would be outfitted with an oxygen propellant module, feed system, and afterburner nozzle for 'bipropellant' operation. The LANTR cislunar LTV now transitions to a reusable mode with smaller vehicle and payload doubling benefits on

  9. A Revolutionary Lunar Space Transportation System Architecture Using Extraterrestrial Lox-augmented NTR Propulsion

    NASA Technical Reports Server (NTRS)

    Borowski, Stanley K.; Corban, Robert R.; Culver, Donald W.; Bulman, Melvin J.; Mcilwain, Mel C.

    1994-01-01

    The concept of a liquid oxygen (LOX)-augmented nuclear thermal rocket (NTR) engine is introduced, and its potential for revolutionizing lunar space transportation system (LTS) performance using extraterrestrial 'lunar-derived' liquid oxygen (LUNOX) is outlined. The LOX-augmented NTR (LANTR) represents the marriage of conventional liquid hydrogen (LH2)-cooled NTR and airbreathing engine technologies. The large divergent section of the NTR nozzle functions as an 'afterburner' into which oxygen is injected and supersonically combusted with nuclear preheated hydrogen emerging from the NTR's choked sonic throat: 'scramjet propulsion in reverse.' By varying the oxygen-to-fuel mixture ratio (MR), the LANTR concept can provide variable thrust and specific impulse (Isp) capability with a LH2-cooled NTR operating at relatively constant power output. For example, at a MR = 3, the thrust per engine can be increased by a factor of 2.75 while the Isp decreases by only 30 percent. With this thrust augmentation option, smaller, 'easier to develop' NTR's become more acceptable from a mission performance standpoint (e.g., earth escape gravity losses are reduced and perigee propulsion requirements are eliminated). Hydrogen mass and volume is also reduced resulting in smaller space vehicles. An evolutionary NTR-based lunar architecture requiring only Shuttle C and/or 'in-line' shuttle-derived launch vehicles (SDV's) would operate initially in an 'expandable mode' with NTR lunar transfer vehicles (LTV's) delivering 80 percent more payload on piloted missions than their LOX/LH2 chemical propulsion counterparts. With the establishment of LUNOX production facilities on the lunar surface and 'fuel/oxidizer' depot in low lunar orbit (LLO), monopropellant NTR's would be outfitted with an oxygen propellant module, feed system, and afterburner nozzle for 'bipropellant' operation. The LANTR cislunar LTV now transitions to a reusable mode with smaller vehicle and payload doubling benefits on

  10. The Final Approach Spacing Tool

    NASA Technical Reports Server (NTRS)

    Davis, Thomas J.; Bergh, Christopher; Krzeczowski, Ken J.; Schlickenmaier, H. W. (Technical Monitor)

    1994-01-01

    A system for assisting terminal area air traffic controllers in the management and control of arrival traffic, referred to as the Final Approach Spacing Tool (FAST), is being developed at NASA Ames Research Center. In a cooperative program, NASA and FAA have efforts underway to install and evaluate the system at the Dallas/Fort Worth Terminal Radar Approach Control facility. This paper will review the software architecture, the algorithms components, and the human-machine interface. The system is based on continuous updates of a detailed trajectory analyses of all arrival aircraft. FAST interprets the results of these trajectory analyses to build an efficient and procedurally acceptable plan for the arrival traffic that consists of a sequence, schedule, and runway assignment. The system utilizes a heuristically-based conflict resolution algorithm to build a solution trajectory that satisfies the plan, It extracts a series of speed and heading advisories from the solution trajectory to assist the controller in efficiently managing and controlling the arrival traffic down to the runway. The advisories are displayed in a graphical format to the controller. In addition to the radar tracking data, the system also relies on a series of data bases. These data bases contain aircraft performance models, airline preferred operational procedures, airspace structure, air traffic procedural models, and a three dimensional wind model. Field evaluation of FAST is expected to begin in 1994.

  11. A remotely augmented vehicle approach to flight testing RPV control systems

    NASA Technical Reports Server (NTRS)

    Deets, D. A.; Edwards, J. W.

    1974-01-01

    A remotely augmented vehicle concept for flight testing advanced control systems was developed as an outgrowth of a remotely piloted research vehicle (RPV) program in which control laws are implemented through telemetry uplink and downlink data channels using a general purpose ground based digital computer which provides the control law computations. Some advantages of this approach are that the cost of one control system facility is spread over a number of RPV programs, and control laws can be changed quickly as required, without changing the flight hardware. The remotely augmented vehicle concept is described, and flight test results from a subscale F-15 program are discussed. Suggestions of how the concept could lead to more effective testing of RPV control system concepts, and how it is applicable to a military RPV reconnaissance mission are given.

  12. Augmentation therapy for alpha-1 antitrypsin deficiency: towards a personalised approach

    PubMed Central

    2013-01-01

    Background Intravenous augmentation therapy is the only specific treatment available for emphysema associated with alpha-1 antitrypsin deficiency. Despite large observational studies and limited interventional studies there remains controversy about the efficacy of this treatment due to the impracticality of conducting adequately powered studies to evaluate the rate of decline in lung function, due to the low prevalence and the slow progression of the disease. However, measurement of lung density by computed tomography is a more specific and sensitive marker of the evolution of emphysema and two small placebo-controlled clinical trials have provided evidence supporting a reduction in the rate of decline in lung density with augmentation therapy. The problem Where augmentation therapy has become available there has been little consideration of a structured approach to therapy which is often introduced on the basis of functional impairment at diagnosis. Data from registries have shown a great variability in the evolution of lung disease according to patient acquisition and the presence of recognised risk factors. Avoidance of risk factors may, in many cases, stabilise the disease. Since augmentation therapy itself will at best preserve the presenting level of lung damage yet require intravenous administration for life with associated costs, identification of patients at risk of continued rapid or long term progression is essential to select those for whom this treatment can be most appropriate and hence generally more cost-effective. This represents a major reconsideration of the current practice in order to develop a consistent approach to management world wide. Purpose of this review The current review assesses the evidence for efficacy of augmentation therapy and considers how the combination of age, physiological impairment, exacerbation history and rate of decline in spirometry and other measures of emphysema may be used to improve therapeutic decision making

  13. Sensory augmentation: integration of an auditory compass signal into human perception of space

    PubMed Central

    Schumann, Frank; O’Regan, J. Kevin

    2017-01-01

    Bio-mimetic approaches to restoring sensory function show great promise in that they rapidly produce perceptual experience, but have the disadvantage of being invasive. In contrast, sensory substitution approaches are non-invasive, but may lead to cognitive rather than perceptual experience. Here we introduce a new non-invasive approach that leads to fast and truly perceptual experience like bio-mimetic techniques. Instead of building on existing circuits at the neural level as done in bio-mimetics, we piggy-back on sensorimotor contingencies at the stimulus level. We convey head orientation to geomagnetic North, a reliable spatial relation not normally sensed by humans, by mimicking sensorimotor contingencies of distal sounds via head-related transfer functions. We demonstrate rapid and long-lasting integration into the perception of self-rotation. Short training with amplified or reduced rotation gain in the magnetic signal can expand or compress the perceived extent of vestibular self-rotation, even with the magnetic signal absent in the test. We argue that it is the reliability of the magnetic signal that allows vestibular spatial recalibration, and the coding scheme mimicking sensorimotor contingencies of distal sounds that permits fast integration. Hence we propose that contingency-mimetic feedback has great potential for creating sensory augmentation devices that achieve fast and genuinely perceptual experiences. PMID:28195187

  14. Sensory augmentation: integration of an auditory compass signal into human perception of space.

    PubMed

    Schumann, Frank; O'Regan, J Kevin

    2017-02-14

    Bio-mimetic approaches to restoring sensory function show great promise in that they rapidly produce perceptual experience, but have the disadvantage of being invasive. In contrast, sensory substitution approaches are non-invasive, but may lead to cognitive rather than perceptual experience. Here we introduce a new non-invasive approach that leads to fast and truly perceptual experience like bio-mimetic techniques. Instead of building on existing circuits at the neural level as done in bio-mimetics, we piggy-back on sensorimotor contingencies at the stimulus level. We convey head orientation to geomagnetic North, a reliable spatial relation not normally sensed by humans, by mimicking sensorimotor contingencies of distal sounds via head-related transfer functions. We demonstrate rapid and long-lasting integration into the perception of self-rotation. Short training with amplified or reduced rotation gain in the magnetic signal can expand or compress the perceived extent of vestibular self-rotation, even with the magnetic signal absent in the test. We argue that it is the reliability of the magnetic signal that allows vestibular spatial recalibration, and the coding scheme mimicking sensorimotor contingencies of distal sounds that permits fast integration. Hence we propose that contingency-mimetic feedback has great potential for creating sensory augmentation devices that achieve fast and genuinely perceptual experiences.

  15. Electronic structure calculations with GPAW: a real-space implementation of the projector augmented-wave method

    NASA Astrophysics Data System (ADS)

    Enkovaara, J.; Rostgaard, C.; Mortensen, J. J.; Chen, J.; Dułak, M.; Ferrighi, L.; Gavnholt, J.; Glinsvad, C.; Haikola, V.; Hansen, H. A.; Kristoffersen, H. H.; Kuisma, M.; Larsen, A. H.; Lehtovaara, L.; Ljungberg, M.; Lopez-Acevedo, O.; Moses, P. G.; Ojanen, J.; Olsen, T.; Petzold, V.; Romero, N. A.; Stausholm-Møller, J.; Strange, M.; Tritsaris, G. A.; Vanin, M.; Walter, M.; Hammer, B.; Häkkinen, H.; Madsen, G. K. H.; Nieminen, R. M.; Nørskov, J. K.; Puska, M.; Rantala, T. T.; Schiøtz, J.; Thygesen, K. S.; Jacobsen, K. W.

    2010-06-01

    Electronic structure calculations have become an indispensable tool in many areas of materials science and quantum chemistry. Even though the Kohn-Sham formulation of the density-functional theory (DFT) simplifies the many-body problem significantly, one is still confronted with several numerical challenges. In this article we present the projector augmented-wave (PAW) method as implemented in the GPAW program package (https://wiki.fysik.dtu.dk/gpaw) using a uniform real-space grid representation of the electronic wavefunctions. Compared to more traditional plane wave or localized basis set approaches, real-space grids offer several advantages, most notably good computational scalability and systematic convergence properties. However, as a unique feature GPAW also facilitates a localized atomic-orbital basis set in addition to the grid. The efficient atomic basis set is complementary to the more accurate grid, and the possibility to seamlessly switch between the two representations provides great flexibility. While DFT allows one to study ground state properties, time-dependent density-functional theory (TDDFT) provides access to the excited states. We have implemented the two common formulations of TDDFT, namely the linear-response and the time propagation schemes. Electron transport calculations under finite-bias conditions can be performed with GPAW using non-equilibrium Green functions and the localized basis set. In addition to the basic features of the real-space PAW method, we also describe the implementation of selected exchange-correlation functionals, parallelization schemes, ΔSCF-method, x-ray absorption spectra, and maximally localized Wannier orbitals.

  16. Passive damping augmentation of flexible beam-like lattice trusses for large space structures

    NASA Technical Reports Server (NTRS)

    Cohen, K.; Weller, T.

    1992-01-01

    A Timoshenko beam continuum model is developed to determine the transient response of a beam-like latticed large space structure, subjected to a unit impulse. It is demonstrated that an increase in diagonal stiffness, on account of the stiffness of the vertical girder, leads to a rise in the transverse shear rigidity. This results in higher natural frequencies and reduction in peak displacement. In addition, in an asymmetrical truss configuration, coupling between the extensional and shear modes raises the maximum peak displacement compared with that obtained for a symmetrical truss. The model is modified to investigate the introduction of passive damping in the form of several dynamic vibration absorbers. A unique absorber parameter optimization procedure, based on the classical steady-state criteria, is used to tune the absorbers, having a total allocated mass budget of 10%, to the first two frequencies of the latticed structure. It is found that inclusion of transverse shear rigidity as a design parameter in damping augmentation studies reduces settling time for predetermined maximum peak displacements.

  17. Analysis of Correlation between Ionospheric Spatial Gradients and Space Weather Intensity under Nominal Conditions for Ground-Based Augmentation Systems

    NASA Astrophysics Data System (ADS)

    Lee, J.

    2013-12-01

    Ground-Based Augmentation Systems (GBAS) support aircraft precision approach and landing by providing differential GPS corrections to aviation users. For GBAS applications, most of ionospheric errors are removed by applying the differential corrections. However, ionospheric correction errors may exist due to ionosphere spatial decorrelation between GBAS ground facility and users. Thus, the standard deviation of ionosphere spatial decorrelation (σvig) is estimated and included in the computation of error bounds on user position solution. The σvig of 4mm/km, derived for the Conterminous United States (CONUS), bounds one-sigma ionospheric spatial gradients under nominal conditions (including active, but not stormy condition) with an adequate safety margin [1]. The conservatism residing in the current σvig by fixing it to a constant value for all non-stormy conditions could be mitigated by subdividing ionospheric conditions into several classes and using different σvig for each class. This new concept, real-time σvig adaptation, will be possible if the level of ionospheric activity can be well classified based on space weather intensity. This paper studies correlation between the statistics of nominal ionospheric spatial gradients and space weather indices. The analysis was carried out using two sets of data collected from Continuous Operating Reference Station (CORS) Network; 9 consecutive (nominal and ionospherically active) days in 2004 and 19 consecutive (relatively 'quiet') days in 2010. Precise ionospheric delay estimates are obtained using the simplified truth processing method and vertical ionospheric gradients are computed using the well-known 'station pair method' [2]. The remaining biases which include carrier-phase leveling errors and Inter-frequency Bias (IFB) calibration errors are reduced by applying linear slip detection thresholds. The σvig was inflated to overbound the distribution of vertical ionospheric gradients with the required confidence

  18. Performance analysis of IMU-augmented GNSS tracking systems for space launch vehicles

    NASA Astrophysics Data System (ADS)

    Braun, Benjamin; Markgraf, Markus; Montenbruck, Oliver

    2016-06-01

    European space launch operators consider the potential of GNSS (global navigation satellite system) as a promising novel means of localization for the purpose of range safety of launch vehicles like Ariane and Vega, since it is expected that recurring costs are lower and accuracy is higher than currently existing systems like radar tracking. Range safety requires continuous information about the position and velocity of the launch vehicle to quickly detect the occurrence of catastrophic events. However, GNSS outages due, for example, to high jerks at fairing and stage jettisons or other external interferences like (un-)intentional jamming cannot be precluded. The OCAM-G experiment on Ariane 5 flight VA219 has provided evidence that GNSS is capable of providing a highly accurate position and velocity solution during most of the flight, but that outages of several seconds do occur. To increase the continuity of a GNSS-based localization system, it is proposed that the GNSS receiver is augmented by an inertial measurement unit (IMU), which is able to output a position and velocity solution even during GNSS outages. Since these outages are expected to be short, a tactical- or even consumer-grade IMU is expected to be sufficient. In this paper, the minimum IMU performance that is required to bridge outages of up to 10 s, and thereby meeting the accuracy requirements of range safety, is determined by means of a thorough simulation study. The focus of the analysis is on current generation microelectromechanical system (MEMS)-based IMU, which is lightweight, low-cost, available commercially and has reached acceptable maturity in the last decade.

  19. Measuring the Usability of Augmented Reality e-Learning Systems: A User-Centered Evaluation Approach

    NASA Astrophysics Data System (ADS)

    Pribeanu, Costin; Balog, Alexandru; Iordache, Dragoş Daniel

    The development of Augmented Reality (AR) systems is creating new challenges and opportunities for the designers of e-learning systems. The mix of real and virtual requires appropriate interaction techniques that have to be evaluated with users in order to avoid usability problems. Formative usability aims at finding usability problems as early as possible in the development life cycle and is suitable to support the development of such novel interactive systems. This work presents an approach to the user-centered usability evaluation of an e-learning scenario for Biology developed on an Augmented Reality educational platform. The evaluation has been carried on during and after a summer school held within the ARiSE research project. The basic idea was to perform usability evaluation twice. In this respect, we conducted user testing with a small number of students during the summer school in order to get a fast feedback from users having good knowledge in Biology. Then, we repeated the user testing in different conditions and with a relatively larger number of representative users. In this paper we describe both experiments and compare the usability evaluation results.

  20. Real-time prediction of respiratory motion based on a local dynamic model in an augmented space

    NASA Astrophysics Data System (ADS)

    Hong, S.-M.; Jung, B.-H.; Ruan, D.

    2011-03-01

    Motion-adaptive radiotherapy aims to deliver ablative radiation dose to the tumor target with minimal normal tissue exposure, by accounting for real-time target movement. In practice, prediction is usually necessary to compensate for system latency induced by measurement, communication and control. This work focuses on predicting respiratory motion, which is most dominant for thoracic and abdominal tumors. We develop and investigate the use of a local dynamic model in an augmented space, motivated by the observation that respiratory movement exhibits a locally circular pattern in a plane augmented with a delayed axis. By including the angular velocity as part of the system state, the proposed dynamic model effectively captures the natural evolution of respiratory motion. The first-order extended Kalman filter is used to propagate and update the state estimate. The target location is predicted by evaluating the local dynamic model equations at the required prediction length. This method is complementary to existing work in that (1) the local circular motion model characterizes 'turning', overcoming the limitation of linear motion models; (2) it uses a natural state representation including the local angular velocity and updates the state estimate systematically, offering explicit physical interpretations; (3) it relies on a parametric model and is much less data-satiate than the typical adaptive semiparametric or nonparametric method. We tested the performance of the proposed method with ten RPM traces, using the normalized root mean squared difference between the predicted value and the retrospective observation as the error metric. Its performance was compared with predictors based on the linear model, the interacting multiple linear models and the kernel density estimator for various combinations of prediction lengths and observation rates. The local dynamic model based approach provides the best performance for short to medium prediction lengths under relatively

  1. A computationally efficient approach for hidden-Markov model-augmented fingerprint-based positioning

    NASA Astrophysics Data System (ADS)

    Roth, John; Tummala, Murali; McEachen, John

    2016-09-01

    This paper presents a computationally efficient approach for mobile subscriber position estimation in wireless networks. A method of data scaling assisted by timing adjust is introduced in fingerprint-based location estimation under a framework which allows for minimising computational cost. The proposed method maintains a comparable level of accuracy to the traditional case where no data scaling is used and is evaluated in a simulated environment under varying channel conditions. The proposed scheme is studied when it is augmented by a hidden-Markov model to match the internal parameters to the channel conditions that present, thus minimising computational cost while maximising accuracy. Furthermore, the timing adjust quantity, available in modern wireless signalling messages, is shown to be able to further reduce computational cost and increase accuracy when available. The results may be seen as a significant step towards integrating advanced position-based modelling with power-sensitive mobile devices.

  2. Non-US approaches to space commercialization

    NASA Technical Reports Server (NTRS)

    Smith, P. G.

    1984-01-01

    The approaches to the commercialization of space taken by the four foreign countries most active in the field - Canada, France, the Federal Republic of Germany, and Japan are described. National space program elements with commercial potential are examined in the context of national industrial and science policies, with special attention to objectives, timetables, and budgetary priority relative to other sectors. The role of the European Space Agency in attaining national and regional commercialization objectives is also examined.

  3. Augmented design and analysis of computer experiments: a novel tolerance embedded global optimization approach applied to SWIR hyperspectral illumination design.

    PubMed

    Keresztes, Janos C; John Koshel, R; D'huys, Karlien; De Ketelaere, Bart; Audenaert, Jan; Goos, Peter; Saeys, Wouter

    2016-12-26

    A novel meta-heuristic approach for minimizing nonlinear constrained problems is proposed, which offers tolerance information during the search for the global optimum. The method is based on the concept of design and analysis of computer experiments combined with a novel two phase design augmentation (DACEDA), which models the entire merit space using a Gaussian process, with iteratively increased resolution around the optimum. The algorithm is introduced through a series of cases studies with increasing complexity for optimizing uniformity of a short-wave infrared (SWIR) hyperspectral imaging (HSI) illumination system (IS). The method is first demonstrated for a two-dimensional problem consisting of the positioning of analytical isotropic point sources. The method is further applied to two-dimensional (2D) and five-dimensional (5D) SWIR HSI IS versions using close- and far-field measured source models applied within the non-sequential ray-tracing software FRED, including inherent stochastic noise. The proposed method is compared to other heuristic approaches such as simplex and simulated annealing (SA). It is shown that DACEDA converges towards a minimum with 1 % improvement compared to simplex and SA, and more importantly requiring only half the number of simulations. Finally, a concurrent tolerance analysis is done within DACEDA for to the five-dimensional case such that further simulations are not required.

  4. Flight Testing of the Space Launch System (SLS) Adaptive Augmenting Control (AAC) Algorithm on an F/A-18

    NASA Technical Reports Server (NTRS)

    Dennehy, Cornelius J.; VanZwieten, Tannen S.; Hanson, Curtis E.; Wall, John H.; Miller, Chris J.; Gilligan, Eric T.; Orr, Jeb S.

    2014-01-01

    The Marshall Space Flight Center (MSFC) Flight Mechanics and Analysis Division developed an adaptive augmenting control (AAC) algorithm for launch vehicles that improves robustness and performance on an as-needed basis by adapting a classical control algorithm to unexpected environments or variations in vehicle dynamics. This was baselined as part of the Space Launch System (SLS) flight control system. The NASA Engineering and Safety Center (NESC) was asked to partner with the SLS Program and the Space Technology Mission Directorate (STMD) Game Changing Development Program (GCDP) to flight test the AAC algorithm on a manned aircraft that can achieve a high level of dynamic similarity to a launch vehicle and raise the technology readiness of the algorithm early in the program. This document reports the outcome of the NESC assessment.

  5. Dynamic analysis to evaluate viscoelastic passive damping augmentation for the Space Shuttle Remote Manipulator System

    NASA Technical Reports Server (NTRS)

    Alberts, Thomas E.; Xia, Houchun; Chen, Yung

    1992-01-01

    The effectiveness of constrained viscoelastic layer damping treatment designs is evaluated separately as passive control measures for low frequency joint dominated modes and higher frequency boom flexure dominated modes using a NASTRAN finite element analysis. Passive damping augmentation is proposed which is based on a constrained viscoelastic layer damping treatment applied to the surface of the manipulators's flexible booms. It is pointed out that even the joint compliance dominated modes can be damped to some degree through appropriate design of the treatment.

  6. Probabilistic Approaches for Evaluating Space Shuttle Risks

    NASA Technical Reports Server (NTRS)

    Vesely, William

    2001-01-01

    The objectives of the Space Shuttle PRA (Probabilistic Risk Assessment) are to: (1) evaluate mission risks; (2) evaluate uncertainties and sensitivities; (3) prioritize contributors; (4) evaluate upgrades; (5) track risks; and (6) provide decision tools. This report discusses the significance of a Space Shuttle PRA and its participants. The elements and type of losses to be included are discussed. The program and probabilistic approaches are then discussed.

  7. An augmented reality home-training system based on the mirror training and imagery approach.

    PubMed

    Trojan, Jörg; Diers, Martin; Fuchs, Xaver; Bach, Felix; Bekrater-Bodmann, Robin; Foell, Jens; Kamping, Sandra; Rance, Mariela; Maaß, Heiko; Flor, Herta

    2014-09-01

    Mirror training and movement imagery have been demonstrated to be effective in treating several clinical conditions, such as phantom limb pain, stroke-induced hemiparesis, and complex regional pain syndrome. This article presents an augmented reality home-training system based on the mirror and imagery treatment approaches for hand training. A head-mounted display equipped with cameras captures one hand held in front of the body, mirrors this hand, and displays it in real time in a set of four different training tasks: (1) flexing fingers in a predefined sequence, (2) moving the hand into a posture fitting into a silhouette template, (3) driving a "Snake" video game with the index finger, and (4) grasping and moving a virtual ball. The system records task performance and transfers these data to a central server via the Internet, allowing monitoring of training progress. We evaluated the system by having 7 healthy participants train with it over the course of ten sessions of 15-min duration. No technical problems emerged during this time. Performance indicators showed that the system achieves a good balance between relatively easy and more challenging tasks and that participants improved significantly over the training sessions. This suggests that the system is well suited to maintain motivation in patients, especially when it is used for a prolonged period of time.

  8. A Novel Approach on Designing Augmented Fuzzy Cognitive Maps Using Fuzzified Decision Trees

    NASA Astrophysics Data System (ADS)

    Papageorgiou, Elpiniki I.

    This paper proposes a new methodology for designing Fuzzy Cognitive Maps using crisp decision trees that have been fuzzified. Fuzzy cognitive map is a knowledge-based technique that works as an artificial cognitive network inheriting the main aspects of cognitive maps and artificial neural networks. Decision trees, in the other hand, are well known intelligent techniques that extract rules from both symbolic and numeric data. Fuzzy theoretical techniques are used to fuzzify crisp decision trees in order to soften decision boundaries at decision nodes inherent in this type of trees. Comparisons between crisp decision trees and the fuzzified decision trees suggest that the later fuzzy tree is significantly more robust and produces a more balanced decision making. The approach proposed in this paper could incorporate any type of fuzzy decision trees. Through this methodology, new linguistic weights were determined in FCM model, thus producing augmented FCM tool. The framework is consisted of a new fuzzy algorithm to generate linguistic weights that describe the cause-effect relationships among the concepts of the FCM model, from induced fuzzy decision trees.

  9. Structural stability augmentation system design using BODEDIRECT: A quick and accurate approach

    NASA Technical Reports Server (NTRS)

    Goslin, T. J.; Ho, J. K.

    1989-01-01

    A methodology is presented for a modal suppression control law design using flight test data instead of mathematical models to obtain the required gain and phase information about the flexible airplane. This approach is referred to as BODEDIRECT. The purpose of the BODEDIRECT program is to provide a method of analyzing the modal phase relationships measured directly from the airplane. These measurements can be achieved with a frequency sweep at the control surface input while measuring the outputs of interest. The measured Bode-models can be used directly for analysis in the frequency domain, and for control law design. Besides providing a more accurate representation for the system inputs and outputs of interest, this method is quick and relatively inexpensive. To date, the BODEDIRECT program has been tested and verified for computational integrity. Its capabilities include calculation of series, parallel and loop closure connections between Bode-model representations. System PSD, together with gain and phase margins of stability may be calculated for successive loop closures of multi-input/multi-output systems. Current plans include extensive flight testing to obtain a Bode-model representation of a commercial aircraft for design of a structural stability augmentation system.

  10. A learning performance study between the conventional approach and augmented reality textbook among secondary school students

    NASA Astrophysics Data System (ADS)

    Gopalan, Valarmathie; Zulkifli, Abdul Nasir; Bakar, Juliana Aida Abu

    2016-08-01

    Malaysia is moving towards becoming a developed nation by 2020. As such, the need for adequate human resources in science-related fields is one of the requirements to achieve a developed nation status. Unfortunately, there is a downward trend in the number of students pursuing the science stream at the secondary school level. This paper introduces an enhanced science textbook using Augmented Reality (eSTAR) that is intended to motivate students to be interested in science. The eSTAR was implemented to provide a supplement to the conventional science teaching and learning methods in the secondary schools. A learning performance study with a control group was conducted to investigate the effectiveness of the eSTAR for science learning among a sample of 140 Form Two secondary school students. The results indicate that the learning performance of the students in both groups had a significant difference in mean scores between the pre-test and post-test. Students using the eSTAR have a better score in the post-test and eventually resulted in a better learning performance compared to those who were exposed to the conventional science learning. Overall, the results show that the students benefited from the use of the conventional and eSTAR learning approaches.

  11. Space Acquisitions: Challenges Facing DOD as it Changes Approaches to Space Acquisitions

    DTIC Science & Technology

    2016-03-09

    SPACE ACQUISITIONS Challenges Facing DOD as it Changes Approaches to Space Acquisitions Statement of Cristina T. Chaplain...2016 SPACE ACQUISITIONS Challenges Facing DOD as it Changes Approaches to Space Acquisitions Why GAO Did This Study DOD is shifting its traditional...approach to space acquisitions, bolstering its protection of space systems, and engaging with more commercial providers. Given the time and

  12. A preliminary look at control augmented dynamic response of structures

    NASA Technical Reports Server (NTRS)

    Ryan, R. S.; Jewell, R. E.

    1983-01-01

    The augmentation of structural characteristics, mass, damping, and stiffness through the use of control theory in lieu of structural redesign or augmentation was reported. The standard single-degree-of-freedom system was followed by a treatment of the same system using control augmentation. The system was extended to elastic structures using single and multisensor approaches and concludes with a brief discussion of potential application to large orbiting space structures.

  13. Semantics Enabled Queries in EuroGEOSS: a Discovery Augmentation Approach

    NASA Astrophysics Data System (ADS)

    Santoro, M.; Mazzetti, P.; Fugazza, C.; Nativi, S.; Craglia, M.

    2010-12-01

    One of the main challenges in Earth Science Informatics is to build interoperability frameworks which allow users to discover, evaluate, and use information from different scientific domains. This needs to address multidisciplinary interoperability challenges concerning both technological and scientific aspects. From the technological point of view, it is necessary to provide a set of special interoperability arrangement in order to develop flexible frameworks that allow a variety of loosely-coupled services to interact with each other. From a scientific point of view, it is necessary to document clearly the theoretical and methodological assumptions underpinning applications in different scientific domains, and develop cross-domain ontologies to facilitate interdisciplinary dialogue and understanding. In this presentation we discuss a brokering approach that extends the traditional Service Oriented Architecture (SOA) adopted by most Spatial Data Infrastructures (SDIs) to provide the necessary special interoperability arrangements. In the EC-funded EuroGEOSS (A European approach to GEOSS) project, we distinguish among three possible functional brokering components: discovery, access and semantics brokers. This presentation focuses on the semantics broker, the Discovery Augmentation Component (DAC), which was specifically developed to address the three thematic areas covered by the EuroGEOSS project: biodiversity, forestry and drought. The EuroGEOSS DAC federates both semantics (e.g. SKOS repositories) and ISO-compliant geospatial catalog services. The DAC can be queried using common geospatial constraints (i.e. what, where, when, etc.). Two different augmented discovery styles are supported: a) automatic query expansion; b) user assisted query expansion. In the first case, the main discovery steps are: i. the query keywords (the what constraint) are “expanded” with related concepts/terms retrieved from the set of federated semantic services. A default expansion

  14. The Delay Fill Technique: A Safer Approach to Combination Augmentation Mastopexy

    PubMed Central

    Patronella, Christopher K.; Mentz, Henry A.; Johnson-Alviza, Jaclyn

    2015-01-01

    Combining breast augmentation with mastopexy is a challenging procedure that has a relatively high revision rate in the literature. Some surgeons prefer a two-stage procedure to avoid the potential for skin flap or nipple–areolar complex necrosis that can occur with a one-stage procedure. The authors compared 101 patients who had subpectoral breast augmentation with immediate implant fill and mastopexy with 203 patients who had subpectoral breast augmentation with delayed (10–14 days) implant fill and mastopexy. They found the revision rate for immediate implant fill was 24%; in the delayed implant fill group, the revision rate was 10.3%. Patients had soft tissue-related complications in 16% of the immediate fill group and in 2% of the delayed fill group. Delaying implant fill in combined breast augmentation mastopexy significantly reduces the risk of soft tissue-related complications and revision procedures; the delay flap phenomenon is responsible for fewer wound-healing complications when implant fill is delayed during a combined augmentation mastopexy procedure. PMID:26528084

  15. New approaches to space weather forecasting

    NASA Astrophysics Data System (ADS)

    Parnowski, Aleksei; Cheremnykh, Oleg; Yatsenko, Vitaly

    2010-05-01

    We developed several approaches to the problem of real-time space weather indices forecasting using readily available data from ACE and a number of ground stations. The first one is based on a dynamical-information approach to nonlinear modeling of space plasma [1]. It uses new nonlinear mathematical models of geomagnetic indices and original algorithms for detection of structure and parameters. The identification problem is formulated as a constrained optimization problem. Novel algorithms provide an optimal structure of discrete dynamical system using fuzzy systems modeling. The second one is based on the regression modeling method [2], which combines the benefits of empirical and statistical approaches. It uses such statistical methods as the linear regression analysis, maximum likelihood method, dispersion analysis and Monte-Carlo simulations to deduce the empirical relationships in the system. In both cases the typical elapsed time per forecast is about several seconds on an average PC. Such techniques can be easily extended to other indices like AE and Kp. The proposed system can also be useful for investigating of physical phenomena related to interactions between the solar wind and the magnetosphere - it already helped uncovering two new geoeffective parameters. In addition, we performed the risk analysis of damage to VUV, EUV and X-ray optics due to space weather factors and analyzed the safety of space instruments. We plan combining short-term and medium-term approaches to accurately predict geomagnetic storms at least 5-10 hours before commencement. Practical applications of such a system include (but are not limited to): - spacecraft safety (prediction of radiation threat); - human health (putting emergency services on alert); - prevention of technological disasters (power grid failures, major radio blackouts). 1. Cheremnykh O.K., Yatsenko V.A., Semeniv O.V., Shatokhina Yu.V. Nonlinear dynamics and prediction for space weather // Ukr. J. Phys. — 2008

  16. Communicative Competence Inventory for Students Who Use Augmentative and Alternative Communication: A Team Approach

    ERIC Educational Resources Information Center

    Chung, Yun-Ching; Douglas, Karen H.

    2014-01-01

    Students who use augmentative and alternative communication (AAC) represent a heterogonous group with complex communication needs. AAC--including aided communication means (e.g., pictures, devices) and unaided (e.g., signs, gestures)--is often used to support students who have difficulties with speech production, language comprehension, and…

  17. Grafts and implants in nasal and chin augmentation. A rational approach to material selection.

    PubMed

    Adams, J S

    1987-11-01

    Two major factors are involved in choosing augmentation materials: (1) the specific properties and limitations of the materials themselves (Table 2) and (2) the characteristics of the site for implantation. A wide variety of materials are currently available and these vary in density, ability to be sculpted, tissue reaction, resorption, migration, incidence of infection, extrusion rate, and ease of removal. Some of these characteristics are self-evident. For example, materials with high infection or extrusion rates (such as Silastic in nasal reconstruction) are clearly not useful in most instances. Likewise, materials that tend to migrate, such as tiny bits of cartilage, can lead to unacceptable results, but cartilage is such a generally good augmentation material in the nose that the measures to ensure stability are worth the additional time required for implantation. Resorption is a potential problem with all the biologic grafts and possibly with Supramid. Again, in certain situations in which alloplasts are unacceptable, such as infected areas, biologicals must be used and the consequences of resorption accepted. Density and ease of sculpting are often a matter of the surgeon's personal choice. As a general rule, bone is best replaced with firm materials and soft tissues are best augmented with soft materials. Should infection or rejection occur, the porous materials are much more difficult to remove; therefore, Silastic or a biological may be the best choice if there is any question about the presence of infection or possible future infection. The effect of the degree of tissue reaction is not well-understood. For example, Supramid elicits a marked tissue response but in general displays high compatibility with the tissues. Further investigation is needed to elucidate the role of tissue reactivity and porosity in the development of infection and extrusion. When choosing the implant material, the specific characteristics of the site for augmentation must be

  18. Artificial intelligence for Space Station automation: Crew safety, productivity, autonomy, augmented capability

    NASA Technical Reports Server (NTRS)

    Firschein, O.; Georgeff, M. P.; Park, W.; Cheeseman, P. C.; Geldberg, J.

    1986-01-01

    Artificial intelligence (AI) R&D projects for the successful and efficient operation of the Space Station are described. The book explores the most advanced AI-based technologies, reviews the results of concept design studies to determine required AI capabilities, details demonstrations that would indicate the existence of these capabilities, and develops an R&D plan leading to such demonstrations. Particular attention is given to teleoperation and robotics, sensors, expert systems, computers, planning, and man-machine interface.

  19. Artificial intelligence for Space Station automation: crew safety, productivity, autonomy, augmented capability

    SciTech Connect

    Firschein, O.; Georgeff, M.P.; Park, W.; Cheeseman, P.C.; Geldberg, J.

    1986-01-01

    Artificial intelligence (AI) RandD projects for the successful and efficient operation of the Space Station are described. The book explores the most advanced AI-based technologies, reviews the results of concept design studies to determine required AI capabilities, details demonstrations that would indicate the existence of these capabilities, and develops an RandD plan leading to such demonstrations. Particular attention is given to teleoperation and robotics, sensors, expert systems, computers, planning, and man-machine interface. 293 references.

  20. Affordability Approaches for Human Space Exploration

    NASA Technical Reports Server (NTRS)

    Holladay, Jon; Smith, David Alan

    2012-01-01

    The design and development of historical NASA Programs (Apollo, Shuttle and International Space Station), have been based on pre-agreed missions which included specific pre-defined destinations (e.g., the Moon and low Earth orbit). Due to more constrained budget profiles, and the desire to have a more flexible architecture for Mission capture as it is affordable, NASA is working toward a set of Programs that are capability based, rather than mission and/or destination specific. This means designing for a performance capability that can be applied to a specific human exploration mission/destination later (sometime years later). This approach does support developing systems to flatter budgets over time, however, it also poses the challenge of how to accomplish this effectively while maintaining a trained workforce, extensive manufacturing, test and launch facilities, and ensuring mission success ranging from Low Earth Orbit to asteroid destinations. NASA Marshall Space Flight Center (MSFC) in support of Exploration Systems Directorate (ESD) in Washington, DC has been developing approaches to track affordability across multiple Programs. The first step is to ensure a common definition of affordability: the discipline to bear cost in meeting a budget with margin over the life of the program. The second step is to infuse responsibility and accountability for affordability into all levels of the implementing organization since affordability is no single person s job; it is everyone s job. The third step is to use existing data to identify common affordability elements organized by configuration (vehicle/facility), cost, schedule, and risk. The fourth step is to analyze and trend this affordability data using an affordability dashboard to provide status, measures, and trends for ESD and Program level of affordability tracking. This paper will provide examples of how regular application of this approach supports affordable and therefore sustainable human space exploration

  1. An Evidence-Based Approach to Augmentation and Combination Strategies for

    PubMed Central

    Barowsky, Jeremy

    2006-01-01

    Design, setting, participants: This paper is a review article that collects and synthesizes up-to-date information about the practice of augmenting and combining medications in regards to treatment resistant major depressive disorder. The authors have written the paper in an evidence-based model in order to show the reader where adequate data exists in regards to these strategies. A thorough MEDLINE search was utilized to collect many papers dedicated to this area of study spanning 1989-2005. Measurements: Papers were divided based upon drug intervention and scientific merit, where randomized controlled trials were given the most evidence-based weight and case studies the least. Results: The literature review data is divided into augmentation and combination strategies in descending order of scientific stringency. For augmentation, lithium, antipsychotic, and thyroid addition has the most empirical support. For combination strategies, heterocyclic addition is the best studied. Conclusion: There is much literature regarding complex medication management of major depression that is generally supportive of this practice. However, much of the literature contains underpowered and uncontrolled studies. PMID:20975817

  2. A piloted simulator investigation of static stability and stability/control augmentation effects on helicopter handling qualities for instrument approach

    NASA Technical Reports Server (NTRS)

    Lebacqz, J. V.; Forrest, R. D.

    1980-01-01

    A ground simulator experiment was conducted on the Flight Simulator for Advanced Aircraft at Ames Research Center to investigate the influence of several static stability and stability/control augmentation design parameters on helicopter flying qualities during terminal area operations in instrument conditions. Effects of light turbulence were included. Two levels of static stability in each rotational axis (pitch, roll, yaw) were examined for a hingeless rotor configuration. The variations in pitch and roll were: (1) stable and (2) neutral static stability; in yaw there were two stable levels. Four types of stability/control augmentation were also examined for the lower level of static stability in each axis. This latter investigation covered three helicopter rotor types: hingeless, articulated, and teetering. Four pilots performed a total of 105 evaluations of these parameters for a representative VOR instrument approach task. Pilot rating results indicate the acceptability of neutral static stability longitudinally and laterally and the need for pitch-roll attitude augmentation to achieve a satisfactory system.

  3. Bayesian accelerated failure time model for space-time dependency in a geographically augmented survival model

    PubMed Central

    Onicescu, Georgiana; Lawson, Andrew; Zhang, Jiajia; Gebregziabher, Mulugeta; Wallace, Kristin; Eberth, Jan M

    2016-01-01

    In this paper, we extend the spatially explicit survival model for small area cancer data by allowing dependency between space and time and using accelerated failure time models. Spatial dependency is modeled directly in the definition of the survival, density, and hazard functions. The models are developed in the context of county level aggregated data. Two cases are considered: the first assumes that the spatial and temporal distributions are independent; the second allows for dependency between the spatial and temporal components. We apply the models to prostate cancer data from the Louisiana SEER cancer registry. PMID:26220537

  4. An MBSE Approach to Space Suit Development

    NASA Technical Reports Server (NTRS)

    Cordova, Lauren; Kovich, Christine; Sargusingh, Miriam

    2012-01-01

    The EVA/Space Suit Development Office (ESSD) Systems Engineering and Integration (SE&I) team has utilized MBSE in multiple programs. After developing operational and architectural models, the MBSE framework was expanded to link the requirements space to the system models through functional analysis and interfaces definitions. By documenting all the connections within the technical baseline, ESSD experienced significant efficiency improvements in analysis and identification of change impacts. One of the biggest challenges presented to the MBSE structure was a program transition and restructuring effort, which was completed successfully in 4 months culminating in the approval of a new EVA Technical Baseline. During this time three requirements sets spanning multiple DRMs were streamlined into one NASA-owned Systems Requirement Document (SRD) that successfully identified requirements relevant to the current hardware development effort while remaining extensible to support future hardware developments. A capability-based hierarchy was established to provide a more flexible framework for future space suit development that can support multiple programs with minimal rework of basic EVA/Space Suit requirements. This MBSE approach was most recently applied for generation of an EMU Demonstrator technical baseline being developed for an ISS DTO. The relatively quick turnaround of operational concepts, architecture definition, and requirements for this new suit development has allowed us to test and evolve the MBSE process and framework in an extremely different setting while still offering extensibility and traceability throughout ESSD projects. The ESSD MBSE framework continues to be evolved in order to support integration of all products associated with the SE&I engine.

  5. Distribution function approach to redshift space distortions

    SciTech Connect

    Seljak, Uroš; McDonald, Patrick E-mail: pvmcdonald@lbl.gov

    2011-11-01

    We develop a phase space distribution function approach to redshift space distortions (RSD), in which the redshift space density can be written as a sum over velocity moments of the distribution function. These moments are density weighted and have well defined physical interpretation: their lowest orders are density, momentum density, and stress energy density. The series expansion is convergent if kμu/aH < 1, where k is the wavevector, H the Hubble parameter, u the typical gravitational velocity and μ = cos θ, with θ being the angle between the Fourier mode and the line of sight. We perform an expansion of these velocity moments into helicity modes, which are eigenmodes under rotation around the axis of Fourier mode direction, generalizing the scalar, vector, tensor decomposition of perturbations to an arbitrary order. We show that only equal helicity moments correlate and derive the angular dependence of the individual contributions to the redshift space power spectrum. We show that the dominant term of μ{sup 2} dependence on large scales is the cross-correlation between the density and scalar part of momentum density, which can be related to the time derivative of the matter power spectrum. Additional terms contributing to μ{sup 2} and dominating on small scales are the vector part of momentum density-momentum density correlations, the energy density-density correlations, and the scalar part of anisotropic stress density-density correlations. The second term is what is usually associated with the small scale Fingers-of-God damping and always suppresses power, but the first term comes with the opposite sign and always adds power. Similarly, we identify 7 terms contributing to μ{sup 4} dependence. Some of the advantages of the distribution function approach are that the series expansion converges on large scales and remains valid in multi-stream situations. We finish with a brief discussion of implications for RSD in galaxies relative to dark matter

  6. Space Shuttle Orbiter Approach and Landing Test

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The Approach and Landing Test Program consisted of a series of steps leading to the demonstration of the capability of the Space Shuttle orbiter to safely approach and land under conditions similar to those planned for the final phases of an orbital flight. The tests were conducted with the orbiter mounted on top of a specially modified carrier aircraft. The first step provided airworthiness and performance verification of the carrier aircraft after modification. The second step consisted of three taxi tests and five flight tests with an inert unmanned orbiter. The third step consisted of three mated tests with an active manned orbiter. The fourth step consisted of five flights in which the orbiter was separated from the carrier aircraft. For the final two flights, the orbiter tail cone was replaced by dummy engines to simulate the actual orbital configuration. Landing gear braking and steering tests were accomplished during rollouts following the free flight landings. Ferry testing was integrated into the Approach and Landing Test Program to the extent possible. In addition, four ferry test flights were conducted with the orbiter mated to the carrier aircraft in the ferry configuration after the free-flight tests were completed.

  7. GyroWand: An Approach to IMU-Based Raycasting for Augmented Reality.

    PubMed

    Hincapié-Ramos, Juan David; Özacar, Kasim; Irani, Pourang P; Kitamura, Yoshifumi

    2016-01-01

    Optical see-through head-mounted displays enable augmented reality (AR) applications that display virtual objects overlaid on the real world. At the core of this new generation of devices are low-cost tracking technologies that allow us to interpret users' motion in the real world in relation to the virtual content for the purposes of navigation and interaction. The advantages of pervasive tracking come at the cost of limiting interaction possibilities, however. To address these challenges the authors introduce GyroWand, a raycasting technique for AR HMDs using inertial measurement unit (IMU) rotational data from a handheld controller.

  8. Space vehicle approach velocity judgments under simulated visual space conditions.

    PubMed

    Haines, R F

    1989-02-01

    There were 35 volunteers who responded when they first perceived an increase in apparent size of a collimated, two-dimensional perspective image of an Orbiter vehicle. The variables of interest included the presence (or absence) of a fixed reticle within the field of view (FOV), background starfield velocity, initial range to the vehicle and vehicle closure velocity. It was found that: 1) increasing vehicle approach velocity yielded a very small (but significant) effect of faster detection of vehicle movement, nevertheless, response variability was relatively large; 2) including the fixed reticle in the FOV produced significantly slower detection of vehicle radial movement, however this occurred only at the largest range and the magnitude of the effect was only about 15% of the one sigma value; and 3) increasing background star velocity during this judgment led to slower detection of vehicle movement. While statistically significant, this effect was small and occurred primarily at the largest range. A possible explanation for the last two findings is that other static and dynamic objects within the visual field may compete for available attention which otherwise would be available for judging image expansion; thus, the target's retinal image has to expand more than otherwise for its movement to be detected. This study also showed that the Proximity Operations Research Mockup at NASA/Ames can be used effectively to investigate a variety of visual judgment questions related to future space operations. These findings are discussed in relation to previous research and possible underlying mechanisms.

  9. Cerebellar tDCS: A Novel Approach to Augment Language Treatment Post-stroke.

    PubMed

    Sebastian, Rajani; Saxena, Sadhvi; Tsapkini, Kyrana; Faria, Andreia V; Long, Charltien; Wright, Amy; Davis, Cameron; Tippett, Donna C; Mourdoukoutas, Antonios P; Bikson, Marom; Celnik, Pablo; Hillis, Argye E

    2016-01-01

    People with post-stroke aphasia may have some degree of chronic deficit for which current rehabilitative treatments are variably effective. Accumulating evidence suggests that transcranial direct current stimulation (tDCS) may be useful for enhancing the effects of behavioral aphasia treatment. However, it remains unclear which brain regions should be stimulated to optimize effects on language recovery. Here, we report on the therapeutic potential of right cerebellar tDCS in augmenting language recovery in SMY, who sustained bilateral MCA infarct resulting in aphasia and anarthria. We investigated the effects of 15 sessions of anodal cerebellar tDCS coupled with spelling therapy using a randomized, double-blind, sham controlled within-subject crossover trial. We also investigated changes in functional connectivity using resting state functional magnetic resonance imaging before and 2 months post-treatment. Both anodal and sham treatments resulted in improved spelling to dictation for trained and untrained words immediately after and 2 months post-treatment. However, there was greater improvement with tDCS than with sham, especially for untrained words. Further, generalization to written picture naming was only noted during tDCS but not with sham. The resting state functional connectivity data indicate that improvement in spelling was accompanied by an increase in cerebro-cerebellar network connectivity. These results highlight the therapeutic potential of right cerebellar tDCS to augment spelling therapy in an individual with large bilateral chronic strokes.

  10. Cerebellar tDCS: A Novel Approach to Augment Language Treatment Post-stroke

    PubMed Central

    Sebastian, Rajani; Saxena, Sadhvi; Tsapkini, Kyrana; Faria, Andreia V.; Long, Charltien; Wright, Amy; Davis, Cameron; Tippett, Donna C.; Mourdoukoutas, Antonios P.; Bikson, Marom; Celnik, Pablo; Hillis, Argye E.

    2017-01-01

    People with post-stroke aphasia may have some degree of chronic deficit for which current rehabilitative treatments are variably effective. Accumulating evidence suggests that transcranial direct current stimulation (tDCS) may be useful for enhancing the effects of behavioral aphasia treatment. However, it remains unclear which brain regions should be stimulated to optimize effects on language recovery. Here, we report on the therapeutic potential of right cerebellar tDCS in augmenting language recovery in SMY, who sustained bilateral MCA infarct resulting in aphasia and anarthria. We investigated the effects of 15 sessions of anodal cerebellar tDCS coupled with spelling therapy using a randomized, double-blind, sham controlled within-subject crossover trial. We also investigated changes in functional connectivity using resting state functional magnetic resonance imaging before and 2 months post-treatment. Both anodal and sham treatments resulted in improved spelling to dictation for trained and untrained words immediately after and 2 months post-treatment. However, there was greater improvement with tDCS than with sham, especially for untrained words. Further, generalization to written picture naming was only noted during tDCS but not with sham. The resting state functional connectivity data indicate that improvement in spelling was accompanied by an increase in cerebro-cerebellar network connectivity. These results highlight the therapeutic potential of right cerebellar tDCS to augment spelling therapy in an individual with large bilateral chronic strokes. PMID:28127284

  11. Weighted augmented Jacobian matrix with a variable coefficient method for kinematics mapping of space teleoperation based on human-robot motion similarity

    NASA Astrophysics Data System (ADS)

    Shi, Zhong; Huang, Xuexiang; Hu, Tianjian; Tan, Qian; Hou, Yuzhuo

    2016-10-01

    Space teleoperation is an important space technology, and human-robot motion similarity can improve the flexibility and intuition of space teleoperation. This paper aims to obtain an appropriate kinematics mapping method of coupled Cartesian-joint space for space teleoperation. First, the coupled Cartesian-joint similarity principles concerning kinematics differences are defined. Then, a novel weighted augmented Jacobian matrix with a variable coefficient (WAJM-VC) method for kinematics mapping is proposed. The Jacobian matrix is augmented to achieve a global similarity of human-robot motion. A clamping weighted least norm scheme is introduced to achieve local optimizations, and the operating ratio coefficient is variable to pursue similarity in the elbow joint. Similarity in Cartesian space and the property of joint constraint satisfaction is analysed to determine the damping factor and clamping velocity. Finally, a teleoperation system based on human motion capture is established, and the experimental results indicate that the proposed WAJM-VC method can improve the flexibility and intuition of space teleoperation to complete complex space tasks.

  12. Space Sustainment: A New Approach for America in Space

    DTIC Science & Technology

    2014-12-01

    collection of information if it does not display a currently valid OMB control number. 1. REPORT DATE DEC 2014 2 . REPORT TYPE 3. DATES COVERED...emerged. Many com- mercial space companies are on the cusp of fiscal viability or are al- ready sustaining profits. 2 The Cold War ended, and the United...advantages despite a space domain that is increasingly “congested, contested, and competitive.”3 Reforming Space Law The current body of both

  13. A Strategic Approach for Space Acquisition

    DTIC Science & Technology

    2012-03-14

    satellite missions. Space Exploration Technologies, known as SpaceX , is also fielding several launch vehicles to compete with the existing launch industry...multiple small satellites into either low earth orbit or geosynchronous transfer orbit. NASA has already contracted with SpaceX to resupply the...International Space Station.56 Currently, SpaceX is in the process of building a strong flight safety track record in order to compete for high value

  14. A framework-based approach to designing simulation-augmented surgical education and training programs.

    PubMed

    Cristancho, Sayra M; Moussa, Fuad; Dubrowski, Adam

    2011-09-01

    The goal of simulation-based medical education and training is to help trainees acquire and refine the technical and cognitive skills necessary to perform clinical procedures. When designers incorporate simulation into programs, their efforts should be in line with training needs, rather than technology. Designers of simulation-augmented surgical training programs, however, face particular problems related to identifying a framework that guides the curricular design activity to fulfill the particular requirements of such training programs. These problems include the lack of (1) an objective identification of training needs, (2) a systematic design methodology to match training objectives with simulation resources, (3) structured assessments of performance, and (4) a research-centered view to evaluate and validate systematically the educational effectiveness of the program. In this report, we present a process called "Aim - FineTune - FollowThrough" to enable the connection of the identified problems to solutions, using frameworks from psychology, motor learning, education and experimental design.

  15. Approach and Evaluation of a Mobile Video-Based and Location-Based Augmented Reality Platform for Information Brokerage

    NASA Astrophysics Data System (ADS)

    Dastageeri, H.; Storz, M.; Koukofikis, A.; Knauth, S.; Coors, V.

    2016-09-01

    Providing mobile location-based information for pedestrians faces many challenges. On one hand the accuracy of localisation indoors and outdoors is restricted due to technical limitations of GPS and Beacons. Then again only a small display is available to display information as well as to develop a user interface. Plus, the software solution has to consider the hardware characteristics of mobile devices during the implementation process for aiming a performance with minimum latency. This paper describes our approach by including a combination of image tracking and GPS or Beacons to ensure orientation and precision of localisation. To communicate the information on Points of Interest (POIs), we decided to choose Augmented Reality (AR). For this concept of operations, we used besides the display also the acceleration and positions sensors as a user interface. This paper especially goes into detail on the optimization of the image tracking algorithms, the development of the video-based AR player for the Android platform and the evaluation of videos as an AR element in consideration of providing a good user experience. For setting up content for the POIs or even generate a tour we used and extended the Open Geospatial Consortium (OGC) standard Augmented Reality Markup Language (ARML).

  16. Automatic localization of endoscope in intraoperative CT image: A simple approach to augmented reality guidance in laparoscopic surgery.

    PubMed

    Bernhardt, Sylvain; Nicolau, Stéphane A; Agnus, Vincent; Soler, Luc; Doignon, Christophe; Marescaux, Jacques

    2016-05-01

    The use of augmented reality in minimally invasive surgery has been the subject of much research for more than a decade. The endoscopic view of the surgical scene is typically augmented with a 3D model extracted from a preoperative acquisition. However, the organs of interest often present major changes in shape and location because of the pneumoperitoneum and patient displacement. There have been numerous attempts to compensate for this distortion between the pre- and intraoperative states. Some have attempted to recover the visible surface of the organ through image analysis and register it to the preoperative data, but this has proven insufficiently robust and may be problematic with large organs. A second approach is to introduce an intraoperative 3D imaging system as a transition. Hybrid operating rooms are becoming more and more popular, so this seems to be a viable solution, but current techniques require yet another external and constraining piece of apparatus such as an optical tracking system to determine the relationship between the intraoperative images and the endoscopic view. In this article, we propose a new approach to automatically register the reconstruction from an intraoperative CT acquisition with the static endoscopic view, by locating the endoscope tip in the volume data. We first describe our method to localize the endoscope orientation in the intraoperative image using standard image processing algorithms. Secondly, we highlight that the axis of the endoscope needs a specific calibration process to ensure proper registration accuracy. In the last section, we present quantitative and qualitative results proving the feasibility and the clinical potential of our approach.

  17. Ginger augmented chemotherapy: A novel multitarget nontoxic approach for cancer management.

    PubMed

    Saxena, Roopali; Rida, Padmashree C G; Kucuk, Omer; Aneja, Ritu

    2016-06-01

    Cancer, referred to as the 'disease of civilization', continues to haunt humanity due to its dreadful manifestations and limited success of therapeutic interventions such as chemotherapy in curing the disease. Although effective, chemotherapy has repeatedly demonstrated inadequacy in disease management due to its debilitating side effects arising from its deleterious nonspecific effects on normal healthy cells. In addition, development of chemoresistance due to mono-targeting often results in cessation of chemotherapy. This urgently demands development and implementation of multitargeted alternative therapies with mild or no side effects. One extremely promising strategy that yet remains untapped in the clinic is augmenting chemotherapy with dietary phytochemicals or extracts. Ginger, depository of numerous bioactive molecules, not only targets cancer cells but can also mitigate chemotherapy-associated side effects. Consequently, combination therapy involving ginger extract and chemotherapeutic agents may offer the advantage of being efficacious with reduced toxicity. Here we discuss the remarkable and often overlooked potential of ginger extract to manage cancer, the possibility of developing ginger-based combinational therapies, and the major roadblocks along with strategies to overcome them in clinical translation of such inventions. We are optimistic that clinical implementation of such combination regimens would be a much sought after modality in cancer management.

  18. An Augmented Reality-Based Approach for Surgical Telementoring in Austere Environments.

    PubMed

    Andersen, Dan; Popescu, Voicu; Cabrera, Maria Eugenia; Shanghavi, Aditya; Mullis, Brian; Marley, Sherri; Gomez, Gerardo; Wachs, Juan P

    2017-03-01

    Telementoring can improve treatment of combat trauma injuries by connecting remote experienced surgeons with local less-experienced surgeons in an austere environment. Current surgical telementoring systems force the local surgeon to regularly shift focus away from the operating field to receive expert guidance, which can lead to surgery delays or even errors. The System for Telementoring with Augmented Reality (STAR) integrates expert-created annotations directly into the local surgeon's field of view. The local surgeon views the operating field by looking at a tablet display suspended between the patient and the surgeon that captures video of the surgical field. The remote surgeon remotely adds graphical annotations to the video. The annotations are sent back and displayed to the local surgeon while being automatically anchored to the operating field elements they describe. A technical evaluation demonstrates that STAR robustly anchors annotations despite tablet repositioning and occlusions. In a user study, participants used either STAR or a conventional telementoring system to precisely mark locations on a surgical simulator under a remote surgeon's guidance. Participants who used STAR completed the task with fewer focus shifts and with greater accuracy. The STAR reduces the local surgeon's need to shift attention during surgery, allowing him or her to continuously work while looking "through" the tablet screen.

  19. A computational study of thrust augmenting ejectors based on a viscous-inviscid approach

    NASA Technical Reports Server (NTRS)

    Lund, Thomas S.; Tavella, Domingo A.; Roberts, Leonard

    1987-01-01

    A viscous-inviscid interaction technique is advocated as both an efficient and accurate means of predicting the performance of two-dimensional thrust augmenting ejectors. The flow field is subdivided into a viscous region that contains the turbulent jet and an inviscid region that contains the ambient fluid drawn into the device. The inviscid region is computed with a higher-order panel method, while an integral method is used for the description of the viscous part. The strong viscous-inviscid interaction present within the ejector is simulated in an iterative process where the two regions influence each other en route to a converged solution. The model is applied to a variety of parametric and optimization studies involving ejectors having either one or two primary jets. The effects of nozzle placement, inlet and diffuser shape, free stream speed, and ejector length are investigated. The inlet shape for single jet ejectors is optimized for various free stream speeds and Reynolds numbers. Optimal nozzle tilt and location are identified for various dual-ejector configurations.

  20. Yeast Augmented Network Analysis (YANA): a new systems approach to identify therapeutic targets for human genetic diseases

    PubMed Central

    Wiley, David J.; Juan, Ilona; Le, Hao; Cai, Xiaodong; Baumbach, Lisa; Beattie, Christine; D'Urso, Gennaro

    2014-01-01

    Genetic interaction networks that underlie most human diseases are highly complex and poorly defined. Better-defined networks will allow identification of a greater number of therapeutic targets. Here we introduce our Yeast Augmented Network Analysis (YANA) approach and test it with the X-linked spinal muscular atrophy (SMA) disease gene UBA1. First, we express UBA1 and a mutant variant in fission yeast and use high-throughput methods to identify fission yeast genetic modifiers of UBA1. Second, we analyze available protein-protein interaction network databases in both fission yeast and human to construct UBA1 genetic networks. Third, from these networks we identified potential therapeutic targets for SMA. Finally, we validate one of these targets in a vertebrate (zebrafish) SMA model. This study demonstrates the power of combining synthetic and chemical genetics with a simple model system to identify human disease gene networks that can be exploited for treating human diseases. PMID:25075304

  1. Suicide Note Sentiment Classification: A Supervised Approach Augmented by Web Data

    PubMed Central

    Xu, Yan; Wang, Yue; Liu, Jiahua; Tu, Zhuowen; Sun, Jian-Tao; Tsujii, Junichi; Chang, Eric

    2012-01-01

    Objective: To create a sentiment classification system for the Fifth i2b2/VA Challenge Track 2, which can identify thirteen subjective categories and two objective categories. Design: We developed a hybrid system using Support Vector Machine (SVM) classifiers with augmented training data from the Internet. Our system consists of three types of classification-based systems: the first system uses spanning n-gram features for subjective categories, the second one uses bag-of-n-gram features for objective categories, and the third one uses pattern matching for infrequent or subtle emotion categories. The spanning n-gram features are selected by a feature selection algorithm that leverages emotional corpus from weblogs. Special normalization of objective sentences is generalized with shallow parsing and external web knowledge. We utilize three sources of web data: the weblog of LiveJournal which helps to improve the feature selection, the eBay List which assists in special normalization of information and instructions categories, and the suicide project web which provides unlabeled data with similar properties as suicide notes. Measurements: The performance is evaluated by the overall micro-averaged precision, recall and F-measure. Result: Our system achieved an overall micro-averaged F-measure of 0.59. Happiness_peacefulness had the highest F-measure of 0.81. We were ranked as the second best out of 26 competing teams. Conclusion: Our results indicated that classifying fine-grained sentiments at sentence level is a non-trivial task. It is effective to divide categories into different groups according to their semantic properties. In addition, our system performance benefits from external knowledge extracted from publically available web data of other purposes; performance can be further enhanced when more training data is available. PMID:22879758

  2. Space Science Informatics: A Canadian Approach

    NASA Astrophysics Data System (ADS)

    Rankin, R.; Shillington, J.; Gordon, M.

    2011-02-01

    The rapidly increasing volume of space science data is leading to a growing need for tools for scientists to access, analyze, and share data. To address this need, the Canadian Space Science Data Portal (CSSDP) provides space scientists with access to a wide range of space data, observations, and investigative tools. CSSDP serves as a one-stop shop for scientists to discover, gather, and visualize relevant data. The data portal has embedded analysis tools and workflows to simplify common research tasks, along with a rich collaboration framework to develop and share scientific findings (see Figure 1). The data portal is accessible at http://www.cssdp.ca.

  3. A hybrid approach to space power control

    NASA Technical Reports Server (NTRS)

    Gholdston, E. W.; Janik, D. F.; Newton, K. A.

    1990-01-01

    Conventional control systems have traditionally been utilized for space-based power designs. However, the use of expert systems is becoming important for NASA applications. Rocketdyne has been pursuing the development of expert systems to aid and enhance control designs of space-based power systems. The need for integrated expert systems is vital for the development of autonomous power systems.

  4. Predicting core level binding energies shifts: Suitability of the projector augmented wave approach as implemented in VASP.

    PubMed

    Pueyo Bellafont, Noèlia; Viñes, Francesc; Hieringer, Wolfgang; Illas, Francesc

    2017-03-30

    Here, we assess the accuracy of various approaches implemented in Vienna ab initio simulation package code to estimate core-level binding energy shifts (ΔBEs) using a projector augmented wave method to treat core electrons. The performance of the Perdew-Burke-Ernzerhof (PBE) and the Tao-Perdew-Staroverov-Scuseria (TPSS) exchange-correlation density functionals is examined on a dataset of 68 molecules containing B→F atoms in diverse chemical environments, accounting for 185 different 1s core level binding energy shifts, for which both experimental gas-phase X-ray photoemission (XPS) data and accurate all electron ΔBEs are available. Four procedures to calculate core-level shifts are investigated. Janak-Slater transition state approach yields mean absolute errors of 0.37 (0.21) eV at PBE (TPSS) level, similar to highly accurate all electron ΔSCF approaches using same functionals, and close to XPS experimental accuracy of 0.1 eV. The study supports the use of these procedures to assign ΔBEs of molecular moieties on material surfaces of interest in surface science, nanotechnology, and heterogeneous catalysis. © 2017 Wiley Periodicals, Inc.

  5. Towards Pervasive Augmented Reality: Context-Awareness in Augmented Reality.

    PubMed

    Grubert, Jens; Langlotz, Tobias; Zollmann, Stefanie; Regenbrecht, Holger

    2016-03-17

    Augmented Reality is a technique that enables users to interact with their physical environment through the overlay of digital information. While being researched for decades, more recently, Augmented Reality moved out of the research labs and into the field. While most of the applications are used sporadically and for one particular task only, current and future scenarios will provide a continuous and multi-purpose user experience. Therefore, in this paper, we present the concept of Pervasive Augmented Reality, aiming to provide such an experience by sensing the user's current context and adapting the AR system based on the changing requirements and constraints. We present a taxonomy for Pervasive Augmented Reality and context-aware Augmented Reality, which classifies context sources and context targets relevant for implementing such a context-aware, continuous Augmented Reality experience. We further summarize existing approaches that contribute towards Pervasive Augmented Reality. Based our taxonomy and survey, we identify challenges for future research directions in Pervasive Augmented Reality.

  6. Space Station overall management approach for operations

    NASA Technical Reports Server (NTRS)

    Paules, G.

    1986-01-01

    An Operations Management Concept developed by NASA for its Space Station Program is discussed. The operational goals, themes, and design principles established during program development are summarized. The major operations functions are described, including: space systems operations, user support operations, prelaunch/postlanding operations, logistics support operations, market research, and cost/financial management. Strategic, tactical, and execution levels of operational decision-making are defined.

  7. CNES reliability approach for the qualification of MEMS for space

    NASA Astrophysics Data System (ADS)

    Pressecq, Francis; Lafontan, Xavier; Perez, Guy; Fortea, Jean-Pierre

    2001-10-01

    This paper describes the reliability approach performs at CNES to evaluate MEMS for space application. After an introduction and a detailed state of the art on the space requirements and on the use of MEMS for space, different approaches for taking into account MEMS in the qualification phases are presented. CNES proposes improvement to theses approaches in term of failure mechanisms identification. Our approach is based on a design and test phase deeply linked with a technology study. This workflow is illustrated with an example: the case of a variable capacitance processed with MUMPS process is presented.

  8. A Psychosocial Approach to Understanding Underground Spaces

    PubMed Central

    Lee, Eun H.; Christopoulos, George I.; Kwok, Kian W.; Roberts, Adam C.; Soh, Chee-Kiong

    2017-01-01

    With a growing need for usable land in urban areas, subterranean development has been gaining attention. While construction of large underground complexes is not a new concept, our understanding of various socio-cultural aspects of staying underground is still at a premature stage. With projected emergence of underground built environments, future populations may spend much more of their working, transit, and recreational time in underground spaces. Therefore, it is essential to understand the challenges and advantages that such environments have to improve the future welfare of users of underground spaces. The current paper discusses various psycho-social aspects of underground spaces, the impact they can have on the culture shared among the occupants, and possible solutions to overcome some of these challenges.

  9. An innovative approach to space education

    NASA Technical Reports Server (NTRS)

    Marton, Christine; Berinstain, Alain B.; Criswick, John

    1994-01-01

    At present, Canada does not have enough scientists to be competitive in the global economy, which is rapidly changing from a reliance on natural resources and industry to information and technology. Space is the final frontier and it is a multidisciplinary endeavor. It requires a knowledge of science and math, as well as non-science areas such as architecture and law. Thus, it can attract a large number of students with a diverse range of interests and career goals. An overview is presented of the space education program designed by Canadian Alumni of the International Space University (CAISU) to encourage students to pursue studies and careers in science and technology and to improve science literacy in Canada.

  10. A new approach to electrophoresis in space

    NASA Technical Reports Server (NTRS)

    Snyder, Robert S.; Rhodes, Percy H.

    1990-01-01

    Previous electrophoresis experiments performed in space are reviewed. There is sufficient data available from the results of these experiments to show that they were designed with incomplete knowledge of the fluid dynamics of the process including electrohydrodynamics. Redesigning laboratory chambers and operating procedures developed on Earth for space without understanding both the advantages and disadvantages of the microgravity environment has yielded poor separations of both cells and proteins. However, electrophoreris is still an important separation tool in the laboratory and thermal convection does limit its performance. Thus, there is a justification for electrophoresis but the emphasis of future space experiments must be directed toward basic research with model experiments to understand the microgravity environment and fluid analysis to test the basic principles of the process.

  11. A Concept for Airborne Precision Spacing for Dependent Parallel Approaches

    NASA Technical Reports Server (NTRS)

    Barmore, Bryan E.; Baxley, Brian T.; Abbott, Terence S.; Capron, William R.; Smith, Colin L.; Shay, Richard F.; Hubbs, Clay

    2012-01-01

    The Airborne Precision Spacing concept of operations has been previously developed to support the precise delivery of aircraft landing successively on the same runway. The high-precision and consistent delivery of inter-aircraft spacing allows for increased runway throughput and the use of energy-efficient arrivals routes such as Continuous Descent Arrivals and Optimized Profile Descents. This paper describes an extension to the Airborne Precision Spacing concept to enable dependent parallel approach operations where the spacing aircraft must manage their in-trail spacing from a leading aircraft on approach to the same runway and spacing from an aircraft on approach to a parallel runway. Functionality for supporting automation is discussed as well as procedures for pilots and controllers. An analysis is performed to identify the required information and a new ADS-B report is proposed to support these information needs. Finally, several scenarios are described in detail.

  12. Autonomous space processor for orbital debris removal and flame augmentation additives in scramjets for the National Aerospace Plane

    NASA Technical Reports Server (NTRS)

    1988-01-01

    This is a brief description of the USRA-sponsored design project at the University of Arizona. Approximately eighty-percent of this effort was spent pursuing a novel engineering concept for the in-situ processing of orbital debris utilizing resources available in low Earth orbit (LEO); the other twenty-percent was devoted to discovering innovative additives for the anchoring of supersonic combustion zones that find direct use in the Aerospace Plane that is expected to use scramjets. The seriousness of the orbital debris problem is briefly described. Available 'solutions' are outlined from the literature. The engineering design is briefly mentioned, with an emphasis on the positive aspects of the space environment that should be used in an economical approach. The aspects of operating in microgravity, vacuum, and in utilizing solar energy are mentioned. A quantitative computer animation was developed to provide design data. Three specific dead spacecraft were identified for an initial cleanup mission. The design concept, which includes a solar processor, remote arm manipulators, and the gradual processing of the debris, is also described. This is followed by a description of hardware construction. Operation and actual processing of simulated debris parts (aluminum, for now) are demonstrated in the NASP task, construction of the new design for measuring the radiation from the key free radicals (as enhanced by the additives) is described. Immediate (1988) and long-range (through 1992) future plans are shown to clearly indicate the full engineering design strategy in the light of the national space program thrusts.

  13. In-Flight Suppression of a De-Stabilized F/A-18 Structural Mode Using the Space Launch System Adaptive Augmenting Control System

    NASA Technical Reports Server (NTRS)

    Wall, John; VanZwieten, Tannen; Giiligan Eric; Miller, Chris; Hanson, Curtis; Orr, Jeb

    2015-01-01

    Adaptive Augmenting Control (AAC) has been developed for NASA's Space Launch System (SLS) family of launch vehicles and implemented as a baseline part of its flight control system (FCS). To raise the technical readiness level of the SLS AAC algorithm, the Launch Vehicle Adaptive Control (LVAC) flight test program was conducted in which the SLS FCS prototype software was employed to control the pitch axis of Dryden's specially outfitted F/A-18, the Full Scale Advanced Systems Test Bed (FAST). This presentation focuses on a set of special test cases which demonstrate the successful mitigation of the unstable coupling of an F/A-18 airframe structural mode with the SLS FCS.

  14. Current status of augmentation and combination treatments for major depressive disorder: a literature review and a proposal for a novel approach to improve practice.

    PubMed

    Fava, Maurizio; Rush, A John

    2006-01-01

    Most patients with major depressive disorder (MDD) do not reach symptom remission. These patients with residual symptoms have worse function and worse prognosis than those who remit. Several augmentation and combination treatments are used to either increase the chances of achieving remission or to eliminate/minimize residual depressive symptoms. Evidence for these pharmacological approaches rests primarily on open, uncontrolled studies, and there are clearly not enough controlled studies. Clinicians should carefully weigh these different treatment options to increase their patients' chances of achieving and sustaining remission from depression. This paper will review the pertinent studies and will propose a novel approach to improve practice involving the use of augmentation or combination strategies at the outset of initial treatment to primarily enhance the chances of remission through synergy and/or a broader spectrum of action. This novel approach could potentially enhance retention and/or increase remission rates since the lack of response with antidepressant monotherapy may lead many depressed patients with little or no benefit to drop out of treatment, precluding the subsequent use of augmentation or combination strategies altogether. In addition, the emergence of certain side-effects (e.g., agitation, insomnia) or the persistence of some initial baseline symptoms (e.g., anxiety, insomnia) may lead to premature discontinuation from monotherapy in the absence of concomitant use of augmenting pharmacological options targeting these symptoms.

  15. Augmenting saturated LTP by broadly spaced episodes of theta-burst stimulation in hippocampal area CA1 of adult rats and mice

    PubMed Central

    Cao, Guan

    2014-01-01

    Hippocampal long-term potentiation (LTP) is a model system for studying cellular mechanisms of learning and memory. Recent interest in mechanisms underlying the advantage of spaced over massed learning has prompted investigation into the effects of distributed episodes of LTP induction. The amount of LTP induced in hippocampal area CA1 by one train (1T) of theta-burst stimulation (TBS) in young Sprague-Dawley rats was further enhanced by additional bouts of 1T given at 1-h intervals. However, in young Long-Evans (LE) rats, 1T did not initially saturate LTP. Instead, a stronger LTP induction paradigm using eight trains of TBS (8T) induced saturated LTP in hippocampal slices from both young and adult LE rats as well as adult mice. The saturated LTP induced by 8T could be augmented by another episode of 8T following an interval of at least 90 min. The success rate across animals and slices in augmenting LTP by an additional episode of 8T increased significantly with longer intervals between the first and last episodes, ranging from 0% at 30- and 60-min intervals to 13–66% at 90- to 180-min intervals to 90–100% at 240-min intervals. Augmentation above initially saturated LTP was blocked by the N-methyl-d-aspartate (NMDA) glutamate receptor antagonist d-2-amino-5-phosphonovaleric acid (d-APV). These findings suggest that the strength of induction and interval between episodes of TBS, as well as the strain and age of the animal, are important components in the augmentation of LTP. PMID:25057146

  16. A Discourse Approach to Theorising HRD: Opening a Discursive Space

    ERIC Educational Resources Information Center

    Lawless, Aileen; Sambrook, Sally; Garavan, Tom; Valentin, Claire

    2011-01-01

    Purpose: The purpose of this paper is to discuss how a discourse approach to theorising human resource development (HRD) can open a "discursive space" to challenge dominant discourses within the field; enabling a more critical discourse to emerge. Design/methodology/approach: Discusses two approaches to discourse analysis, a "practice" and a…

  17. A Precision Microbiome Approach Using Sucrose for Selective Augmentation of Staphylococcus epidermidis Fermentation against Propionibacterium acnes

    PubMed Central

    Wang, Yanhan; Kao, Ming-Shan; Yu, Jinghua; Huang, Stephen; Marito, Shinta; Gallo, Richard L.; Huang, Chun-Ming

    2016-01-01

    Acne dysbiosis happens when there is a microbial imbalance of the over-growth of Propionibacterium acnes (P. acnes) in the acne microbiome. In our previous study, we demonstrated that Staphylococcus epidermidis (S. epidermidis, a probiotic skin bacterium) can exploit glycerol fermentation to produce short-chain fatty acids (SCFAs) which have antimicrobial activities to suppress the growth of P. acnes. Unlike glycerol, sucrose is chosen here as a selective fermentation initiator (SFI) that can specifically intensify the fermentation activity of S. epidermidis, but not P. acnes. A co-culture of P. acnes and fermenting S. epidermidis in the presence of sucrose significantly led to a reduction in the growth of P. acnes. The reduction was abolished when P. acnes was co-cultured with non-fermenting S. epidermidis. Results from nuclear magnetic resonance (NMR) analysis revealed four SCFAs (acetic acid, butyric acid, lactic acid, and succinic acid) were detectable in the media of S. epidermidis sucrose fermentation. To validate the interference of S. epidermidis sucrose fermentation with P. acnes, mouse ears were injected with both P. acnes and S. epidermidis plus sucrose or phosphate buffered saline (PBS). The level of macrophage-inflammatory protein-2 (MIP-2) and the number of P. acnes in ears injected with two bacteria plus sucrose were considerably lower than those in ears injected with two bacteria plus PBS. Our results demonstrate a precision microbiome approach by using sucrose as a SFI for S. epidermidis, holding future potential as a novel modality to equilibrate dysbiotic acne. PMID:27834859

  18. A Precision Microbiome Approach Using Sucrose for Selective Augmentation of Staphylococcus epidermidis Fermentation against Propionibacterium acnes.

    PubMed

    Wang, Yanhan; Kao, Ming-Shan; Yu, Jinghua; Huang, Stephen; Marito, Shinta; Gallo, Richard L; Huang, Chun-Ming

    2016-11-09

    Acne dysbiosis happens when there is a microbial imbalance of the over-growth of Propionibacterium acnes (P. acnes) in the acne microbiome. In our previous study, we demonstrated that Staphylococcus epidermidis (S. epidermidis, a probiotic skin bacterium) can exploit glycerol fermentation to produce short-chain fatty acids (SCFAs) which have antimicrobial activities to suppress the growth of P. acnes. Unlike glycerol, sucrose is chosen here as a selective fermentation initiator (SFI) that can specifically intensify the fermentation activity of S. epidermidis, but not P. acnes. A co-culture of P. acnes and fermenting S. epidermidis in the presence of sucrose significantly led to a reduction in the growth of P. acnes. The reduction was abolished when P. acnes was co-cultured with non-fermenting S. epidermidis. Results from nuclear magnetic resonance (NMR) analysis revealed four SCFAs (acetic acid, butyric acid, lactic acid, and succinic acid) were detectable in the media of S. epidermidis sucrose fermentation. To validate the interference of S. epidermidis sucrose fermentation with P. acnes, mouse ears were injected with both P. acnes and S. epidermidis plus sucrose or phosphate buffered saline (PBS). The level of macrophage-inflammatory protein-2 (MIP-2) and the number of P. acnes in ears injected with two bacteria plus sucrose were considerably lower than those in ears injected with two bacteria plus PBS. Our results demonstrate a precision microbiome approach by using sucrose as a SFI for S. epidermidis, holding future potential as a novel modality to equilibrate dysbiotic acne.

  19. Chin augmentation

    MedlinePlus

    ... chisel to make a second cut through the jaw bone. The jaw bone is moved and wired or screwed in ... see the final appearance of your chin and jaw for 3 to 4 months. Alternative Names Augmentation ...

  20. Formal Approaches to Ensuring the Safety of Space Software

    NASA Technical Reports Server (NTRS)

    Denney, Ewen; Fischer, Bernd

    2006-01-01

    A viewgraph describing formal approaches taken to assure the safety of space software is presented. The topics include: 1) Certifiable Program Generation; 2) Certification Framework; 3) Annotation Generation; 4) Experiments; and 5) Future Work.

  1. An approach to design knowledge capture for the space station

    NASA Technical Reports Server (NTRS)

    Wechsler, D. B.; Crouse, K. R.

    1986-01-01

    The design of NASA's space station has begun. During the design cycle, and after activation of the space station, the reoccurring need will exist to access not only designs, but also deeper knowledge about the designs, which is only hinted in the design definition. Areas benefiting from this knowledge include training, fault management, and onboard automation. NASA's Artificial Intelligence Office at Johnson Space Center and The MITRE Corporation have conceptualized an approach for capture and storage of design knowledge.

  2. Cooperative synthesis of control and display augmentation for a STOL aircraft in the approach and landing task

    NASA Technical Reports Server (NTRS)

    Garg, Sanjay; Schmidt, David K.

    1988-01-01

    Application of the Cooperative methodology to synthesize control/display augmentation systems for the piloted longitudinal landing task with a modern, statically-unstable, fighter aircraft is considered. Starting with a control augmentation law which yields augmented vehicle dynamics that meet Level I handling qualities specifications, the effect of time-delay in the Head-up-display is studied using model-based criterion. This evaluation showed that even with 'good' conventional dynamics, a realistic value of display time-delay will cause significant deterioration in pilot workload and piloted-system performance. Application of the Cooperative methodology to control augmentation alone resulted in augmented vehicle dynamics which provide direct control of the flight path from the pilot stick. Analytical evaluation of these dynamics indicates that such dynamics might lead to improved pilot ratings over conventional dynamics, especially in the presence of time-delays in the system. Also, application of the methodology to simultaneous synthesis of control augmentation and flight director laws revealed that it might be advantageous to consider the control/display trade-off in the early design stages.

  3. Human Augmentics: augmenting human evolution.

    PubMed

    Kenyon, Robert V; Leigh, Jason

    2011-01-01

    Human Augmentics (HA) refers to technologies for expanding the capabilities, and characteristics of humans. One can think of Human Augmentics as the driving force in the non-biological evolution of humans. HA devices will provide technology to compensate for human biological limitations either natural or acquired. The strengths of HA lie in its applicability to all humans. Its interoperability enables the formation of ecosystems whereby augmented humans can draw from other realms such as "the Cloud" and other augmented humans for strength. The exponential growth in new technologies portends such a system but must be designed for interaction through the use of open-standards and open-APIs for system development. We discuss the conditions needed for HA to flourish with an emphasis on devices that provide non-biological rehabilitation.

  4. Approaches to radiation guidelines for space travel

    SciTech Connect

    Fry, R.J.M.

    1984-01-01

    There are obvious risks in space travel that have loomed larger than any risk from radiation. Nevertheless, NASA has maintained a radiation program that has involved maintenance of records of radiation exposure, and planning so that the astronauts' exposures are kept as low as possible, and not just within the current guidelines. These guidelines are being reexamined currently by NCRP Committee 75 because new information is available, for example, risk estimates for radiation-induced cancer and about the effects of HZE particles. Furthermore, no estimates of risk or recommendations were made for women in 1970 and must now be considered. The current career limit is 400 rem. The appropriateness of this limit and its basis are being examined as well as the limits for specific organs. There is now considerably more information about age-dependency for radiation and this will be taken into account. Work has been carried out on the so-called microlesions caused by HZE particles and on the relative carcinogenic effect of heavy ions, including iron. A remaining question is whether the fluence of HZE particles could reach levels of concern in missions under consideration. Finally, it is the intention of the committee to indicate clearly the areas requiring further research. 21 references, 1 figure, 7 tables.

  5. Mirror contamination in space I: approach

    NASA Astrophysics Data System (ADS)

    Krijger, J. M.; Snel, R.; van Harten, G.; Rietjens, J. H. H.; Aben, I.

    2014-02-01

    We present a comprehensive model that can be employed to describe and correct for degradation of (scan) mirrors and diffusers in satellite instruments that suffer from changing optical UV-VIS properties during their operational lifetime. As trend studies become more important, so does the importance to understand and correct for this degradation. This is the case not only with respect to the transmission of the optical components, but also with respect to wavelength, polarisation or scan-angle-effects. Our hypothesis is that mirrors in-flight suffer from the deposition of a thin absorbing layer of contaminant, which slowly builds up over time. We describe this with the Mueller matrix formalism and Fresnel equations for thin multi-layer contamination films. Special care is taken to avoid the confusion often present in earlier publications concerning Mueller matrix calculus with out of plane reflections. The method can be applied to any UV-VIS satellite instrument, and in any orbit, both low and geostationary. We illustrate and verify our approach on the optical behaviour of the multiple scan mirrors of SCIAMACHY (on board of ENVISAT).

  6. Flight evaluation of stabilization and command augmentation system concepts and cockpit displays during approach and landing of powered-lift STOL aircraft

    NASA Technical Reports Server (NTRS)

    Franklin, J. A.; Innis, R. C.; Hardy, G. H.

    1980-01-01

    A flight research program was conducted to assess the effectiveness of manual control concepts and various cockpit displays in improving altitude (pitch, roll, and yaw) and longitudinal path control during short takeoff aircraft approaches and landings. Satisfactory flying qualities were demonstrared to minimum decision heights of 30 m (100 ft) for selected stabilization and command augmentation systems and flight director combinations. Precise landings at low touchdown sink rates were achieved with a gentle flare maneuver.

  7. Effects of ATC automation on precision approaches to closely space parallel runways

    NASA Technical Reports Server (NTRS)

    Slattery, R.; Lee, K.; Sanford, B.

    1995-01-01

    Improved navigational technology (such as the Microwave Landing System and the Global Positioning System) installed in modern aircraft will enable air traffic controllers to better utilize available airspace. Consequently, arrival traffic can fly approaches to parallel runways separated by smaller distances than are currently allowed. Previous simulation studies of advanced navigation approaches have found that controller workload is increased when there is a combination of aircraft that are capable of following advanced navigation routes and aircraft that are not. Research into Air Traffic Control automation at Ames Research Center has led to the development of the Center-TRACON Automation System (CTAS). The Final Approach Spacing Tool (FAST) is the component of the CTAS used in the TRACON area. The work in this paper examines, via simulation, the effects of FAST used for aircraft landing on closely spaced parallel runways. The simulation contained various combinations of aircraft, equipped and unequipped with advanced navigation systems. A set of simulations was run both manually and with an augmented set of FAST advisories to sequence aircraft, assign runways, and avoid conflicts. The results of the simulations are analyzed, measuring the airport throughput, aircraft delay, loss of separation, and controller workload.

  8. Experiences of non-progressive and augmented labour among nulliparous women: a qualitative interview study in a Grounded Theory approach

    PubMed Central

    Kjaergaard, Hanne; Foldgast, Anne Maria; Dykes, Anna-Karin

    2007-01-01

    Background Non-progressive labour is the most common complication in nulliparas and is primarily treated by augmentation. Augmented labour is often terminated by instrumental delivery. Little qualitative research has addressed experiences of non-progressive and augmented deliveries. The aim of this study was to gain a deeper understanding of the experience of non-progressive and augmented labour among nulliparas and their experience of the care they received. Methods A qualitative study was conducted using individual interviews. Data was collected and analysed according to the Grounded Theory method. The participants were a purposive sample of ten women. The interviews were conducted 4–15 weeks after delivery. Results The women had contrasting experiences during the birth process. During labour there was a conflict between the expectation of having a natural delivery and actually having a medical delivery. The women experienced a feeling of separation between mind and body. Interacting with the midwife had a major influence on feelings of losing and regaining control. Reconciliation between the contrasting feelings during labour was achieved. The core category was named Dialectical Birth Process and comprised three categories: Balancing natural and medical delivery, Interacting, Losing and regaining control. Conclusion A dialectical process was identified in these women's experiences of non-progressive labour. The process is susceptible to interaction with the midwife; especially her support to the woman's feeling of being in control. Midwives should secure that the woman's recognition of the fact that the labour is non-progressive and augmentation is required is handled with respect for the dialectical process. Augmentation of labour should be managed as close to the course of natural labour and delivery as possible. PMID:17662152

  9. Toward a global space exploration program: A stepping stone approach

    NASA Astrophysics Data System (ADS)

    Ehrenfreund, Pascale; McKay, Chris; Rummel, John D.; Foing, Bernard H.; Neal, Clive R.; Masson-Zwaan, Tanja; Ansdell, Megan; Peter, Nicolas; Zarnecki, John; Mackwell, Steve; Perino, Maria Antionetta; Billings, Linda; Mankins, John; Race, Margaret

    2012-01-01

    In response to the growing importance of space exploration in future planning, the Committee on Space Research (COSPAR) Panel on Exploration (PEX) was chartered to provide independent scientific advice to support the development of exploration programs and to safeguard the potential scientific assets of solar system objects. In this report, PEX elaborates a stepwise approach to achieve a new level of space cooperation that can help develop world-wide capabilities in space science and exploration and support a transition that will lead to a global space exploration program. The proposed stepping stones are intended to transcend cross-cultural barriers, leading to the development of technical interfaces and shared legal frameworks and fostering coordination and cooperation on a broad front. Input for this report was drawn from expertise provided by COSPAR Associates within the international community and via the contacts they maintain in various scientific entities. The report provides a summary and synthesis of science roadmaps and recommendations for planetary exploration produced by many national and international working groups, aiming to encourage and exploit synergies among similar programs. While science and technology represent the core and, often, the drivers for space exploration, several other disciplines and their stakeholders (Earth science, space law, and others) should be more robustly interlinked and involved than they have been to date. The report argues that a shared vision is crucial to this linkage, and to providing a direction that enables new countries and stakeholders to join and engage in the overall space exploration effort. Building a basic space technology capacity within a wider range of countries, ensuring new actors in space act responsibly, and increasing public awareness and engagement are concrete steps that can provide a broader interest in space exploration, worldwide, and build a solid basis for program sustainability. By engaging

  10. a Web Service Approach for Linking Sensors and Cellular Spaces

    NASA Astrophysics Data System (ADS)

    Isikdag, U.

    2013-09-01

    More and more devices are starting to be connected to the Internet. In the future the Internet will not only be a communication medium for people, it will in fact be a communication environment for devices. The connected devices which are also referred as Things will have an ability to interact with other devices over the Internet, i.) provide information in interoperable form and ii.) consume /utilize such information with the help of sensors embedded in them. This overall concept is known as Internet-of- Things (IoT). This requires new approaches to be investigated for system architectures to establish relations between spaces and sensors. The research presented in this paper elaborates on an architecture developed with this aim, i.e. linking spaces and sensors using a RESTful approach. The objective is making spaces aware of (sensor-embedded) devices, and making devices aware of spaces in a loosely coupled way (i.e. a state/usage/function change in the spaces would not have effect on sensors, similarly a location/state/usage/function change in sensors would not have any effect on spaces). The proposed architecture also enables the automatic assignment of sensors to spaces depending on space geometry and sensor location.

  11. Space Network Control Conference on Resource Allocation Concepts and Approaches

    NASA Technical Reports Server (NTRS)

    Moe, Karen L. (Editor)

    1991-01-01

    The results are presented of the Space Network Control (SNC) Conference. In the late 1990s, when the Advanced Tracking and Data Relay Satellite System is operational, Space Network communication services will be supported and controlled by the SNC. The goals of the conference were to survey existing resource allocation concepts and approaches, to identify solutions applicable to the Space Network, and to identify avenues of study in support of the SNC development. The conference was divided into three sessions: (1) Concepts for Space Network Allocation; (2) SNC and User Payload Operations Control Center (POCC) Human-Computer Interface Concepts; and (3) Resource Allocation Tools, Technology, and Algorithms. Key recommendations addressed approaches to achieving higher levels of automation in the scheduling process.

  12. Pilot-optimal augmentation synthesis

    NASA Technical Reports Server (NTRS)

    Schmidt, D. K.

    1978-01-01

    An augmentation synthesis method usable in the absence of quantitative handling qualities specifications, and yet explicitly including design objectives based on pilot-rating concepts, is presented. The algorithm involves the unique approach of simultaneously solving for the stability augmentation system (SAS) gains, pilot equalization and pilot rating prediction via optimal control techniques. Simultaneous solution is required in this case since the pilot model (gains, etc.) depends upon the augmented plant dynamics, and the augmentation is obviously not a priori known. Another special feature is the use of the pilot's objective function (from which the pilot model evolves) to design the SAS.

  13. In-Flight Suppression of a Destabilized F/A-18 Structural Mode Using the Space Launch System Adaptive Augmenting Control System

    NASA Technical Reports Server (NTRS)

    Wall, John H.; VanZwieten, Tannen S.; Gilligan, Eric T.; Miller, Christopher J.; Hanson, Curtis E.; Orr, Jeb S.

    2015-01-01

    NASA's Space Launch System (SLS) Flight Control System (FCS) includes an Adaptive Augmenting Control (AAC) component which employs a multiplicative gain update law to enhance the performance and robustness of the baseline control system for extreme off nominal scenarios. The SLS FCS algorithm including AAC has been flight tested utilizing a specially outfitted F/A-18 fighter jet in which the pitch axis control of the aircraft was performed by a Non-linear Dynamic Inversion (NDI) controller, SLS reference models, and the SLS flight software prototype. This paper describes test cases from the research flight campaign in which the fundamental F/A-18 airframe structural mode was identified using frequency-domain reconstruction of flight data, amplified to result in closed loop instability, and suppressed in-flight by the SLS adaptive control system.

  14. In-Flight Suppression of an Unstable F/A-18 Structural Mode Using the Space Launch System Adaptive Augmenting Control System

    NASA Technical Reports Server (NTRS)

    VanZwieten, Tannen S.; Gilligan, Eric T.; Wall, John H.; Miller, Christopher J.; Hanson, Curtis E.; Orr, Jeb S.

    2015-01-01

    NASA's Space Launch System (SLS) Flight Control System (FCS) includes an Adaptive Augmenting Control (AAC) component which employs a multiplicative gain update law to enhance the performance and robustness of the baseline control system for extreme off-nominal scenarios. The SLS FCS algorithm including AAC has been flight tested utilizing a specially outfitted F/A-18 fighter jet in which the pitch axis control of the aircraft was performed by a Non-linear Dynamic Inversion (NDI) controller, SLS reference models, and the SLS flight software prototype. This paper describes test cases from the research flight campaign in which the fundamental F/A-18 airframe structural mode was identified using post-flight frequency-domain reconstruction, amplified to result in closed loop instability, and suppressed in-flight by the SLS adaptive control system.

  15. Magnetohydrodynamic Augmented Propulsion Experiment

    NASA Technical Reports Server (NTRS)

    Litchford, Ron J.; Cole, John; Lineberry, John; Chapman, Jim; Schmidt, Harold; Cook, Stephen (Technical Monitor)

    2002-01-01

    A fundamental obstacle to routine space access is the specific energy limitations associated with chemical fuels. In the case of vertical take-off, the high thrust needed for vertical liftoff and acceleration to orbit translates into power levels in the 10 GW range. Furthermore, useful payload mass fractions are possible only if the exhaust particle energy (i.e., exhaust velocity) is much greater than that available with traditional chemical propulsion. The electronic binding energy released by the best chemical reactions (e.g., LOX/LH2 for example, is less than 2 eV per product molecule (approx. 1.8 eV per H2O molecule), which translates into particle velocities less than 5 km/s. Useful payload fractions, however, will require exhaust velocities exceeding 15 km/s (i.e., particle energies greater than 20 eV). As an added challenge, the envisioned hypothetical RLV (reusable launch vehicle) should accomplish these amazing performance feats while providing relatively low acceleration levels to orbit (2-3g maximum). From such fundamental considerations, it is painfully obvious that planned and current RLV solutions based on chemical fuels alone represent only a temporary solution and can only result in minor gains, at best. What is truly needed is a revolutionary approach that will dramatically reduce the amount of fuel and size of the launch vehicle. This implies the need for new compact high-power energy sources as well as advanced accelerator technologies for increasing engine exhaust velocity. Electromagnetic acceleration techniques are of immense interest since they can be used to circumvent the thermal limits associated with conventional propulsion systems. This paper describes the Magnetohydrodynamic Augmented Propulsion Experiment (MAPX) being undertaken at NASA Marshall Space Flight Center (MSFC). In this experiment, a 1-MW arc heater is being used as a feeder for a 1-MW magnetohydrodynamic (MHD) accelerator. The purpose of the experiment is to demonstrate

  16. Enabling CSPA Operations Through Pilot Involvement in Longitudinal Approach Spacing

    NASA Technical Reports Server (NTRS)

    Battiste, Vernol (Technical Monitor); Pritchett, Amy

    2003-01-01

    Several major airports around the United States have, or plan to have, closely-spaced parallel runways. This project complemented current and previous research by examining the pilots ability to control their position longitudinally within their approach stream.This project s results considered spacing for separation from potential positions of wake vortices from the parallel approach. This preventive function could enable CSPA operations to very closely spaced runways. This work also considered how pilot involvement in longitudinal spacing could allow for more efficient traffic flow, by allowing pilots to keep their aircraft within tighter arrival slots then air traffic control (ATC) might be able to establish, and by maintaining space within the arrival stream for corresponding departure slots. To this end, this project conducted several research studies providing an analytic and computational basis for calculating appropriate aircraft spacings, experimental results from a piloted flight simulator test, and an experimental testbed for future simulator tests. The following sections summarize the results of these three efforts.

  17. Outlier Detection In Linear Regression Using Standart Parity Space Approach

    NASA Astrophysics Data System (ADS)

    Mustafa Durdag, Utkan; Hekimoglu, Serif

    2013-04-01

    Despite all technological advancements, outliers may occur due to some mistakes in engineering measurements. Before estimation of unknown parameters, aforementioned outliers must be detected and removed from the measurements. There are two main outlier detection methods: the conventional tests based on least square approach (e.g. Baarda, Pope etc.) and the robust tests (e.g. Huber, Hampel etc.) are used to identify outliers in a set of measurement. Standart Parity Space Approach is one of the important model-based Fault Detection and Isolation (FDI) technique that usually uses in Control Engineering. In this study the standart parity space method is used for outlier detection in linear regression. Our main goal is to compare success of two approaches of standart parity space method and conventional tests in linear regression through the Monte Carlo simulation with each other. The least square estimation is the most common estimator as known and it minimizes the sum of squared residuals. In standart parity space approach to eliminate unknown vector, the measurement vector projected onto the left null space of the coefficient matrix. Thus, the orthogonal condition of parity vector is satisfied and only the effects of noise vector noticed. The residual vector is derived from two cases that one is absence of an outlier; the other is occurrence of an outlier. Its likelihood function is used for determining the detection decision function for global Test. Localization decision function is calculated for each column of parity matrix and the maximum one of these values is accepted as an outlier. There are some results obtained from two different intervals that one of them is between 3σ and 6σ (small outlier) the other one is between 6σ and 12σ (large outlier) for outlier generator when the number of unknown parameter is chosen 2 and 3. The measure success rates (MSR) of Baarda's method is better than the standart parity space method when the confidence intervals are

  18. Nanotechnologies and regenerative medical approaches for space and terrestrial medicine.

    PubMed

    Grattoni, Alessandro; Tasciotti, Ennio; Fine, Daniel; Fernandez-Moure, Joseph S; Sakamoto, Jason; Hu, Ye; Weiner, Bradley; Ferrari, Mauro; Parazynski, Scott

    2012-11-01

    One purpose of the International Space Station (ISS) is to explore powerful new areas of biomedical science in microgravity. Recent advances in nanotechnology applied to medicine--what we now refer to as nano-medicine--and regenerative medicine have enormous untapped potential for future space and terrestrial medical applications. Novel means for drug delivery and nanoscale screening tools will one day benefit astronauts venturing to Mars and places beyond, while the space laboratory will foster advances in nanotechnologies for diagnostic and therapeutic tools to help our patients here on Earth. Herein we review a series of nanotechnologies and selected regenerative medical approaches and highlight key areas of ongoing and future investigation that will benefit both space and terrestrial medicine. These studies target significant areas of human disease such as osteoporosis, diabetes, radiation injury, and many others.

  19. An AI approach for scheduling space-station payloads at Kennedy Space Center

    NASA Technical Reports Server (NTRS)

    Castillo, D.; Ihrie, D.; Mcdaniel, M.; Tilley, R.

    1987-01-01

    The Payload Processing for Space-Station Operations (PHITS) is a prototype modeling tool capable of addressing many Space Station related concerns. The system's object oriented design approach coupled with a powerful user interface provide the user with capabilities to easily define and model many applications. PHITS differs from many artificial intelligence based systems in that it couples scheduling and goal-directed simulation to ensure that on-orbit requirement dates are satisfied.

  20. NASA Research For Instrument Approaches To Closely Spaced Parallel Runways

    NASA Technical Reports Server (NTRS)

    Elliott, Dawn M.; Perry, R. Brad

    2000-01-01

    Within the NASA Aviation Systems Capacity Program, the Terminal Area Productivity (TAP) Project is addressing airport capacity enhancements during instrument meteorological condition (IMC). The Airborne Information for Lateral Spacing (AILS) research within TAP has focused on an airborne centered approach for independent instrument approaches to closely spaced parallel runways using Differential Global Positioning System (DGPS) and Automatic Dependent Surveillance-Broadcast (ADS-B) technologies. NASA Langley Research Center (LaRC), working in partnership with Honeywell, Inc., completed in AILS simulation study, flight test, and demonstration in 1999 examining normal approaches and potential collision scenarios to runways with separation distances of 3,400 and 2,500 feet. The results of the flight test and demonstration validate the simulation study.

  1. Prediction of free air space in initial composting mixtures by a statistical design approach.

    PubMed

    Soares, Micaela A R; Quina, Margarida J; Quinta-Ferreira, Rosa

    2013-10-15

    Free air space (FAS) is a physical parameter that can play an important role in composting processes to maintain favourable aerobic conditions. Aiming to predict the FAS of initial composting mixtures, specific materials proportions ranged from 0 to 1 were tested for a case study comprising industrial potato peel, which is characterized by low air void volume, thus requiring additional components for its composting. The characterization and prediction of FAS for initial mixtures involving potato peel, grass clippings and rice husks (set A) or sawdust (set B) was accomplished by means of an augmented simplex-centroid mixture design approach. The experimental data were fitted to second order Scheffé polynomials. Synergistic or antagonistic effects of mixture proportions in the FAS response were identified from the surface and response trace plots in the FAS response. Moreover, a good agreement was achieved between the model predictions and supplementary experimental data. Moreover, theoretical and empirical approaches for estimating FAS available in literature were compared with the predictions generated by the mixture design approach. This study demonstrated that the mixture design methodology can be a valuable tool to predict the initial FAS of composting mixtures, specifically in making adjustments to improve composting processes containing primarily potato peel.

  2. A Proposal for the Common Safety Approach of Space Programs

    NASA Astrophysics Data System (ADS)

    Grimard, Max

    2002-01-01

    For all applications, business and systems related to Space programs, Quality is mandatory and is a key factor for the technical as well as the economical performances. Up to now the differences of applications (launchers, manned space-flight, sciences, telecommunications, Earth observation, planetary exploration, etc.) and the difference of technical culture and background of the leading countries (USA, Russia, Europe) have generally led to different approaches in terms of standards and processes for Quality. At a time where international cooperation is quite usual for the institutional programs and globalization is the key word for the commercial business, it is considered of prime importance to aim at common standards and approaches for Quality in Space Programs. For that reason, the International Academy of Astronautics has set up a Study Group which mandate is to "Make recommendations to improve the Quality, Reliability, Efficiency, and Safety of space programmes, taking into account the overall environment in which they operate : economical constraints, harsh environments, space weather, long life, no maintenance, autonomy, international co-operation, norms and standards, certification." The paper will introduce the activities of this Study Group, describing a first list of topics which should be addressed : Through this paper it is expected to open the discussion to update/enlarge this list of topics and to call for contributors to this Study Group.

  3. Approach to an Affordable and Sustainable Space Transportation System

    NASA Technical Reports Server (NTRS)

    McCleskey, Caey M.; Rhodes, R. E.; Robinson, J. W.; Henderson, E. M.

    2012-01-01

    This paper describes an approach and a general procedure for creating space transportation architectural concepts that are at once affordable and sustainable. Previous papers by the authors and other members of the Space Propulsion Synergy Team (SPST) focused on a functional system breakdown structure for an architecture and definition of high-payoff design techniques with a technology integration strategy. This paper follows up by using a structured process that derives architectural solutions focused on achieving life cycle affordability and sustainability. Further, the paper includes an example concept that integrates key design techniques discussed in previous papers. !

  4. Requirements and approach for a space tourism launch system

    NASA Astrophysics Data System (ADS)

    Penn, Jay P.; Lindley, Charles A.

    2003-01-01

    Market surveys suggest that a viable space tourism industry will require flight rates about two orders of magnitude higher than those required for conventional spacelift. Although enabling round-trip cost goals for a viable space tourism business are about 240/pound (529/kg), or 72,000/passenger round-trip, goals should be about 50/pound (110/kg) or approximately 15,000 for a typical passenger and baggage. The lower price will probably open space tourism to the general population. Vehicle reliabilities must approach those of commercial aircraft as closely as possible. This paper addresses the development of spaceplanes optimized for the ultra-high flight rate and high reliability demands of the space tourism mission. It addresses the fundamental operability, reliability, and cost drivers needed to satisfy this mission need. Figures of merit similar to those used to evaluate the economic viability of conventional commercial aircraft are developed, including items such as payload/vehicle dry weight, turnaround time, propellant cost per passenger, and insurance and depreciation costs, which show that infrastructure can be developed for a viable space tourism industry. A reference spaceplane design optimized for space tourism is described. Subsystem allocations for reliability, operability, and costs are made and a route to developing such a capability is discussed. The vehicle's ability to satisfy the traditional spacelift market is also shown.

  5. An integrated mission planning approach for the space exploration initiative

    SciTech Connect

    Coomes, E.P.; Dagle, J.E.; Bamberger, J.A.; Noffsinger, K.E.

    1992-01-01

    A fully integrated energy-based approach to mission planning is needed if the Space Exploration Initiative (SEI) is to succeed. Such an approach would reduce the number of new systems and technologies requiring development. The resultant horizontal commonality of systems and hardware would reduce the direct economic impact of SEI and provide an economic benefit by greatly enhancing our international technical competitiveness through technology spin-offs and through the resulting early return on investment. Integrated planning and close interagency cooperation must occur if the SEI is to achieve its goal of expanding the human presence into the solar system and be an affordable endeavor. An energy-based mission planning approach gives each mission planner the needed power, yet preserves the individuality of mission requirements and objectives while reducing the concessions mission planners must make. This approach may even expand the mission options available and enhance mission activities.

  6. An integrated mission planning approach for the Space Exploration Initiative

    SciTech Connect

    Coomes, E.P.; Dagle, J.E.; Bamberger, J.A.; Noffsinger, K.E.

    1992-08-01

    This report discusses a fully integrated energy-based approach to mission planning which is needed if the Space Exploration Initiative (SEI) is to succeed. Such an approach would reduce the number of new systems and technologies requiring development. The resultant horizontal commonality of systems and hardware would reduce the direct economic impact of SEI and provide an economic benefit by greatly enhancing our international technical competitiveness through technology spin-offs and through the resulting early return on investment. Integrated planning and close interagency cooperation must occur if the SEI is to achieve its goal of expanding the human presence into the solar system and be an affordable endeavor. An energy-based mission planning approach gives each mission planner the needed power, yet preserves the individuality of mission requirements and objectives while reducing the concessions mission planners must make. This approach may even expand the mission options available and enhance mission activities.

  7. Approach to transaction management for Space Station Freedom

    NASA Technical Reports Server (NTRS)

    Easton, C. R.; Cressy, Phil; Ohnesorge, T. E.; Hector, Garland

    1989-01-01

    An approach to managing the operations of the Space Station Freedom based on their external effects is described. It is assumed that there is a conflict-free schedule that, if followed, will allow only appropriate operations to occur. The problem is then reduced to that of ensuring that the operations initiated are within the limits allowed by the schedule, or that the external effects of such operations are within those allowed by the schedule. The main features of the currently adopted transaction management approach are discussed.

  8. Approach to transaction management for Space Station Freedom

    NASA Technical Reports Server (NTRS)

    Easton, C. R.; Cressy, Phil; Ohnesorge, T. E.; Hector, Garland

    1990-01-01

    The Space Station Freedom Manned Base (SSFMB) will support the operation of the many payloads that may be located within the pressurized modules or on external attachment points. The transaction management (TM) approach presented provides a set of overlapping features that will assure the effective and safe operation of the SSFMB and provide a schedule that makes potentially hazardous operations safe, allocates resources within the capability of the resource providers, and maintains an environment conducive to the operations planned. This approach provides for targets of opportunity and schedule adjustments that give the operators the flexibility to conduct a vast majority of their operations with no conscious involvement with the TM function.

  9. Approach to an Affordable and Productive Space Transportation System

    NASA Technical Reports Server (NTRS)

    McCleskey, Carey M.; Rhodes, Russel E.; Lepsch, Roger A.; Henderson, Edward M.; Robinson, John W.

    2012-01-01

    This paper describes an approach for creating space transportation architectures that are affordable, productive, and sustainable. The architectural scope includes both flight and ground system elements, and focuses on their compatibility to achieve a technical solution that is operationally productive, and also affordable throughout its life cycle. Previous papers by the authors and other members of the Space Propulsion Synergy Team (SPST) focused on space flight system engineering methods, along with operationally efficient propulsion system concepts and technologies. This paper follows up previous work by using a structured process to derive examples of conceptual architectures that integrate a number of advanced concepts and technologies. The examples are not intended to provide a near-term alternative architecture to displace current near-term design and development activity. Rather, the examples demonstrate an approach that promotes early investments in advanced system concept studies and trades (flight and ground), as well as in advanced technologies with the goal of enabling highly affordable, productive flight and ground space transportation systems.

  10. Nucleus-Dependent Valence-Space Approach to Nuclear Structure

    NASA Astrophysics Data System (ADS)

    Stroberg, S. R.; Calci, A.; Hergert, H.; Holt, J. D.; Bogner, S. K.; Roth, R.; Schwenk, A.

    2017-01-01

    We present a nucleus-dependent valence-space approach for calculating ground and excited states of nuclei, which generalizes the shell-model in-medium similarity renormalization group to an ensemble reference with fractionally filled orbitals. Because the ensemble is used only as a reference, and not to represent physical states, no symmetry restoration is required. This allows us to capture three-nucleon (3 N ) forces among valence nucleons with a valence-space Hamiltonian specifically targeted to each nucleus of interest. Predicted ground-state energies from carbon through nickel agree with results of other large-space ab initio methods, generally to the 1% level. In addition, we show that this new approach is required in order to obtain convergence for nuclei in the upper p and s d shells. Finally, we address the 1+/3+ inversion problem in 22Na and 46V. This approach extends the reach of ab initio nuclear structure calculations to essentially all light- and medium-mass nuclei.

  11. Space Missions Trade Space Generation and Assessment Using JPL Rapid Mission Architecture (RMA) Team Approach

    NASA Technical Reports Server (NTRS)

    Moeller, Robert C.; Borden, Chester; Spilker, Thomas; Smythe, William; Lock, Robert

    2011-01-01

    The JPL Rapid Mission Architecture (RMA) capability is a novel collaborative team-based approach to generate new mission architectures, explore broad trade space options, and conduct architecture-level analyses. RMA studies address feasibility and identify best candidates to proceed to further detailed design studies. Development of RMA first began at JPL in 2007 and has evolved to address the need for rapid, effective early mission architectural development and trade space exploration as a precursor to traditional point design evaluations. The RMA approach integrates a small team of architecture-level experts (typically 6-10 people) to generate and explore a wide-ranging trade space of mission architectures driven by the mission science (or technology) objectives. Group brainstorming and trade space analyses are conducted at a higher level of assessment across multiple mission architectures and systems to enable rapid assessment of a set of diverse, innovative concepts. This paper describes the overall JPL RMA team, process, and high-level approach. Some illustrative results from previous JPL RMA studies are discussed.

  12. Parapharyngeal space tumours: video-assisted minimally invasive transcervical approach.

    PubMed

    Pilolli, F; Giordano, L; Galli, A; Bussi, M

    2016-08-01

    The purpose of the present study was to evaluate the advantages of a video-assisted, minimally invasive transcervical approach to benign and malignant parapharyngeal space (PPS) tumours. Ten patients affected by benign and malignant PPS neoplasms underwent a combined transcervical and video-assisted minimally invasive approach, using Hopkins telescopes. We describe the operative technique and perform a review of the literature. Definitive histology revealed 3 pleomorphic adenomas, 2 schwannomas, 2 metastatic papillary thyroid carcinomas, one carcinoma ex pleomorphic adenoma, one cavernous haemangioma and one basal cell adenoma. Mean tumour size was 37.2 mm (range: 19-60). Operation time ranged from 75 min to 185 min (mean: 146.7). One case was converted to transcervical-transparotid approach. Patients were discharged on postoperative day 2-5. One patients presented hypoglossal nerve paresis. The minimally invasive video-assisted transcervical approach is safe and feasible for selected benign and malignant PPS tumours. Furthermore, it offers harmless dissection in a deep and narrow space, accurate haemostasis and continuous control of critical anatomic structures.

  13. Artificial intelligence approaches in space power systems automation at Marshall Space Flight Center

    NASA Technical Reports Server (NTRS)

    Weeks, David J.

    1988-01-01

    Various applications of AI to spacecraft electrical power systems are described. Particular attention is given to NICBES (nickel-cadmium battery expert system which is interfaced with the Hubble Space Telescope electrical power system test bed); the SSES; the three cooperating AI systems in the Space Station module power management and distribution system test bed; and I-DARE, the intelligent data reduction expert. It is found that the utilization of AI approaches permits comprehensive fault management and dynamic rescheduling capabilities for the electrical power system.

  14. A nonlinear state-space approach to hysteresis identification

    NASA Astrophysics Data System (ADS)

    Noël, J. P.; Esfahani, A. F.; Kerschen, G.; Schoukens, J.

    2017-02-01

    Most studies tackling hysteresis identification in the technical literature follow white-box approaches, i.e. they rely on the assumption that measured data obey a specific hysteretic model. Such an assumption may be a hard requirement to handle in real applications, since hysteresis is a highly individualistic nonlinear behaviour. The present paper adopts a black-box approach based on nonlinear state-space models to identify hysteresis dynamics. This approach is shown to provide a general framework to hysteresis identification, featuring flexibility and parsimony of representation. Nonlinear model terms are constructed as a multivariate polynomial in the state variables, and parameter estimation is performed by minimising weighted least-squares cost functions. Technical issues, including the selection of the model order and the polynomial degree, are discussed, and model validation is achieved in both broadband and sine conditions. The study is carried out numerically by exploiting synthetic data generated via the Bouc-Wen equations.

  15. General background and approach to multibody dynamics for space applications

    NASA Astrophysics Data System (ADS)

    Santini, Paolo; Gasbarri, Paolo

    2009-06-01

    Multibody dynamics for space applications is dictated by space environment such as space-varying gravity forces, orbital and attitude perturbations, control forces if any. Several methods and formulations devoted to the modeling of flexible bodies undergoing large overall motions were developed in recent years. Most of these different formulations were aimed to face one of the main problems concerning the analysis of spacecraft dynamics namely the reduction of computer simulation time. By virtue of this, the use of symbolic manipulation, recursive formulation and parallel processing algorithms were proposed. All these approaches fall into two categories, the one based on Newton/Euler methods and the one based on Lagrangian methods; both of them have their advantages and disadvantages although in general, Newtonian approaches lend to a better understanding of the physics of problems and in particular of the magnitude of the reactions and of the corresponding structural stresses. Another important issue which must be addressed carefully in multibody space dynamics is relevant to a correct choice of kinematics variables. In fact, when dealing with flexible multibody system the resulting equations include two different types of state variables, the ones associated with large (rigid) displacements and the ones associated with elastic deformations. These two sets of variables have generally two different time scales if we think of the attitude motion of a satellite whose period of oscillation, due to the gravity gradient effects, is of the same order of magnitude as the orbital period, which is much bigger than the one associated with the structural vibration of the satellite itself. Therefore, the numerical integration of the equations of the system represents a challenging problem. This was the abstract and some of the arguments that Professor Paolo Santini intended to present for the Breakwell Lecture; unfortunately a deadly disease attacked him and shortly took him

  16. Model-space approach to parity violation in heavy nuclei

    SciTech Connect

    Johnson, M.B.

    1996-06-01

    The model-space approach is the basis of both shell model and statistical spectroscopy analyses of nuclear phenomena. The goal of this session is to bring out the main theoretical issues involved in its application to parity violation in the compound nucleus. Section 1 of the current paper sets the stage for the session, and Sect. 2 introduces and explores the model-space formulation as it underlies quantitative connections that are being made between the mean-square matrix element M{sup 2} measured in polarized neutron scattering from compound nuclei and the underlying parity violating interaction. This is followed in the paper by Tomsovic by a description of how statistical spectroscopy is applied to this problem, and in the paper by Hayes by a discussion of shell-model aspects of parity violation in the compound nucleus.

  17. Hybrid x-space: a new approach for MPI reconstruction

    NASA Astrophysics Data System (ADS)

    Tateo, A.; Iurino, A.; Settanni, G.; Andrisani, A.; Stifanelli, P. F.; Larizza, P.; Mazzia, F.; Mininni, R. M.; Tangaro, S.; Bellotti, R.

    2016-06-01

    Magnetic particle imaging (MPI) is a new medical imaging technique capable of recovering the distribution of superparamagnetic particles from their measured induced signals. In literature there are two main MPI reconstruction techniques: measurement-based (MB) and x-space (XS). The MB method is expensive because it requires a long calibration procedure as well as a reconstruction phase that can be numerically costly. On the other side, the XS method is simpler than MB but the exact knowledge of the field free point (FFP) motion is essential for its implementation. Our simulation work focuses on the implementation of a new approach for MPI reconstruction: it is called hybrid x-space (HXS), representing a combination of the previous methods. Specifically, our approach is based on XS reconstruction because it requires the knowledge of the FFP position and velocity at each time instant. The difference with respect to the original XS formulation is how the FFP velocity is computed: we estimate it from the experimental measurements of the calibration scans, typical of the MB approach. Moreover, a compressive sensing technique is applied in order to reduce the calibration time, setting a fewer number of sampling positions. Simulations highlight that HXS and XS methods give similar results. Furthermore, an appropriate use of compressive sensing is crucial for obtaining a good balance between time reduction and reconstructed image quality. Our proposal is suitable for open geometry configurations of human size devices, where incidental factors could make the currents, the fields and the FFP trajectory irregular.

  18. Hybrid x-space: a new approach for MPI reconstruction.

    PubMed

    Tateo, A; Iurino, A; Settanni, G; Andrisani, A; Stifanelli, P F; Larizza, P; Mazzia, F; Mininni, R M; Tangaro, S; Bellotti, R

    2016-06-07

    Magnetic particle imaging (MPI) is a new medical imaging technique capable of recovering the distribution of superparamagnetic particles from their measured induced signals. In literature there are two main MPI reconstruction techniques: measurement-based (MB) and x-space (XS). The MB method is expensive because it requires a long calibration procedure as well as a reconstruction phase that can be numerically costly. On the other side, the XS method is simpler than MB but the exact knowledge of the field free point (FFP) motion is essential for its implementation. Our simulation work focuses on the implementation of a new approach for MPI reconstruction: it is called hybrid x-space (HXS), representing a combination of the previous methods. Specifically, our approach is based on XS reconstruction because it requires the knowledge of the FFP position and velocity at each time instant. The difference with respect to the original XS formulation is how the FFP velocity is computed: we estimate it from the experimental measurements of the calibration scans, typical of the MB approach. Moreover, a compressive sensing technique is applied in order to reduce the calibration time, setting a fewer number of sampling positions. Simulations highlight that HXS and XS methods give similar results. Furthermore, an appropriate use of compressive sensing is crucial for obtaining a good balance between time reduction and reconstructed image quality. Our proposal is suitable for open geometry configurations of human size devices, where incidental factors could make the currents, the fields and the FFP trajectory irregular.

  19. 14 CFR 117.17 - Flight duty period: Augmented flightcrew.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Flight duty period: Augmented flightcrew. 117.17 Section 117.17 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF...: Augmented flightcrew. (a) For flight operations conducted with an acclimated augmented flightcrew,...

  20. 14 CFR 117.17 - Flight duty period: Augmented flightcrew.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Flight duty period: Augmented flightcrew. 117.17 Section 117.17 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... period: Augmented flightcrew. (a) For flight operations conducted with an acclimated augmented...

  1. Alternative approaches to environmental regulation: Prescription, process, incentives and space

    SciTech Connect

    Cunningham, R.D.

    1997-08-01

    The aim of this paper is to perform a systematic, comparative analysis of several approaches to environmental regulation and planning. These include such approaches as prescription (Command-Control), process (EMS), incentives (Market Mechanisms), and space (New Urbanism). The wider analysis is timely given the attention that has been recently directed toward such new approaches as Environmental Management Systems (EMS) under ISO 14001. This paper will initially examine the aim, purpose, requirements, and outcomes of each of these alternative regimes. Doing this in terms of common considerations will facilitate a constructive analysis across all regimes. In turn, the advantages and disadvantages of each of these approaches will be analyzed. Relevant examples will be utilized to illustrate points. Rather than emphasizing the merits or demerits of one approach vs. another, it will be shown that a more constructive strategy would be to consider contextual factors when determining which regime or combination of regimes to apply. In this way, better guidance can be provided when considering possible regulatory alternatives thereby contributing to the more effective attainment of environmental planning goals.

  2. Quality factors for space radiation: A new approach.

    PubMed

    Borak, Thomas B; Heilbronn, Lawrence H; Townsend, Lawrence W; McBeth, Rafe A; de Wet, Wouter

    2014-04-01

    NASA has derived new models for radiological risk assessment based on epidemiological data and radiation biology including differences in Relative Biological Effectiveness for leukemia and solid tumors. Comprehensive approaches were used to develop new risk cross sections and the extension of these into recommendations for risk assessment during space missions. The methodology relies on published data generated and the extensive research initiative managed by the NASA Human Research Program (HRP) and reviewed by the National Academy of Sciences. This resulted in recommendations for revised specifications of quality factors, QNASA(Z,β) in terms of track structure concepts that extend beyond LET alone. The new paradigm for quality factors placed demands on radiation monitoring procedures that are not satisfied by existing dosimetry systems or particle spectrometers that are practical for space exploration where mass, volume, band width and power consumption are highly constrained. We have proposed a new definition of quality factors that relaxes the requirements for identifying charge, Z, and velocity, β, of the incident radiation while still preserving the functional form of the inherent risk functions. The departure from the exact description of QNASA(Z,β) is that the revised values are new functions of LET for solid cancers and leukemia. We present the motivation and process for developing the revised quality factors. We describe results of extensive simulations using GCR distributions in free space as well as the resulting spectra of primary and secondary particles behind aluminum shields and penetration through water. In all cases the revised dose averaged quality factors agreed with those based on the values obtained using QNASA(Z,β). This provides confidence that emerging technologies for space radiation dosimetry can provide real time measurements of dose and dose equivalent while satisfying constraints on size, mass, power and bandwidth. The revised

  3. Quality factors for space radiation: A new approach

    NASA Astrophysics Data System (ADS)

    Borak, Thomas B.; Heilbronn, Lawrence H.; Townsend, Lawrence W.; McBeth, Rafe A.; de Wet, Wouter

    2014-04-01

    NASA has derived new models for radiological risk assessment based on epidemiological data and radiation biology including differences in Relative Biological Effectiveness for leukemia and solid tumors. Comprehensive approaches were used to develop new risk cross sections and the extension of these into recommendations for risk assessment during space missions. The methodology relies on published data generated and the extensive research initiative managed by the NASA Human Research Program (HRP) and reviewed by the National Academy of Sciences. This resulted in recommendations for revised specifications of quality factors, QNASA (Z , β) in terms of track structure concepts that extend beyond LET alone. The new paradigm for quality factors placed demands on radiation monitoring procedures that are not satisfied by existing dosimetry systems or particle spectrometers that are practical for space exploration where mass, volume, band width and power consumption are highly constrained. We have proposed a new definition of quality factors that relaxes the requirements for identifying charge, Z, and velocity, β, of the incident radiation while still preserving the functional form of the inherent risk functions. The departure from the exact description of QNASA (Z , β) is that the revised values are new functions of LET for solid cancers and leukemia. We present the motivation and process for developing the revised quality factors. We describe results of extensive simulations using GCR distributions in free space as well as the resulting spectra of primary and secondary particles behind aluminum shields and penetration through water. In all cases the revised dose averaged quality factors agreed with those based on the values obtained using QNASA (Z , β). This provides confidence that emerging technologies for space radiation dosimetry can provide real time measurements of dose and dose equivalent while satisfying constraints on size, mass, power and bandwidth. The

  4. Predicting Space Weather Effects on Close Approach Events

    NASA Technical Reports Server (NTRS)

    Hejduk, Matthew D.; Newman, Lauri K.; Besser, Rebecca L.; Pachura, Daniel A.

    2015-01-01

    The NASA Robotic Conjunction Assessment Risk Analysis (CARA) team sends ephemeris data to the Joint Space Operations Center (JSpOC) for conjunction assessment screening against the JSpOC high accuracy catalog and then assesses risk posed to protected assets from predicted close approaches. Since most spacecraft supported by the CARA team are located in LEO orbits, atmospheric drag is the primary source of state estimate uncertainty. Drag magnitude and uncertainty is directly governed by atmospheric density and thus space weather. At present the actual effect of space weather on atmospheric density cannot be accurately predicted because most atmospheric density models are empirical in nature, which do not perform well in prediction. The Jacchia-Bowman-HASDM 2009 (JBH09) atmospheric density model used at the JSpOC employs a solar storm active compensation feature that predicts storm sizes and arrival times and thus the resulting neutral density alterations. With this feature, estimation errors can occur in either direction (i.e., over- or under-estimation of density and thus drag). Although the exact effect of a solar storm on atmospheric drag cannot be determined, one can explore the effects of JBH09 model error on conjuncting objects' trajectories to determine if a conjunction is likely to become riskier, less risky, or pass unaffected. The CARA team has constructed a Space Weather Trade-Space tool that systematically alters the drag situation for the conjuncting objects and recalculates the probability of collision for each case to determine the range of possible effects on the collision risk. In addition to a review of the theory and the particulars of the tool, the different types of observed output will be explained, along with statistics of their frequency.

  5. Verification of Space Weather Forecasts using Terrestrial Weather Approaches

    NASA Astrophysics Data System (ADS)

    Henley, E.; Murray, S.; Pope, E.; Stephenson, D.; Sharpe, M.; Bingham, S.; Jackson, D.

    2015-12-01

    The Met Office Space Weather Operations Centre (MOSWOC) provides a range of 24/7 operational space weather forecasts, alerts, and warnings, which provide valuable information on space weather that can degrade electricity grids, radio communications, and satellite electronics. Forecasts issued include arrival times of coronal mass ejections (CMEs), and probabilistic forecasts for flares, geomagnetic storm indices, and energetic particle fluxes and fluences. These forecasts are produced twice daily using a combination of output from models such as Enlil, near-real-time observations, and forecaster experience. Verification of forecasts is crucial for users, researchers, and forecasters to understand the strengths and limitations of forecasters, and to assess forecaster added value. To this end, the Met Office (in collaboration with Exeter University) has been adapting verification techniques from terrestrial weather, and has been working closely with the International Space Environment Service (ISES) to standardise verification procedures. We will present the results of part of this work, analysing forecast and observed CME arrival times, assessing skill using 2x2 contingency tables. These MOSWOC forecasts can be objectively compared to those produced by the NASA Community Coordinated Modelling Center - a useful benchmark. This approach cannot be taken for the other forecasts, as they are probabilistic and categorical (e.g., geomagnetic storm forecasts give probabilities of exceeding levels from minor to extreme). We will present appropriate verification techniques being developed to address these forecasts, such as rank probability skill score, and comparing forecasts against climatology and persistence benchmarks. As part of this, we will outline the use of discrete time Markov chains to assess and improve the performance of our geomagnetic storm forecasts. We will also discuss work to adapt a terrestrial verification visualisation system to space weather, to help

  6. An Expert System Approach to Large Space Systems Control

    DTIC Science & Technology

    1988-10-01

    ISPONSORING 8b. OFFICE SYMBOL 9. PROCUREMENT INSTRUMENT IDENTIFICATION NUMBER ORGANIZATION Of appil ,k) FOSR F49620-87- C --0105 8¢. ADDRESS (CRtY, Stat...oo...0 - An Expert System Approach To Large Space Systems Control Octobe 1988Accession For NTIS R& DTIC TAB C . GartrmII Unannounced E W...4.4.1 Case A: I Newton Harmonic Wave with a Frequency of 0.14 Hz 4-12 4.4.2 Case B: 1 Newton Impulse at x = 2.5 m 4-13 4.4.3 Case C : Traveling Wave with

  7. Monitoring Atmospheric CO2 From Space: Challenge & Approach

    NASA Technical Reports Server (NTRS)

    Lin, Bing; Harrison, F. Wallace; Nehrir, Amin; Browell, Edward; Dobler, Jeremy; Campbell, Joel; Meadows, Byron; Obland, Michael; Kooi, Susan; Fan, Tai-Fang; Ismail, Syed

    2015-01-01

    Atmospheric CO2 is the key radiative forcing for the Earth's climate and may contribute a major part of the Earth's warming during the past 150 years. Advanced knowledge on the CO2 distributions and changes can lead considerable model improvements in predictions of the Earth's future climate. Large uncertainties in the predictions have been found for decades owing to limited CO2 observations. To obtain precise measurements of atmospheric CO2, certain challenges have to be overcome. For an example, global annual means of the CO2 are rather stable, but, have a very small increasing trend that is significant for multi-decadal long-term climate. At short time scales (a second to a few hours), regional and subcontinental gradients in the CO2 concentration are very small and only in an order of a few parts per million (ppm) compared to the mean atmospheric CO2 concentration of about 400 ppm, which requires atmospheric CO2 space monitoring systems with extremely high accuracy and precision (about 0.5 ppm or 0.125%) in spatiotemporal scales around 75 km and 10-s. It also requires a decadal-scale system stability. Furthermore, rapid changes in high latitude environments such as melting ice, snow and frozen soil, persistent thin cirrus clouds in Amazon and other tropical areas, and harsh weather conditions over Southern Ocean all increase difficulties in satellite atmospheric CO2 observations. Space lidar approaches using Integrated Path Differential Absorption (IPDA) technique are considered to be capable of obtaining precise CO2 measurements and, thus, have been proposed by various studies including the 2007 Decadal Survey (DS) of the U.S. National Research Council. This study considers to use the Intensity-Modulated Continuous-Wave (IM-CW) lidar to monitor global atmospheric CO2 distribution and variability from space. Development and demonstration of space lidar for atmospheric CO2 measurements have been made through joint adventure of NASA Langley Research Center and

  8. Medical care capabilities for Space Station Freedom: A phase approach

    NASA Astrophysics Data System (ADS)

    Doarn, C. R.; Lloyd, C. W.

    1992-05-01

    As a result of Congressional mandate Space Station Freedom (SSF) was restructured. This restructuring activity has affected the capabilities for providing medical care on board the station. This presentation addresses the health care facility to be built and used on the orbiting space station. This unit, named the Health Maintenance Facility (HMF) is based on and modeled after remote, terrestrial medical facilities. It will provide a phased approach to health care for the crews of SSF. Beginning with a stabilization and transport phase, HMF will expand to provide the most advanced state of the art therapeutic and diagnostic capabilities. This presentation details the capabilities of such a phased HMF. As Freedom takes form over the next decade there will be ever-increasing engineering and scientific developmental activities. The HMF will evolve with this process until it eventually reaches a mature, complete stand-alone health care facility that provides a foundation to support interplanetary travel. As man's experience in space continues to grow so will the ability to provide advanced health care for Earth-orbital and exploratory missions as well.

  9. Medical care capabilities for Space Station Freedom: A phase approach

    NASA Technical Reports Server (NTRS)

    Doarn, C. R.; Lloyd, C. W.

    1992-01-01

    As a result of Congressional mandate Space Station Freedom (SSF) was restructured. This restructuring activity has affected the capabilities for providing medical care on board the station. This presentation addresses the health care facility to be built and used on the orbiting space station. This unit, named the Health Maintenance Facility (HMF) is based on and modeled after remote, terrestrial medical facilities. It will provide a phased approach to health care for the crews of SSF. Beginning with a stabilization and transport phase, HMF will expand to provide the most advanced state of the art therapeutic and diagnostic capabilities. This presentation details the capabilities of such a phased HMF. As Freedom takes form over the next decade there will be ever-increasing engineering and scientific developmental activities. The HMF will evolve with this process until it eventually reaches a mature, complete stand-alone health care facility that provides a foundation to support interplanetary travel. As man's experience in space continues to grow so will the ability to provide advanced health care for Earth-orbital and exploratory missions as well.

  10. Compositional Space Parameterization Approach for Reservoir Flow Simulation

    NASA Astrophysics Data System (ADS)

    Voskov, D.

    2011-12-01

    Phase equilibrium calculations are the most challenging part of a compositional flow simulation. For every gridblock and at every time step, the number of phases and their compositions must be computed for the given overall composition, temperature, and pressure conditions. The conventional approach used in petroleum industry is based on performing a phase-stability test, and solving the fugacity constraints together with the coupled nonlinear flow equations when the gridblock has more than one phase. The multi-phase compositional space can be parameterized in terms of tie-simplexes. For example, a tie-triangle can be used such that its interior encloses the three-phase region, and the edges represent the boundary with specific two-phase regions. The tie-simplex parameterization can be performed for pressure, temperature, and overall composition. The challenge is that all of these parameters can change considerably during the course of a simulation. It is possible to prove that the tie-simplexes change continuously with respect to pressure, temperature, and overall composition. The continuity of the tie-simplex parameterization allows for interpolation using discrete representations of the tie-simplex space. For variations of composition, a projection to the nearest tie-simplex is used, and if the tie-simplex is within a predefined tolerance, it can be used directly to identify the phase-state of this composition. In general, our parameterization approach can be seen as the generalization of negative flash idea for systems with two or more phases. Theory of dispersion-free compositional displacements, as well as computational experience of general-purpose compositional flow simulation indicates that the displacement path in compositional space is determined by a limited number of tie-simplexes. Therefore, only few tie-simplex tables are required to parameterize the entire displacement. The small number of tie-simplexes needed in a course of a simulation motivates

  11. L1 Adaptive Control Augmentation System with Application to the X-29 Lateral/Directional Dynamics: A Multi-Input Multi-Output Approach

    NASA Technical Reports Server (NTRS)

    Griffin, Brian Joseph; Burken, John J.; Xargay, Enric

    2010-01-01

    This paper presents an L(sub 1) adaptive control augmentation system design for multi-input multi-output nonlinear systems in the presence of unmatched uncertainties which may exhibit significant cross-coupling effects. A piecewise continuous adaptive law is adopted and extended for applicability to multi-input multi-output systems that explicitly compensates for dynamic cross-coupling. In addition, explicit use of high-fidelity actuator models are added to the L1 architecture to reduce uncertainties in the system. The L(sub 1) multi-input multi-output adaptive control architecture is applied to the X-29 lateral/directional dynamics and results are evaluated against a similar single-input single-output design approach.

  12. Motion simulator study of longitudinal stability requirements for large delta wing transport airplanes during approach and landing with stability augmentation systems failed

    NASA Technical Reports Server (NTRS)

    Snyder, C. T.; Fry, E. B.; Drinkwater, F. J., III; Forrest, R. D.; Scott, B. C.; Benefield, T. D.

    1972-01-01

    A ground-based simulator investigation was conducted in preparation for and correlation with an-flight simulator program. The objective of these studies was to define minimum acceptable levels of static longitudinal stability for landing approach following stability augmentation systems failures. The airworthiness authorities are presently attempting to establish the requirements for civil transports with only the backup flight control system operating. Using a baseline configuration representative of a large delta wing transport, 20 different configurations, many representing negative static margins, were assessed by three research test pilots in 33 hours of piloted operation. Verification of the baseline model to be used in the TIFS experiment was provided by computed and piloted comparisons with a well-validated reference airplane simulation. Pilot comments and ratings are included, as well as preliminary tracking performance and workload data.

  13. New Approaches to Waterproofing of Space Shuttle Insulating Materials

    NASA Technical Reports Server (NTRS)

    Blum, Yigal D.; Johnson, Sylvia M.; Chen, Paul

    1997-01-01

    Future reusable space vehicles will be in service much more frequently than current space shuttles. Therefore, rapid reconditioning of spacecraft will be required. Currently, the waterproofing of space shuttles after each re-entry takes 72 hours and requires substantial labor. In addition, the currently used waterproofing reagent, DiMethylEthoxySilane (DMES), is considered toxic, and ethanol fumes are released during its hydrolytic activation. Consequently, a long time period, which is not acceptable for future operations, is needed to ensure that 0 the excess volatile compounds are removed before further maintenance of the space vehicle can be performed. The objective of this project was to assist NASA Ames in finding improved waterproofing systems by identifying suitable waterproofing agents that can be applied by vapor phase deposition and will be less toxic, bond more rapidly to the insulation material surface, and potentially have higher thermal stability than the DMES system. Several approaches to achieve faster waterproofing with less toxicity were assessed using the following alternatives: Reactive volatile compounds that are rapidly deposited by chemical bonding at the surface and leave no toxic volatiles. Reactive reagents that are the least toxic. Nonvolatile reagents that are very reactive and bond strongly to the insulating material surface. Three specific types of potential reagents were chosen for evaluation in this project: 1. Volatile reagents with Si-Cl functional groups for vapor deposition 2. Volatile reagents with Si-H functional groups for vapor deposition 3. Nonvolatile oligomeric or polymeric reactive siloxanes that are assumed to have higher thermal stability and/or strong bonding to the insulating material. The chemistry involved in the project was targeted at the generation of intermediates having reactive Si-OH bonds for the formation of either volatile species or polymeric species that bond rapidly to the surface and also cure rapidly

  14. Carbon turnover in pore spaces - CIPS model approach

    NASA Astrophysics Data System (ADS)

    Kuka, Katrin

    2010-05-01

    The CIPS (Carbon turnover In Pore Spaces) model has been developed to overcome the constraints of conceptual pools and to get a better insight into the nature of carbon stabilization in soil (KUKA, 2007). This pure carbon turnover model was implemented in CANDY (CArbon and Nitrogen Dynamics) model system (Franko, 1995). The CIPS model did overcome the empirical pools taking into account soil structure effects. It is based on quality driven primary stabilisation mechanism (recalcitrance of SOM) and process driven secondary stabilisation mechanism (place of turnover) of SOM in soil. In addition to the division of SOM in the qualitative pools on the basis of chemical measurability, a dependence of the turnover conditions from the location of SOM in pore space is implemented taking into account different turnover conditions in the particular pore space and the accessibility for microbial biomass. The main assumption of the CIPS model is that the biological activity is not evenly distributed through the whole pore space. The pore space classes - micro, meso and macro pores - used in the model are marked by wilting point, field capacity and pore volume as a first approach. Because of the poor aeration in the micro pores they show very low biological activity leading to a strong protection of the carbon localized in this pore space. The biological active time (BAT) concept of the CANDY model was adapted to the CIPS model in order to calculate the distribution of biological activity for each pore space class. The reduction functions of the turnover active time concept of CANDY model, related to soil temperature, soil moisture, soil texture, relative air volume and distance to the soil surface are multiplied by the step width of calendar time producing the transformed time step as total BAT (BATtot). The calculated BATtot corresponds to the time that would be required under optimal conditions in the laboratory to perform the same turnover result as under the given

  15. Space Culture: Innovative Cultural Approaches To Public Engagement With Astronomy, Space Science And Astronautics

    NASA Astrophysics Data System (ADS)

    Malina, Roger F.

    2012-01-01

    In recent years a number of cultural organizations have established ongoing programs of public engagement with astronomy, space science and astronautics. Many involve elements of citizen science initiatives, artists’ residencies in scientific laboratories and agencies, art and science festivals, and social network projects as well as more traditional exhibition venues. Recognizing these programs several agencies and organizations have established mechanisms for facilitating public engagement with astronomy and space science through cultural activities. The International Astronautics Federation has established an Technical Activities Committee for the Cultural Utilization of Space. Over the past year the NSF and NEA have organized disciplinary workshops to develop recommendations relating to art-science interaction and community building efforts. Rationales for encouraging public engagement via cultural projects range from theory of creativity, innovation and invention to cultural appropriation in the context of `socially robust science’ as advocated by Helga Nowotny of the European Research Council. Public engagement with science, as opposed to science education and outreach initiatives, require different approaches. Just as organizations have employed education professionals to lead education activities, so they must employ cultural professionals if they wish to develop public engagement projects via arts and culture. One outcome of the NSF and NEA workshops has been development of a rationale for converting STEM to STEAM by including the arts in STEM methodologies, particularly for K-12 where students can access science via arts and cultural contexts. Often these require new kinds of informal education approaches that exploit locative media, gaming platforms, artists projects and citizen science. Incorporating astronomy and space science content in art and cultural projects requires new skills in `cultural translation’ and `trans-mediation’ and new kinds

  16. An innovative approach of risk planning for space programs.

    PubMed

    Ray, P

    2000-07-01

    According to the current rule-based risk management approach at the National Aeronautics and Space Administration (NASA), the effort is directed to contain all identified risks of a program. The identification of hazards and mitigation effort proceeds along with the development of the system hardware, till all the tradable resources for a program is exhausted. In this process, no conscious effort is made to evaluate risks and associated cost, and the final design is likely to have undesirable residual risks. This approach also results in allocating a significant amount of resources to gain only marginal mitigation of hazard and leave some undesirable hazards in the system due to the budget limitation. The approach in the proposed knowledge-based risk planning system makes a conscious attempt to trade risk with other resources, e.g., schedule, cost, reliability, performance, and others in a judicious and cost-effective way. A knowledge of the feasible option sets requiring high incremental cost for a marginal gain in hazard reduction helps the management to make decision for residual risk that falls within an acceptable range for an option set.

  17. Augmented Reality for Close Quarters Combat

    SciTech Connect

    2013-09-20

    Sandia National Laboratories has developed a state-of-the-art augmented reality training system for close-quarters combat (CQB). This system uses a wearable augmented reality system to place the user in a real environment while engaging enemy combatants in virtual space (Boston Dynamics DI-Guy). Umbra modeling and simulation environment is used to integrate and control the AR system.

  18. Augmented Reality for Close Quarters Combat

    ScienceCinema

    None

    2016-07-12

    Sandia National Laboratories has developed a state-of-the-art augmented reality training system for close-quarters combat (CQB). This system uses a wearable augmented reality system to place the user in a real environment while engaging enemy combatants in virtual space (Boston Dynamics DI-Guy). Umbra modeling and simulation environment is used to integrate and control the AR system.

  19. NASA Communications Augmentation network

    NASA Technical Reports Server (NTRS)

    Omidyar, Guy C.; Butler, Thomas E.; Laios, Straton C.

    1990-01-01

    The NASA Communications (Nascom) Division of the Mission Operations and Data Systems Directorate (MO&DSD) is to undertake a major initiative to develop the Nascom Augmentation (NAUG) network to achieve its long-range service objectives for operational data transport to support the Space Station Freedom Program, the Earth Observing System (EOS), and other projects. The NAUG is the Nascom ground communications network being developed to accommodate the operational traffic of the mid-1990s and beyond. The NAUG network development will be based on the Open Systems Interconnection Reference Model (OSI-RM). This paper describes the NAUG network architecture, subsystems, topology, and services; addresses issues of internetworking the Nascom network with other elements of the Space Station Information System (SSIS); discusses the operations environment. This paper also notes the areas of related research and presents the current conception of how the network will provide broadband services in 1998.

  20. Understanding space weather with new physical, mathematical and philosophical approaches

    NASA Astrophysics Data System (ADS)

    Mateev, Lachezar; Velinov, Peter; Tassev, Yordan

    2016-07-01

    The actual problems of solar-terrestrial physics, in particular of space weather are related to the prediction of the space environment state and are solved by means of different analyses and models. The development of these investigations can be considered also from another side. This is the philosophical and mathematical approach towards this physical reality. What does it constitute? We have a set of physical processes which occur in the Sun and interplanetary space. All these processes interact with each other and simultaneously participate in the general process which forms the space weather. Let us now consider the Leibniz's monads (G.W. von Leibniz, 1714, Monadologie, Wien; Id., 1710, Théodicée, Amsterdam) and use some of their properties. There are total 90 theses for monads in the Leibniz's work (1714), f.e. "(1) The Monad, of which we shall here speak, is nothing but a simple substance, which enters into compounds. By 'simple' is meant 'without parts'. (Theod. 10.); … (56) Now this connexion or adaptation of all created things to each and of each to all, means that each simple substance has relations which express all the others, and, consequently, that it is a perpetual living mirror of the universe. (Theod. 130, 360.); (59) … this universal harmony, according to which every substance exactly expresses all others through the relations it has with them. (63) … every Monad is, in its own way, a mirror of the universe, and the universe is ruled according to a perfect order. (Theod. 403.)", etc. Let us introduce in the properties of monads instead of the word "monad" the word "process". We obtain the following statement: Each process reflects all other processes and all other processes reflect this process. This analogy is not formal at all, it reflects accurately the relation between the physical processes and their unity. The category monad which in the Leibniz's Monadology reflects generally the philosophical sense is fully identical with the

  1. The development of the Final Approach Spacing Tool (FAST): A cooperative controller-engineer design approach

    NASA Technical Reports Server (NTRS)

    Lee, Katharine K.; Davis, Thomas J.

    1995-01-01

    Historically, the development of advanced automation for air traffic control in the United States has excluded the input of the air traffic controller until the need of the development process. In contrast, the development of the Final Approach Spacing Tool (FAST), for the terminal area controller, has incorporated the end-user in early, iterative testing. This paper describes a cooperative between the controller and the developer to create a tool which incorporates the complexity of the air traffic controller's job. This approach to software development has enhanced the usability of FAST and has helped smooth the introduction of FAST into the operational environment.

  2. A hierarchical state space approach to affective dynamics

    PubMed Central

    Lodewyckx, Tom; Tuerlinckx, Francis; Kuppens, Peter; Allen, Nicholas; Sheeber, Lisa

    2010-01-01

    Linear dynamical system theory is a broad theoretical framework that has been applied in various research areas such as engineering, econometrics and recently in psychology. It quantifies the relations between observed inputs and outputs that are connected through a set of latent state variables. State space models are used to investigate the dynamical properties of these latent quantities. These models are especially of interest in the study of emotion dynamics, with the system representing the evolving emotion components of an individual. However, for simultaneous modeling of individual and population differences, a hierarchical extension of the basic state space model is necessary. Therefore, we introduce a Bayesian hierarchical model with random effects for the system parameters. Further, we apply our model to data that were collected using the Oregon adolescent interaction task: 66 normal and 67 depressed adolescents engaged in a conflict interaction with their parents and second-to-second physiological and behavioral measures were obtained. System parameters in normal and depressed adolescents were compared, which led to interesting discussions in the light of findings in recent literature on the links between cardiovascular processes, emotion dynamics and depression. We illustrate that our approach is flexible and general: The model can be applied to any time series for multiple systems (where a system can represent any entity) and moreover, one is free to focus on whatever component of the versatile model. PMID:21516216

  3. TDRSS Augmentation System for Satellites

    NASA Technical Reports Server (NTRS)

    Heckler, Gregory W.; Gramling, Cheryl; Valdez, Jennifer; Baldwin, Philip

    2016-01-01

    In 2015, NASA Goddard Space Flight Center (GSFC) reinvigorated the development of the TDRSS Augmentation Service for Satellites (TASS). TASS is a global, space-based, communications and navigation service for users of Global Navigation Satellite Systems(GNSS) and the Tracking and Data Relay Satellite System (TDRSS). TASS leverages the existing TDRSS to provide an S-band beacon radio navigation and messaging source to users at orbital altitudes 1400 km and below.

  4. Image-guided transorbital procedures with endoscopic video augmentation

    PubMed Central

    DeLisi, Michael P.; Mawn, Louise A.; Galloway, Robert L.

    2014-01-01

    Purpose: Surgical interventions to the orbital space behind the eyeball are limited to highly invasive procedures due to the confined nature of the region along with the presence of several intricate soft tissue structures. A minimally invasive approach to orbital surgery would enable several therapeutic options, particularly new treatment protocols for optic neuropathies such as glaucoma. The authors have developed an image-guided system for the purpose of navigating a thin flexible endoscope to a specified target region behind the eyeball. Navigation within the orbit is particularly challenging despite its small volume, as the presence of fat tissue occludes the endoscopic visual field while the surgeon must constantly be aware of optic nerve position. This research investigates the impact of endoscopic video augmentation to targeted image-guided navigation in a series of anthropomorphic phantom experiments. Methods: A group of 16 surgeons performed a target identification task within the orbits of four skull phantoms. The task consisted of identifying the correct target, indicated by the augmented video and the preoperative imaging frames, out of four possibilities. For each skull, one orbital intervention was performed with video augmentation, while the other was done with the standard image guidance technique, in random order. Results: The authors measured a target identification accuracy of 95.3% and 85.9% for the augmented and standard cases, respectively, with statistically significant improvement in procedure time (Z = −2.044, p = 0.041) and intraoperator mean procedure time (Z = 2.456, p = 0.014) when augmentation was used. Conclusions: Improvements in both target identification accuracy and interventional procedure time suggest that endoscopic video augmentation provides valuable additional orientation and trajectory information in an image-guided procedure. Utilization of video augmentation in transorbital interventions could further minimize

  5. A Web Based Approach to Integrate Space Culture and Education

    NASA Astrophysics Data System (ADS)

    Gerla, F.

    2002-01-01

    , who can use it to prepare their lessons, retrieve information and organize the didactic material in order to support their lessons. We think it important to use a user centered "psychology" based on UM: we have to know the needs and expectations of the students. Our intent is to use usability tests not just to prove the site effectiveness and clearness, but also to investigate aesthetical preferences of children and young people. Physics, mathematics, chemistry are just some of the difficult learning fields connected with space technologies. Space culture is a potentially never-ending field, and our scope will be to lead students by hand in this universe of knowledge. This paper will present MARS activities in the framework of the above methodologies aimed at implementing a web based approach to integrate space culture and education. The activities are already in progress and some results will be presented in the final paper.

  6. Novel Approaches to Cellular Transplantation from the US Space Program

    NASA Technical Reports Server (NTRS)

    Pellis, Neal R.; Homick, Jerry L. (Technical Monitor)

    1999-01-01

    Research in the treatment of type I diabetes is entering a new era that takes advantage of our knowledge in an ever increasing variety of scientific disciplines. Some may originate from very diverse sources, one of which is the Space Program at National Aeronautics and Space Administration (NASA). The Space Program contributes to diabetes-related research in several treatment modalities. As an ongoing effort for medical monitoring of personnel involved in space exploration activities NASA and the extramural scientific community investigate strategies for noninvasive estimation of blood glucose levels. Part of the effort in the space protein crystal growth program is high-resolution structural analysis insulin as a means to better understand the interaction with its receptor and with host immune components and as a basis for rational design of a "better" insulin molecule. The Space Program is also developing laser technology for potential early cataract detection as well as a noninvasive analyses for addressing preclinical diabetic retinopathy. Finally, NASA developed an exciting cell culture system that affords some unique advantages in the propagation and maintenance of mammalian cells in vitro. The cell culture system was originally designed to maintain cell suspensions with a minimum of hydrodynamic and mechanical sheer while awaiting launch into microgravity. Currently the commercially available NASA bioreactor (Synthecon, Inc., Houston, TX) is used as a research tool in basic and applied cell biology. In recent years there is continued strong interest in cellular transplantation as treatment for type I diabetes. The advantages are the potential for successful long-term amelioration and a minimum risk for morbidity in the event of rejection of the transplanted cells. The pathway to successful application of this strategy is accompanied by several substantial hurdles: (1) isolation and propagation of a suitable uniform donor cell population; (2) management of

  7. System analysis approach to deriving design criteria (loads) for Space Shuttle and its payloads. Volume 1: General statement of approach

    NASA Technical Reports Server (NTRS)

    Ryan, R. S.; Bullock, T.; Holland, W. B.; Kross, D. A.; Kiefling, L. A.

    1981-01-01

    Space shuttle, the most complex transportation system designed to date, illustrates the requirement for an analysis approach that considers all major disciplines simultaneously. Its unique cross coupling and high sensitivity to aerodynamic uncertainties and high performance requirements dictated a less conservative approach than those taken in programs. Analyses performed for the space shuttle and certain payloads, Space Telescope and Spacelab, are used a examples. These illustrate the requirements for system analysis approaches and criteria, including dynamic modeling requirements, test requirements control requirements and the resulting design verification approaches. A survey of the problem, potential approaches available as solutions, implications for future systems, and projected technology development areas are addressed.

  8. An Open and Holistic Approach for Geo and Space Sciences

    NASA Astrophysics Data System (ADS)

    Ritschel, Bernd; Seelus, Christoph; Neher, Günther; Toshihiko, Iyemori; Yatagai, Akiyo; Koyama, Yukinobu; Murayama, Yasuhiro; King, Todd; Hughes, Steve; Fung, Shing; Galkin, Ivan; Hapgood, Mike; Belehaki, Anna

    2016-04-01

    Geo and space sciences thus far have been very successful, even often an open, cross-domain and holistic approach did not play an essential role. But this situation is changing rapidly. The research focus is shifting into more complex, non-linear and multi-domain specified phenomena, such as e.g. climate change or space environment. This kind of phenomena only can be understood step by step using the holistic idea. So, what is necessary for a successful cross-domain and holistic approach in geo and space sciences? Research and science in general become more and more dependent from a rich fundus of multi-domain data sources, related context information and the use of highly advanced technologies in data processing. Such buzzword phrases as Big Data and Deep Learning are reflecting this development. Big Data also addresses the real exponential growing of data and information produced by measurements or simulations. Deep Learning technology may help to detect new patterns and relationships in data describing high sophisticated natural phenomena. And further on, we should not forget science and humanities are only two sides of the same medal in the continuing human process of knowledge discovery. The concept of Open Data or in particular the open access to scientific data is addressing the free and open availability of -at least publicly founded and generated- data. The open availability of data covers the free use, reuse and redistribution of data which have been established with the formation of World Data Centers already more than 50 years ago. So, we should not forget, the foundation for open data is the responsibility of the individual scientist up until the big science institutions and organizations for a sustainable management of data. Other challenges are discovering and collecting the appropriate data, and preferably all of them or at least the majority of the right data. Therefore a network of individual or even better institutional catalog-based and at least

  9. Augmentation cystoplasty in neurogenic bladder

    PubMed Central

    Kocjancic, Ervin; Demirdağ, Çetin

    2016-01-01

    The aim of this review is to update the indications, contraindications, technique, complications, and the tissue engineering approaches of augmentation cystoplasty (AC) in patients with neurogenic bladder. PubMed/MEDLINE was searched for the keywords "augmentation cystoplasty," "neurogenic bladder," and "bladder augmentation." Additional relevant literature was determined by examining the reference lists of articles identified through the search. The update review of of the indications, contraindications, technique, outcome, complications, and tissue engineering approaches of AC in patients with neurogenic bladder is presented. Although some important progress has been made in tissue engineering AC, conventional AC still has an important role in the surgical treatment of refractory neurogenic lower urinary tract dysfunction. PMID:27617312

  10. Analysis of multinomial models with unknown index using data augmentation

    USGS Publications Warehouse

    Royle, J. Andrew; Dorazio, R.M.; Link, W.A.

    2007-01-01

    Multinomial models with unknown index ('sample size') arise in many practical settings. In practice, Bayesian analysis of such models has proved difficult because the dimension of the parameter space is not fixed, being in some cases a function of the unknown index. We describe a data augmentation approach to the analysis of this class of models that provides for a generic and efficient Bayesian implementation. Under this approach, the data are augmented with all-zero detection histories. The resulting augmented dataset is modeled as a zero-inflated version of the complete-data model where an estimable zero-inflation parameter takes the place of the unknown multinomial index. Interestingly, data augmentation can be justified as being equivalent to imposing a discrete uniform prior on the multinomial index. We provide three examples involving estimating the size of an animal population, estimating the number of diabetes cases in a population using the Rasch model, and the motivating example of estimating the number of species in an animal community with latent probabilities of species occurrence and detection.

  11. Towards synthetic biological approaches to resource utilization on space missions

    PubMed Central

    Menezes, Amor A.; Cumbers, John; Hogan, John A.; Arkin, Adam P.

    2015-01-01

    This paper demonstrates the significant utility of deploying non-traditional biological techniques to harness available volatiles and waste resources on manned missions to explore the Moon and Mars. Compared with anticipated non-biological approaches, it is determined that for 916 day Martian missions: 205 days of high-quality methane and oxygen Mars bioproduction with Methanobacterium thermoautotrophicum can reduce the mass of a Martian fuel-manufacture plant by 56%; 496 days of biomass generation with Arthrospira platensis and Arthrospira maxima on Mars can decrease the shipped wet-food mixed-menu mass for a Mars stay and a one-way voyage by 38%; 202 days of Mars polyhydroxybutyrate synthesis with Cupriavidus necator can lower the shipped mass to three-dimensional print a 120 m3 six-person habitat by 85% and a few days of acetaminophen production with engineered Synechocystis sp. PCC 6803 can completely replenish expired or irradiated stocks of the pharmaceutical, thereby providing independence from unmanned resupply spacecraft that take up to 210 days to arrive. Analogous outcomes are included for lunar missions. Because of the benign assumptions involved, the results provide a glimpse of the intriguing potential of ‘space synthetic biology’, and help focus related efforts for immediate, near-term impact. PMID:25376875

  12. NAESA Augmentation Pilot Project

    NASA Technical Reports Server (NTRS)

    Hoover, John J.

    1998-01-01

    This project was one project within the Native American Earth and Space Academy (NAESA). NAESA is a national initiative comprised of several organizations that support programs which focus on 1) enhancing the technological, scientific and pedagogical skills of K-14 teachers who instruct Native Americans, 2) enhancing the understanding and applications of science, technology, and engineering of college-bound Native Americans and teaching them general college "survival skills" (e.g., test taking, time management, study habits), 3) enhancing the scientific and pedagogical skills of the faculty of tribally-controllcd colleges and community colleges with large Native American enrollments, and 4) strengthening the critical relationships between students, their parents, tribal elders, and their communities. This Augmentation Pilot Project focused on the areas of community-school alliances and intemet technology use in teaching and learning and daily living addressing five major objectives.

  13. Augmented Virtual Reality Laboratory

    NASA Technical Reports Server (NTRS)

    Tully-Hanson, Benjamin

    2015-01-01

    Real time motion tracking hardware has for the most part been cost prohibitive for research to regularly take place until recently. With the release of the Microsoft Kinect in November 2010, researchers now have access to a device that for a few hundred dollars is capable of providing redgreenblue (RGB), depth, and skeleton data. It is also capable of tracking multiple people in real time. For its original intended purposes, i.e. gaming, being used with the Xbox 360 and eventually Xbox One, it performs quite well. However, researchers soon found that although the sensor is versatile, it has limitations in real world applications. I was brought aboard this summer by William Little in the Augmented Virtual Reality (AVR) Lab at Kennedy Space Center to find solutions to these limitations.

  14. NASA's approach to the commercial use of space

    NASA Technical Reports Server (NTRS)

    Gillam, I. T., IV

    1984-01-01

    NASA planning activities in the area of commercial development of space resources are reviewed. Examples of specific types of commercial space ventures are given, according to three different categories: new commercial high-technology ventures; new commercial application of existing space technology, and commercial ventures resulting from the transfer of existing space programs to the private sector. Basic objectives for reducing technical, financial and institutional risks for commercial space operations are considered. Attention is given to the cooperative working environment encouraged by Joint Endeavor Agreements (JEAs) and Technical Exchange Agreements (TEAs) between industrial organizations in the development of space systems. Benefits of the commercial development of space resources include the production of purer pharmaceuticals for the treatment of cancers, kidney diseases, and diabetes; and the development of ultra-pure semiconductor crystals for use in next generation electronic equipment.

  15. An MDO augmented value-based systems engineering approach to holistic design decision-making: A satellite system case study

    NASA Astrophysics Data System (ADS)

    Kannan, Hanumanthrao

    The design of large scale complex engineered systems (LSCES) involves hundreds or thousands of designers making decisions at different levels of an organizational hierarchy. Traditionally, these LSCES are designed using systems engineering methods and processes, where the preferences of the stakeholder are flowed down the hierarchy using requirements that act as surrogates for preference. Current processes do not provide a system level guidance to subsystem designers. Value-Driven Design (VDD) offers a new perspective on complex system design, where the value preferences of the stakeholder are communicated directly through a decomposable value function, thereby providing a mechanism for improved system consistency. Requirements-based systems engineering approaches do not offer a mathematically rigorous way to capture the couplings present in the system. Multidisciplinary Design Optimization (MDO) was specifically developed to address couplings in both analysis and optimization thereby enabling physics-based consistency. MDO uses an objective function with constraints but does not provide a way to formulate the objective function. Current systems engineering processes do not provide a mathematically sound way to make design decisions when designers are faced with uncertainties. Designers tend to choose designs based on their preferences towards risky/uncertain designs, and past research has shown that there needs to be a consistency in risk preferences to enable design decisions that are consistent with stakeholder's desires. This research exploits the complimentary nature of VDD, MDO and Decision Analysis (DA) to enable consistency in communication of system preferences, consistency in physics and consistency in risk preferences. The role of VDD in this research is in formulating a value function for true preferences, whereas the role of MDO is to capture couplings and enable optimization using the value function, and the role of DA is to enable consistent design

  16. A Systems Approach to Developing an Affordable Space Ground Transportation Architecture using a Commonality Approach

    NASA Technical Reports Server (NTRS)

    Garcia, Jerry L.; McCleskey, Carey M.; Bollo, Timothy R.; Rhodes, Russel E.; Robinson, John W.

    2012-01-01

    This paper presents a structured approach for achieving a compatible Ground System (GS) and Flight System (FS) architecture that is affordable, productive and sustainable. This paper is an extension of the paper titled "Approach to an Affordable and Productive Space Transportation System" by McCleskey et al. This paper integrates systems engineering concepts and operationally efficient propulsion system concepts into a structured framework for achieving GS and FS compatibility in the mid-term and long-term time frames. It also presents a functional and quantitative relationship for assessing system compatibility called the Architecture Complexity Index (ACI). This paper: (1) focuses on systems engineering fundamentals as it applies to improving GS and FS compatibility; (2) establishes mid-term and long-term spaceport goals; (3) presents an overview of transitioning a spaceport to an airport model; (4) establishes a framework for defining a ground system architecture; (5) presents the ACI concept; (6) demonstrates the approach by presenting a comparison of different GS architectures; and (7) presents a discussion on the benefits of using this approach with a focus on commonality.

  17. A risk-based approach to flammable gas detector spacing.

    PubMed

    Defriend, Stephen; Dejmek, Mark; Porter, Leisa; Deshotels, Bob; Natvig, Bernt

    2008-11-15

    Flammable gas detectors allow an operating company to address leaks before they become serious, by automatically alarming and by initiating isolation and safe venting. Without effective gas detection, there is very limited defense against a flammable gas leak developing into a fire or explosion that could cause loss of life or escalate to cascading failures of nearby vessels, piping, and equipment. While it is commonly recognized that some gas detectors are needed in a process plant containing flammable gas or volatile liquids, there is usually a question of how many are needed. The areas that need protection can be determined by dispersion modeling from potential leak sites. Within the areas that must be protected, the spacing of detectors (or alternatively, number of detectors) should be based on risk. Detector design can be characterized by spacing criteria, which is convenient for design - or alternatively by number of detectors, which is convenient for cost reporting. The factors that influence the risk are site-specific, including process conditions, chemical composition, number of potential leak sites, piping design standards, arrangement of plant equipment and structures, design of isolation and depressurization systems, and frequency of detector testing. Site-specific factors such as those just mentioned affect the size of flammable gas cloud that must be detected (within a specified probability) by the gas detection system. A probability of detection must be specified that gives a design with a tolerable risk of fires and explosions. To determine the optimum spacing of detectors, it is important to consider the probability that a detector will fail at some time and be inoperative until replaced or repaired. A cost-effective approach is based on the combined risk from a representative selection of leakage scenarios, rather than a worst-case evaluation. This means that probability and severity of leak consequences must be evaluated together. In marine and

  18. Space-Wise approach for airborne gravity data modelling

    NASA Astrophysics Data System (ADS)

    Sampietro, D.; Capponi, M.; Mansi, A. H.; Gatti, A.; Marchetti, P.; Sansò, F.

    2016-12-01

    Regional gravity field modelling by means of remove-compute-restore procedure is nowadays widely applied in different contexts: it is the most used technique for regional gravimetric geoid determination, and it is also used in exploration geophysics to predict grids of gravity anomalies (Bouguer, free-air, isostatic, etc.), which are useful to understand and map geological structures in a specific region. Considering this last application, due to the required accuracy and resolution, airborne gravity observations are usually adopted. However, due to the relatively high acquisition velocity, presence of atmospheric turbulence, aircraft vibration, instrumental drift, etc., airborne data are usually contaminated by a very high observation error. For this reason, a proper procedure to filter the raw observations in both the low and high frequencies should be applied to recover valuable information. In this work, a software to filter and grid raw airborne observations is presented: the proposed solution consists in a combination of an along-track Wiener filter and a classical Least Squares Collocation technique. Basically, the proposed procedure is an adaptation to airborne gravimetry of the Space-Wise approach, developed by Politecnico di Milano to process data coming from the ESA satellite mission GOCE. Among the main differences with respect to the satellite application of this approach, there is the fact that, while in processing GOCE data the stochastic characteristics of the observation error can be considered a-priori well known, in airborne gravimetry, due to the complex environment in which the observations are acquired, these characteristics are unknown and should be retrieved from the dataset itself. The presented solution is suited for airborne data analysis in order to be able to quickly filter and grid gravity observations in an easy way. Some innovative theoretical aspects focusing in particular on the theoretical covariance modelling are presented too

  19. Decomposing Large Inverse Problems with an Augmented Lagrangian Approach: Application to Joint Inversion of Body-Wave Travel Times and Surface-Wave Dispersion Measurements

    NASA Astrophysics Data System (ADS)

    Reiter, D. T.; Rodi, W. L.

    2015-12-01

    Constructing 3D Earth models through the joint inversion of large geophysical data sets presents numerous theoretical and practical challenges, especially when diverse types of data and model parameters are involved. Among the challenges are the computational complexity associated with large data and model vectors and the need to unify differing model parameterizations, forward modeling methods and regularization schemes within a common inversion framework. The challenges can be addressed in part by decomposing the inverse problem into smaller, simpler inverse problems that can be solved separately, providing one knows how to merge the separate inversion results into an optimal solution of the full problem. We have formulated an approach to the decomposition of large inverse problems based on the augmented Lagrangian technique from optimization theory. As commonly done, we define a solution to the full inverse problem as the Earth model minimizing an objective function motivated, for example, by a Bayesian inference formulation. Our decomposition approach recasts the minimization problem equivalently as the minimization of component objective functions, corresponding to specified data subsets, subject to the constraints that the minimizing models be equal. A standard optimization algorithm solves the resulting constrained minimization problems by alternating between the separate solution of the component problems and the updating of Lagrange multipliers that serve to steer the individual solution models toward a common model solving the full problem. We are applying our inversion method to the reconstruction of the·crust and upper-mantle seismic velocity structure across Eurasia.· Data for the inversion comprise a large set of P and S body-wave travel times·and fundamental and first-higher mode Rayleigh-wave group velocities.

  20. Basic approaches to and tasks of space technology

    NASA Technical Reports Server (NTRS)

    Okhotin, A. S.

    1978-01-01

    The high vacuum and weightlessness of outer space offer great possibilities for the new field of space technology. To take advantage of this, it is necessary to study such physical and chemical phenomena as diffusion, surface tension, heat exchange, and crystallization. The research shows the possibility of obtaining materials with a more perfect structure. Methods of treating materials can be used in space which are impossible on earth. Achievements in material science in outer space will have a large impact on the national economy.

  1. Stacks Management: An Organic Approach to Growing Space

    ERIC Educational Resources Information Center

    Case, Jackie L.; Ingram, Marion Thorp

    2006-01-01

    Most library buildings were built thirty or more years ago. As a result libraries are sharing a common situation. There is little or no room to add more books onto the shelves, and there are odd spaces throughout the stacks which are not being used. Jackson Library, University of North Carolina at Greensboro, faced this challenge and grew space by…

  2. A new conceptual design approach for habitative space modules

    NASA Astrophysics Data System (ADS)

    Burattini, C.; Bisegna, F.; Gugliermetti, F.; Marchetti, M.

    2014-04-01

    Existing Space modules were designed to meet the standards established by NASA, basically oriented to functionality. In future Space environments a high level of habitability in long duration missions will become a priority: besides comfort and ergonomics, these habitats will require the application of criteria to address human needs for living in confined environments.

  3. Visions for Space Exploration: ILS Issues and Approaches

    NASA Technical Reports Server (NTRS)

    Watson, Kevin

    2005-01-01

    This viewgraph presentation reviews some of the logistic issues that the Vision for Space Exploration will entail. There is a review of the vision and the timeline for the return to the moon that will lead to the first human exploration of Mars. The lessons learned from the International Space Station (ISS) and other such missions are also reviewed.

  4. Space commerce in a global economy - Comparison of international approaches to commercial space

    NASA Technical Reports Server (NTRS)

    Stone, Barbara A.; Kleber, Peter

    1992-01-01

    A historical perspective, current status, and comparison of national government/commercial space industry relationships in the United States and Europe are presented. It is noted that space technology has been developed and used primarily to meet the needs of civil and military government initiatives. Two future trends of space technology development include new space enterprises, and the national drive to achieve a more competitive global economic position.

  5. An automated, integrated approach to Space Station structural modeling

    NASA Technical Reports Server (NTRS)

    Lindenmoyer, Alan J.; Habermeyer, John A.

    1989-01-01

    NASA and its contractors have developed an integrated, interdisciplinary CAD/analysis system designated IDEAS(double asterisk)2 in order to conduct evaluations of alternative Space Station concepts' performance over the projected course of the Station's evolution in orbit. Attention is presently given to the requirements associated with automated FEM-building methods applicable to Space Station system-level structural dynamic analysis, and the ways in which IDEAS(double asterisk)2 addresses these requirements. Advantage is taken of the interactive capabilities of the SUPERTAB FEM preprocessor system for Space Station model manipulation and modification.

  6. The liquid droplet radiator in space: A parametric approach

    NASA Astrophysics Data System (ADS)

    Buckner, Gerald L.; Tuttle, Ronald F.

    The Liquid Droplet Radiator (LDR) consists of a column or sheet of liquid droplets moving through space from a droplet generator to a collector. The droplets carry the waste heat generated by a space power system and radiate this waste heat directly to space during their flight. The liquid droplets are collected at a lower temperature, reheated and pumped to the generator and reused to remove waste heat from the thermodynamic power cycle. A parametric analysis is given of a cylindrical LDR to estimate its performance and operating characteristics using a new pump specific mass term.

  7. Approaches to the utilization of space for CO2 research

    NASA Technical Reports Server (NTRS)

    Glaser, P.; Aronson, J.; Brecher, A.; Csigi, K.; Mcarthur, R.

    1985-01-01

    A system study of the potential of space technology to monitor climate changes and improve the understanding of the coupling beteen CO2 and cloud cover is summarized. The basis for the study is scientific data requirements pertinent to the U.S. Department of Energy's CO2 Research Program. The capabilities of space-based sensor systems are matched to meet these requirements. New sensor system concepts are identified, including a Space Shuttle-launched recalibration package to provide for continuity of measurement and recalibration between satellites, a high-orbit radiation budget satellite, or parallax sensor to measure cloud altitude, a passive method for the direct measurements of CO2 and a high-altitude powered platform to monitor select regional parameters. Space-based sensor systems that could be the development focus for the time frames of 0-5, 5-10 and 10-20 years are recommended.

  8. A geometric approach to quantum control in projective hilbert spaces

    NASA Astrophysics Data System (ADS)

    Pastorello, Davide

    2017-02-01

    A quantum theory in a finite-dimensional Hilbert space can be formulated as a proper geometric Hamiltonian theory as explained in [2, 3, 7, 9]. From this point of view a quantum system can be described within a classical-like framework where quantum dynamics is represented by a Hamiltonian flow in the phase space given by a projective Hilbert space. This paper is devoted to investigating how the notion of an accessibility algebra from classical control theory can be applied within the geometric Hamiltonian formulation of quantum mechanics to study controllability of a quantum system. A new characterization of quantum controllability in terms of Killing vector fields w.r.t. the Fubini-Study metric on projective space is also discussed.

  9. Space Physics for Graduate Students: An Activities-Based Approach

    NASA Astrophysics Data System (ADS)

    Gross, N. A.; Arge, N.; Bruntz, R.; Burns, A. G.; Hughes, W. J.; Knipp, D.; Lyon, J.; McGregor, S.; Owens, M.; Siscoe, G.; Solomon, S. C.; Wiltberger, M.

    2009-01-01

    The geospace environment is controlled largely by events on the Sun, such as solar flares and coronal mass ejections, which generate significant geomagnetic and upper atmospheric disturbances. The study of this Sun-Earth system, which has become known as space weather, has both intrinsic scientific interest and practical applications. Adverse conditions in space can damage satellites and disrupt communications, navigation, and electric power grids, as well as endanger astronauts. The Center for Integrated Space Weather Modeling (CISM), a Science and Technology Center (STC) funded by the U.S. National Science Foundation (see http://www.bu.edu/cism/), is developing a suite of integrated physics-based computer models that describe the space environment from the Sun to the Earth for use in both research and operations [Hughes and Hudson, 2004, p. 1241]. To further this mission, advanced education and training programs sponsored by CISM encourage students to view space weather as a system that encompasses the Sun, the solar wind, the magnetosphere, and the ionosphere/thermosphere. This holds especially true for participants in the CISM space weather summer school [Simpson, 2004].

  10. Augmented Reality in astrophysics

    NASA Astrophysics Data System (ADS)

    Vogt, Frédéric P. A.; Shingles, Luke J.

    2013-09-01

    Augmented Reality consists of merging live images with virtual layers of information. The rapid growth in the popularity of smartphones and tablets over recent years has provided a large base of potential users of Augmented Reality technology, and virtual layers of information can now be attached to a wide variety of physical objects. In this article, we explore the potential of Augmented Reality for astrophysical research with two distinct experiments: (1) Augmented Posters and (2) Augmented Articles. We demonstrate that the emerging technology of Augmented Reality can already be used and implemented without expert knowledge using currently available apps. Our experiments highlight the potential of Augmented Reality to improve the communication of scientific results in the field of astrophysics. We also present feedback gathered from the Australian astrophysics community that reveals evidence of some interest in this technology by astronomers who experimented with Augmented Posters. In addition, we discuss possible future trends for Augmented Reality applications in astrophysics, and explore the current limitations associated with the technology. This Augmented Article, the first of its kind, is designed to allow the reader to directly experiment with this technology.

  11. Colombia an approach to create a national space agency

    NASA Astrophysics Data System (ADS)

    Arenales, O.

    Space exploration is a great human adventure: culturally, scientifically, technologically and industrially. Since the earliest of times, civilizations have been united in their awe of, and inspiration by, the cosmos, as testified in particularly by the peoples and cultures of the Central and South American continent in pre- Columbian times. Today, space systems have become an essential tool for the scientific disciplines related to the knowledge of the universe, including our own planet and its close or its remote environment. The main objective of this research is to explain the way in which Colombia, rich in myths and secular legends connecting mankind to the universe, must in the present tackle the issue of its development of space activities. The context in which it could be carried out is also described, along with a perspective of the current state of science and technology in the space sector on a global scale. Any modern nation is concerned with its independence, whether political, economic, or intellectual. That is why we support the concept of countries in the process of development becoming actively involved in the international space scene. Indeed, having limitations in industrial and technological exchange, we feel excluded today from key fields for our tomorrow. This paper thus proposes to demonstrate how in a time that can be regarded as one of the most serious crises in its history, Colombia could, in an atmosphere free from fratricidal conflicts, exploit its space matter capabilities. We do not limit our focus to the scientific field, but also consider the social, economic and cultural aspects. The results of this research delineate how Colombia could start a new optimistic phas e of its development, joining the international space programs within the framework of agreements among the regional governments in Latin America.

  12. ULISSE -a new approach of archiving space experiment data

    NASA Astrophysics Data System (ADS)

    Brinckmann, Enno; Hauan, Tore Martin; Karoliussen, Irene; Fossum, Knut R.

    The evaluation of Space experiments is usually completed by a scientific publication. The re-maining sample material might be re-assessed by new techniques or with reference to other experiments, which might be difficult due to lacking of a common flight data archive. A new way of archiving Space experiment data has been initiated by the European Commission in the ULISSE Project ("USOCs KnowLedge Integration and dissemination for Space Science Experimentation") which is built around the User Support Operation Centers (USOCs) and their industrial partners. ULISSE will be a collaborative open network able to allow informa-tion and knowledge exchange. Due to the vast amount of data in this network, Web based interfaces need to be implemented. Therefore, each experiment will be described in a topic map containing experimental methods, the experiment environment, hardware and software methods and products, biological processes, and the experimental results. Each topic needs to have an identifier, i.e. a link to a Web based thesaurus where the definition of this topic is described. Existing databases (e.g. ontologies for genetic information) have been used to define recent Space experiments, but the range of topics needs to be extended in ULISSE to cover the specific features of Space experiments. Credits: European Commission (FP7/2007-2013, grant agreement n218815).

  13. New Approaches for DC Balanced SpaceWire

    NASA Technical Reports Server (NTRS)

    Kisin, Alex; Rakow, Glenn

    2016-01-01

    Direct Current (DC) line balanced SpaceWire is attractive for a number of reasons. Firstly, a DC line balanced interface provides the ability to isolate the physical layer with either a transformer or capacitor to achieve higher common mode voltage rejection and/or the complete galvanic isolation in the case of a transformer. Secondly, it provides the possibility to reduce the number of conductors and transceivers in the classical SpaceWire interface by half by eliminating the Strobe line. Depending on the modulator scheme - the clock data recovery frequency requirements may be only twice that of the transmit clock, or even match the transmit clock: depending on the Field Programmable Gate Array (FPGA) decoder design. In this paper, several different implementation scenarios will be discussed. Two of these scenarios are backward compatible with the existing SpaceWire hardware standards except for changes at the character level. Three other scenarios, while decreasing by half the standard SpaceWire hardware components, will require changes at both the character and signal levels and work with fixed rates. Other scenarios with variable data rates will require an additional SpaceWire interface handshake initialization sequence.

  14. New Approaches for Direct Current (DC) Balanced SpaceWire

    NASA Technical Reports Server (NTRS)

    Kisin, Alex; Rakow, Glenn

    2016-01-01

    Direct Current (DC) line balanced SpaceWire is attractive for a number of reasons. Firstly, a DC line balanced interface provides the ability to isolate the physical layer with either a transformer or capacitor to achieve higher common mode voltage rejection and or the complete galvanic isolation in the case of a transformer. And secondly, it provides the possibility to reduce the number of conductors and transceivers in the classical SpaceWire interface by half by eliminating the Strobe line. Depending on the modulator scheme the clock data recovery frequency requirements may be only twice that of the transmit clock, or even match the transmit clock: depending on the Field Programmable Gate Array (FPGA) decoder design. In this paper, several different implementation scenarios will be discussed. Two of these scenarios are backward compatible with the existing SpaceWire hardware standards except for changes at the character level. Three other scenarios, while decreasing by half the standard SpaceWire hardware components, will require changes at both the character and signal levels and work with fixed rates. Other scenarios with variable data rates will require an additional SpaceWire interface handshake initialization sequence.

  15. Space fusion energy conversion using a field reversed configuration reactor: A new technical approach for space propulsion and power

    NASA Technical Reports Server (NTRS)

    Schulze, Norman R.; Miley, George H.; Santarius, John F.

    1991-01-01

    The fusion energy conversion design approach, the Field Reversed Configuration (FRC) - when burning deuterium and helium-3, offers a new method and concept for space transportation with high energy demanding programs, like the Manned Mars Mission and planetary science outpost missions require. FRC's will increase safety, reduce costs, and enable new missions by providing a high specific power propulsion system from a high performance fusion engine system that can be optimally designed. By using spacecraft powered by FRC's the space program can fulfill High Energy Space Missions (HESM) in a manner not otherwise possible. FRC's can potentially enable the attainment of high payload mass fractions while doing so within shorter flight times.

  16. Phase-space approach to continuous variable quantum teleportation

    SciTech Connect

    Ban, Masashi

    2004-05-01

    The phase-space method is applied for considering continuous variable quantum teleportation. It is found that the continuous variable quantum teleportation transforms the s-parametrized phase-space function of an input state into the (s+{delta})-parametrized phase-space function, where the parameter {delta} is determined by the shared quantum entanglement. It is shown from this result that the Wigner function of the teleported state is always non-negative for F{sub c}{<=}2/3 and the Glauber-Sudarshan P function non-negative for F{sub c}{<=}1/2, where F{sub c} is the fidelity of the coherent-state teleportation. Furthermore the fidelity between input and output states is calculated when Gaussian states are teleported.

  17. Phase-space representation of quantum state vectors: The relative-state approach and the displacement-operator approach

    NASA Astrophysics Data System (ADS)

    Ban, Masashi

    1999-08-01

    Phase-space representation of quantum state vectors has been recently formulated by means of the relative-state method developed by the present author [J. Math. Phys. 39, 1744 (1998)]. It is, however, pointed out by Mo/ller that the displacement-operator method provides another basis of phase-space representation of quantum state vectors [J. Math. Phys. (to appear)]. Hence the relation between the relative-state approach and the displacement-operator approach is discussed, both of which yield equivalent phase-space representations.

  18. Ischiofemoral Space Decompression Through Posterolateral Approach: Cutting Block Technique

    PubMed Central

    Howse, Elizabeth A.; Mannava, Sandeep; Tamam, Cüneyt; Martin, Hal D.; Bredella, Miriam A.; Stubbs, Allston J.

    2014-01-01

    Ischiofemoral space impingement has become an increasingly recognized extracapsular cause of atypical hip, deep gluteal, and groin pain that can be treated endoscopically. We present a minimally invasive posterolateral technique that preserves the attachment of the iliopsoas tendon and quadratus femoris insertion while decompressing the ischiofemoral space by resecting the lesser trochanter. Furthermore, we present tips to perform this technique in a manner that minimizes the potential for damage to the sciatic nerve. This technique also allows the surgeon to treat concurrent hip pathology arthroscopically. PMID:25685670

  19. Hyperspectral Imaging on the International Space Station: An Innovative Approach to Commercial Development of Space

    NASA Technical Reports Server (NTRS)

    2003-01-01

    NASA s Space Partnership Division (SPD) was established to promote the commercial development of space by providing access to space ai opportunity to perform commercial research in the microgravity environment. NASA, through SPD, has established Research Partnership Centers (RPC s) that bring the government, universities at private industry together to perform research in space for commercial applica!.!lons. The SPD Office has fostered a re!ationship between an RPC and an aerospace company to perform hyperspectral imaging on the Window Observational Research Facility (WORF) on board the International Space Station (ISS). As a result of this relationship and M the capabilities of the WORF, the ISS will serve the private sector with platform to conduct hyperspectral imaging for commercial research.

  20. Reflective pattern-based approach to collaborative media space management

    NASA Astrophysics Data System (ADS)

    Robbins, Wayne; Georganas, Nicolas D.

    1998-12-01

    The role of traditional multimedia systems has been to disseminate information. The advent of media spaces, however, offers an increased potential in terms of presentation as well as facilitating a natural and intuitive environment for interpersonal communication. Combined with Computer Supported Cooperative Work technologies, these shared, media-rich environments offer a natural basis for distributed collaboration through a seamless blend of presentational, conversational and interactive multimedia. The resulting notion underlies the definition of a collaborative media space in which users interact with each other through the experience and manipulation of shared media. The integration of such a diverse array of entities presents many challenges, ranging from the need to support a variety of media types to managing how objects in such a system interact. Indeed, a primary consideration with such system is the coordination (including both causal and temporal synchronization) of entities within the space. This work addresses how to facilitate media space design by employing a pattern-based meta-level architecture and management infrastructure in which reflection is used to isolate system-level issues such as behavioral coordination from low-level, media-specific computation. The architectural framework and its underlying topology are illustrated along with the model's application to a distance education system.

  1. Neural Networks Based Approach to Enhance Space Hardware Reliability

    NASA Technical Reports Server (NTRS)

    Zebulum, Ricardo S.; Thakoor, Anilkumar; Lu, Thomas; Franco, Lauro; Lin, Tsung Han; McClure, S. S.

    2011-01-01

    This paper demonstrates the use of Neural Networks as a device modeling tool to increase the reliability analysis accuracy of circuits targeted for space applications. The paper tackles a number of case studies of relevance to the design of Flight hardware. The results show that the proposed technique generates more accurate models than the ones regularly used to model circuits.

  2. Hybrid Enhanced Epidermal SpaceSuit Design Approaches

    NASA Astrophysics Data System (ADS)

    Jessup, Joseph M.

    A Space suit that does not rely on gas pressurization is a multi-faceted problem that requires major stability controls to be incorporated during design and construction. The concept of Hybrid Epidermal Enhancement space suit integrates evolved human anthropomorphic and physiological adaptations into its functionality, using commercially available bio-medical technologies to address shortcomings of conventional gas pressure suits, and the impracticalities of MCP suits. The prototype HEE Space Suit explored integumentary homeostasis, thermal control and mobility using advanced bio-medical materials technology and construction concepts. The goal was a space suit that functions as an enhanced, multi-functional bio-mimic of the human epidermal layer that works in attunement with the wearer rather than as a separate system. In addressing human physiological requirements for design and construction of the HEE suit, testing regimes were devised and integrated into the prototype which was then subject to a series of detailed tests using both anatomical reproduction methods and human subject.

  3. An approach to developing user interfaces for space systems

    NASA Astrophysics Data System (ADS)

    Shackelford, Keith; McKinney, Karen

    1993-08-01

    Inherent weakness in the traditional waterfall model of software development has led to the definition of the spiral model. The spiral model software development lifecycle model, however, has not been applied to NASA projects. This paper describes its use in developing real time user interface software for an Environmental Control and Life Support System (ECLSS) Process Control Prototype at NASA's Marshall Space Flight Center.

  4. A Regression Design Approach to Optimal and Robust Spacing Selection.

    DTIC Science & Technology

    1981-07-01

    release and sale; its distribution is unlimited Acceso For NTIS GRA&I DEPARTMENT OF STATISTICS DTIC TAB Unannounced Southern Methodist University F...such as the Cauchy where A is a constant multiple of the identity. In fact, for the Cauchy distribution asymptotically optimal spacing sequences for

  5. A Computationally Efficient State Space Approach to Estimating Multilevel Regression Models and Multilevel Confirmatory Factor Models.

    PubMed

    Gu, Fei; Preacher, Kristopher J; Wu, Wei; Yung, Yiu-Fai

    2014-01-01

    Although the state space approach for estimating multilevel regression models has been well established for decades in the time series literature, it does not receive much attention from educational and psychological researchers. In this article, we (a) introduce the state space approach for estimating multilevel regression models and (b) extend the state space approach for estimating multilevel factor models. A brief outline of the state space formulation is provided and then state space forms for univariate and multivariate multilevel regression models, and a multilevel confirmatory factor model, are illustrated. The utility of the state space approach is demonstrated with either a simulated or real example for each multilevel model. It is concluded that the results from the state space approach are essentially identical to those from specialized multilevel regression modeling and structural equation modeling software. More importantly, the state space approach offers researchers a computationally more efficient alternative to fit multilevel regression models with a large number of Level 1 units within each Level 2 unit or a large number of observations on each subject in a longitudinal study.

  6. Embodied Space: a Sensorial Approach to Spatial Experience

    NASA Astrophysics Data System (ADS)

    Durão, Maria João

    2009-03-01

    A reflection is presented on the significance of the role of the body in the interpretation and future creation of spatial living structures. The paper draws on the body as cartography of sensorial meaning that includes vision, touch, smell, hearing, orientation and movement to discuss possible relationships with psychological and sociological parameters of 'sensorial space'. The complex dynamics of body-space is further explored from the standpoint of perceptual variables such as color, light, materialities, texture and their connections with design, technology, culture and symbology. Finally, the paper discusses the integration of knowledge and experimentation in the design of future habitats where body-sensitive frameworks encompass flexibility, communication, interaction and cognitive-driven solutions.

  7. A multi-spacecraft formation approach to space debris surveillance

    NASA Astrophysics Data System (ADS)

    Felicetti, Leonard; Emami, M. Reza

    2016-10-01

    This paper proposes a new mission concept devoted to the identification and tracking of space debris through observations made by multiple spacecraft. Specifically, a formation of spacecraft has been designed taking into account the characteristics and requirements of the utilized optical sensors as well as the constraints imposed by sun illumination and visibility conditions. The debris observations are then shared among the team of spacecraft, and processed onboard of a "hosting leader" to estimate the debris motion by means of Kalman filtering techniques. The primary contribution of this paper resides on the application of a distributed coordination architecture, which provides an autonomous and robust ability to dynamically form spacecraft teams once the target has been detected, and to dynamically build a processing network for the orbit determination of space debris. The team performance, in terms of accuracy, readiness and number of the detected objects, is discussed through numerical simulations.

  8. An Approach to Autonomous Control for Space Nuclear Power Systems

    SciTech Connect

    Wood, Richard Thomas; Upadhyaya, Belle R.

    2011-01-01

    Under Project Prometheus, the National Aeronautics and Space Administration (NASA) investigated deep space missions that would utilize space nuclear power systems (SNPSs) to provide energy for propulsion and spacecraft power. The initial study involved the Jupiter Icy Moons Orbiter (JIMO), which was proposed to conduct in-depth studies of three Jovian moons. Current radioisotope thermoelectric generator (RTG) and solar power systems cannot meet expected mission power demands, which include propulsion, scientific instrument packages, and communications. Historically, RTGs have provided long-lived, highly reliable, low-power-level systems. Solar power systems can provide much greater levels of power, but power density levels decrease dramatically at {approx} 1.5 astronomical units (AU) and beyond. Alternatively, an SNPS can supply high-sustained power for space applications that is both reliable and mass efficient. Terrestrial nuclear reactors employ varying degrees of human control and decision-making for operations and benefit from periodic human interaction for maintenance. In contrast, the control system of an SNPS must be able to provide continuous operatio for the mission duration with limited immediate human interaction and no opportunity for hardware maintenance or sensor calibration. In effect, the SNPS control system must be able to independently operate the power plant while maintaining power production even when subject to off-normal events and component failure. This capability is critical because it will not be possible to rely upon continuous, immediate human interaction for control due to communications delays and periods of planetary occlusion. In addition, uncertainties, rare events, and component degradation combine with the aforementioned inaccessibility and unattended operation to pose unique challenges that an SNPS control system must accommodate. Autonomous control is needed to address these challenges and optimize the reactor control design.

  9. Statistical Approach to the Operational Testing of Space Fence

    DTIC Science & Technology

    2015-07-01

    Officer, an Orbital Analyst, and a radar signature analyst at the FPS-85 phased array radar and the FPS-79 dish radar. While at the FPS-79 he...unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT Space Fence will be a terrestrial-based radar designed to perform surveillance on earth- orbiting ...ensuring a reasonable test duration. We propose a rigorous statistical test design with candidate on- orbit test targets that span orbital limits defined by

  10. Equating of Augmented Subscores

    ERIC Educational Resources Information Center

    Sinharay, Sandip; Haberman, Shelby J.

    2011-01-01

    Recently, there has been an increasing level of interest in subscores for their potential diagnostic value. Haberman (2008b) suggested reporting an augmented subscore that is a linear combination of a subscore and the total score. Sinharay and Haberman (2008) and Sinharay (2010) showed that augmented subscores often lead to more accurate…

  11. Confronting an Augmented Reality

    ERIC Educational Resources Information Center

    Munnerley, Danny; Bacon, Matt; Wilson, Anna; Steele, James; Hedberg, John; Fitzgerald, Robert

    2012-01-01

    How can educators make use of augmented reality technologies and practices to enhance learning and why would we want to embrace such technologies anyway? How can an augmented reality help a learner confront, interpret and ultimately comprehend reality itself ? In this article, we seek to initiate a discussion that focuses on these questions, and…

  12. Learning the Task Management Space of an Aircraft Approach Model

    NASA Technical Reports Server (NTRS)

    Krall, Joseph; Menzies, Tim; Davies, Misty

    2014-01-01

    Validating models of airspace operations is a particular challenge. These models are often aimed at finding and exploring safety violations, and aim to be accurate representations of real-world behavior. However, the rules governing the behavior are quite complex: nonlinear physics, operational modes, human behavior, and stochastic environmental concerns all determine the responses of the system. In this paper, we present a study on aircraft runway approaches as modeled in Georgia Tech's Work Models that Compute (WMC) simulation. We use a new learner, Genetic-Active Learning for Search-Based Software Engineering (GALE) to discover the Pareto frontiers defined by cognitive structures. These cognitive structures organize the prioritization and assignment of tasks of each pilot during approaches. We discuss the benefits of our approach, and also discuss future work necessary to enable uncertainty quantification.

  13. Deep space network resource scheduling approach and application

    NASA Technical Reports Server (NTRS)

    Eggemeyer, William C.; Bowling, Alan

    1987-01-01

    Deep Space Network (DSN) resource scheduling is the process of distributing ground-based facilities to track multiple spacecraft. The Jet Propulsion Laboratory has carried out extensive research to find ways of automating this process in an effort to reduce time and manpower costs. This paper presents a resource-scheduling system entitled PLAN-IT with a description of its design philosophy. The PLAN-IT's current on-line usage and limitations in scheduling the resources of the DSN are discussed, along with potential enhancements for DSN application.

  14. Augmented assessment as a means to augmented reality.

    PubMed

    Bergeron, Bryan

    2006-01-01

    Rigorous scientific assessment of educational technologies typically lags behind the availability of the technologies by years because of the lack of validated instruments and benchmarks. Even when the appropriate assessment instruments are available, they may not be applied because of time and monetary constraints. Work in augmented reality, instrumented mannequins, serious gaming, and similar promising educational technologies that haven't undergone timely, rigorous evaluation, highlights the need for assessment methodologies that address the limitations of traditional approaches. The most promising augmented assessment solutions incorporate elements of rapid prototyping used in the software industry, simulation-based assessment techniques modeled after methods used in bioinformatics, and object-oriented analysis methods borrowed from object oriented programming.

  15. Ion beam figuring approach for thermally sensitive space optics.

    PubMed

    Yin, Xiaolin; Deng, Weijie; Tang, Wa; Zhang, Binzhi; Xue, Donglin; Zhang, Feng; Zhang, Xuejun

    2016-10-01

    During the ion beam figuring (IBF) of a space mirror, thermal radiation of the neutral filament and particle collisions will heat the mirror. The adhesive layer used to bond the metal parts and the mirror is very sensitive to temperature rise. When the temperature exceeds the designed value, the mirror surface shape will change markedly because of the thermal deformation and stress release of the adhesive layer, thereby reducing the IBF accuracy. To suppress the thermal effect, we analyzed the heat generation mechanism. By using thermal radiation theory, we established a thermal radiation model of the neutral filament. Additionally, we acquired a surface-type Gaussian heat source model of the ion beam sputtering based on the removal function and Faraday scan result. Using the finite-element-method software ABAQUS, we developed a method that can simulate the thermal effect of the IBF for the full path and all dwell times. Based on the thermal model, which was experimentally confirmed, we simulated the thermal effects for a 675  mm×374  mm rectangular SiC space mirror. By optimizing the dwell time distribution, the peak temperature value of the adhesive layer during the figuring process was reduced under the designed value. After one round of figuring, the RMS value of the surface error changed from 0.094 to 0.015λ (λ=632.8  nm), which proved the effectiveness of the thermal analysis and suppression method.

  16. Raw Data Maximum Likelihood Estimation for Common Principal Component Models: A State Space Approach.

    PubMed

    Gu, Fei; Wu, Hao

    2016-09-01

    The specifications of state space model for some principal component-related models are described, including the independent-group common principal component (CPC) model, the dependent-group CPC model, and principal component-based multivariate analysis of variance. Some derivations are provided to show the equivalence of the state space approach and the existing Wishart-likelihood approach. For each model, a numeric example is used to illustrate the state space approach. In addition, a simulation study is conducted to evaluate the standard error estimates under the normality and nonnormality conditions. In order to cope with the nonnormality conditions, the robust standard errors are also computed. Finally, other possible applications of the state space approach are discussed at the end.

  17. Trajectories and causal phase-space approach to relativistic quantum mechanics

    SciTech Connect

    Holland, P.R.; Kyprianidis, A.; Vigier, J.P.

    1987-05-01

    The authors analyze phase-space approaches to relativistic quantum mechanics from the viewpoint of the causal interpretation. In particular, they discuss the canonical phase space associated with stochastic quantization, its relation to Hilbert space, and the Wigner-Moyal formalism. They then consider the nature of Feynman paths, and the problem of nonlocality, and conclude that a perfectly consistent relativistically covariant interpretation of quantum mechanics which retains the notion of particle trajectory is possible.

  18. A multidisciplinary approach to optimization of controlled space structures

    NASA Technical Reports Server (NTRS)

    Woodard, Stanley E.; Padula, Sharon L.; Graves, Philip C.; James, Benjamin B.

    1990-01-01

    A fundamental problem facing controls-structures analysts is a means of determining the trade-offs between structural design parameters and control design parameters in meeting some particular performance criteria. Developing a general optimization-based design methodology integrating the disciplines of structural dynamics and controls is a logical approach. The objective of this study is to develop such a method. Classical design methodology involves three phases. The first is structural optimization, wherein structural member sizes are varied to minimize structural mass, subject to open-loop frequency constraints. The next phase integrates control and structure design with control gains as additional design variables. The final phase is analysis of the 'optimal' integrated design phase considering 'real' actuators and 'standard' member sizes. The control gains could be further optimized for fixed structure, and actuator saturation constraints could be imposed. However, such an approach does not take full advantage of opportunities to tailor the structure and control system design as one system.

  19. Space Shuttle Program Orbiter Approach and Landing Test

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The orbiter approach and landing test (ALT) reports are published to provide senior NASA management with timely information on ALT program plans and accomplishments. The ALT reports will be comprised of this pre-ALT report, ALT pre-flight memoranda, and an ALT post-flight report following each flight. The purpose of this pre-ALT report is to provide an overview of the ALT program, describing the flight vehicles involved and summarizing the planned flights.

  20. The twistor approach to space-time structures

    NASA Astrophysics Data System (ADS)

    Penrose, Roger

    2005-11-01

    An outline of twistor theory is presented. Initial motivations (from 1963) are given for this type of non-local geometry, as an intended scheme for unifying quantum theory and space-time structure. Basic twistor geometry and algebra is exhibited, and it is shown that this provides a complex-manifold description of classical (spinning) massless particles. Simple quantum commutation rules lead to a concise representation of massless particle wavefunctions, in terms of contour integrals or (more profoundly) holomorphic 1st cohomology. Non-linear versions give elegant representations of anti-self-dual Einstein (or Yang-Mills) fields, describing left-handed non-linear gravitons (or Yang-Mills particles). A brief outline of the current status of the "googly problem" is provided, whereby the right-handed particles would also be incorporated.

  1. NASA's Approach to Critical Risks for Extended Human Space Flight

    NASA Technical Reports Server (NTRS)

    Shelhamer, Mark

    2014-01-01

    Planetary Robotic and Human Spaceflight Exploration Humans are exposed to a great variety of hazards in the space environment. These include the effects of weightlessness, radiation, isolation and confinement, altered day-night cycles, and others. These inherent hazards have both physiological and behavioral consequences. The adaptive capabilities of humans in these situations is remarkable, and often exceed our expectations. However, the demanding environment and challenging operational pace can push some of these adaptive processes to their limits. The NASA Human Research Program (HRP) is tasked with mitigating the most serious of these effects on human health, safety, and performance, in long-duration space flight. This can involve the development and deployment of physiological countermeasures, better understanding of the physiological alterations and avoidance of exacerbating situations, inputs to the design of future spacecraft to minimize risks, and in some cases the awareness that some level of risk might have to be accepted based on the resulting consequences and their likelihood. HRP has identified a few areas that are of special concern due to their severity, lack of understanding of underlying causes, or potential for negative impact on health or performance. Some of these areas are visual impairment possibly due to increased intracranial pressure, behavioral and performance problems due to sleep deficits and isolation, and acute and chronic effects of radiation. These problems can, if not addressed, be expected to increase on longer and more distant missions. The evidence from spaceflight, laboratory, and analog studies that supports the selection of the most critical risks will be discussed. Current and planned research programs that address these risks, and their anticipated outcomes, will also be described.

  2. Earth based approaches to enhancing the health and safety of space operations

    NASA Technical Reports Server (NTRS)

    Koller, A. M., Jr.

    1985-01-01

    This paper provides an overview of the current state of our earth based knowledge of space safety hazards; identification of several key areas of concern for space operations; and proposed approaches to providing technology enhancement and information needed to improve the health and safety to those conducting space operations. Included are a review of the identified hazards for space oeprations by hazard classification; a summarization of the information currently available on space experiences and an assessment of potential hazards for long duration spaceflight; a discussion of potential failure modes and their significance for Space Station work: and an assessment of current work which indicates additional research and experimentation which can only be accomplished in actual space missions.

  3. Control Augmented Structural Synthesis

    NASA Technical Reports Server (NTRS)

    Lust, Robert V.; Schmit, Lucien A.

    1988-01-01

    A methodology for control augmented structural synthesis is proposed for a class of structures which can be modeled as an assemblage of frame and/or truss elements. It is assumed that both the plant (structure) and the active control system dynamics can be adequately represented with a linear model. The structural sizing variables, active control system feedback gains and nonstructural lumped masses are treated simultaneously as independent design variables. Design constraints are imposed on static and dynamic displacements, static stresses, actuator forces and natural frequencies to ensure acceptable system behavior. Multiple static and dynamic loading conditions are considered. Side constraints imposed on the design variables protect against the generation of unrealizable designs. While the proposed approach is fundamentally more general, here the methodology is developed and demonstrated for the case where: (1) the dynamic loading is harmonic and thus the steady state response is of primary interest; (2) direct output feedback is used for the control system model; and (3) the actuators and sensors are collocated.

  4. Augmented Likelihood Image Reconstruction.

    PubMed

    Stille, Maik; Kleine, Matthias; Hägele, Julian; Barkhausen, Jörg; Buzug, Thorsten M

    2016-01-01

    The presence of high-density objects remains an open problem in medical CT imaging. Data of projections passing through objects of high density, such as metal implants, are dominated by noise and are highly affected by beam hardening and scatter. Reconstructed images become less diagnostically conclusive because of pronounced artifacts that manifest as dark and bright streaks. A new reconstruction algorithm is proposed with the aim to reduce these artifacts by incorporating information about shape and known attenuation coefficients of a metal implant. Image reconstruction is considered as a variational optimization problem. The afore-mentioned prior knowledge is introduced in terms of equality constraints. An augmented Lagrangian approach is adapted in order to minimize the associated log-likelihood function for transmission CT. During iterations, temporally appearing artifacts are reduced with a bilateral filter and new projection values are calculated, which are used later on for the reconstruction. A detailed evaluation in cooperation with radiologists is performed on software and hardware phantoms, as well as on clinically relevant patient data of subjects with various metal implants. Results show that the proposed reconstruction algorithm is able to outperform contemporary metal artifact reduction methods such as normalized metal artifact reduction.

  5. Freedom Space for Rivers: A Sustainable Management Approach to Enhance River Resilience

    NASA Astrophysics Data System (ADS)

    Biron, Pascale M.; Buffin-Bélanger, Thomas; Larocque, Marie; Choné, Guénolé; Cloutier, Claude-André; Ouellet, Marie-Audray; Demers, Sylvio; Olsen, Taylor; Desjarlais, Claude; Eyquem, Joanna

    2014-11-01

    River systems are increasingly under stress and pressure from agriculture and urbanization in riparian zones, resulting in frequent engineering interventions such as bank stabilization or flood protection. This study provides guidelines for a more sustainable approach to river management based on hydrogeomorphology concepts applied to three contrasted rivers in Quebec (Canada). Mobility and flooding spaces are determined for the three rivers, and three levels of "freedom space" are subsequently defined based on the combination of the two spaces. The first level of freedom space includes very frequently flooded and highly mobile zones over the next 50 years, as well as riparian wetlands. It provides the minimum space for both fluvial and ecological functionality of the river system. On average for the three studied sites, this minimum space was approximately 1.7 times the channel width, but this minimum space corresponds to a highly variable width which must be determined from a thorough hydrogeomorphic assessment and cannot be predicted using a representative average. The second level includes space for floods of larger magnitude and provides for meanders to migrate freely over a longer time period. The last level of freedom space represents exceptional flood zones. We propose the freedom space concept to be implemented in current river management legislation because it promotes a sustainable way to manage river systems, and it increases their resilience to climate and land use changes in comparison with traditional river management approaches which are based on frequent and spatially restricted interventions.

  6. Freedom space for rivers: a sustainable management approach to enhance river resilience.

    PubMed

    Biron, Pascale M; Buffin-Bélanger, Thomas; Larocque, Marie; Choné, Guénolé; Cloutier, Claude-André; Ouellet, Marie-Audray; Demers, Sylvio; Olsen, Taylor; Desjarlais, Claude; Eyquem, Joanna

    2014-11-01

    River systems are increasingly under stress and pressure from agriculture and urbanization in riparian zones, resulting in frequent engineering interventions such as bank stabilization or flood protection. This study provides guidelines for a more sustainable approach to river management based on hydrogeomorphology concepts applied to three contrasted rivers in Quebec (Canada). Mobility and flooding spaces are determined for the three rivers, and three levels of "freedom space" are subsequently defined based on the combination of the two spaces. The first level of freedom space includes very frequently flooded and highly mobile zones over the next 50 years, as well as riparian wetlands. It provides the minimum space for both fluvial and ecological functionality of the river system. On average for the three studied sites, this minimum space was approximately 1.7 times the channel width, but this minimum space corresponds to a highly variable width which must be determined from a thorough hydrogeomorphic assessment and cannot be predicted using a representative average. The second level includes space for floods of larger magnitude and provides for meanders to migrate freely over a longer time period. The last level of freedom space represents exceptional flood zones. We propose the freedom space concept to be implemented in current river management legislation because it promotes a sustainable way to manage river systems, and it increases their resilience to climate and land use changes in comparison with traditional river management approaches which are based on frequent and spatially restricted interventions.

  7. Media-Augmented Exercise Machines

    NASA Astrophysics Data System (ADS)

    Krueger, T.

    2002-01-01

    Cardio-vascular exercise has been used to mitigate the muscle and cardiac atrophy associated with adaptation to micro-gravity environments. Several hours per day may be required. In confined spaces and long duration missions this kind of exercise is inevitably repetitive and rapidly becomes uninteresting. At the same time, there are pressures to accomplish as much as possible given the cost- per-hour for humans occupying orbiting or interplanetary. Media augmentation provides a the means to overlap activities in time by supplementing the exercise with social, recreational, training or collaborative activities and thereby reducing time pressures. In addition, the machine functions as an interface to a wide range of digital environments allowing for spatial variety in an otherwise confined environment. We hypothesize that the adoption of media augmented exercise machines will have a positive effect on psycho-social well-being on long duration missions. By organizing and supplementing exercise machines, data acquisition hardware, computers and displays into an interacting system this proposal increases functionality with limited additional mass. This paper reviews preliminary work on a project to augment exercise equipment in a manner that addresses these issues and at the same time opens possibilities for additional benefits. A testbed augmented exercise machine uses a specialty built cycle trainer as both input to a virtual environment and as an output device from it using spatialized sound, and visual displays, vibration transducers and variable resistance. The resulting interactivity increases a sense of engagement in the exercise, provides a rich experience of the digital environments. Activities in the virtual environment and accompanying physiological and psychological indicators may be correlated to track and evaluate the health of the crew.

  8. An approach towards problem-based learning in virtual space.

    PubMed

    Freudenberg, Lutz S; Bockisch, Andreas; Beyer, Thomas

    2010-01-01

    Problem-based learning (PBL) is an established and efficient approach to sustainable teaching. Here, we describe translation of PBL into the virtual classroom thereby offering novel teaching aspects in the field of Nuclear Medicine. Our teaching approach is implemented on a "moodle" platform and consists of 2 modules: complementary seminar teaching materials and a virtual PBL-classroom, which can be attended via Skype.Over the course of 4 semesters 539 students have accessed our teaching platform. 21 students have participated in the PBL seminar (module 2). After resolving some minor technical difficulties our virtual seminars have evolved into a forum of intense studies, whereby the participating students have learned to become more independent along the workup of the teaching cases. This was reflected in the results of the intra-group presentations and discussions.Quantitative and qualitative evaluation of our moodle-based PBL platform indicates an increasing level of acceptance and enthusiasm by the students. This has initiated discussions about opening our PBL concept to a wider audience within the university and beyond the Nuclear Medicine specialty.

  9. PET image reconstruction: a robust state space approach.

    PubMed

    Liu, Huafeng; Tian, Yi; Shi, Pengcheng

    2005-01-01

    Statistical iterative reconstruction algorithms have shown improved image quality over conventional nonstatistical methods in PET by using accurate system response models and measurement noise models. Strictly speaking, however, PET measurements, pre-corrected for accidental coincidences, are neither Poisson nor Gaussian distributed and thus do not meet basic assumptions of these algorithms. In addition, the difficulty in determining the proper system response model also greatly affects the quality of the reconstructed images. In this paper, we explore the usage of state space principles for the estimation of activity map in tomographic PET imaging. The proposed strategy formulates the organ activity distribution through tracer kinetics models, and the photon-counting measurements through observation equations, thus makes it possible to unify the dynamic reconstruction problem and static reconstruction problem into a general framework. Further, it coherently treats the uncertainties of the statistical model of the imaging system and the noisy nature of measurement data. Since H(infinity) filter seeks minimummaximum-error estimates without any assumptions on the system and data noise statistics, it is particular suited for PET image reconstruction where the statistical properties of measurement data and the system model are very complicated. The performance of the proposed framework is evaluated using Shepp-Logan simulated phantom data and real phantom data with favorable results.

  10. Integrated approach to free space optical communications in strong turbulence

    NASA Astrophysics Data System (ADS)

    Tellez, Jason A.

    The propagation of a free space optical communication signal through atmospheric turbulence experiences random fluctuations in intensity, including signal fades which negatively impact the communications link performance. This research develops an analytical probability density function (PDF) to model the best case scenario of using multiple independent beams to reduce the intensity fluctuations. The PDF was further developed to account for partially correlated beams, such as would be experienced by beams having finite separation. The PDF was validated with results obtained from digital simulations as well as lab experiments. The research showed that as the number of transmitted beams increases the probability of fade decreases. While fade probability is reduced by adding more beams, using more than four transmitters does little to improve the overall performance. Additionally, the use of pulse position modulation (PPM) provided significant improvement over traditional fixed threshold on/off keying with the impact of signal fading reduced. Combining PPM with multiple transmitters produced the best overall bit error rate results.

  11. Trajectory analysis via a geometric feature space approach

    SciTech Connect

    Rintoul, Mark D.; Wilson, Andrew T.

    2015-10-05

    This study aimed to organize a body of trajectories in order to identify, search for and classify both common and uncommon behaviors among objects such as aircraft and ships. Existing comparison functions such as the Fréchet distance are computationally expensive and yield counterintuitive results in some cases. We propose an approach using feature vectors whose components represent succinctly the salient information in trajectories. These features incorporate basic information such as the total distance traveled and the distance between start/stop points as well as geometric features related to the properties of the convex hull, trajectory curvature and general distance geometry. Additionally, these features can generally be mapped easily to behaviors of interest to humans who are searching large databases. Most of these geometric features are invariant under rigid transformation. Furthermore, we demonstrate the use of different subsets of these features to identify trajectories similar to an exemplar, cluster a database of several hundred thousand trajectories and identify outliers.

  12. Airborne LaCoste & Romberg gravimetry: a space domain approach

    NASA Astrophysics Data System (ADS)

    Abbasi, M.; Barriot, J. P.; Verdun, J.

    2007-04-01

    This paper introduces a new approach to reduce the airborne gravity data acquired by a LaCoste & Romberg (L&R) air/sea gravimeter, or other similar gravimeters. The acceleration exerted on the gravimeter is the sum of gravity and the vertical and Eötvös accelerations of the aircraft. The L&R gravimeter outputs are: (1) the beam position, (2) the spring tension and (3) the cross coupling. Vertical and Eötvös accelerations are computed from GPS-derived aircraft positions. However, the vertical perturbing acceleration sensed by the gravimeter is not the same as the one sensed by the aircraft (via GPS). A determination of the aircraft-to-sensor transfer function is necessary. The second-order differential equation of the motion of the gravimeter’s beam mixes all the input and output parameters of the gravimeter. Conventionally, low-pass filtering in the frequency domain is used to extract the gravity signal, the filter being applied to each flight-line individually. By transforming the differential equation into an integral equation and by introducing related covariance matrices, we develop a new filtering method based on a least-squares approach that is able to take into account, in one stage, the data corresponding to all flight-lines. The a posteriori covariance matrix of the estimated gravity signal is an internal criterion of the precision of the method. As an example, we estimate the gravity values along the flight-lines from an airborne gravity survey over the Alps and introduce an a priori covariance matrix of the gravity disturbances from a global geopotential model. This matrix is used to regularize the ill-posed Fredholm integral equation introduced in this paper.

  13. A Cost Effective System Design Approach for Critical Space Systems

    NASA Technical Reports Server (NTRS)

    Abbott, Larry Wayne; Cox, Gary; Nguyen, Hai

    2000-01-01

    NASA-JSC required an avionics platform capable of serving a wide range of applications in a cost-effective manner. In part, making the avionics platform cost effective means adhering to open standards and supporting the integration of COTS products with custom products. Inherently, operation in space requires low power, mass, and volume while retaining high performance, reconfigurability, scalability, and upgradability. The Universal Mini-Controller project is based on a modified PC/104-Plus architecture while maintaining full compatibility with standard COTS PC/104 products. The architecture consists of a library of building block modules, which can be mixed and matched to meet a specific application. A set of NASA developed core building blocks, processor card, analog input/output card, and a Mil-Std-1553 card, have been constructed to meet critical functions and unique interfaces. The design for the processor card is based on the PowerPC architecture. This architecture provides an excellent balance between power consumption and performance, and has an upgrade path to the forthcoming radiation hardened PowerPC processor. The processor card, which makes extensive use of surface mount technology, has a 166 MHz PowerPC 603e processor, 32 Mbytes of error detected and corrected RAM, 8 Mbytes of Flash, and I Mbytes of EPROM, on a single PC/104-Plus card. Similar densities have been achieved with the quad channel Mil-Std-1553 card and the analog input/output cards. The power management built into the processor and its peripheral chip allows the power and performance of the system to be adjusted to meet the requirements of the application, allowing another dimension to the flexibility of the Universal Mini-Controller. Unique mechanical packaging allows the Universal Mini-Controller to accommodate standard COTS and custom oversized PC/104-Plus cards. This mechanical packaging also provides thermal management via conductive cooling of COTS boards, which are typically

  14. Breast augmentation surgery

    MedlinePlus

    ... the shape of your breasts. Talk with a plastic surgeon if you are considering breast augmentation. Discuss ... mammograms or breast x-rays before surgery. The plastic surgeon will do a routine breast exam. Several ...

  15. Unified Approach to Modeling and Simulation of Space Communication Networks and Systems

    NASA Technical Reports Server (NTRS)

    Barritt, Brian; Bhasin, Kul; Eddy, Wesley; Matthews, Seth

    2010-01-01

    Network simulator software tools are often used to model the behaviors and interactions of applications, protocols, packets, and data links in terrestrial communication networks. Other software tools that model the physics, orbital dynamics, and RF characteristics of space systems have matured to allow for rapid, detailed analysis of space communication links. However, the absence of a unified toolset that integrates the two modeling approaches has encumbered the systems engineers tasked with the design, architecture, and analysis of complex space communication networks and systems. This paper presents the unified approach and describes the motivation, challenges, and our solution - the customization of the network simulator to integrate with astronautical analysis software tools for high-fidelity end-to-end simulation. Keywords space; communication; systems; networking; simulation; modeling; QualNet; STK; integration; space networks

  16. Spectral functions with the density matrix renormalization group: Krylov-space approach for correction vectors

    NASA Astrophysics Data System (ADS)

    Nocera, A.; Alvarez, G.

    2016-11-01

    Frequency-dependent correlations, such as the spectral function and the dynamical structure factor, help illustrate condensed matter experiments. Within the density matrix renormalization group (DMRG) framework, an accurate method for calculating spectral functions directly in frequency is the correction-vector method. The correction vector can be computed by solving a linear equation or by minimizing a functional. This paper proposes an alternative to calculate the correction vector: to use the Krylov-space approach. This paper then studies the accuracy and performance of the Krylov-space approach, when applied to the Heisenberg, the t-J, and the Hubbard models. The cases studied indicate that the Krylov-space approach can be more accurate and efficient than the conjugate gradient, and that the error of the former integrates best when a Krylov-space decomposition is also used for ground state DMRG.

  17. The Epistemic, the Cognitive, the Human: A Commentary on the Mathematical Working Space Approach

    ERIC Educational Resources Information Center

    Radford, Luis

    2016-01-01

    This article is a commentary on the mathematical working space (MWS) approach and draws on the articles contained in this "ZDM" issue. The article is divided into three parts. In the first part I discuss the place of the MWS approach among the French theories of didactique des mathématiques. In the second part I outline what I think are…

  18. An alternate approach to space missions involving a long tether

    NASA Astrophysics Data System (ADS)

    Netzer, Ehud

    1992-07-01

    Uses of tethers for a variety of purposes in space have been investigated extensively for many years. Currently, interest is focused on two NASA missions, TSS-1 and TSS-2, in which, a satellite is to be deployed, by means of a tether, from the Shuttle, and performs a series of experiments. The tethers to be used in TSS-1 and TSS-2 are very long, namely 20 km and 100 km, respectively. Hence, significant problems of dynamics and control arise in connection with all mission phases, and it is not yet clear that all of these problems possess satisfactory solutions. This must be a source of concern, given the fact that TSS-1 and TSS-2 are manned missions involving the very valuable Shuttle. It is the purpose of this dissertation to propose alternative means to accomplish the goals of missions such as those of TSS-1 and TSS-2, a way that involves the Shuttle and astronauts either minimally or not at all. Stated most simply, the proposal is this: replace the Shuttle with an unmanned spacecraft. Although this idea was mentioned in early papers on tethered systems, its feasibility remained to be investigated. A comprehensive study of such a system is the topic of the present dissertation. The system is composed of a primary satellite, a tether, and a secondary satellite. The primary satellite carries scientific instruments, whereas the secondary one is equipped with a set of thrusters for purposes of control. First, a 3D model, in which the tether is represented by two segments, is analyzed. Thereafter, multi-segment models for the tether are considered; only part of the system states are measured, and the other states are estimated by means of a reduced order estimator. To optimize the deployment and retrieval phases, a multi-controller, MATLAB based algorithm, is employed. The result is improved performance and a significant reduction in fuel consumption. Finally, to use electrodynamic forces for orbit transfer without exciting tether bending motions, the notion of

  19. Coherence spectroscopy in dissipative media: a Liouville space pathway approach.

    PubMed

    Ramakrishna, S; Seideman, Tamar

    2005-02-22

    We address the possibility of using coherent control tools to extract useful information about the interaction of a system with a dissipative environment. To that end we extend previous work, which developed a coherence spectroscopy based on two-pathway excitation phase control, from the isolated molecule limit to dense media. Specifically, we explore the properties of the channel phase, an observable of energy-domain two-pathway excitation experiments that was shown in the isolated molecule limit to carry information about the phase properties of the material system. Our analysis is based on the combination of steady state and time-dependent analytical perturbative approaches within the density matrix formalism, complemented by nonperturbative numerical simulations. We find that the channel phase carries significantly richer information in the presence of decoherence mechanisms than in their absence. In particular, rescattering events in the structured continuum introduce new features in the channel phase spectrum, whose structure conveys information about both the molecular continuum and the system bath interaction.

  20. Trajectory analysis via a geometric feature space approach

    DOE PAGES

    Rintoul, Mark D.; Wilson, Andrew T.

    2015-10-05

    This study aimed to organize a body of trajectories in order to identify, search for and classify both common and uncommon behaviors among objects such as aircraft and ships. Existing comparison functions such as the Fréchet distance are computationally expensive and yield counterintuitive results in some cases. We propose an approach using feature vectors whose components represent succinctly the salient information in trajectories. These features incorporate basic information such as the total distance traveled and the distance between start/stop points as well as geometric features related to the properties of the convex hull, trajectory curvature and general distance geometry. Additionally,more » these features can generally be mapped easily to behaviors of interest to humans who are searching large databases. Most of these geometric features are invariant under rigid transformation. Furthermore, we demonstrate the use of different subsets of these features to identify trajectories similar to an exemplar, cluster a database of several hundred thousand trajectories and identify outliers.« less

  1. Wake Encounter Analysis for a Closely Spaced Parallel Runway Paired Approach Simulation

    NASA Technical Reports Server (NTRS)

    Mckissick,Burnell T.; Rico-Cusi, Fernando J.; Murdoch, Jennifer; Oseguera-Lohr, Rosa M.; Stough, Harry P, III; O'Connor, Cornelius J.; Syed, Hazari I.

    2009-01-01

    A Monte Carlo simulation of simultaneous approaches performed by two transport category aircraft from the final approach fix to a pair of closely spaced parallel runways was conducted to explore the aft boundary of the safe zone in which separation assurance and wake avoidance are provided. The simulation included variations in runway centerline separation, initial longitudinal spacing of the aircraft, crosswind speed, and aircraft speed during the approach. The data from the simulation showed that the majority of the wake encounters occurred near or over the runway and the aft boundaries of the safe zones were identified for all simulation conditions.

  2. Automating an orbiter approach to Space Station Freedom to minimize plume impingement

    NASA Technical Reports Server (NTRS)

    Spehar, Peter T.; Le, Thomas Quan

    1991-01-01

    The Space shuttle orbiter Reaction Control System's (RCS) plume impingement during proximity operations with Space Station Freedom (SSF) is a structural design driver for the SSF solar panels and radiators. A study underway at JSC is investigating whether the use of an automated approach controller could result in the reduction of plume impingement induced loads during orbiter approach to SSF. Ongoing real time person-in-the-loop (PIL) simulations of an orbiter approaching the SSF show that orbiter trajectory control can vary significantly from one pilot to the next. This variation is a cause for concern since current analyses predict that plume impingement loads resulting from PIL orbiter approaches may exceed the solar panel and radiator load limits. The use of an automated approach controller is expected to reduce peak loads by both minimizing orbiter translational jet firings in certain directions and controlling the frequency at which they occur during various phases of the approach.

  3. Augmenting Plasticity Induction in Human Motor Cortex by Disinhibition Stimulation.

    PubMed

    Cash, Robin F H; Murakami, Takenobu; Chen, Robert; Thickbroom, Gary W; Ziemann, Ulf

    2016-01-01

    Cellular studies showed that disinhibition, evoked pharmacologically or by a suitably timed priming stimulus, can augment long-term plasticity (LTP) induction. We demonstrated previously that transcranial magnetic stimulation evokes a period of presumably GABA(B)ergic late cortical disinhibition (LCD) in human primary motor cortex (M1). Here, we hypothesized that, in keeping with cellular studies, LCD can augment LTP-like plasticity in humans. In Experiment 1, patterned repetitive TMS was applied to left M1, consisting of 6 trains (intertrain interval, 8 s) of 4 doublets (interpulse interval equal to individual peak I-wave facilitation, 1.3-1.5 ms) spaced by the individual peak LCD (interdoublet interval (IDI), 200-250 ms). This intervention (total of 48 pulses applied over ∼45 s) increased motor-evoked potential amplitude, a marker of corticospinal excitability, in a right hand muscle by 147% ± 4%. Control experiments showed that IDIs shorter or longer than LCD did not result in LTP-like plasticity. Experiment 2 indicated topographic specificity to the M1 hand region stimulated by TMS and duration of the LTP-like plasticity of 60 min. In conclusion, GABA(B)ergic LCD offers a powerful new approach for augmenting LTP-like plasticity induction in human cortex. We refer to this protocol as disinhibition stimulation (DIS).

  4. Navigation and Control Based on LOS Angle of Space Robot to Approach the Target Satellite

    NASA Astrophysics Data System (ADS)

    Sugahara, Masayuki; Masutani, Yasuhiro; Miyazaki, Fumio

    This paper presents a method of navigation and control for a space robot (chaser) flying around a troubled satellite (target) on a circular orbit around the earth to approach the target satellite. Orbital dynamics of the chaser is represented by the Hill’s equation. The technique based on LOS angle of approaching the target is proposed. We prove the validity of the technique on the situation that the chaser approach the target satellite after the circular trajectory, which is periodically free motion.

  5. 14 CFR 91.1061 - Augmented flight crews.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Augmented flight crews. 91.1061 Section 91... Operations Program Management § 91.1061 Augmented flight crews. (a) No program manager may assign any flight crewmember, and no flight crewmember may accept an assignment, for flight time as a member of an...

  6. 14 CFR 91.1061 - Augmented flight crews.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Augmented flight crews. 91.1061 Section 91... Operations Program Management § 91.1061 Augmented flight crews. (a) No program manager may assign any flight crewmember, and no flight crewmember may accept an assignment, for flight time as a member of an...

  7. 14 CFR 91.1061 - Augmented flight crews.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Augmented flight crews. 91.1061 Section 91... Operations Program Management § 91.1061 Augmented flight crews. (a) No program manager may assign any flight crewmember, and no flight crewmember may accept an assignment, for flight time as a member of an...

  8. 14 CFR 91.1061 - Augmented flight crews.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Augmented flight crews. 91.1061 Section 91... Operations Program Management § 91.1061 Augmented flight crews. (a) No program manager may assign any flight crewmember, and no flight crewmember may accept an assignment, for flight time as a member of an...

  9. 14 CFR 91.1061 - Augmented flight crews.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Augmented flight crews. 91.1061 Section 91... Operations Program Management § 91.1061 Augmented flight crews. (a) No program manager may assign any flight crewmember, and no flight crewmember may accept an assignment, for flight time as a member of an...

  10. Spatial Polygamy and Contextual Exposures (SPACEs): Promoting Activity Space Approaches in Research on Place and Health

    PubMed Central

    Matthews, Stephen A.; Yang, Tse-Chuan

    2014-01-01

    Exposure science has developed rapidly and there is an increasing call for greater precision in the measurement of individual exposures across space and time. Social science interest in an individual’s environmental exposure, broadly conceived, has arguably been quite limited conceptually and methodologically. Indeed, we appear to lag behind our exposure science colleagues in our theories, data, and methods. In this paper we discuss a framework based on the concept of spatial polygamy to demonstrate the need to collect new forms of data on human spatial behavior and contextual exposures across time and space. Adopting new data and methods will be essential if we want to better understand social inequality in terms of exposure to health risks and access to health resources. We discuss the opportunities and challenges focusing on the potential seemingly offered by focusing on human mobility, and specifically the utilization of activity space concepts and data. A goal of the paper is to spatialize social and health science concepts and research practice vis-a-vis the complexity of exposure. The paper concludes with some recommendations for future research focusing on theoretical and conceptual development, promoting research on new types of places and human movement, the dynamic nature of contexts, and on training. “When we elect wittingly or unwittingly, to work within a level … we tend to discern or construct – whichever emphasis you prefer – only those kinds of systems whose elements are confined to that level.”Otis Dudley Duncan (1961, p. 141). “…despite the new ranges created by improved transportation, local government units have tended to remain medieval in size.”Torsten Hägerstrand (1970, p.18) “A detective investigating a crime needs both tools and understanding. If he has no fingerprint powder, he will fail to find fingerprints on most surfaces. If he does not understand where the criminal is likely to have put his fingers, he will not

  11. Spatial Polygamy and Contextual Exposures (SPACEs): Promoting Activity Space Approaches in Research on Place and Health.

    PubMed

    Matthews, Stephen A; Yang, Tse-Chuan

    2013-08-01

    Exposure science has developed rapidly and there is an increasing call for greater precision in the measurement of individual exposures across space and time. Social science interest in an individual's environmental exposure, broadly conceived, has arguably been quite limited conceptually and methodologically. Indeed, we appear to lag behind our exposure science colleagues in our theories, data, and methods. In this paper we discuss a framework based on the concept of spatial polygamy to demonstrate the need to collect new forms of data on human spatial behavior and contextual exposures across time and space. Adopting new data and methods will be essential if we want to better understand social inequality in terms of exposure to health risks and access to health resources. We discuss the opportunities and challenges focusing on the potential seemingly offered by focusing on human mobility, and specifically the utilization of activity space concepts and data. A goal of the paper is to spatialize social and health science concepts and research practice vis-a-vis the complexity of exposure. The paper concludes with some recommendations for future research focusing on theoretical and conceptual development, promoting research on new types of places and human movement, the dynamic nature of contexts, and on training. "When we elect wittingly or unwittingly, to work within a level … we tend to discern or construct - whichever emphasis you prefer - only those kinds of systems whose elements are confined to that level."Otis Dudley Duncan (1961, p. 141)."…despite the new ranges created by improved transportation, local government units have tended to remain medieval in size."Torsten Hägerstrand (1970, p.18)"A detective investigating a crime needs both tools and understanding. If he has no fingerprint powder, he will fail to find fingerprints on most surfaces. If he does not understand where the criminal is likely to have put his fingers, he will not look in the right

  12. An approach for autonomous space object identification based on normalized AMI and illumination invariant MSA

    NASA Astrophysics Data System (ADS)

    Ding, Hao; Li, Xudong; Zhao, Huijie

    2013-03-01

    The space environment is becoming more and more severe and crowded because of the rapid growth of space objects, which reveals an urgent demand to protect active satellites and other space assets. To accomplish such missions, e.g. the collision warning, the identification of space objects is important. In this paper, a three-stage approach for autonomous space object identification based on optical images is proposed. Firstly, on the basis of the approximate perspective imaging model, a scale and illumination invariant descriptor, composed of the normalized affine moment invariants (AMI) and the illumination invariant multiscale autoconvolution (MSA) transform, is developed to characterize the space object. Secondly, a multi-view modeling method is applied to construct multi-view databases of space objects for handling the viewpoint change. Finally, considering the extensibility of the databases, a K-nearest neighbor classifier is employed, and a K-means clustering is adopted to boost the search speed. Furthermore, to test the performance, a novel system based on the proposed approach is built and evaluated. The experimental evidence suggests that the system is stable and works well when the scale of a space object, the phase angle and the viewpoint change.

  13. An Augmented Lagrangian Method for a Class of Inverse Quadratic Programming Problems

    SciTech Connect

    Zhang Jianzhong; Zhang Liwei

    2010-02-15

    We consider an inverse quadratic programming (QP) problem in which the parameters in the objective function of a given QP problem are adjusted as little as possible so that a known feasible solution becomes the optimal one. We formulate this problem as a minimization problem with a positive semidefinite cone constraint and its dual is a linearly constrained semismoothly differentiable (SC{sup 1}) convex programming problem with fewer variables than the original one. We demonstrate the global convergence of the augmented Lagrangian method for the dual problem and prove that the convergence rate of primal iterates, generated by the augmented Lagrange method, is proportional to 1/r, and the rate of multiplier iterates is proportional to 1/{radical}r, where r is the penalty parameter in the augmented Lagrangian. As the objective function of the dual problem is a SC{sup 1} function involving the projection operator onto the cone of symmetrically semi-definite matrices, the analysis requires extensive tools such as the singular value decomposition of matrices, an implicit function theorem for semismooth functions, and properties of the projection operator in the symmetric-matrix space. Furthermore, the semismooth Newton method with Armijo line search is applied to solve the subproblems in the augmented Lagrange approach, which is proven to have global convergence and local quadratic rate. Finally numerical results, implemented by the augmented Lagrangian method, are reported.

  14. TDRSS Augmentation Service for Satellites (TASS)

    NASA Technical Reports Server (NTRS)

    Heckler, Gregory W.; Gramling, Cheryl; Valdez, Jennifer; Baldwin, Philip

    2016-01-01

    In 2015, NASA Goddard Space Flight Center (GSFC) reinvigorated the development of the TDRSS Augmentation Service for Satellites (TASS). TASS is a global, space-based, communications and navigation service for users of Global Navigation Satellite Systems (GNSS) and the Tracking and Data Relay Satellite System (TDRSS). TASS leverages the existing TDRSS to provide an S-band beacon radio navigation and messaging source to users at orbital altitudes 1400 km and below.

  15. Augmented-plane-wave forces

    NASA Astrophysics Data System (ADS)

    Soler, José M.; Williams, Arthur R.

    1990-11-01

    Results are presented that demonstrate the effectiveness of a calculational method of electronic-structure theory. The method combines the power (tractable basis-set size) and flexibility (transition and first-row elements) of the augmented-plane-wave method with the computational efficiency of the Car-Parrinello method of molecular dynamics and total-energy minimization. Equilibrium geometry and vibrational frequencies in agreement with experiment are presented for Si, to demonstrate agreement with existing methods and for Cu, N2, and H2O to demonstrate the broader applicability of the approach.

  16. Space ecosynthesis: An approach to the design of closed ecosystems for use in space

    NASA Technical Reports Server (NTRS)

    Macelroy, R. D.; Averner, M. M.

    1978-01-01

    The use of closed ecological systems for the regeneration of wastes, air, and water is discussed. It is concluded that such systems, if they are to be used for the support of humans in space, will require extensive mechanical and physico-chemical support. The reason for this is that the buffering capacity available in small systems is inadequate, and that natural biological and physical regulatory mechanisms rapidly become inoperative. It is proposed that mathematical models of the dynamics of a closed ecological system may provide the best means of studying the initial problems of ecosystem closure. A conceptual and mathematical model of a closed ecosystem is described which treats the biological components as a farm, calculates the rates of flow of elements through the system by mass-balance techniques and control theory postulates, and can evaluate the requirements for mechanical buffering activities. It is suggested that study of the closure of ecosystems can significantly aid in the establishment of general principles of ecological systems.

  17. Augmenting computer networks

    NASA Technical Reports Server (NTRS)

    Bokhari, S. H.; Raza, A. D.

    1984-01-01

    Three methods of augmenting computer networks by adding at most one link per processor are discussed: (1) A tree of N nodes may be augmented such that the resulting graph has diameter no greater than 4log sub 2((N+2)/3)-2. Thi O(N(3)) algorithm can be applied to any spanning tree of a connected graph to reduce the diameter of that graph to O(log N); (2) Given a binary tree T and a chain C of N nodes each, C may be augmented to produce C so that T is a subgraph of C. This algorithm is O(N) and may be used to produce augmented chains or rings that have diameter no greater than 2log sub 2((N+2)/3) and are planar; (3) Any rectangular two-dimensional 4 (8) nearest neighbor array of size N = 2(k) may be augmented so that it can emulate a single step shuffle-exchange network of size N/2 in 3(t) time steps.

  18. Space Station Freedom - Configuration management approach to supporting concurrent engineering and total quality management. [for NASA Space Station Freedom Program

    NASA Technical Reports Server (NTRS)

    Gavert, Raymond B.

    1990-01-01

    Some experiences of NASA configuration management in providing concurrent engineering support to the Space Station Freedom program for the achievement of life cycle benefits and total quality are discussed. Three change decision experiences involving tracing requirements and automated information systems of the electrical power system are described. The potential benefits of concurrent engineering and total quality management include improved operational effectiveness, reduced logistics and support requirements, prevention of schedule slippages, and life cycle cost savings. It is shown how configuration management can influence the benefits attained through disciplined approaches and innovations that compel consideration of all the technical elements of engineering and quality factors that apply to the program development, transition to operations and in operations. Configuration management experiences involving the Space Station program's tiered management structure, the work package contractors, international partners, and the participating NASA centers are discussed.

  19. Person Re-Identification by Camera Correlation Aware Feature Augmentation.

    PubMed

    Chen, Ying-Cong; Zhu, Xiatian; Zheng, Wei-Shi; Lai, Jian-Huang

    2017-02-09

    The challenge of person re-identification (re-id) is to match individual images of the same person captured by different non-overlapping camera views against significant and unknown cross-view feature distortion. While a large number of distance metric/subspace learning models have been developed for re-id, the cross-view transformations they learned are view-generic and thus potentially less effective in quantifying the feature distortion inherent to each camera view. Learning view-specific feature transformations for re-id (i.e., view-specific re-id), an under-studied approach, becomes an alternative resort for this problem. In this work, we formulate a novel view-specific person re-identification framework from the feature augmentation point of view, called Camera coRrelation Aware Feature augmenTation (CRAFT). Specifically, CRAFT performs cross-view adaptation by automatically measuring camera correlation from cross-view visual data distribution and adaptively conducting feature augmentation to transform the original features into a new adaptive space. Through our augmentation framework, view-generic learning algorithms can be readily generalized to learn and optimize view-specific sub-models whilst simultaneously modelling view-generic discrimination information. Therefore, our framework not only inherits the strength of view-generic model learning but also provides an effective way to take into account view specific characteristics. Our CRAFT framework can be extended to jointly learn view-specific feature transformations for person re-id across a large network with more than two cameras, a largely under-investigated but realistic re-id setting. Additionally, we present a domain-generic deep person appearance representation which is designed particularly to be towards view invariant for facilitating cross-view adaptation by CRAFT. We conducted extensively comparative experiments to validate the superiority and advantages of our proposed framework over state

  20. Heating Augmentation for Short Hypersonic Protuberances

    NASA Technical Reports Server (NTRS)

    Mazaheri, Alireza R.; Wood, William A.

    2008-01-01

    Computational aeroheating analyses of the Space Shuttle Orbiter plug repair models are validated against data collected in the Calspan University of Buffalo Research Center (CUBRC) 48 inch shock tunnel. The comparison shows that the average difference between computed heat transfer results and the data is about 9:5%. Using CFD and Wind Tunnel (WT) data, an empirical correlation for estimating heating augmentation on short hyper- sonic protuberances (k/delta < 0.33) is proposed. This proposed correlation is compared with several computed flight simulation cases and good agreement is achieved. Accordingly, this correlation is proposed for further investigation on other short hypersonic protuberances for estimating heating augmentation.

  1. Heating Augmentation for Short Hypersonic Protuberances

    NASA Technical Reports Server (NTRS)

    Mazaheri, Ali R.; Wood, William A.

    2008-01-01

    Computational aeroheating analyses of the Space Shuttle Orbiter plug repair models are validated against data collected in the Calspan University of Buffalo Research Center (CUBRC) 48 inch shock tunnel. The comparison shows that the average difference between computed heat transfer results and the data is about 9.5%. Using CFD and Wind Tunnel (WT) data, an empirical correlation for estimating heating augmentation on short hypersonic protuberances (k/delta less than 0.3) is proposed. This proposed correlation is compared with several computed flight simulation cases and good agreement is achieved. Accordingly, this correlation is proposed for further investigation on other short hypersonic protuberances for estimating heating augmentation.

  2. Approaches to dealing with meteoroid and orbital debris protection on the Space Station

    NASA Technical Reports Server (NTRS)

    Kessler, Donald J.

    1990-01-01

    Viewgraphs and discussion on approaches to dealing with meteoroid and orbital debris protection on the space station are presented. The National Space Policy of February, 1988, included the following: 'All sectors will seek to minimize the creation of space debris. Design and operations of space tests, experiments, and systems will strive to minimize or reduce accumulation of space debris consistent with mission requirements and cost effectiveness.' The policy also tasked the National Security Council, which established an Interagency Group, which in turn produced an Interagency Report. NASA and DoD tasks to establish a joint plan to determine techniques to measure the environment, and techniques to reduce the environment are addressed. Topics covered include: orbital debris environment, meteoroids, orbital debris population, cataloged earth satellite population, USSPACECOM cataloged objects, and orbital debris radar program.

  3. Open for business: A New Approach to Commercialisation of the International Space Station

    NASA Astrophysics Data System (ADS)

    Master Of Space Studies 1998-1999 (Mss4) Class

    2000-01-01

    The International Space Station (ISS) is the result of collaboration between fifteen countries (IGA, 1998). Originally planned as a scientific facility, a shift in policy of the partners has recently occurred towards commercialisation of the Station. Open for Business: A New Approach to Commercialisation of the International Space Station is written in response to this policy shift. It sets out to identify the major constraints in which the potential commercial user must operate and proposes solutions for both commercial user and the partner space agencies to facilitate this commercialisation process. In a time when space-faring nations face reduced fiscal resources and increasing pressure from their constituencies to justify the huge costs of the ISS, commercialising utilisation seems a logical solution. Clearly, successful commercialisation can help recover some of the development and operating costs of the ISS. The structure of Open for Business is divided into two main parts. Part One is entitled ``Constraint and Solutions.'' It proposes new solutions to existing constraint to ISS commercialisation in areas of policy, law, technology and business. The conclusions of Part One are integrated and unified into A New Approach towards ISS commercialisation. This approach is then applied in Part Two to two case studies: the International Space Satellite Servicing Station (I4S) and protein crystallization. Open for Business then concludes with a recommended approach to the future of ISS commercialisation. .

  4. An Approach to Integrate a Space-Time GIS Data Model with High Performance Computers

    SciTech Connect

    Wang, Dali; Zhao, Ziliang; Shaw, Shih-Lung

    2011-01-01

    In this paper, we describe an approach to integrate a Space-Time GIS data model on a high performance computing platform. The Space-Time GIS data model has been developed on a desktop computing environment. We use the Space-Time GIS data model to generate GIS module, which organizes a series of remote sensing data. We are in the process of porting the GIS module into an HPC environment, in which the GIS modules handle large dataset directly via parallel file system. Although it is an ongoing project, authors hope this effort can inspire further discussions on the integration of GIS on high performance computing platforms.

  5. The Faster, Better, Cheaper Approach to Space Missions: An Engineering Management Assessment

    NASA Technical Reports Server (NTRS)

    Hamaker, Joe

    2000-01-01

    This paper describes, in viewgraph form, the faster, better, cheaper approach to space missions. The topics include: 1) What drives "Faster, Better, Cheaper"? 2) Why Space Programs are Costly; 3) Background; 4) Aerospace Project Management (Old Culture); 5) Aerospace Project Management (New Culture); 6) Scope of Analysis Limited to Engineering Management Culture; 7) Qualitative Analysis; 8) Some Basic Principles of the New Culture; 9) Cause and Effect; 10) "New Ways of Doing Business" Survey Results; 11) Quantitative Analysis; 12) Recent Space System Cost Trends; 13) Spacecraft Dry Weight Trend; 14) Complexity Factor Trends; 15) Cost Normalization; 16) Cost Normalization Algorithm; 17) Unnormalized Cost vs. Normalized Cost; and 18) Concluding Observations.

  6. CCSDS - An approach to the definition of common standards for space data and information systems

    NASA Technical Reports Server (NTRS)

    Greene, Edward P.; Honvault, Claude

    1990-01-01

    The Consultative Committee for Space Data Systems (CCSDS) was formed in 1982 to develop common space system data structures, protocols, and interfaces which would facilitate mutual international support and interoperability. It soon emerged that CCSDS's activities exerted synergistic forces on systems development efforts. Currently, CCSDS is composed of both member-status and observer-status agencies; while only one member agency is admitted from any one country, multiple additional agencies may participate as observers. CCSDS recommendations to date have identified a common architectural approach for the handling and processing of space data.

  7. A Random Finite Set Approach to Space Junk Tracking and Identification

    DTIC Science & Technology

    2014-09-03

    Jah, “An AEGIS-FISST integrated detection and tracking approach to Space Situational Awareness,” Proc. Int. Conf. Information Fusion, pp. 2065-2072...Final 3. DATES COVERED (From - To) 31 Jan 13 – 29 Apr 14 4. TITLE AND SUBTITLE A Random Finite Set Approach to Space Junk Tracking and...Identification 5a. CONTRACT NUMBER FA2386-13-1-4010 5b. GRANT NUMBER Grant AOARD-134010 5c. PROGRAM ELEMENT NUMBER 61102F 6. AUTHOR(S

  8. A Scalable Approach to Probabilistic Latent Space Inference of Large-Scale Networks.

    PubMed

    Yin, Junming; Ho, Qirong; Xing, Eric P

    2013-01-01

    We propose a scalable approach for making inference about latent spaces of large networks. With a succinct representation of networks as a bag of triangular motifs, a parsimonious statistical model, and an efficient stochastic variational inference algorithm, we are able to analyze real networks with over a million vertices and hundreds of latent roles on a single machine in a matter of hours, a setting that is out of reach for many existing methods. When compared to the state-of-the-art probabilistic approaches, our method is several orders of magnitude faster, with competitive or improved accuracy for latent space recovery and link prediction.

  9. Comparing Laser Interferometry and Atom Interferometry Approaches to Space-Based Gravitational-Wave Measurement

    NASA Technical Reports Server (NTRS)

    Baker, John; Thorpe, Ira

    2012-01-01

    Thoroughly studied classic space-based gravitational-wave missions concepts such as the Laser Interferometer Space Antenna (LISA) are based on laser-interferometry techniques. Ongoing developments in atom-interferometry techniques have spurred recently proposed alternative mission concepts. These different approaches can be understood on a common footing. We present an comparative analysis of how each type of instrument responds to some of the noise sources which may limiting gravitational-wave mission concepts. Sensitivity to laser frequency instability is essentially the same for either approach. Spacecraft acceleration reference stability sensitivities are different, allowing smaller spacecraft separations in the atom interferometry approach, but acceleration noise requirements are nonetheless similar. Each approach has distinct additional measurement noise issues.

  10. An Integrated Optimal Estimation Approach to Spitzer Space Telescope Focal Plane Survey

    NASA Technical Reports Server (NTRS)

    Bayard, David S.; Kang, Bryan H.; Brugarolas, Paul B.; Boussalis, D.

    2004-01-01

    This paper discusses an accurate and efficient method for focal plane survey that was used for the Spitzer Space Telescope. The approach is based on using a high-order 37-state Instrument Pointing Frame (IPF) Kalman filter that combines both engineering parameters and science parameters into a single filter formulation. In this approach, engineering parameters such as pointing alignments, thermomechanical drift and gyro drifts are estimated along with science parameters such as plate scales and optical distortions. This integrated approach has many advantages compared to estimating the engineering and science parameters separately. The resulting focal plane survey approach is applicable to a diverse range of science instruments such as imaging cameras, spectroscopy slits, and scanning-type arrays alike. The paper will summarize results from applying the IPF Kalman Filter to calibrating the Spitzer Space Telescope focal plane, containing the MIPS, IRAC, and the IRS science Instrument arrays.

  11. A Bayesian approach to the ICH Q8 definition of design space.

    PubMed

    Peterson, John J

    2008-01-01

    Manufacturers of pharmaceuticals and biopharmaceuticals are facing increased regulatory pressure to understand how their manufacturing processes work and to be able to quantify the reliability and robustness of their manufacturing processes. In particular, the ICH Q8 guidance has introduced the concept of design space. The ICH Q8 defines design space as "the multidimensional combination and interaction of input variables (e.g., material attributes) and process parameters that have been demonstrated to provide assurance of quality." However, relatively little has been put forth to date on how to construct a design space from data composed of such variables. This study presents a Bayesian approach to design space based upon a type of credible region first appearing in Peterson's work.This study considers the issues of constructing a Bayesian design space, design space reliability, the inclusion of process noise variables, and utilization of prior information, as well as an outline for organizing information about a design space so that manufacturing engineers can make informed changes as may be needed within the design space.

  12. Possibility of a new approach to processing space pulse radio signals

    NASA Technical Reports Server (NTRS)

    Bocharov, A. A.

    1981-01-01

    A approach to the processing of space pulse radio signals, which makes it possible to achieve a high level of time resolution is proposed. The approach is based on the utilization of the Fourier transform of a radio pulse envelope in the interstellar medium effect. The conditions of applicability of the proposed method and the requirements for recording equipment are substantiated. Also indicated is the possibility of obtaining superresolution with the utilization of the given method of signal processing.

  13. A novel approach to establishing the design space for the oral formulation manufacturing process.

    PubMed

    Norioka, Tadashi; Hayashi, Yoshihiro; Onuki, Yoshinori; Andou, Hirotaka; Tsunashima, Daisuke; Yamashita, Kazunari; Takayama, Kozo

    2013-01-01

    A novel approach to establishing the design space for the oral formulation manufacturing process was investigated. A response surface method incorporating multivariate spline interpolation was applied to overcome the nonlinear problem, which is always problematic in pharmaceutical development studies, and a bootstrap resampling technique, polynomial approximation technique, and 95% confidence intervals based on a nonparametric approach were applied to estimate the reliability of the established design space derived from the nonlinear response surface model. The critical quality attributes (CQAs) of intermediate material rather than the critical process parameters (CPPs) were chosen as the causal factors for the response variables, which were CQAs of the final product to avoid scale-gap and equipment-gap. This enabled the effective use of data sets accumulated during all pharmaceutical development studies. It was confirmed that a conservative border as well as an optimistic border of the design space for practical use was obtained considering the variability of the border of the design spaces on nonlinear response surfaces. Furthermore, the nonlinear response surface model using CQAs of intermediate material derived from data sets of a laboratory scale study and pilot scale studies could predict the CQA of the final product (2.5 h dissolution of commercial-scale study) with high accuracy. Consequently, the proposed novel approach overcame all of the difficulties for the manufacturing process development of oral formulations and this is the first study to demonstrate the effectiveness of the design space using CQA of intermediate material for the oral formulation manufacturing process.

  14. Multi-atlas and unsupervised learning approach to perirectal space segmentation in CT images.

    PubMed

    Ghose, Soumya; Denham, James W; Ebert, Martin A; Kennedy, Angel; Mitra, Jhimli; Dowling, Jason A

    2016-12-01

    Perirectal space segmentation in computed tomography images aids in quantifying radiation dose received by healthy tissues and toxicity during the course of radiation therapy treatment of the prostate. Radiation dose normalised by tissue volume facilitates predicting outcomes or possible harmful side effects of radiation therapy treatment. Manual segmentation of the perirectal space is time consuming and challenging in the presence of inter-patient anatomical variability and may suffer from inter- and intra-observer variabilities. However automatic or semi-automatic segmentation of the perirectal space in CT images is a challenging task due to inter patient anatomical variability, contrast variability and imaging artifacts. In the model presented here, a volume of interest is obtained in a multi-atlas based segmentation approach. Un-supervised learning in the volume of interest with a Gaussian-mixture-modeling based clustering approach is adopted to achieve a soft segmentation of the perirectal space. Probabilities from soft clustering are further refined by rigid registration of the multi-atlas mask in a probabilistic domain. A maximum a posteriori approach is adopted to achieve a binary segmentation from the refined probabilities. A mean volume similarity value of 97% and a mean surface difference of 3.06 ± 0.51 mm is achieved in a leave-one-patient-out validation framework with a subset of a clinical trial dataset. Qualitative results show a good approximation of the perirectal space volume compared to the ground truth.

  15. Computer Augmented Video Education.

    ERIC Educational Resources Information Center

    Sousa, M. B.

    1979-01-01

    Describes project CAVE (Computer Augmented Video Education), an ongoing effort at the U.S. Naval Academy to present lecture material on videocassette tape, reinforced by drill and practice through an interactive computer system supported by a 12 channel closed circuit television distribution and production facility. (RAO)

  16. Chin augmentation - slideshow

    MedlinePlus

    ... anatomy URL of this page: //medlineplus.gov/ency/presentations/100009.htm Chin augmentation - series—Normal anatomy To use the sharing features on this page, please enable JavaScript. Go to slide 1 out of 5 Go to slide 2 ...

  17. Augmentative & Alternative Communication

    ERIC Educational Resources Information Center

    Murphy, Patti

    2007-01-01

    There is no definitive recipe for augmentative and alternative communication (AAC) success, but its universal ingredients can be found at home. The main ones are: (1) Understanding that all children need to express themselves, however outgoing or shy they may be; (2) Willingness to embrace the technology that may help your child regardless of your…

  18. Augmented Thermal Bus

    NASA Technical Reports Server (NTRS)

    Schrage, Dean S. (Inventor)

    1996-01-01

    The present invention is directed to an augmented thermal bus. In the present design a plurality of thermo-electric heat pumps are used to couple a source plate to a sink plate. Each heat pump is individually controlled by a model based controller. The controller coordinates the heat pumps to maintain isothermality in the source.

  19. Augmented thermal bus

    NASA Technical Reports Server (NTRS)

    Schrage, Dean S. (Inventor)

    1993-01-01

    The present invention is directed to an augmented thermal bus. In the present design a plurity of thermo-electric heat pumps are used to couple a source plate to a sink plate. Each heat pump is individually controlled by a model based controller. The controller coordinates the heat pump to maintain isothermality in the source.

  20. Augmented Reality Binoculars.

    PubMed

    Oskiper, Taragay; Sizintsev, Mikhail; Branzoi, Vlad; Samarasekera, Supun; Kumar, Rakesh

    2015-05-01

    In this paper we present an augmented reality binocular system to allow long range high precision augmentation of live telescopic imagery with aerial and terrain based synthetic objects, vehicles, people and effects. The inserted objects must appear stable in the display and must not jitter and drift as the user pans around and examines the scene with the binoculars. The design of the system is based on using two different cameras with wide field of view and narrow field of view lenses enclosed in a binocular shaped shell. Using the wide field of view gives us context and enables us to recover the 3D location and orientation of the binoculars much more robustly, whereas the narrow field of view is used for the actual augmentation as well as to increase precision in tracking. We present our navigation algorithm that uses the two cameras in combination with an inertial measurement unit and global positioning system in an extended Kalman filter and provides jitter free, robust and real-time pose estimation for precise augmentation. We have demonstrated successful use of our system as part of information sharing example as well as a live simulated training system for observer training, in which fixed and rotary wing aircrafts, ground vehicles, and weapon effects are combined with real world scenes.

  1. DMS augmented monitoring and diganosis application (DMS AMDA) prototype

    NASA Technical Reports Server (NTRS)

    Patterson-Hine, F. A.; Boyd, Mark A.; Iverson, David L.; Donnell, Brian; Lauritsen, Janet; Doubek, Sharon; Gibson, Jim; Monahan, Christine; Rosenthal, Donald A.

    1993-01-01

    The Data Management System Augmented Monitoring and Diagnosis Application (DMS AMDA) is currently under development at NASA Ames Research Center (ARC). It will provide automated monitoring and diagnosis capabilities for the Space Station Freedom (SSF) Data Management System (DMS) in the Control Center Complex (CCC) at NASA Johnson Space Center. Several advanced automation applications are under development for use in the CCC for other SSF subsystems. The DMS AMDA, however, is the first application to utilize digraph failure analysis techniques and the Extended Realtime FEAT (ERF) application as the core of its diagnostic system design, since the other projects were begun before the digraph tools were available. Model-based diagnosis and expert systems techniques will provide additional capabilities and augment ERF where appropriate. Utilization of system knowledge captured in the design phase of a system in digraphs should result in both a cost savings and a technical advantage during implementation of the diagnostic software. This paper addresses both the programmatic and technical considerations of this approach, and describes the software design and initial prototyping effort.

  2. Preliminary Assessment of Thrust Augmentation of NEP Based Missions

    NASA Technical Reports Server (NTRS)

    Chew, Gilbert; Pelaccio, Dennis G.; Chiroux, Robert; Pervan, Sherry; Rauwolf, Gerald A.; White, Charles

    2005-01-01

    Science Applications International Corporation (SAIC), with support from NASA Marshall Space Flight Center, has conducted a preliminary study to compare options for augmenting the thrust of a conventional nuclear electric propulsion (NEP) system. These options include a novel nuclear propulsion system concept known as Hybrid Indirect Nuclear Propulsion (HINP) and conventional chemical propulsion. The utility and technical feasibility of the HINP concept are assessed, and features and potential of this new in-space propulsion system concept are identified. As part of the study, SAIC developed top-level design tools to model the size and performance of an HINP system, as well as for several chemical propulsion options, including liquid and gelled propellants. A mission trade study was performed to compare a representative HINP system with chemical propulsion options for thrust augmentation of NEP systems for a mission to Saturn's moon Titan. Details pertaining to the approach, features, initial demonstration results for HINP model development, and the mission trade study are presented. Key technology and design issues associated with the HINP concept and future work recommendations are also identified.

  3. A low cost commercial approach to space systems development and operations

    NASA Astrophysics Data System (ADS)

    Bonner, T. F.; Faget, M. A.; Allen, J. P.; Langstaff, D. H.

    In recent years a number of factors have led to increased attention to the lowering of costs for space flight systems and the operation of those systems. To that end Space Industries Inc. (SII), a small commercial space company based in Houston, Tex., is employing proven methods derived from over three decades of space flight development and space operations. These methods are based on a philosophy that is cost-sensitive focused with a primary objective to drive the cost of space systems and their operations down to the lowest level practical, consistent with the mission objectives, acceptable risk and safety considerations. This approach involves a process of: (1) addressing the basic requirements in the simplest and most cost effective manner, i.e. limit new development wherever possible, maximize use of proven and existing technology and eliminate non-essential requirements; (2) incorporation of proven industrial practices where possible, i.e. focus on performance envelopes (not on restrictive, specific and detailed specifications) and streamline program management, documentation, testing and other procedures; and (3) delivery of the "best" price, i.e. maximum customer utility at minimum cost with emphasis on customer service. The overriding factor, and indeed the most important aspect of the low cost commercial approach, is the willingness to accept greater risks to achieve all of the user's objectives. Our development approach is customer focused with emphasis on fully understanding the customer needs while striving constantly to limit new development requirements and, consequently, additional costs. This approach involves a process of designing for operations, i.e. low operation and life-cycle costs, while ensuring a reliability level consistent with customer budget constraints, mission objectives and safety consideration. In executing this low cost, customer-focused approach, we strive to maintain minimal overheads, simple interfaces, reduced documentation

  4. Pilot Non-Conformance to Alerting System Commands During Closely Spaced Parallel Approaches

    NASA Technical Reports Server (NTRS)

    Pritchett, Amy R.; Hansman, R. John

    1997-01-01

    Pilot non-conformance to alerting system commands has been noted in general and to a TCAS-like collision avoidance system in a previous experiment. This paper details two experiments studying collision avoidance during closely-spaced parallel approaches in instrument meteorological conditions (IMC), and specifically examining possible causal factors of, and design solutions to, pilot non-conformance.

  5. Diversifying Our Perspectives on Mathematics about Space and Geometry: An Ecocultural Approach

    ERIC Educational Resources Information Center

    Owens, Kay

    2014-01-01

    School mathematics tends to have developed from the major cultures of Asia, the Mediterranean and Europe. However, indigenous cultures in particular may have distinctly different systematic ways of referring to space and thinking mathematically about spatial activity. Their approaches are based on the close link between the environment and…

  6. Quantum-field-theoretical approach to phase-space techniques: Generalizing the positive-P representation

    SciTech Connect

    Plimak, L.I.; Fleischhauer, M.; Olsen, M.K.; Collett, M.J.

    2003-01-01

    We present an introduction to phase-space techniques (PST) based on a quantum-field-theoretical (QFT) approach. In addition to bridging the gap between PST and QFT, our approach results in a number of generalizations of the PST. First, for problems where the usual PST do not result in a genuine Fokker-Planck equation (even after phase-space doubling) and hence fail to produce a stochastic differential equation (SDE), we show how the system in question may be approximated via stochastic difference equations (S{delta}E). Second, we show that introducing sources into the SDE's (or S{delta}E's) generalizes them to a full quantum nonlinear stochastic response problem (thus generalizing Kubo's linear reaction theory to a quantum nonlinear stochastic response theory). Third, we establish general relations linking quantum response properties of the system in question to averages of operator products ordered in a way different from time normal. This extends PST to a much wider assemblage of operator products than are usually considered in phase-space approaches. In all cases, our approach yields a very simple and straightforward way of deriving stochastic equations in phase space.

  7. Learning in Earth and Space Science: A Review of Conceptual Change Instructional Approaches

    ERIC Educational Resources Information Center

    Mills, Reece; Tomas, Louisa; Lewthwaite, Brian

    2016-01-01

    In response to calls for research into effective instruction in the Earth and space sciences, and to identify directions for future research, this systematic review of the literature explores research into instructional approaches designed to facilitate conceptual change. In total, 52 studies were identified and analyzed. Analysis focused on the…

  8. Learning in the Liminal Space: A Semiotic Approach to Threshold Concepts

    ERIC Educational Resources Information Center

    Land, Ray; Rattray, Julie; Vivian, Peter

    2014-01-01

    The threshold concepts approach to student learning and curriculum design now informs an empirical research base comprising over 170 disciplinary and professional contexts. It draws extensively on the notion of troublesomeness in a "liminal" space of learning. The latter is a transformative state in the process of learning in which there…

  9. Perturbative Approaching for Boson Fields' System in a Lewis-Papapetrou Space-Time

    SciTech Connect

    Murariu, G.; Dariescu, M. A.; Dariescu, C.

    2010-08-04

    In this paper the first order solutions of a Klein--Gordon--Maxwell--Einstein coupled system equations were derived for boson fields in a Lewis Papapetrou space time. The results expand the previous static solutions obtained in literature. A main goal is represented by the symbolic script built for such approach.

  10. Investigation of velocity-space coupling approach in DSMC for tail-driven processes

    NASA Astrophysics Data System (ADS)

    Pan, Tzu-Jung; Stephani, Kelly A.

    2016-11-01

    In this study, a velocity-space coupling approach is investigated to improve the poor statistics of tail-driven processes in DSMC. The velocity distribution function is separated into bulk and tail regions in velocity space according to the location of a velocity space interface. The highly-populated bulk distribution, fbulk, is evolved in DSMC through selective particle collisions where there are suffcient particles to resolve the distribution with relatively low stochastic noise. The distribution tail, ftail, is computed based on the solution of the Boltzmann equation through discontinuous Galerkin (DG) method in a reduced region of velocity space, which provides a statistically smooth, kinetic "correction" to the DSMC tail. The spatially homogeneous relaxation problem is solved to test the DSMC/DG coupling approach and the results are compared with the standard DSMC solver. The result shows that the coupling approach successfully computes the correct relaxation rate and the evolution of entropy agrees with the DSMC result. Furthermore, using the same initial number of simulation particles, the coupling approach achieves better resolution of the tail velocity bins than DSMC and the results are in good agreement with the DG solution.

  11. An integrated mission approach to the space exploration initiative will ensure success

    SciTech Connect

    Coomes, E.P.; Dagle, J.E.; Bamberger, J.A.; Noffsinger, K.E.

    1990-10-01

    The direction of the American space program, as defined by President Bush and the National Commission on Space, is to expand human presence into the solar system. Landing an American on Mars by the 50th anniversary of the Apollo 11 lunar landing is the goal. This challenge has produced a level of excitement among young Americans not seen for nearly three decades. The exploration and settlement of the space frontier will occupy the creative thoughts and energies of generations of Americans well into the next century. The return of Americans to the moon and beyond must be viewed as a national effort with strong public support if it is to become a reality. Key to making this an actuality is the mission approach selected. Developing a permanent presence in space requires a continual stepping outward from Earth in a logical progressive manner. If we seriously plan to go and to stay, then not only must we plan what we are to do and how we are to do it, we must address the logistic support infrastructure that will allow us to stay there once we arrive. A fully integrated approach to mission planning is needed if the Space Exploration Initiative (SEI) is to be successful. Only in this way can a permanent human presence in space be sustained. An integrated infrastructure approach would reduce the number of new systems and technologies requiring development. The resultant horizontal commonality of systems and hardware would reduce the direct economic impact of SEI while an early return on investment through technology spin-offs would be an economic benefit by greatly enhancing our international technical competitiveness. If the exploration, development, and colonization of space is to be affordable and acceptable, careful consideration must be given to such things as return on investment'' and commercial product potential'' of the technologies developed. 7 refs., 3 figs.

  12. An integrated mission approach to the space exploration initiative will ensure success

    SciTech Connect

    Coomes, E.P.; Dagle, J.E.; Bamberger, J.A.; Noffsinger, K.E. )

    1991-01-05

    The direction of the American space program, as defined by President Bush and the National Commission on Space, is to expand human presence into the solar system. Landing an American on Mars by the 50th anniversary of the Apollo 11 lunar landing is the goal. This challenge has produced a level of excitement among young Americans not seen for nearly three decades. The exploration and settlement of the space frontier will occupy the creative thoughts and energies of generations of Americans well into the next century. The return of Americans to the moon and beyond must be viewed as a national effort with strong public support if it is to become a reality. Key to making this an actuality is the mission approach selected. Developing a permanent presence in space requires a continual stepping outward from Earch in a logical progressive manner. If we seriously plan to go and to stay, then not only must we plan what we are to do and how we are to do it, we must address the logistic support infrastructure that will allow us to stay there once we arrive. A fully integrated approach to mission planning is needed if the Space exploration Initiative (SEI) is to be successful. Only in this way can a permanent human presence in space be sustained. An integrated infrastructure approach would reduce the number of new systems and technologies requiring development. The resultant horizontal commonality of systems and hardware would reduce the direct economic impact of SEI while an early return on investment through technology spin-offs would be an economic benefit by greatly enhancing our international technical competitiveness. If the exploration, development, and colonization of space is to be affordable and acceptable, careful consideration must be given to such things as return on investment'' and commercial product potential'' of the technologies developed.

  13. Concept of Draft International Standard for a Unified Approach to Space Program Quality Assurance

    NASA Astrophysics Data System (ADS)

    Stryzhak, Y.; Vasilina, V.; Kurbatov, V.

    2002-01-01

    For want of the unified approach to guaranteed space project and product quality assurance, implementation of many international space programs has become a challenge. Globalization of aerospace industry and participation of various international ventures with diverse quality assurance requirements in big international space programs requires for urgent generation of unified international standards related to this field. To ensure successful fulfillment of space missions, aerospace companies should design and process reliable and safe products with properties complying or bettering User's (or Customer's) requirements. Quality of the products designed or processed by subcontractors (or other suppliers) should also be in compliance with the main user (customer)'s requirements. Implementation of this involved set of unified requirements will be made possible by creating and approving a system (series) of international standards under a generic title Space Product Quality Assurance based on a system consensus principle. Conceptual features of the baseline standard in this system (series) should comprise: - Procedures for ISO 9000, CEN and ECSS requirements adaptation and introduction into space product creation, design, manufacture, testing and operation; - Procedures for quality assurance at initial (design) phases of space programs, with a decision on the end product made based on the principle of independence; - Procedures to arrange incoming inspection of products delivered by subcontractors (including testing, audit of supplier's procedures, review of supplier's documentation), and space product certification; - Procedures to identify materials and primary products applied; - Procedures for quality system audit at the component part, primary product and materials supplier facilities; - Unified procedures to form a list of basic performances to be under configuration management; - Unified procedures to form a list of critical space product components, and unified

  14. Intelligent Augmented Reality Training for Motherboard Assembly

    ERIC Educational Resources Information Center

    Westerfield, Giles; Mitrovic, Antonija; Billinghurst, Mark

    2015-01-01

    We investigate the combination of Augmented Reality (AR) with Intelligent Tutoring Systems (ITS) to assist with training for manual assembly tasks. Our approach combines AR graphics with adaptive guidance from the ITS to provide a more effective learning experience. We have developed a modular software framework for intelligent AR training…

  15. Asteroid Redirect Mission concept: A bold approach for utilizing space resources

    NASA Astrophysics Data System (ADS)

    Mazanek, Daniel D.; Merrill, Raymond G.; Brophy, John R.; Mueller, Robert P.

    2015-12-01

    The utilization of natural resources from asteroids is an idea that is older than the Space Age. The technologies are now available to transform this endeavor from an idea into reality. The Asteroid Redirect Mission (ARM) is a mission concept which includes the goal of robotically returning a small Near-Earth Asteroid (NEA) or a multi-ton boulder from a large NEA to cislunar space in the mid-2020s using an advanced Solar Electric Propulsion (SEP) vehicle and currently available technologies. The paradigm shift enabled by the ARM concept would allow in-situ resource utilization (ISRU) to be used at the human mission departure location (i.e., cislunar space) versus exclusively at the deep-space mission destination. This approach drastically reduces the barriers associated with utilizing ISRU for human deep-space missions. The successful testing of ISRU techniques and associated equipment could enable large-scale commercial ISRU operations to become a reality and enable a future space-based economy utilizing processed asteroidal materials. This paper provides an overview of the ARM concept and discusses the mission objectives, key technologies, and capabilities associated with the mission, as well as how the ARM and associated operations would benefit humanity's quest for the exploration and settlement of space.

  16. Service Areas of Local Urban Green Spaces: AN Explorative Approach in Arroios, Lisbon

    NASA Astrophysics Data System (ADS)

    Figueiredo, R.; Gonçalves, A. B.; Ramos, I. L.

    2016-09-01

    The identification of service areas of urban green spaces and areas with lack of these is increasingly necessary within city planning and management, as it translates into important indicators for the assessment of quality of life. In this setting, it is important to evaluate the attractiveness and accessibility dynamics through a set of attributes, taking into account the local reality of the territory under study. This work presents an operational methodology associated with these dynamics in local urban green spaces, assisting in the planning and management of this type of facilities. The methodology is supported firstly on questionnaire surveys and then on network analysis, processing spatial data in a Geographic Information Systems (GIS) environment. In the case study, two local green spaces in Lisbon were selected, on a local perspective explorative approach. Through field data, it was possible to identify service areas for both spaces, and compare the results with references in the literature. It was also possible to recognise areas with lack of these spaces. The difficulty to evaluate the dynamics of real individuals in their choices of urban green spaces and the respective route is a major challenge to the application of the methodology. In this sense it becomes imperative to develop different instruments and adapt them to other types of urban green spaces.

  17. Asteroid Redirect Mission Concept: A Bold Approach for Utilizing Space Resources

    NASA Technical Reports Server (NTRS)

    Mazanek, Daniel D.; Merrill, Raymond G.; Brophy, John R.; Mueller, Robert P.

    2014-01-01

    The utilization of natural resources from asteroids is an idea that is older than the Space Age. The technologies are now available to transform this endeavour from an idea into reality. The Asteroid Redirect Mission (ARM) is a mission concept which includes the goal of robotically returning a small Near-Earth Asteroid (NEA) or a multi-ton boulder from a large NEA to cislunar space in the mid 2020's using an advanced Solar Electric Propulsion (SEP) vehicle and currently available technologies. The paradigm shift enabled by the ARM concept would allow in-situ resource utilization (ISRU) to be used at the human mission departure location (i.e., cislunar space) versus exclusively at the deep-space mission destination. This approach drastically reduces the barriers associated with utilizing ISRU for human deep-space missions. The successful testing of ISRU techniques and associated equipment could enable large-scale commercial ISRU operations to become a reality and enable a future space-based economy utilizing processed asteroidal materials. This paper provides an overview of the ARM concept and discusses the mission objectives, key technologies, and capabilities associated with the mission, as well as how the ARM and associated operations would benefit humanity's quest for the exploration and settlement of space.

  18. Leadership for long-duration space missions: A shift toward a collective approach

    NASA Astrophysics Data System (ADS)

    Mulhearn, Tyler; McIntosh, Tristan; Gibson, Carter; Mumford, Michael D.; Yammarino, Francis J.; Connelly, Shane; Day, Eric Anthony; Vessey, Brandon

    2016-12-01

    For many years, leadership operations within the National Aeronautics and Space Administration (NASA) have utilized a primarily hierarchical approach. In the present effort, we investigated the leadership needs and considerations given the increased interest in and potential for long-duration space exploration. Specifically, it is argued that a collective leadership approach in which leadership is shared and distributed based on expertise would be beneficial for these types of missions. Interviews were conducted with eleven subject matter experts with wide-ranging experience in NASA and its missions. A mixed-methods analytic approach applied to these interviews provided support for the viability of a collective leadership framework. Implications for NASA and other similar organizational contexts are discussed.

  19. Predictive filtering-based fast reacquisition approach for space-borne acquisition, tracking, and pointing systems.

    PubMed

    Bai, Shuai; Wang, Jianyu; Qiang, Jia; Zhang, Liang; Wang, Juanjuan

    2014-11-03

    We propose a novel approach for recapturing targets as quickly as possible after the space-borne ATP (Acquisition, Tracking, and Pointing) system target loss in free-space laser communication. The approach uses past angular information to predict the target trajectory. An optimized finite memory filter is designed as the prediction algorithm. To obtain optimal prediction performance, the designed filter determines the filter parameters of different curve parts during offline training, and the parameters are adjusted according to the curve characteristics during predictive filtering. Simulation results indicate prediction accuracy above 0.1 degrees within 5 seconds. An experimental system was constructed in the lab to simulate the reacquisition process using a dynamic target and a real ATP system. Experimental results show that, compared with the classical orbit prediction method, this approach can effectively yield shorter acquisition times.

  20. Probabilistic Analysis of Impact of Wake Vortices on Closely-Spaced Parallel Approaches

    NASA Technical Reports Server (NTRS)

    Hardy, Gordon H.; Rossow, Vernon J.; Meyn, Larry A.

    2005-01-01

    One of the primary constraints on the capacity of the nation's air transportation system is the landing capacity of its largest airports. Many airports with closely spaced parallel runways suffer a severe runway acceptance rate when the weather conditions do not allow full utilization of these parallel runways. The present requirement for simultaneous independent landings in Instrument Meteorological Conditions, IMC, is at least 4300 feet of lateral runway spacing (as close as 3000 feet for runways with a Precision Runway Monitor). Operations in Visual Meteorological Conditions, VMC, to Closely Spaced Parallel Approaches only require a lateral runway spacing greater than 750 feet. A study by Hardy and Lewis integrated and extended earlier studies and concepts in lateral traffic separation, longitudinal station keeping, wake prediction, wake display, and the concepts of R N P into a preliminary system concept for Closely Spaced Parallel Approaches in IMC. This system allows IMC airport acceptance rates to approach those for VMC. The system concept that was developed, presented traffic and wake information on the NAVigation Display, NAV, and developed operational procedures for a mix of conventional and Runway Independent Aircraft with different approach speeds to Closely Spaced Parallel Runways. This paper first describes some improvements made on the technology needed to better predict and formulate a probabilistic representation for the time-dependent motion and spreading of the hazardous region associated with the lift-generated vortex wakes of preceding aircraft. In this way, the time at which the vortex wakes of leading aircraft intrude into the airspace of adjacent flight-corridor/runway combinations can be more reliably predicted. Such a prediction is needed because it determines restraints to be placed on in-trail separation distances; or, the allowable time intervals between aircraft executing nearly simultaneous landings or takeoffs on very closely-spaced

  1. Augmented Lagrangian formulation of orbital-free density functional theory

    NASA Astrophysics Data System (ADS)

    Suryanarayana, Phanish; Phanish, Deepa

    2014-10-01

    We present an Augmented Lagrangian formulation and its real-space implementation for non-periodic Orbital-Free Density Functional Theory (OF-DFT) calculations. In particular, we rewrite the constrained minimization problem of OF-DFT as a sequence of minimization problems without any constraint, thereby making it amenable to powerful unconstrained optimization algorithms. Further, we develop a parallel implementation of this approach for the Thomas-Fermi-von Weizsacker (TFW) kinetic energy functional in the framework of higher-order finite-differences and the conjugate gradient method. With this implementation, we establish that the Augmented Lagrangian approach is highly competitive compared to the penalty and Lagrange multiplier methods. Additionally, we show that higher-order finite-differences represent a computationally efficient discretization for performing OF-DFT simulations. Overall, we demonstrate that the proposed formulation and implementation are both efficient and robust by studying selected examples, including systems consisting of thousands of atoms. We validate the accuracy of the computed energies and forces by comparing them with those obtained by existing plane-wave methods.

  2. Augmented Lagrangian formulation of orbital-free density functional theory

    SciTech Connect

    Suryanarayana, Phanish Phanish, Deepa

    2014-10-15

    We present an Augmented Lagrangian formulation and its real-space implementation for non-periodic Orbital-Free Density Functional Theory (OF-DFT) calculations. In particular, we rewrite the constrained minimization problem of OF-DFT as a sequence of minimization problems without any constraint, thereby making it amenable to powerful unconstrained optimization algorithms. Further, we develop a parallel implementation of this approach for the Thomas–Fermi–von Weizsacker (TFW) kinetic energy functional in the framework of higher-order finite-differences and the conjugate gradient method. With this implementation, we establish that the Augmented Lagrangian approach is highly competitive compared to the penalty and Lagrange multiplier methods. Additionally, we show that higher-order finite-differences represent a computationally efficient discretization for performing OF-DFT simulations. Overall, we demonstrate that the proposed formulation and implementation are both efficient and robust by studying selected examples, including systems consisting of thousands of atoms. We validate the accuracy of the computed energies and forces by comparing them with those obtained by existing plane-wave methods.

  3. Collaborative Approaches in Developing Environmental and Safety Management Systems for Commercial Space Transportation

    NASA Technical Reports Server (NTRS)

    Zee, Stacey; Murray, D.

    2009-01-01

    The Federal Aviation Administration (FAA), Office of Commercial Space Transportation (AST) licenses and permits U.S. commercial space launch and reentry activities, and licenses the operation of non-federal launch and reentry sites. ASTs mission is to ensure the protection of the public, property, and the national security and foreign policy interests of the United States during commercial space transportation activities and to encourage, facilitate, and promote U.S. commercial space transportation. AST faces unique challenges of ensuring the protection of public health and safety while facilitating and promoting U.S. commercial space transportation. AST has developed an Environmental Management System (EMS) and a Safety Management System (SMS) to help meet its mission. Although the EMS and SMS were developed independently, the systems share similar elements. Both systems follow a Plan-Do-Act-Check model in identifying potential environmental aspects or public safety hazards, assessing significance in terms of severity and likelihood of occurrence, developing approaches to reduce risk, and verifying that the risk is reduced. This paper will describe the similarities between ASTs EMS and SMS elements and how AST is building a collaborative approach in environmental and safety management to reduce impacts to the environment and risks to the public.

  4. A real-space stochastic density matrix approach for density functional electronic structure.

    PubMed

    Beck, Thomas L

    2015-12-21

    The recent development of real-space grid methods has led to more efficient, accurate, and adaptable approaches for large-scale electrostatics and density functional electronic structure modeling. With the incorporation of multiscale techniques, linear-scaling real-space solvers are possible for density functional problems if localized orbitals are used to represent the Kohn-Sham energy functional. These methods still suffer from high computational and storage overheads, however, due to extensive matrix operations related to the underlying wave function grid representation. In this paper, an alternative stochastic method is outlined that aims to solve directly for the one-electron density matrix in real space. In order to illustrate aspects of the method, model calculations are performed for simple one-dimensional problems that display some features of the more general problem, such as spatial nodes in the density matrix. This orbital-free approach may prove helpful considering a future involving increasingly parallel computing architectures. Its primary advantage is the near-locality of the random walks, allowing for simultaneous updates of the density matrix in different regions of space partitioned across the processors. In addition, it allows for testing and enforcement of the particle number and idempotency constraints through stabilization of a Feynman-Kac functional integral as opposed to the extensive matrix operations in traditional approaches.

  5. Swamp Works: A New Approach to Develop Space Mining and Resource Extraction Technologies at the National Aeronautics Space Administration (NASA) Kennedy Space Center (KSC)

    NASA Technical Reports Server (NTRS)

    Mueller, R. P.; Sibille, L.; Leucht, K.; Smith, J. D.; Townsend, I. I.; Nick, A. J.; Schuler, J. M.

    2015-01-01

    environment and methodology, with associated laboratories that uses lean development methods and creativity-enhancing processes to invent and develop new solutions for space exploration. This paper will discuss the Swamp Works approach to developing space mining and resource extraction systems and the vision of space development it serves. The ultimate goal of the Swamp Works is to expand human civilization into the solar system via the use of local resources utilization. By mining and using the local resources in situ, it is conceivable that one day the logistics supply train from Earth can be eliminated and Earth independence of a space-based community will be enabled.

  6. Innovative Approaches to Space-Based Manufacturing and Rapid Prototyping of Composite Materials

    NASA Technical Reports Server (NTRS)

    Hill, Charles S.

    2012-01-01

    The ability to deploy large habitable structures, construct, and service exploration vehicles in low earth orbit will be an enabling capability for continued human exploration of the solar system. It is evident that advanced manufacturing methods to fabricate replacement parts and re-utilize launch vehicle structural mass by converting it to different uses will be necessary to minimize costs and allow flexibility to remote crews engaged in space travel. Recent conceptual developments and the combination of inter-related approaches to low-cost manufacturing of composite materials and structures are described in context leading to the possibility of on-orbit and space-based manufacturing.

  7. Evolution of classical and quantum phase-space distributions: A new trajectory approach for phase space hydrodynamics

    NASA Astrophysics Data System (ADS)

    Trahan, Corey J.; Wyatt, Robert E.

    2003-10-01

    Recently, Donoso and Martens described a method for evolving both classical and quantum phase-space distribution functions, W(q,p,t), that involves the propagation of an ensemble of correlated trajectories. The trajectories are linked into a unified whole by spatial and momentum derivatives of density dependent terms in the equations of motion. On each time step, these nonlocal terms were evaluated by fitting the density around each trajectory to an assumed functional form. In the present study, we develop a different trajectory method for propagating phase-space distribution functions. A hierarchy of coupled analytic equations of motion are derived for the q and p derivatives of the density and a truncated set of these are integrated along each trajectory concurrently with the equation of motion for the density. The advantage of this approach is that individual trajectories can be propagated, one at a time, and function fitting is not required to evaluate the nonlocal terms. Regional nonlocality can be incorporated at various levels of approximation to "dress" what would otherwise be "thin" locally propagating trajectories. This derivative propagation method is used to obtain trajectory solutions for the Klein-Kramers equation, the Husimi equation, and for a smoothed version of the Caldeira-Leggett equation derived by the Diosi. Trajectory solutions are obtained for the relaxation of an oscillator in contact with a thermal bath and for the decay of a metastable state.

  8. Comparison of mouse brain DTI maps using K-space average, image-space average, or no average approach.

    PubMed

    Sun, Shu-Wei; Mei, Jennifer; Tuel, Keelan

    2013-11-01

    Diffusion tensor imaging (DTI) is achieved by collecting a series of diffusion-weighted images (DWIs). Signal averaging of multiple repetitions can be performed in the k-space (k-avg) or in the image space (m-avg) to improve the image quality. Alternatively, one can treat each acquisition as an independent image and use all of the data to reconstruct the DTI without doing any signal averaging (no-avg). To compare these three approaches, in this study, in vivo DTI data were collected from five normal mice. Noisy data with signal-to-noise ratios (SNR) that varied between five and 30 (before averaging) were then simulated. The DTI indices, including relative anisotropy (RA), trace of diffusion tensor (TR), axial diffusivity (λ║), and radial diffusivity (λ⊥), derived from the k-avg, m-avg, and no-avg, were then compared in the corpus callosum white matter, cortex gray matter, and the ventricles. We found that k-avg and m-avg enhanced the SNR of DWI with no significant differences. However, k-avg produced lower RA in the white matter and higher RA in the gray matter, compared to the m-avg and no-avg, regardless of SNR. The latter two produced similar DTI quantifications. We concluded that k-avg is less preferred for DTI brain imaging.

  9. Batten augmented triangular beam

    NASA Technical Reports Server (NTRS)

    Adams, Louis R.; Hedgepeth, John M.

    1986-01-01

    The BAT (Batten-Augmented Triangular) BEAM is characterized by battens which are buckled in the deployed state, thus preloading the truss. The preload distribution is determined, and the effects of various external loading conditions are investigated. The conceptual design of a deployer is described and loads are predicted. The influence of joint imperfections on effective member stiffness is investigated. The beam is assessed structurally.

  10. Combined Endonasal-Transcervical Approach to a Metastatic Parapharyngeal Space Papillary Thyroid Carcinoma

    PubMed Central

    Benet, Arnau; El-Sayed, Ivan

    2015-01-01

    Purpose: Although papillary thyroid carcinoma metastases to the parapharyngeal space are rare, the high amount of fat tissue allows tumors to grow clinically undetectable until they invade most of the parapharyngeal space. We describe for the first time a combined endonasal and transcervical approach for a parapharyngeal metastasis from a papillary thyroid carcinoma. Materials and Methods: A 51-year-old male with a previous history of papillary thyroid carcinoma presented with left ear fullness and left-sided facial numbness. Imaging revealed a 4x3 cm pre-styloid parapharyngeal space mass invading the foramen ovale and extending below the palate. Needle biopsy confirmed metastatic papillary thyroid carcinoma. Results: The lesion was resected with a combined endoscopic endonasal and transcervical approach. Postoperative MRI revealed gross total resection, and the patient recovered from his symptoms. Conclusion: This novel approach provides access to pre-styloid parapharyngeal tumors with superior extension to the skull base, avoiding more extensive traditional open approaches. PMID:26203403

  11. Emotion-inducing approaching sounds shape the boundaries of multisensory peripersonal space.

    PubMed

    Ferri, Francesca; Tajadura-Jiménez, Ana; Väljamäe, Aleksander; Vastano, Roberta; Costantini, Marcello

    2015-04-01

    In order to survive in a complex environment, inhabited by potentially threatening and noxious objects or living beings, we need to constantly monitor our surrounding space, especially in the vicinity of our body. Such a space has been commonly referred to as one's 'peripersonal space' (PPS). In this study we investigated whether emotion-inducing approaching sound sources impact the boundaries of PPS. Previous studies have indeed showed that the boundaries of PPS are not fixed but modulate according to properties of stimuli in the surrounding environment. In Experiment 1, participants performed a simple tactile detection task of targets presented to their right hand. Concurrently, they were presented with intensity-changing task-irrelevant artificial sound sources perceived as approaching toward their body. The physical properties of the sound elicited emotional responses of either neutral or negative valence. Results showed larger PPS when the approaching stimulus had negative as compared to neutral emotional valence. In Experiment 2, we used ecological sounds which content (i.e., psychological associations to the sound producing source), rather than physical properties, elicited emotional responses of negative, positive or neutral valence. In agreement with results from experiment 1, we found larger PPS when the approaching stimuli had negative emotional valence as compared to both neutral and positive ones. Results are discussed within the theoretical framework that conceives PPS as a safety zone around one's body.

  12. A hybrid space approach for ensemble-based 4-D variational data assimilation

    NASA Astrophysics Data System (ADS)

    Shao, Aimei; Xi, Shuang; Qiu, Chongjian; Xu, Qin

    2009-09-01

    A new scheme is developed to improve the ensemble-based 4-D variational data assimilation (En4DVar). In this scheme, leading singular vectors are extracted from 4-D ensemble perturbations in a hybrid space and then used to construct the analysis increment to fit the 4-D innovation (observation minus background) data. The hybrid space combines the 4-D observation space with only a gridded 3-D subspace at the end of each assimilation cycle, so its dimension can be much smaller than the dimension of the fully gridded 4-D space used in the original En4DVar. This improves the computational efficiency. With this hybrid space approach, the analysis increment can fit the 4-D innovation data in the observation space directly and also provide the necessary initial condition in the gridded 3-D subspace exclusively for the model integration into the next assimilation cycle, so the background covariance matrix can be and only needs to be constructed by the ensemble perturbations in the 3-D subspace. This reduces the rank deficiency of the ensemble-constructed covariance matrix and improves analysis accuracy as long as the observations are not too sparse. The potential merits of the new scheme are demonstrated by assimilation experiments performed with an imperfect shallow-water equation model and simulated observations.

  13. Astronaut Ross Approaches Assembly Concept for Construction of Erectable Space Structure (ACCESS)

    NASA Technical Reports Server (NTRS)

    1999-01-01

    The crew assigned to the STS-61B mission included Bryan D. O'Conner, pilot; Brewster H. Shaw, commander; Charles D. Walker, payload specialist; mission specialists Jerry L. Ross, Mary L. Cleave, and Sherwood C. Spring; and Rodolpho Neri Vela, payload specialist. Launched aboard the Space Shuttle Atlantis November 28, 1985 at 7:29:00 pm (EST), the STS-61B mission's primary payload included three communications satellites: MORELOS-B (Mexico); AUSSAT-2 (Australia); and SATCOM KU-2 (RCA Americom). Two experiments were conducted to test assembling erectable structures in space: EASE (Experimental Assembly of Structures in Extravehicular Activity), and ACCESS (Assembly Concept for Construction of Erectable Space Structure). In a joint venture between NASA/Langley Research Center in Hampton, Virginia, and the Marshall Space Flight Center (MSFC), EASE and ACCESS were developed and demonstrated at MSFC's Neutral Buoyancy Simulator (NBS). In this STS-61B onboard photo, astronaut Ross, perched on the Manipulator Foot Restraint (MFR) approaches the erected ACCESS. The primary objective of these experiments was to test the structural assembly concepts for suitability as the framework for larger space structures and to identify ways to improve the productivity of space construction.

  14. A multidisciplinary approach to assess the welfare of weaned pigs during transport at three space allowances.

    PubMed

    Sutherland, Mhairi A; Bryer, Pamela J; Davis, Brittany L; McGlone, John J

    2010-01-01

    Transport can be a stressful experience for pigs, especially in pigs simultaneously experiencing weaning stress. The objective of this study was to use a multidisciplinary approach to assess the welfare of weaned pigs during transport at 3 space allowances. A commercial semitrailer, fitted with compartments, provided 0.05, 0.06, and 0.07 m(2)/pig. The study recorded frequency of standing, lying, sitting, and standing-rearing on another pig during the entire duration of transport. Blood samples, body weights, and lesion scores were collected from a subset of pigs (n = 48 per space allowance) in each experimental compartment. Transport time for the pigs was 148.0 +/- 10.0 min to the wean-to-finishing site. Total white blood cell counts, cortisol, and several blood chemistry values increased (p < .05) after transport regardless of space allowance. Glucose and body weight decreased (p < .05) after transport regardless of space allowance. Space allowance influenced stand-rearing, sitting, standing, and lying behaviors in pigs. Combining behavioral and physiological measures of stress provides a robust picture of piglet welfare during transport at different space allowances.

  15. Simple Implant Augmentation Rhinoplasty

    PubMed Central

    Nguyen, Anh H.; Bartlett, Erica L.; Kania, Katarzyna; Bae, Sang Mo

    2015-01-01

    Augmentation rhinoplasty among Asian patients is often performed to improve the height of the nasal dorsum. As the use of autogenous tissues poses certain limitations, alloplastic materials are a viable alternative with a long history of use in Asia. The superiority of one implant prosthesis over another for augmentation rhinoplasty is a matter of debate, with each material representing varying strengths and weaknesses, indications for use, and precautions to consider in nasal implant placement. An implant prosthesis should be used on a case-by-case basis. Augmentation rhinoplasty requires the consideration of specific anatomical preoperative factors, including the external nose, nasal length, nasofrontal angle, humps, and facial proportions. It is equally important to consider several operative guidelines to appropriately shape implants to minimize the occurrence of adverse effects and postoperative complications. The most common postoperative complications include infection, nasal height change, movement of implant prosthesis, and silicone implant protrusion. In addition, the surgeon should consider the current standards of Asian beauty aesthetics to better understand the patient's desired outcome. PMID:26648804

  16. An integrated mission approach to the space exploration initiative will ensure success

    NASA Astrophysics Data System (ADS)

    Coomes, Edmund P.; Dagle, Jefferey E.; Bamberger, Judith A.; Noffsinger, Kent E.

    1991-01-01

    The direction of the American space program, as defined by President Bush and the National Commission on Space, is to expand human presence into the solar system. Landing an American on Mars by the 50th anniversary of the Apollo 11 lunar landing is the goal. This challenge has produced a level of excitement among young Americans not seen for nearly three decades. The exploration and settlement of the space frontier will occupy the creative thoughts and energies of generations of Americans well into the next century. The return of Americans to the moon and beyond must be viewed as a national effort with strong public support if it is to become a reality. Key to making this an actuality is the mission approach selected. Developing a permanent presence in space requires a continual stepping outward from Earch in a logical progressive manner. If we seriously plan to go and to stay, then not only must we plan what we are to do and how we are to do it, we must address the logistic support infrastructure that will allow us to stay there once we arrive. A fully integrated approach to mission planning is needed if the Space exploration Initiative (SEI) is to be successful. Only in this way can a permanent human presence in space be sustained. An integrated infrastructure approach would reduce the number of new systems and technologies requiring development. The resultant horizontal commonality of systems and hardware would reduce the direct economic impact of SEI while an early return on investment through technology spin-offs would be an economic benefit by greatly enhancing our international technical competitiveness. If the exploration, development, and colonization of space is to be affordable and acceptable, careful consideration must be given to such things as ``return on investment'' and ``commercial product potential'' of the technologies developed. This integrated approach will win the Congressional support needed to secure the financial backing necessary to assure

  17. Autonomous space target recognition and tracking approach using star sensors based on a Kalman filter.

    PubMed

    Ye, Tao; Zhou, Fuqiang

    2015-04-10

    When imaged by detectors, space targets (including satellites and debris) and background stars have similar point-spread functions, and both objects appear to change as detectors track targets. Therefore, traditional tracking methods cannot separate targets from stars and cannot directly recognize targets in 2D images. Consequently, we propose an autonomous space target recognition and tracking approach using a star sensor technique and a Kalman filter (KF). A two-step method for subpixel-scale detection of star objects (including stars and targets) is developed, and the combination of the star sensor technique and a KF is used to track targets. The experimental results show that the proposed method is adequate for autonomously recognizing and tracking space targets.

  18. Analytic halo approach to the bispectrum of galaxies in redshift space

    NASA Astrophysics Data System (ADS)

    Yamamoto, Kazuhiro; Nan, Yue; Hikage, Chiaki

    2017-02-01

    We present an analytic formula for the galaxy bispectrum in redshift space on the basis of the halo approach description with the halo occupation distribution of central galaxies and satellite galaxies. This work is an extension of a previous work on the galaxy power spectrum, which illuminated the significant contribution of satellite galaxies to the higher multipole spectrum through the nonlinear redshift space distortions of their random motions. Behaviors of the multipoles of the bispectrum are compared with results of numerical simulations assuming a halo occupation distribution of the low-redshift (LOWZ) sample of the Sloan Digital Sky Survey (SDSS) III baryon oscillation spectroscopic survey (BOSS) survey. Also presented are analytic approximate formulas for the multipoles of the bispectrum, which is useful to understanding their characteristic properties. We demonstrate that the Fingers of God effect is quite important for the higher multipoles of the bispectrum in redshift space, depending on the halo occupation distribution parameters.

  19. Approaches in the determination of plant nutrient uptake and distribution in space flight conditions

    NASA Technical Reports Server (NTRS)

    Heyenga, A. G.; Forsman, A.; Stodieck, L. S.; Hoehn, A.; Kliss, M.

    2000-01-01

    The effective growth and development of vascular plants rely on the adequate availability of water and nutrients. Inefficiency in either the initial absorption, transportation, or distribution of these elements are factors which impinge on plant structure and metabolic integrity. The potential effect of space flight and microgravity conditions on the efficiency of these processes is unclear. Limitations in the available quantity of space-grown plant material and the sensitivity of routine analytical techniques have made an evaluation of these processes impractical. However, the recent introduction of new plant cultivating methodologies supporting the application of radionuclide elements and subsequent autoradiography techniques provides a highly sensitive investigative approach amenable to space flight studies. Experiments involving the use of gel based 'nutrient packs' and the radionuclides calcium-45 and iron-59 were conducted on the Shuttle mission STS-94. Uptake rates of the radionuclides between ground and flight plant material appeared comparable.

  20. Approaches in the Determination of Plant Nutrient Uptake and Distribution in Space Flight Conditions

    NASA Technical Reports Server (NTRS)

    Heyenga, A. G.; Forsman, A.; Stodieck, L. S.; Hoehn, A.; Kliss, Mark

    1998-01-01

    The effective growth and development of vascular plants rely on the adequate availability of water and nutrients. Inefficiency in either the initial absorption, transportation, or distribution of these elements are factors which may impinge on plant structure and metabolic integrity. The potential effect of space flight and microgravity conditions on the efficiency of these processes is unclear. Limitations in the available quantity of space-grown plant material and the sensitivity of routine analytical techniques have made an evaluation of these processes impractical. However, the recent introduction of new plant cultivating methodologies supporting the application of radionuclide elements and subsequent autoradiography techniques provides a highly sensitive investigative approach amenable to space flight studies. Experiments involving the use of gel based 'nutrient packs' and the nuclides Ca45 and Fe59 were conducted on the Shuttle mission STS-94. Uptake rates of the radionuclides between ground and flight plant material appeared comparable.

  1. Mentoring SFRM: A New Approach to International Space Station Flight Control Training

    NASA Technical Reports Server (NTRS)

    Huning, Therese; Barshi, Immanuel; Schmidt, Lacey

    2009-01-01

    The Mission Operations Directorate (MOD) of the Johnson Space Center is responsible for providing continuous operations support for the International Space Station (ISS). Operations support requires flight controllers who are skilled in team performance as well as the technical operations of the ISS. Space Flight Resource Management (SFRM), a NASA adapted variant of Crew Resource Management (CRM), is the competency model used in the MOD. ISS flight controller certification has evolved to include a balanced focus on development of SFRM and technical expertise. The latest challenge the MOD faces is how to certify an ISS flight controller (Operator) to a basic level of effectiveness in 1 year. SFRM training uses a twopronged approach to expediting operator certification: 1) imbed SFRM skills training into all Operator technical training and 2) use senior flight controllers as mentors. This paper focuses on how the MOD uses senior flight controllers as mentors to train SFRM skills.

  2. Distribution function approach to redshift space distortions. Part IV: perturbation theory applied to dark matter

    SciTech Connect

    Vlah, Zvonimir; Seljak, Uroš; Baldauf, Tobias; McDonald, Patrick; Okumura, Teppei E-mail: seljak@physik.uzh.ch E-mail: teppei@ewha.ac.kr

    2012-11-01

    We develop a perturbative approach to redshift space distortions (RSD) using the phase space distribution function approach and apply it to the dark matter redshift space power spectrum and its moments. RSD can be written as a sum over density weighted velocity moments correlators, with the lowest order being density, momentum density and stress energy density. We use standard and extended perturbation theory (PT) to determine their auto and cross correlators, comparing them to N-body simulations. We show which of the terms can be modeled well with the standard PT and which need additional terms that include higher order corrections which cannot be modeled in PT. Most of these additional terms are related to the small scale velocity dispersion effects, the so called finger of god (FoG) effects, which affect some, but not all, of the terms in this expansion, and which can be approximately modeled using a simple physically motivated ansatz such as the halo model. We point out that there are several velocity dispersions that enter into the detailed RSD analysis with very different amplitudes, which can be approximately predicted by the halo model. In contrast to previous models our approach systematically includes all of the terms at a given order in PT and provides a physical interpretation for the small scale dispersion values. We investigate RSD power spectrum as a function of μ, the cosine of the angle between the Fourier mode and line of sight, focusing on the lowest order powers of μ and multipole moments which dominate the observable RSD power spectrum. Overall we find considerable success in modeling many, but not all, of the terms in this expansion. This is similar to the situation in real space, but predicting power spectrum in redshift space is more difficult because of the explicit influence of small scale dispersion type effects in RSD, which extend to very large scales.

  3. New pharmacologic approaches to the prevention of space/motion sickness

    NASA Technical Reports Server (NTRS)

    Kohl, Randall L.; Macdonald, Scott

    1991-01-01

    Three fundamental approaches used in the selection of new agents for the evaluation in the prevention of space-motion sickness (SMS) are reviewed, with emphasis on drugs under investigation at the Johnson Space Center. These approaches are: (1) the selection of agents from drug classes that possess pharmacologic properties of established antimotion sickness agents, (2) the selection of drugs that are used to prevent emesis caused by means other than the exposure to motion, and (3) basic research that characterizes individual differences in susceptibility to SMS. In the latter type of studies, it was found that subjects who were more resistant to SMS had higher plasma AVP after severe nausea than subjects with lower resistance. The review details the experimental data collected on AVP and adrenocorticotropin. It is noted that data support interrelated roles for AVP and opioid peptides in SMS.

  4. A Scale-Space Approach for Image Registration of Vessel Structures

    NASA Astrophysics Data System (ADS)

    Heldmann, Stefan; Papenberg, Nils

    We present a multi-scale approach for non-rigid image registration of tubular tree-like structures such as vessels. Therefore, we consider a Gaussian and a combined morphological and Gaussian scale-space. Similar to a multi-level framework, we solve a sequence of registration problems on several scale-space levels using a standard variational approach for non-liner volumetric image registration. The overall idea is to avoid locally ambiguous mappings between parts of the images by removing morphological details but also finding a global optimal solution by spreading remaining local information using Gaussian scaling. We successfully tested our method on registration of 3D CT and ultrasound images of hepatic vessels.

  5. Design of a final approach spacing tool for TRACON air traffic control

    NASA Technical Reports Server (NTRS)

    Davis, Thomas J.; Erzberger, Heinz; Bergeron, Hugh

    1989-01-01

    This paper describes an automation tool that assists air traffic controllers in the Terminal Radar Approach Control (TRACON) Facilities in providing safe and efficient sequencing and spacing of arrival traffic. The automation tool, referred to as the Final Approach Spacing Tool (FAST), allows the controller to interactively choose various levels of automation and advisory information ranging from predicted time errors to speed and heading advisories for controlling time error. FAST also uses a timeline to display current scheduling and sequencing information for all aircraft in the TRACON airspace. FAST combines accurate predictive algorithms and state-of-the-art mouse and graphical interface technology to present advisory information to the controller. Furthermore, FAST exchanges various types of traffic information and communicates with automation tools being developed for the Air Route Traffic Control Center. Thus it is part of an integrated traffic management system for arrival traffic at major terminal areas.

  6. Experimental Studies Of Pilot Performance At Collision Avoidance During Closely Spaced Parallel Approaches

    NASA Technical Reports Server (NTRS)

    Pritchett, Amy R.; Hansman, R. John

    1997-01-01

    Efforts to increase airport capacity include studies of aircraft systems that would enable simultaneous approaches to closely spaced parallel runway in Instrument Meteorological Conditions (IMC). The time-critical nature of a parallel approach results in key design issues for current and future collision avoidance systems. Two part-task flight simulator studies have examined the procedural and display issues inherent in such a time-critical task, the interaction of the pilot with a collision avoidance system, and the alerting criteria and avoidance maneuvers preferred by subjects.

  7. A new approach to long-life noncontacting electromechanical devices. [for space flight applications

    NASA Technical Reports Server (NTRS)

    Devine, E. J.

    1973-01-01

    Brushless dc motors are finding increasing application in space. Likewise, with the advent of the light emitting diode, noncontacting encoders are gradually replacing sliding contact types. The direct drive concept has proved its merit and is now the preferred approach for tape recorders and low to moderate torque instrument drives. The final step in this evolution is the magnetic bearing, which now appears feasible for several applications. Where it can be applied in a totally noncontacting system, life and reliability will be a function of the electronic controls, where redundancy, derating, and quality assurance approaches virtually assure the desired lifetime and failure rate.

  8. Practical approaches to handle the singularities of a wrist-partitioned space manipulator

    NASA Astrophysics Data System (ADS)

    Xu, Wenfu; Liang, Bin; Xu, Yangsheng

    2011-01-01

    Space robotic systems are expected to play an increasingly important role in the future. However, the control methods based on the inverse kinematics are affected by singularities. In this paper, practical approaches are proposed to solve the problems of a wrist-partitioned space manipulator. For spacecraft-referenced end-point motion control, we presented the singularity separation plus damped reciprocal (SSPDR) method, which separates the singularity parameters from the inverse of the Jacobian, and replaces their reciprocals using the damped reciprocals. For another control strategy, i.e. inertially referenced end-point motion control, including spacecraft attitude-controlled mode and free-floating mode, the linear momentum equation is used to eliminate three independent variables. With modifying some expressions, the SSPDR method is utilized to solve the singularities of spacecraft attitude-controlled space robot. When the space robot is free-floating, the singularities, i.e. the so-called dynamic singularities, cannot be predicted according to its kinematic structure. Combining with the measured angular velocity of the base, the dynamic singularity handling problem is transformed into real-time kinematic singularity avoiding problem, which can be solved by the SSPDR method. Since the SVD decomposition, the estimation of the minimum singularity value, and the calculation of the generalized Jacobian matrix are not required, the algorithm has lower computation load. Another advantage is that, only the accuracy of part velocity components is reduced by adding the damped coefficients. Simulation results verify the proposed approaches.

  9. An Indoor Navigation Approach Considering Obstacles and Space Subdivision of 2d Plan

    NASA Astrophysics Data System (ADS)

    Xu, Man; Wei, Shuangfeng; Zlatanova, Sisi

    2016-06-01

    The demand for indoor navigation is increasingly urgent in many applications such as safe management of underground spaces or location services in complex indoor environment, e.g. shopping centres, airports, museums, underground parking lot and hospitals. Indoor navigation is still a challenging research field, as currently applied indoor navigation algorithms commonly ignore important environmental and human factors and therefore do not provide precise navigation. Flexible and detailed networks representing the connectivity of spaces and considering indoor objects such as furniture are very important to a precise navigation. In this paper we concentrate on indoor navigation considering obstacles represented as polygons. We introduce a specific space subdivision based on a simplified floor plan to build the indoor navigation network. The experiments demonstrate that we are able to navigate around the obstacles using the proposed network. Considering to well-known path-finding approaches based on Medial Axis Transform (MAT) or Visibility Graph (VG), the approach in this paper provides a quick subdivision of space and routes, which are compatible with the results of VG.

  10. Approaching the new reality. [changes in NASA space programs due to US economy

    NASA Technical Reports Server (NTRS)

    Diaz, Al V.

    1993-01-01

    The focus on more frequent access to space through smaller, less costly missions, and on NASA's role as a source of technological advance within the U.S. economy is discussed. The Pluto fast flyby mission is examined as an illustration of this approach. Testbeds are to be developed to survive individual programs, becoming permanent facilities, to allow for technological upgrades on an ongoing basis.

  11. Using a Space Filling Curve Approach for the Management of Dynamic Point Clouds

    NASA Astrophysics Data System (ADS)

    Psomadaki, S.; van Oosterom, P. J. M.; Tijssen, T. P. M.; Baart, F.

    2016-10-01

    Point cloud usage has increased over the years. The development of low-cost sensors makes it now possible to acquire frequent point cloud measurements on a short time period (day, hour, second). Based on the requirements coming from the coastal monitoring domain, we have developed, implemented and benchmarked a spatio-temporal point cloud data management solution. For this reason, we make use of the flat model approach (one point per row) in an Index Organised Table within a RDBMS and an improved spatio-temporal organisation using a Space Filling Curve approach. Two variants coming from two extremes of the space-time continuum are also taken into account, along with two treatments of the z dimension: as attribute or as part of the space filling curve. Through executing a benchmark we elaborate on the performance - loading and querying time -, and storage required by those different approaches. Finally, we validate the correctness and suitability of our method, through an out-of-the-box way of managing dynamic point clouds.

  12. A Programmatic and Engineering Approach to the Development of a Nuclear Thermal Rocket for Space Exploration

    NASA Technical Reports Server (NTRS)

    Bordelon, Wayne J., Jr.; Ballard, Rick O.; Gerrish, Harold P., Jr.

    2006-01-01

    With the announcement of the Vision for Space Exploration on January 14, 2004, there has been a renewed interest in nuclear thermal propulsion. Nuclear thermal propulsion is a leading candidate for in-space propulsion for human Mars missions; however, the cost to develop a nuclear thermal rocket engine system is uncertain. Key to determining the engine development cost will be the engine requirements, the technology used in the development and the development approach. The engine requirements and technology selection have not been defined and are awaiting definition of the Mars architecture and vehicle definitions. The paper discusses an engine development approach in light of top-level strategic questions and considerations for nuclear thermal propulsion and provides a suggested approach based on work conducted at the NASA Marshall Space Flight Center to support planning and requirements for the Prometheus Power and Propulsion Office. This work is intended to help support the development of a comprehensive strategy for nuclear thermal propulsion, to help reduce the uncertainty in the development cost estimate, and to help assess the potential value of and need for nuclear thermal propulsion for a human Mars mission.

  13. Kinematic Modeling of Separation Compression for Paired Approaches to Closely-Spaced Parallel Runways

    NASA Technical Reports Server (NTRS)

    Madden, Michael M.

    2014-01-01

    In a simultaneous paired approach to closely-spaced parallel runways, a pair of aircraft flies in close proximity on parallel approach paths. The longitudinal separation between the aircraft must be maintained within a range that avoids wake encounters and, if one of the aircraft blunders, avoids collision. To increase operational availability, the approach procedure must accommodate a mixture of aircraft sizes and, consequently, approach speeds. In these procedures, the slower aircraft is placed in the lead position. The faster aircraft maintains separation from the slow aircraft in a dependent operation until final approach and flies independently afterward. Due to the higher approach speed of the fast aircraft, longitudinal separation will decrease during final approach. Therefore, the fast aircraft must position itself before the final approach so that it will remain within the safe range of separation as separation decreases. Given the approach geometry and speed schedule for each aircraft, one can use kinematics to estimate the separation loss between a pair of aircraft. A kinematic model can complement fast-time Monte-Carlo simulations of the approach by enabling a tailored reduction in the variation of starting position for the fast aircraft. One could also implement the kinematic model in ground-based or on-board decision support tools to compute the optimal initial separation for a given pair of aircraft. To better match the auto-coupled flight of real aircraft, the paper derives a kinematic model where the speed schedule is flown using equivalent airspeed. The predicted time of flight using the equivalent airspeed kinematic model compares well against a high-fidelity aircraft simulation performing the same approach. This model also demonstrates a modest increase in the predicted loss of separation when contrasted against a kinematic model that assumes the scheduled speed is true airspeed.

  14. Review of NASA approach to space radiation risk assessments for Mars exploration.

    PubMed

    Cucinotta, Francis A

    2015-02-01

    Long duration space missions present unique radiation protection challenges due to the complexity of the space radiation environment, which includes high charge and energy particles and other highly ionizing radiation such as neutrons. Based on a recommendation by the National Council on Radiation Protection and Measurements, a 3% lifetime risk of exposure-induced death for cancer has been used as a basis for risk limitation by the National Aeronautics and Space Administration (NASA) for low-Earth orbit missions. NASA has developed a risk-based approach to radiation exposure limits that accounts for individual factors (age, gender, and smoking history) and assesses the uncertainties in risk estimates. New radiation quality factors with associated probability distribution functions to represent the quality factor's uncertainty have been developed based on track structure models and recent radiobiology data for high charge and energy particles. The current radiation dose limits are reviewed for spaceflight and the various qualitative and quantitative uncertainties that impact the risk of exposure-induced death estimates using the NASA Space Cancer Risk (NSCR) model. NSCR estimates of the number of "safe days" in deep space to be within exposure limits and risk estimates for a Mars exploration mission are described.

  15. Telescopic multi-resolution augmented reality

    NASA Astrophysics Data System (ADS)

    Jenkins, Jeffrey; Frenchi, Christopher; Szu, Harold

    2014-05-01

    To ensure a self-consistent scaling approximation, the underlying microscopic fluctuation components can naturally influence macroscopic means, which may give rise to emergent observable phenomena. In this paper, we describe a consistent macroscopic (cm-scale), mesoscopic (micron-scale), and microscopic (nano-scale) approach to introduce Telescopic Multi-Resolution (TMR) into current Augmented Reality (AR) visualization technology. We propose to couple TMR-AR by introducing an energy-matter interaction engine framework that is based on known Physics, Biology, Chemistry principles. An immediate payoff of TMR-AR is a self-consistent approximation of the interaction between microscopic observables and their direct effect on the macroscopic system that is driven by real-world measurements. Such an interdisciplinary approach enables us to achieve more than multiple scale, telescopic visualization of real and virtual information but also conducting thought experiments through AR. As a result of the consistency, this framework allows us to explore a large dimensionality parameter space of measured and unmeasured regions. Towards this direction, we explore how to build learnable libraries of biological, physical, and chemical mechanisms. Fusing analytical sensors with TMR-AR libraries provides a robust framework to optimize testing and evaluation through data-driven or virtual synthetic simulations. Visualizing mechanisms of interactions requires identification of observable image features that can indicate the presence of information in multiple spatial and temporal scales of analog data. The AR methodology was originally developed to enhance pilot-training as well as `make believe' entertainment industries in a user-friendly digital environment We believe TMR-AR can someday help us conduct thought experiments scientifically, to be pedagogically visualized in a zoom-in-and-out, consistent, multi-scale approximations.

  16. System analysis approach to deriving design criteria (Loads) for Space Shuttle and its payloads. Volume 2: Typical examples

    NASA Technical Reports Server (NTRS)

    Ryan, R. S.; Bullock, T.; Holland, W. B.; Kross, D. A.; Kiefling, L. A.

    1981-01-01

    The achievement of an optimized design from the system standpoint under the low cost, high risk constraints of the present day environment was analyzed. Space Shuttle illustrates the requirement for an analysis approach that considers all major disciplines (coupling between structures control, propulsion, thermal, aeroelastic, and performance), simultaneously. The Space Shuttle and certain payloads, Space Telescope and Spacelab, are examined. The requirements for system analysis approaches and criteria, including dynamic modeling requirements, test requirements, control requirements, and the resulting design verification approaches are illustrated. A survey of the problem, potential approaches available as solutions, implications for future systems, and projected technology development areas are addressed.

  17. Innovative Approaches to Development and Ground Testing of Advanced Bimodal Space Power and Propulsion Systems

    SciTech Connect

    Hill, Thomas Johnathan; Noble, Cheryl Ann; Noble, C.; Martinell, John Stephen; Borowski, S.

    2000-07-01

    The last major development effort for nuclear power and propulsion systems ended in 1993. Currently, there is not an initiative at either the National Aeronautical and Space Administration (NASA) or the U.S. Department of Energy (DOE) that requires the development of new nuclear power and propulsion systems. Studies continue to show nuclear technology as a strong technical candidate to lead the way toward human exploration of adjacent planets or provide power for deep space missions, particularly a 15,000 lbf bimodal nuclear system with 115 kW power capability. The development of nuclear technology for space applications would require technology development in some areas and a major flight qualification program. The last major ground test facility considered for nuclear propulsion qualification was the U.S. Air Force/DOE Space Nuclear Thermal Propulsion Project. Seven years have passed since that effort, and the questions remain the same, how to qualify nuclear power and propulsion systems for future space flight. It can be reasonable assumed that much of the nuclear testing required to qualify a nuclear system for space application will be performed at DOE facilities as demonstrated by the Nuclear Rocket Engine Reactor Experiment (NERVA) and Space Nuclear Thermal Propulsion (SNTP) programs. The nuclear infrastructure to support testing in this country is aging and getting smaller, though facilities still exist to support many of the technology development needs. By renewing efforts, an innovative approach to qualifying these systems through the use of existing facilities either in the U.S. (DOE's Advance Test Reactor, High Flux Irradiation Facility and the Contained Test Facility) or overseas should be possible.

  18. Innovation Approaches to Development and Ground Testing of Advanced Bimodal Space Power and Propulsion Systems

    SciTech Connect

    Hill, T.; Noble, C.; Martinell, J.; Borowski, S.

    2000-07-14

    The last major development effort for nuclear power and propulsion systems ended in 1993. Currently, there is not an initiative at either the National Aeronautical and Space Administration (NASA) or the U.S. Department of Energy (DOE) that requires the development of new nuclear power and propulsion systems. Studies continue to show nuclear technology as a strong technical candidate to lead the way toward human exploration of adjacent planets or provide power for deep space missions, particularly a 15,000 lbf bimodal nuclear system with 115 kW power capability. The development of nuclear technology for space applications would require technology development in some areas and a major flight qualification program. The last major ground test facility considered for nuclear propulsion qualification was the U.S. Air Force/DOE Space Nuclear Thermal Propulsion Project. Seven years have passed since that effort, and the questions remain the same, how to qualify nuclear power and propulsion systems for future space flight. It can be reasonably assumed that much of the nuclear testing required to qualify a nuclear system for space application will be performed at DOE facilities as demonstrated by the Nuclear Rocket Engine Reactor Experiment (NERVA) and Space Nuclear Thermal Propulsion (SNTP) programs. The nuclear infrastructure to support testing in this country is aging and getting smaller, though facilities still exist to support many of the technology development needs. By renewing efforts, an innovative approach to qualifying these systems through the use of existing facilities either in the U.S. (DOE's Advance Test Reactor, High Flux Irradiation Facility and the Contained Test Facility) or overseas should be possible.

  19. Critical laser technology developments and ESA space qualification approach in support of ESA's Earth observation missions

    NASA Astrophysics Data System (ADS)

    Zahir, Mustapha; Durand, Yannig

    2011-10-01

    In this paper, ESA's approach to lasers and detectors space evaluation and qualification will be explored. ESA has its own international qualification system, the ESCC system. This system guarantees reliability, assurance and quality of components, and hence a successful space mission. An overview of the ESCC (European Space Component Coordination) system, as well as the relevant ECSS (European Cooperation for Space Standards) related standards addressing components and hybrid qualification will be given. These standards are being constantly updated, through well structured working groups, constantly coming up with new ways of qualifying space components. These components are themselves constantly changing in terms of material, technology, and manufacturing processes. The development of advanced Lidar systems for space applications and their evaluation by airborne or ground based test campaigns is an important strategic element of the ESA Earth Observation Programme. These systems depend on robust and reliable lasers and detector at their core function. Since the early eighties, ESA has been supporting the development of the critical subsystems of any Lidar, i.e. lasers and detectors. Several missions, involving different kinds of lidars, provide the requirements to be addressed in the Lidar risk mitigation activities. They also present a challenge concerning their space qualification and reliability assurance. These missions are: ADM-Aeolus flying ALADIN a Doppler Wind Lidar; EarthCARE embarking ATLID an Atmospheric Backscatter Lidar; three missions studied for their feasibilities: WALES, A-SCOPE and ACCURATE, all using Differential Absorption Lidar in different ways to measure respectively profiles of water vapour, total column of CO2 and greenhouse gases in an occultation geometry.

  20. Wireless Augmented Reality Prototype (WARP)

    NASA Technical Reports Server (NTRS)

    Devereaux, A. S.

    1999-01-01

    Initiated in January, 1997, under NASA's Office of Life and Microgravity Sciences and Applications, the Wireless Augmented Reality Prototype (WARP) is a means to leverage recent advances in communications, displays, imaging sensors, biosensors, voice recognition and microelectronics to develop a hands-free, tetherless system capable of real-time personal display and control of computer system resources. Using WARP, an astronaut may efficiently operate and monitor any computer-controllable activity inside or outside the vehicle or station. The WARP concept is a lightweight, unobtrusive heads-up display with a wireless wearable control unit. Connectivity to the external system is achieved through a high-rate radio link from the WARP personal unit to a base station unit installed into any system PC. The radio link has been specially engineered to operate within the high- interference, high-multipath environment of a space shuttle or space station module. Through this virtual terminal, the astronaut will be able to view and manipulate imagery, text or video, using voice commands to control the terminal operations. WARP's hands-free access to computer-based instruction texts, diagrams and checklists replaces juggling manuals and clipboards, and tetherless computer system access allows free motion throughout a cabin while monitoring and operating equipment.

  1. An Interdisciplinary Approach to the Conceptual Design of Inhabited Space Systems

    NASA Astrophysics Data System (ADS)

    Osburg, Jan

    2002-01-01

    The special skills and abilities of a human crew are the major resource of every manned spaceflight venture. Mission success therefore depends on the ability of the designers, builders and operators of the associated space segments to maximize the safety and productivity of the crew for the total duration of the flight. This can be a challenging task especially when it comes to long-duration missions, which accentuate negative effects on the crew arising from prolonged extreme isolation and confinement in an unforgiving, high-risk, technology-dominated environment. optimum integration of the crew into its living and working environment, i.e. the spacecraft, and on the optimum adaptation of this environment to the abilities and limitations of the crew, starting with the earliest phases of the design process. This calls for a design approach that transcends traditional aerospace systems engineering methodologies, such as those used for robotic or short-duration manned missions. gained in the design and building of Earth-based "living and working environments", i.e. buildings, by utilizing appropriate elements from the field of terrestrial architecture for the design of inhabited space systems. The outcome is a truly interdisciplinary approach that promises to result in designs supporting the sustained high-level crew productivity that is desired. associated software tools, to which key elements from terrestrial architectural practice are added. It emphasizes a straightforward, yet flexible design process, and it offers concise, heuristics-based guidance regarding human-related issues such as habitability, as well as a number of practical tools to support the designers. The approach is also supported by software specifically developed for the analysis of life support systems - a crucial component of human-rated space systems - during the early phase of conceptual design. Several examples of its application, including the international "Space Station Design Workshop

  2. Simulation of the space debris environment in LEO using a simplified approach

    NASA Astrophysics Data System (ADS)

    Kebschull, Christopher; Scheidemann, Philipp; Hesselbach, Sebastian; Radtke, Jonas; Braun, Vitali; Krag, H.; Stoll, Enrico

    2017-01-01

    Several numerical approaches exist to simulate the evolution of the space debris environment. These simulations usually rely on the propagation of a large population of objects in order to determine the collision probability for each object. Explosion and collision events are triggered randomly using a Monte-Carlo (MC) approach. So in many different scenarios different objects are fragmented and contribute to a different version of the space debris environment. The results of the single Monte-Carlo runs therefore represent the whole spectrum of possible evolutions of the space debris environment. For the comparison of different scenarios, in general the average of all MC runs together with its standard deviation is used. This method is computationally very expensive due to the propagation of thousands of objects over long timeframes and the application of the MC method. At the Institute of Space Systems (IRAS) a model capable of describing the evolution of the space debris environment has been developed and implemented. The model is based on source and sink mechanisms, where yearly launches as well as collisions and explosions are considered as sources. The natural decay and post mission disposal measures are the only sink mechanisms. This method reduces the computational costs tremendously. In order to achieve this benefit a few simplifications have been applied. The approach of the model partitions the Low Earth Orbit (LEO) region into altitude shells. Only two kinds of objects are considered, intact bodies and fragments, which are also divided into diameter bins. As an extension to a previously presented model the eccentricity has additionally been taken into account with 67 eccentricity bins. While a set of differential equations has been implemented in a generic manner, the Euler method was chosen to integrate the equations for a given time span. For this paper parameters have been derived so that the model is able to reflect the results of the numerical MC

  3. River flow forecasting: use of phase-space reconstruction and artificial neural networks approaches

    NASA Astrophysics Data System (ADS)

    Sivakumar, B.; Jayawardena, A. W.; Fernando, T. M. K. G.

    2002-08-01

    The use of two non-linear black-box approaches, phase-space reconstruction (PSR) and artificial neural networks (ANN), for forecasting river flow dynamics is studied and a comparison of their performances is made. This is done by attempting 1-day and 7-day ahead forecasts of the daily river flow from the Nakhon Sawan station at the Chao Phraya River basin in Thailand. The results indicate a reasonably good performance of both approaches for both 1-day and 7-day ahead forecasts. However, the performance of the PSR approach is found to be consistently better than that of ANN. One reason for this could be that in the PSR approach the flow series in the phase-space is represented step by step in local neighborhoods, rather than a global approximation as is done in ANN. Another reason could be the use of the multi-layer perceptron (MLP) in ANN, since MLPs may not be most appropriate for forecasting at longer lead times. The selection of training set for the ANN may also contribute to such results. A comparison of the optimal number of variables for capturing the flow dynamics, as identified by the two approaches, indicates a large discrepancy in the case of 7-day ahead forecasts (1 and 7 variables, respectively), though for 1-day ahead forecasts it is found to be consistent (3 variables). A possible explanation for this could be the influence of noise in the data, an observation also made from the 1-day ahead forecast results using the PSR approach. The present results lead to observation on: (1) the use of other neural networks for runoff forecasting, particularly at longer lead times; (2) the influence of training set used in the ANN; and (3) the effect of noise on forecast accuracy, particularly in the PSR approach.

  4. What role for Europe within a future global space exploration approach?

    NASA Astrophysics Data System (ADS)

    Bonneville, Richard

    2014-11-01

    Europe is present in robotic exploration though the European Space Agency's mandatory space science program and the optional Aurora program. In addition some member states are also involved in projects of non-European space faring countries through bilateral co-operations. Europe is also present in human exploration through the ISS utilization program. ESA and some of its member states participate in the activities of the International Space Exploration Coordination Group (ISECG), a club of 14 space agencies working for the elaboration of a global exploration roadmap. Finally, ESA and the European Union have initiated a political approach with the setting up of an international forum so as to elaborate a commonly agreed vision on space exploration at political level. However the role of Europe in such a global strategy is not well defined yet; Europe has to build its own vision and to precise the role it intends to play in a future global space exploration venture. We try in this paper to sketch what could be such a European vision, taking into account the European capabilities and priorities, and also the foreseeable economic situation. With limited resources, Europe cannot be present everywhere. In the field of robotic exploration Europe has the capabilities to implement first class projects where it is the major partner. In the field of human exploration, Europe needs to join a co-operation where it has to accept to be a minor partner while its contributions should benefit from the legacy of the previous European achievements The role of the EU, as a political entity, can be determinant; the high level political forum initiated by ESA and EU can be the nucleus of a global strategy. Also the space part of the new UE R&D program Horizon 2020 can support the European effort by focusing on the technological activities which have been highlighted as key areas for exploration and which may yield applications for the citizen. A key role for EU could be to foster the

  5. Mutually Augmented Cognition

    NASA Astrophysics Data System (ADS)

    Friesdorf, Florian; Pangercic, Dejan; Bubb, Heiner; Beetz, Michael

    In mac, an ergonomic dialog-system and algorithms will be developed that enable human experts and companions to be integrated into knowledge gathering and decision making processes of highly complex cognitive systems (e.g. Assistive Household as manifested further in the paper). In this event we propose to join algorithms and methodologies coming from Ergonomics and Artificial Intelligence that: a) make cognitive systems more congenial for non-expert humans, b) facilitate their comprehension by utilizing a high-level expandable control code for human experts and c) augment representation of such cognitive system into “deep representation” obtained through an interaction with human companions.

  6. Space station MMOD shielding

    NASA Astrophysics Data System (ADS)

    Christiansen, Eric L.; Nagy, Kornel; Lear, Dana M.; Prior, Thomas G.

    2009-10-01

    This paper describes the International Space Station (ISS) micro-meteoroid orbital debris (MMOD) impact shielding including the requirements for protection as well as technical approaches to meeting the requirements. Current activities in providing MMOD protection for ISS are described, including efforts to augment MMOD protection by adding shields on-orbit. Another activity is to observe MMOD impact damage on ISS elements and returned hardware, and to compare the observed damage with predicted damage using Bumper code risk assessment software. A conclusion of this paper is that ISS will be protected adequately from MMOD impact after completing augmentation of ISS shielding for service module, and after improving MMOD protection for Soyuz and Progress vehicles. Another conclusion is that impact damage observed to the ISS mini-pressurized logistics module matches the distribution of impacts predicted by Bumper code.

  7. Design and evaluation of an air traffic control Final Approach Spacing Tool

    NASA Technical Reports Server (NTRS)

    Davis, Thomas J.; Erzberger, Heinz; Green, Steven M.; Nedell, William

    1991-01-01

    This paper describes the design and simulator evaluation of an automation tool for assisting terminal radar approach controllers in sequencing and spacing traffic onto the final approach course. The automation tool, referred to as the Final Approach Spacing Tool (FAST), displays speed and heading advisories for arriving aircraft as well as sequencing information on the controller's radar display. The main functional elements of FAST are a scheduler that schedules and sequences the traffic, a four-dimensional trajectory synthesizer that generates the advisories, and a graphical interface that displays the information to the controller. FAST has been implemented on a high-performance workstation. It can be operated as a stand-alone in the terminal radar approach control facility or as an element of a system integrated with automation tools in the air route traffic control center. FAST was evaluated by experienced air traffic controllers in a real-time air traffic control simulation. simulation results summarized in the paper show that the automation tools significantly reduced controller work load and demonstrated a potential for an increase in landing rate.

  8. Improving confidence in (Q)SAR predictions under Canada's Chemicals Management Plan - a chemical space approach.

    PubMed

    Kulkarni, S A; Benfenati, E; Barton-Maclaren, T S

    2016-10-20

    One of the key challenges of Canada's Chemicals Management Plan (CMP) is assessing chemicals with limited/no empirical hazard data for their risk to human health. In some instances, these chemicals have not been tested broadly for their toxicological potency; as such, limited information exists on their potential to induce human health effects following exposure. Although (quantitative) structure activity relationship ((Q)SAR) models are able to generate predictions to address data gaps for certain toxicological endpoints, the confidence in predictions also needs to be addressed. One way to address this issue is to apply a chemical space approach. This approach uses international toxicological databases, for example, those available in the Organisation for Economic Co-operation and Development (OECD) QSAR Toolbox. The approach,assesses a model's ability to predict the potential hazards of chemicals that have limited hazard data that require assessment under the CMP when compared to a larger, data-rich chemical space that is structurally similar to chemicals of interest. This evaluation of a model's predictive ability makes (Q)SAR analysis more transparent and increases confidence in the application of these predictions in a risk-assessment context. Using this approach, predictions for such chemicals obtained from four (Q)SAR models were successfully classified into high, medium and low confidence levels to better inform their use in decision-making.

  9. Graphical user interface concepts for tactical augmented reality

    NASA Astrophysics Data System (ADS)

    Argenta, Chris; Murphy, Anne; Hinton, Jeremy; Cook, James; Sherrill, Todd; Snarski, Steve

    2010-04-01

    Applied Research Associates and BAE Systems are working together to develop a wearable augmented reality system under the DARPA ULTRA-Vis program†. Our approach to achieve the objectives of ULTRAVis, called iLeader, incorporates a full color 40° field of view (FOV) see-thru holographic waveguide integrated with sensors for full position and head tracking to provide an unobtrusive information system for operational maneuvers. iLeader will enable warfighters to mark-up the 3D battle-space with symbologic identification of graphical control measures, friendly force positions and enemy/target locations. Our augmented reality display provides dynamic real-time painting of symbols on real objects, a pose-sensitive 360° representation of relevant object positions, and visual feedback for a variety of system activities. The iLeader user interface and situational awareness graphical representations are highly intuitive, nondisruptive, and always tactically relevant. We used best human-factors practices, system engineering expertise, and cognitive task analysis to design effective strategies for presenting real-time situational awareness to the military user without distorting their natural senses and perception. We present requirements identified for presenting information within a see-through display in combat environments, challenges in designing suitable visualization capabilities, and solutions that enable us to bring real-time iconic command and control to the tactical user community.

  10. Assessing the standard Molybdenum projector augmented wave VASP potentials

    SciTech Connect

    Mattsson, Ann E.

    2014-07-01

    Density Functional Theory (DFT) based Equation of State (EOS) construction is a prominent part of Sandia’s capabilities to support engineering sciences. This capability is based on augmenting experimental data with information gained from computational investigations, especially in those parts of the phase space where experimental data is hard, dangerous, or expensive to obtain. A key part of the success of the Sandia approach is the fundamental science work supporting the computational capability. Not only does this work enhance the capability to perform highly accurate calculations but it also provides crucial insight into the limitations of the computational tools, providing high confidence in the results even where results cannot be, or have not yet been, validated by experimental data. This report concerns the key ingredient of projector augmented-wave (PAW) potentials for use in pseudo-potential computational codes. Using the tools discussed in SAND2012-7389 we assess the standard Vienna Ab-initio Simulation Package (VASP) PAWs for Molybdenum.

  11. Sensors for Location-Based Augmented Reality the Example of Galileo and Egnos

    NASA Astrophysics Data System (ADS)

    Pagani, Alain; Henriques, José; Stricker, Didier

    2016-06-01

    Augmented Reality has long been approached from the point of view of Computer Vision and Image Analysis only. However, much more sensors can be used, in particular for location-based Augmented Reality scenarios. This paper reviews the various sensors that can be used for location-based Augmented Reality. It then presents and discusses several examples of the usage of Galileo and EGNOS in conjonction with Augmented Reality.

  12. A Logical Approach to Designing Safety Test Plans for Space Nuclear Systems

    SciTech Connect

    Coleman, James R

    2004-02-04

    This paper presents a logical approach to designing a safety test plan for a space nuclear system. It is pointed out that two important facts need to underlie the development of a test plan: first, that sequential insults and the accumulation of damage are the rule; and second that the response of the nuclear system is stochastic (i.e., for any given set of conditions a probabilistic range of outcomes will occur regardless of the state of our knowledge). Because of these facts a deterministic approach can only be a starting point. The substance of the approach consists of undertaking and documenting three basic efforts: (1) a description of the analysts view of the problem and how it fits into the safety analysis, (2) a formal documentation of the purpose and requirements of the test plan (or test), and (3) an assessment of the use or usefulness of existing test data.

  13. 14 CFR Table C to Part 117 - Flight Duty Period: Augmented Operations

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Flight Duty Period: Augmented Operations C Table C to Part 117 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION...—Flight Duty Period: Augmented Operations Scheduled time of start (acclimated time) Maximum flight...

  14. 14 CFR Table C to Part 117 - Flight Duty Period: Augmented Operations

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Flight Duty Period: Augmented Operations C Table C to Part 117 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION...: Augmented Operations Scheduled time of start (acclimated time) Maximum flight duty period (hours) based...

  15. Hearing Loss: Hearing Augmentation.

    PubMed

    Atcherson, Samuel R; Moreland, Christopher; Zazove, Philip; McKee, Michael M

    2015-07-01

    Etiologies of hearing loss vary. When hearing loss is diagnosed, referral to an otology subspecialist, audiology subspecialist, or hearing aid dispenser to discuss treatment options is appropriate. Conventional hearing aids provide increased sound pressure in the ear canal for detection of sounds that might otherwise be soft or inaudible. Hearing aids can be used for sensorineural, conductive, or mixed hearing loss by patients with a wide range of hearing loss severity. The most common type of hearing loss is high-frequency, which affects audibility and perception of speech consonants, but not vowels. As the severity of hearing loss increases, the benefit of hearing aids for speech perception decreases. Implantable devices such as cochlear implants, middle ear implants, and bone-anchored implants can benefit specific patient groups. Hearing assistive technology devices provide auditory, visual, or tactile information to augment hearing and increase environmental awareness of sounds. Hearing assistive devices include wireless assistive listening device systems, closed captioning, hearing aid-compatible telephones, and other devices. For some patients, financial barriers and health insurance issues limit acquisition of hearing aids, implantable devices, and hearing assistive devices. Physicians should be aware that for some patients and families, hearing augmentation may not be desired for cultural reasons.

  16. Planning additional drilling campaign using two-space genetic algorithm: A game theoretical approach

    NASA Astrophysics Data System (ADS)

    Kumral, Mustafa; Ozer, Umit

    2013-03-01

    Grade and tonnage are the most important technical uncertainties in mining ventures because of the use of estimations/simulations, which are mostly generated from drill data. Open pit mines are planned and designed on the basis of the blocks representing the entire orebody. Each block has different estimation/simulation variance reflecting uncertainty to some extent. The estimation/simulation realizations are submitted to mine production scheduling process. However, the use of a block model with varying estimation/simulation variances will lead to serious risk in the scheduling. In the medium of multiple simulations, the dispersion variances of blocks can be thought to regard technical uncertainties. However, the dispersion variance cannot handle uncertainty associated with varying estimation/simulation variances of blocks. This paper proposes an approach that generates the configuration of the best additional drilling campaign to generate more homogenous estimation/simulation variances of blocks. In other words, the objective is to find the best drilling configuration in such a way as to minimize grade uncertainty under budget constraint. Uncertainty measure of the optimization process in this paper is interpolation variance, which considers data locations and grades. The problem is expressed as a minmax problem, which focuses on finding the best worst-case performance i.e., minimizing interpolation variance of the block generating maximum interpolation variance. Since the optimization model requires computing the interpolation variances of blocks being simulated/estimated in each iteration, the problem cannot be solved by standard optimization tools. This motivates to use two-space genetic algorithm (GA) approach to solve the problem. The technique has two spaces: feasible drill hole configuration with minimization of interpolation variance and drill hole simulations with maximization of interpolation variance. Two-space interacts to find a minmax solution

  17. Creating Tangible Interfaces by Augmenting Physical Objects with Multimodal Language

    SciTech Connect

    McGee, David R. ); Cohen, Philip R.

    2001-01-01

    Rasa is a tangible augmented reality environment that digitally enhances the existing paper-based command and control capability in a military command post. By observing and understanding the users' speech, pen, and touch-based multimodal language, Rasa computationally augments the physical objects on a command post map, linking these items to digital representations of the same; for example, linking a paper map to the world and Post-it notes to military units. Herein, we give a thorough account of Rasa's underlying multiagent framework, and its recognition, understanding, and multimodal integration components. Moreover, we examine five properties of language: generativity, comprehensibility, compositionality, referentiality, and, at times, persistence--that render it suitable as an augmentation approach, contrasting these properties to those of other augmentation methods. It is these properties of language that allow users of Rasa to augment physical objects, transforming them into tangible interfaces.

  18. Integrated Development, Verification and Validation Approach for Space Systems Using Autocoding Techniques

    NASA Astrophysics Data System (ADS)

    Barrena-Perez, V.; Colmenarejo-Matellano, P.; Modrego-Contreras, D.; Le Peuvédic, C.; Guiotto, A.

    2008-08-01

    Any space mission is composed by different phases ranging from the mission needs identification to the production of the different elements of the mission and its utilization during the mission lifetime. Traditionally, each mission phase is performed by different types of engineer expert groups and the translation of the results from one phase to the next one is made through documentation and/or models specifications. This approach, inherited from big projects with large development time scales and watertight development phases, becomes, nowadays, inappropriate in terms of cost-effectiveness related to technology development return, while compact and integrated development cycles are becoming more and more efficient. Compact and integrated development cycles results then mandatory and many initiatives to automate the processes are currently on-going in Europe and, particularly, in the European Space Agency. This paper reviews the HARVD (High integrity Autonomous RendezVous and Docking control system) DVV (Development, Verification and Validation) approach for the prototyping of a GNC/AMM/FDIR system (including preliminary design, detailed design, modelling, SW coding and testing in different non-real time and real-time facilities, including dynamic testing with sensors real stimulation) for RendezVous and Docking/Capture scenarios either in Earth or Space Exploration scenarios (e.g. Mars Sample Return).

  19. Quadratic programming-based approach for autonomous vehicle path planning in space

    NASA Astrophysics Data System (ADS)

    Chen, Yang; Han, Jianda; Wu, Huaiyu

    2012-07-01

    Path planning for space vehicles is still a challenging problem although considerable progress has been made over the past decades. The major difficulties are that most of existing methods only adapt to static environment instead of dynamic one, and also can not solve the inherent constraints arising from the robot body and the exterior environment. To address these difficulties, this research aims to provide a feasible trajectory based on quadratic programming(QP) for path planning in three-dimensional space where an autonomous vehicle is requested to pursue a target while avoiding static or dynamic obstacles. First, the objective function is derived from the pursuit task which is defined in terms of the relative distance to the target, as well as the angle between the velocity and the position in the relative velocity coordinates(RVCs). The optimization is in quadratic polynomial form according to QP formulation. Then, the avoidance task is modeled with linear constraints in RVCs. Some other constraints, such as kinematics, dynamics, and sensor range, are included. Last, simulations with typical multiple obstacles are carried out, including in static and dynamic environments and one of human-in-the-loop. The results indicate that the optimal trajectories of the autonomous robot in three-dimensional space satisfy the required performances. Therefore, the QP model proposed in this paper not only adapts to dynamic environment with uncertainty, but also can satisfy all kinds of constraints, and it provides an efficient approach to solve the problems of path planning in three-dimensional space.

  20. A novel variable selection approach that iteratively optimizes variable space using weighted binary matrix sampling.

    PubMed

    Deng, Bai-chuan; Yun, Yong-huan; Liang, Yi-zeng; Yi, Lun-zhao

    2014-10-07

    In this study, a new optimization algorithm called the Variable Iterative Space Shrinkage Approach (VISSA) that is based on the idea of model population analysis (MPA) is proposed for variable selection. Unlike most of the existing optimization methods for variable selection, VISSA statistically evaluates the performance of variable space in each step of optimization. Weighted binary matrix sampling (WBMS) is proposed to generate sub-models that span the variable subspace. Two rules are highlighted during the optimization procedure. First, the variable space shrinks in each step. Second, the new variable space outperforms the previous one. The second rule, which is rarely satisfied in most of the existing methods, is the core of the VISSA strategy. Compared with some promising variable selection methods such as competitive adaptive reweighted sampling (CARS), Monte Carlo uninformative variable elimination (MCUVE) and iteratively retaining informative variables (IRIV), VISSA showed better prediction ability for the calibration of NIR data. In addition, VISSA is user-friendly; only a few insensitive parameters are needed, and the program terminates automatically without any additional conditions. The Matlab codes for implementing VISSA are freely available on the website: https://sourceforge.net/projects/multivariateanalysis/files/VISSA/.

  1. [Design space approach to optimize first ethanol precipitation process of Dangshen].

    PubMed

    Xu, Zhi-lin; Huang, Wen-hua; Gong, Xing-chu; Ye, Tian-tian; Qu, Hai-bin; Song, Yan-gang; Hu, Dong-lai; Wang, Guo-xiang

    2015-11-01

    Design space approach is applied in this study to enhance the robustness of first ethanol precipitation process of Codonopsis Radix (Dangshen) by optimizing parameters. Total flavonoid recovery, dry matter removal, and pigment removal were defined as the process critical quality attributes (CQAs). Plackett-Burman designed experiments were carried out to find the critical process parameters (CPPs). Dry matter content of concentrated extract (DMCE), mass ratio of ethanol to concentrated extract (E/C ratio) and concentration of ethanol (CEA) were identified as the CPPs. Box-Behnken designed experiments were performed to establish the quantitative models between CPPs and CQAs. Probability based design space was obtained and verified using Monte-Carlo simulation method. According to the verification results, the robustness of first ethanol precipitation process of Dangshen can be guaranteed by operating within the design space parameters. Recommended normal operation space are as follows: dry matter content of concentrated extract of 45.0% - 48.0%, E/C ratio of 2.48-2.80 g x g(-1), and the concentration of ethanol of 92.0% - 92.7%.

  2. Space-Hotel Early Bird - An Educational and Public Outreach Approach

    NASA Astrophysics Data System (ADS)

    Amekrane, R.; Holze, C.

    2002-01-01

    education and public outreach can be combined and how a cooperation among an association, the industry and academia can work successfully. Representatives of the DGLR and the academia developed a method to spread space related knowledge in a short time to a motivated working group. The project was a great success in the sense to involve other disciplines in space related topics by interdisciplinary work and in the sense of public and educational outreach. With more than 2.3 million contacts the DGLR e.V. promoted space and the vision of living (in) space to the public. The task of the paper is mainly to describe the approach and the experience made related to the organization, lectures, financing and outreach efforts in respect to similar future international outreach activities, which are planned for the 54th International Astronautical Congress in Bremen/Germany. www.spacehotel.org

  3. Implementation of an open-scenario, long-term space debris simulation approach

    NASA Astrophysics Data System (ADS)

    Stupl, J.; Nelson, B.; Faber, N.; Perez, A.; Carlino, R.; Yang, F.; Henze, C.; Karacalioglu, A.; O'Toole, C.; Swenson, J.

    This paper provides a status update on the implementation of a flexible, long-term space debris simulation approach. The motivation is to build a tool that can assess the long-term impact of various options for debris-remediation, including the LightForce space debris collision avoidance scheme. State-of-the-art simulation approaches that assess the long-term development of the debris environment use either completely statistical approaches, or they rely on large time steps in the order of several (5-15) days if they simulate the positions of single objects over time. They cannot be easily adapted to investigate the impact of specific collision avoidance schemes or de-orbit schemes, because the efficiency of a collision avoidance maneuver can depend on various input parameters, including ground station positions, space object parameters and orbital parameters of the conjunctions and take place in much smaller timeframes than 5-15 days. For example, LightForce only changes the orbit of a certain object (aiming to reduce the probability of collision), but it does not remove entire objects or groups of objects. In the same sense, it is also not straightforward to compare specific de-orbit methods in regard to potential collision risks during a de-orbit maneuver. To gain flexibility in assessing interactions with objects, we implement a simulation that includes every tracked space object in LEO, propagates all objects with high precision, and advances with variable-sized time-steps as small as one second. It allows the assessment of the (potential) impact of changes to any object. The final goal is to employ a Monte Carlo approach to assess the debris evolution during the simulation time-frame of 100 years and to compare a baseline scenario to debris remediation scenarios or other scenarios of interest. To populate the initial simulation, we use the entire space-track object catalog in LEO. We then use a high precision propagator to propagate all objects over the

  4. A tow concept for the space shuttle orbiter approach and landing test

    NASA Technical Reports Server (NTRS)

    Bonner, T. F., Jr.; Pride, J. D., Jr.

    1976-01-01

    The tow concept provides the means for evaluating the orbiter aerodynamic performance and handling qualities in the same configuration as expected in actual space shuttle flight operation. A Boeing 747-100 aircraft has engine-out capability to tow the orbiter to an altitude that permits a safe orbiter approach and landing. The tow concept also provides a means for conducting a comprehensive ground test program before proceeding into the actual ALT flight operations. The implementation of the tow concept requires only a minor structural modification in the nose section of the orbiter vehicle; requires minor modifications in the 747 cargo bay; and makes use of those orbiter onboard systems installed in the ALT orbiter vehicle. The 747 wake turbulence does not constitute a problem for the orbiter during take-off or climb to altitude. The impact that the tow concept would have on the cost and schedule of the space shuttle program was not evaluated in this study.

  5. Formulation design space: a proven approach to maximize flexibility and outcomes within early clinical development.

    PubMed

    McDermott, John; Scholes, Peter

    2015-01-01

    Traditional formulation development studies involve expensive and time-consuming screening of prototypes in preclinical species to select 'lead' systems for evaluation in human clinical pharmacokinetic studies. A new paradigm, Translational Pharmaceutics, has emerged to integrate pharmaceutical development, manufacturing and clinical functions to address these restrictions. Rapid Formulation development and Clinical Testing (RapidFACT) is applied to exploit the benefits of Translational Pharmaceutics in the clinical screening and optimization of drug products. Benefits are maximized by the adapted utilization of the concept of 'formulation design space'. This article presents the experience of the application of design space within RapidFACT and is supported by data from over 200 formulations studied to date, including case studies on how the approach has been applied.

  6. Bioregenerative life support systems for long-term space habitation: a conceptual approach

    NASA Technical Reports Server (NTRS)

    Sadeh, E.; Sadeh, W. Z.

    1996-01-01

    Life support systems represent one of the most critical aspects of human space exploration. Future long-term missions such as the establishment of human-tended Lunar and Martian bases require closed life support systems. A conceptual approach to an Engineered Closed/Controlled EcoSystem incorporating bioregenerative capabilities by integrating humans, plants, and waste management processes is presented. The integration of physical/chemical and biological waste treatment processes is suitable for supporting plant growth through hydroponics and materially closing the human and plant metabolic loops. This conceptual design separates wastes into individual loops for treatment according to the specific metabolic needs of humans and plants. The means through which an integrated Engineered Closed/Controlled EcoSystem meets the life support objectives of long-term space habitation are summarized.

  7. A New Approach to Space Situational Awareness using Small Ground-Based Telescopes

    SciTech Connect

    Anheier, Norman C.; Chen, Cliff S.

    2014-12-01

    This report discusses a new SSA approach evaluated by Pacific Northwest National Laboratory (PNNL) that may lead to highly scalable, small telescope observing stations designed to help manage the growing space surveillance burden. Using the methods and observing tools described in this report, the team was able to acquire and track very faint satellites (near Pluto’s apparent brightness). Photometric data was collected and used to correlate object orbital position as a function of atomic clock-derived time. Object apparent brightness was estimated by image analysis and nearby star calibration. The measurement performance was only limited by weather conditions, object brightness, and the sky glow at the observation site. In the future, these new SSA technologies and techniques may be utilized to protect satellite assets, detect and monitor orbiting debris fields, and support Outer Space Treaty monitoring and transparency.

  8. Alternative Approaches to Mission Control Automation at NASA's Goddard Space Flight Center

    NASA Technical Reports Server (NTRS)

    Rackley, Michael; Cooter, Miranda; Davis, George; Mackey, Jennifer

    2001-01-01

    To meet its objective of reducing operations costs without incurring a corresponding increase in risk, NASA is seeking new methods to automate mission operations. This paper examines the state of the art in automating ground operations for space missions. A summary of available technologies and methods for automating mission operations is provided. Responses from interviews with several space mission FOTs (Flight Operations Teams) to assess the degree and success of those technologies and methods implemented are presented. Mission operators that were interviewed approached automation using different tools and methods resulting in varying degrees of success - from nearly completely automated to nearly completely manual. Two key criteria for successful automation are the active participation of the FOT in the planning, designing, testing, and implementation of the system and the relative degree of complexity of the mission.

  9. Nondestructive Evaluation Approaches Developed for Material Characterization in Aeronautics and Space Applications

    NASA Technical Reports Server (NTRS)

    Baaklini, George Y.; Kautz, Harold E.; Gyekenyesi, Andrew L.; Abdul-Aziz, Ali; Martin, Richard E.

    2001-01-01

    At the NASA Glenn Research Center, nondestructive evaluation (NDE) approaches were developed or tailored for characterizing advanced material systems. The emphasis was on high-temperature aerospace propulsion applications. The material systems included monolithic ceramics, superalloys, and high-temperature composites. In the aeronautics area, the major applications were cooled ceramic plate structures for turbine applications, gamma-TiAl blade materials for low-pressure turbines, thermoelastic stress analysis for residual stress measurements in titanium-based and nickel-based engine materials, and acousto-ultrasonics for creep damage assessment in nickel-based alloys. In the space area, applications consisted of cooled carbon-carbon composites for gas generator combustors and flywheel rotors composed of carbon-fiber-reinforced polymer matrix composites for energy storage on the International Space Station.

  10. Double mandibular osteotomy with segmental mandibular swing approach to parapharyngeal space.

    PubMed

    Satpathy, Shouvanik; Dam, Aniruddha; Hossain, Mollah Arafat; Chatterjee, Jayanta

    2014-01-01

    Surgical removal of benign tumors of the Parapharyngeal space (PPS) is the treatment of choice. PPS tumors may remain undetected for long periods of time and large tumors in the PPS can extend into the Retropharyngeal Space or into the Infra-Temporal Fossa. Anatomically, the mandible represents a significant obstacle to successful PPS surgery. Except for very small tumors, it is difficult to remove larger tumors from this region without some form of mandibular retraction. The standard mandibular "swing" approach involves splitting of the lower lip and a single parasymphysis osteotomy for retraction of the mandible laterally to expose the PPS. However, the morbidity associated with midline lip split and anesthesia of the hemi-labial region caused by the severing of the mental nerve is an unwanted complication of this approach. In this article, we describe an easier double mandibular osteotomy (Segmental Mandibular Swing Approach) which avoids the morbidity associated with lip splitting or intra-oral mucosal incision but allows excellent exposure of the superior and lateral aspect of PPS for easier removal of large tumors in this region.

  11. Evaluation of a Terminal Area In-Trail Approach Spacing, Project and Study

    NASA Technical Reports Server (NTRS)

    Shelden, Stephen; Johnson, Walter (Editor)

    2001-01-01

    Reported here are the results of work completed as a precursor to Distributed Air Ground (DAG), Concept Element 11 (CE11) research. CE11 is a NASA, Advanced Air Transportation Technologies (AATT) concept initiated to promote research on in-trail merging and spacing during approach in the terminal area environment, such that improvements to the National Air Space (NAS) may be realized. A description of the project concept, results of a preliminary study, and a literature review are presented. In terms of conclusions, study results, and reference material respectively: 1) the concept is supported as being significant to NAS capacity improvement, 2) the preliminary study indicated that having more than one downstream, in-trail aircraft present on a CDTI during approach may be advantageous, and that flying traditional Standard Terminal Arrival Routes (STAR) utilizing advanced decision support tools (DST) may be complicated by wake turbulence considerations, a lack of vertical awareness on the part of the flight crew, and the 'step-down' nature of many terminal area approaches, and 3) the results of a literature review are presented for future reference.

  12. Antidepressant augmentation with anti-inflammatory agents.

    PubMed

    Andrade, Chittaranjan

    2014-09-01

    Antidepressant augmentation strategies are commonly employed to treat depressed patients who do not respond to antidepressant monotherapy. Neuroinflammatory mechanisms have been implicated in depression, and nonsteroidal anti-inflammatory drugs (NSAIDs) have been found effective in animal models of depression both in monotherapy and when used to augment antidepressant drugs. However, results with NSAIDs have been mixed in human observational studies, with both better and worse depression outcomes reported. Four small (pooled N = 160) randomized controlled trials suggest that celecoxib (200-400 mg/d) augmentation of antidepressant medication improves 4-6 week outcomes in major depressive disorder. There are no data, however, to support the use of celecoxib or other NSAIDs in antidepressant-resistant depression. There are also concerns about adverse events associated with NSAID treatment, and about pharmacodynamic drug interactions between these drugs and serotonin reuptake inhibitors. A reasonable conclusion for the present is that NSAID augmentation of antidepressants is, at best, a tentative approach in nonrefractory major depression.

  13. An economic analysis of a commercial approach to the design and fabrication of a space power system

    NASA Technical Reports Server (NTRS)

    Putney, Z.; Been, J. F.

    1979-01-01

    A commercial approach to the design and fabrication of an economical space power system is presented. Cost reductions are projected through the conceptual design of a 2 kW space power system built with the capability for having serviceability. The approach to system costing that is used takes into account both the constraints of operation in space and commercial production engineering approaches. The cost of this power system reflects a variety of cost/benefit tradeoffs that would reduce system cost as a function of system reliability requirements, complexity, and the impact of rigid specifications. A breakdown of the system design, documentation, fabrication, and reliability and quality assurance cost estimates are detailed.

  14. Temporal Coherence Strategies for Augmented Reality Labeling.

    PubMed

    Madsen, Jacob Boesen; Tatzqern, Markus; Madsen, Claus B; Schmalstieg, Dieter; Kalkofen, Denis

    2016-04-01

    Temporal coherence of annotations is an important factor in augmented reality user interfaces and for information visualization. In this paper, we empirically evaluate four different techniques for annotation. Based on these findings, we follow up with subjective evaluations in a second experiment. Results show that presenting annotations in object space or image space leads to a significant difference in task performance. Furthermore, there is a significant interaction between rendering space and update frequency of annotations. Participants improve significantly in locating annotations, when annotations are presented in object space, and view management update rate is limited. In a follow-up experiment, participants appear to be more satisfied with limited update rate in comparison to a continuous update rate of the view management system.

  15. Surgical management for upper thoracic spine tumors by a transmanubrium approach and a new space

    PubMed Central

    Xiao, Zeng Ming; Gong, De Feng; De Li, Shi

    2006-01-01

    The anterior aspect of the upper thoracic spine is a difficult region to approach in spinal surgery. Many vital structures including osseus, articular, vascular and nervous ones hinder the exposure. With increasing frequency, spine surgeons are being asked to provide decompression and stabilization in patients with spinal tumors .The traditional exposure is between the esophagus and trachea medially and the left common carotid or the brachiocephalic artery (BCA) laterally, and the disadvantages were that the ligation and section of the left innominate vein is proposed to reach T4 and the injury of the thoracic duct could occur. The right space of the BCA or the ascending aorta (AA) (the exposure between the right brachiocephalic vein and the BCA or between the AA and superior caval vein) is recommended in exposing the upper thoracic vertebrae; this new space is technically feasible; the exposure is sufficient for vertebral body resection and reconstruction and fixation. Twenty-eight patients with upper thoracic spine tumors underwent surgery by the use of this new space between June 2000 and October 2005. A strut graft was fixed anteriorly after decompression of the spinal cord. Levels C7–T5 can be well exposed through this new space, allowing complete vertebral body removal at level T1–T4. After body removal, the posterior longitudinal ligament is well exposed, allowing complete release of the spinal cord. Curettage was performed in one case of aneurysmal bone cyst and three cases of bone giant cell tumors. For other tumors, vertebrectomies or sagittal resections were performed. Four patients underwent surgery by a combination of anterior and posterior approach. PMID:17043896

  16. Surgical management for upper thoracic spine tumors by a transmanubrium approach and a new space.

    PubMed

    Xiao, Zeng Ming; Zhan, Xin Li; Gong, De Feng; De Li, Shi

    2007-03-01

    The anterior aspect of the upper thoracic spine is a difficult region to approach in spinal surgery. Many vital structures including osseus, articular, vascular and nervous ones hinder the exposure. With increasing frequency, spine surgeons are being asked to provide decompression and stabilization in patients with spinal tumors. The traditional exposure is between the esophagus and trachea medially and the left common carotid or the brachiocephalic artery (BCA) laterally, and the disadvantages were that the ligation and section of the left innominate vein is proposed to reach T4 and the injury of the thoracic duct could occur. The right space of the BCA or the ascending aorta (AA) (the exposure between the right brachiocephalic vein and the BCA or between the AA and superior caval vein) is recommended in exposing the upper thoracic vertebrae; this new space is technically feasible; the exposure is sufficient for vertebral body resection and reconstruction and fixation. Twenty-eight patients with upper thoracic spine tumors underwent surgery by the use of this new space between June 2000 and October 2005. A strut graft was fixed anteriorly after decompression of the spinal cord. Levels C7-T5 can be well exposed through this new space, allowing complete vertebral body removal at level T1-T4. After body removal, the posterior longitudinal ligament is well exposed, allowing complete release of the spinal cord. Curettage was performed in one case of aneurysmal bone cyst and three cases of bone giant cell tumors. For other tumors, vertebrectomies or sagittal resections were performed. Four patients underwent surgery by a combination of anterior and posterior approach.

  17. Combined Neuropeptide S and D-Cycloserine Augmentation Prevents the Return of Fear in Extinction-Impaired Rodents: Advantage of Dual versus Single Drug Approaches

    PubMed Central

    Maurer, Verena; Murphy, Conor; Schmuckermair, Claudia; Muigg, Patrick; Neumann, Inga D.; Whittle, Nigel

    2016-01-01

    Background: Despite its success in treating specific anxiety disorders, the effect of exposure therapy is limited by problems with tolerability, treatment resistance, and fear relapse after initial response. The identification of novel drug targets facilitating fear extinction in clinically relevant animal models may guide improved treatment strategies for these disorders in terms of efficacy, acceleration of fear extinction, and return of fear. Methods: The extinction-facilitating potential of neuropeptide S, D-cycloserine, and a benzodiazepine was investigated in extinction-impaired high anxiety HAB rats and 129S1/SvImJ mice using a classical cued fear conditioning paradigm followed by extinction training and several extinction test sessions to study fear relapse. Results: Administration of D-cycloserine improved fear extinction in extinction-limited, but not in extinction-deficient, rodents compared with controls. Preextinction neuropeptide S caused attenuated fear responses in extinction-deficient 129S1/SvImJ mice at extinction training onset and further reduced freezing during this session. While the positive effects of either D-cycloserine or neuropeptide S were not persistent in 129S1/SvImJ mice after 10 days, the combination of preextinction neuropeptide S with postextinction D-cycloserine rendered the extinction memory persistent and context independent up to 5 weeks after extinction training. This dual pharmacological adjunct to extinction learning also protected against fear reinstatement in 129S1/SvImJ mice. Conclusions: By using the potentially nonsedative anxiolytic neuropeptide S and the cognitive enhancer D-cycloserine to facilitate deficient fear extinction, we provide here the first evidence of a purported efficacy of a dual over a single drug approach. This approach may render exposure sessions less aversive and more efficacious for patients, leading to enhanced protection from fear relapse in the long term. PMID:26625894

  18. Augmented reality system

    NASA Astrophysics Data System (ADS)

    Lin, Chien-Liang; Su, Yu-Zheng; Hung, Min-Wei; Huang, Kuo-Cheng

    2010-08-01

    In recent years, Augmented Reality (AR)[1][2][3] is very popular in universities and research organizations. The AR technology has been widely used in Virtual Reality (VR) fields, such as sophisticated weapons, flight vehicle development, data model visualization, virtual training, entertainment and arts. AR has characteristics to enhance the display output as a real environment with specific user interactive functions or specific object recognitions. It can be use in medical treatment, anatomy training, precision instrument casting, warplane guidance, engineering and distance robot control. AR has a lot of vantages than VR. This system developed combines sensors, software and imaging algorithms to make users feel real, actual and existing. Imaging algorithms include gray level method, image binarization method, and white balance method in order to make accurate image recognition and overcome the effects of light.

  19. Augmented nonlinear differentiator design

    NASA Astrophysics Data System (ADS)

    Shao, Xingling; Liu, Jun; Yang, Wei; Tang, Jun; Li, Jie

    2017-06-01

    This paper presents a sigmoid function based augmented nonlinear differentiator (AND) for calculating the noise-less time derivative from a noisy measurement. The prominent advantages of the present differentiation technique are: (i) compared to the existing tracking differentiators, better noise suppression ability can be achieved without appreciable delay; (ii) the enhanced noise-filtering mechanism not only can be applied to the designed differentiator, but also can be extended for improving noise-tolerance capability of the available differentiators. In addition, the convergence property and robustness performance against noises are investigated via singular perturbation theory and describing function method, respectively. Also, comparison with several classical differentiators is given to illustrate the superiority of AND in noise suppression. Finally, applications on autopilot design and displacement following for nonlinear mass spring mechanical system are given to demonstrate the effectiveness and applicability of the proposed AND technique.

  20. Magnetohydrodynamic Augmented Propulsion Experiment

    NASA Technical Reports Server (NTRS)

    Litchford, Ron J.

    2008-01-01

    Over the past several years, efforts have been under way to design and develop an operationally flexible research facility for investigating the use of cross-field MHD accelerators as a potential thrust augmentation device for thermal propulsion systems. The baseline configuration for this high-power experimental facility utilizes a 1.5-MWe multi-gas arc-heater as a thermal driver for a 2-MWe MHD accelerator, which resides in a large-bore 2-tesla electromagnet. A preliminary design study using NaK seeded nitrogen as the working fluid led to an externally diagonalized segmented MHD channel configuration based on an expendable heat-sink design concept. The current status report includes a review of engineering/design work and performance optimization analyses and summarizes component hardware fabrication and development efforts, preliminary testing results, and recent progress toward full-up assembly and testing

  1. Space Shuttle Stiffener Ring Foam Failure Analysis, a Non-Conventional Approach

    NASA Technical Reports Server (NTRS)

    Howard, Philip M.

    2015-01-01

    The Space Shuttle Program made use of the excellent properties of rigid polyurethane foam for cryogenic tank insulation and as structural protection on the solid rocket boosters. When foam applications de-bond, classical methods of failure analysis did not provide root cause of the failure of the foam. Realizing that foam is the ideal media to document and preserve its own mode of failure, thin sectioning was seen as a logical approach for foam failure analysis to observe the three dimensional morphology of the foam cells. The cell foam morphology provided a much greater understanding of the failure modes than previously achieved.

  2. Orotracheal Intubation Using the Retromolar Space: A Reliable Alternative Intubation Approach to Prevent Dental Injury

    PubMed Central

    Thakar, Sudip D.; Truong, Angela T.; Truong, Dam-Thuy

    2016-01-01

    Despite recent advances in airway management, perianesthetic dental injury remains one of the most common anesthesia-related adverse events and cause for malpractice litigation against anesthesia providers. Recommended precautions for prevention of dental damage may not always be effective because these techniques involve contact and pressure exerted on vulnerable teeth. We describe a novel approach using the retromolar space to insert a flexible fiberscope for tracheal tube placement as a reliable method to achieve atraumatic tracheal intubation. Written consent for publication has been obtained from the patient. PMID:28116174

  3. A study of space shuttle energy management, approach and landing analysis

    NASA Technical Reports Server (NTRS)

    Morth, R.

    1973-01-01

    The steering system of the space shuttle vehicle is presented for the several hundred miles of flight preceding landing. The guidance scheme is characterized by a spiral turn to dissipate excess potential energy (altitude) prior to a standard straight-in final approach. In addition, the system features pilot oriented control, drag brakes, phugoid damping, and a navigational capacity founded upon an inertial measurement unit and an on-board computer. Analytic formulas are used to calculate, represent, and insure the workability of the system's specifications

  4. Modern Gemini-Approach to Technology Development for Human Space Exploration

    NASA Technical Reports Server (NTRS)

    White, Harold

    2010-01-01

    In NASA's plan to put men on the moon, there were three sequential programs: Mercury, Gemini, and Apollo. The Gemini program was used to develop and integrate the technologies that would be necessary for the Apollo program to successfully put men on the moon. We would like to present an analogous modern approach that leverages legacy ISS hardware designs, and integrates developing new technologies into a flexible architecture This new architecture is scalable, sustainable, and can be used to establish human exploration infrastructure beyond low earth orbit and into deep space.

  5. Legacy Making Through Illness Blogs: Online Spaces for Young Adults Approaching the End-of-Life.

    PubMed

    Keim-Malpass, Jessica; Adelstein, Katharine; Kavalieratos, Dio

    2015-12-01

    Little is known about young adults with cancer at the end-of-life, but life review and legacy making may be important modalities to process the emotions associated with anticipatory grief. The study analyzed the illness blogs of five young women (aged 25-39 years) at the end-of-life using a narrative approach. Key elements of legacy making and grief processing were explored. The women had varying experiences before their death, but uniform posthumous occurrences with the use of the blog for a space of grief for loved ones. The use of online blogs among adolescents and young adults with advanced cancer is an area of needed further study.

  6. Facing the PA team growth problem in space programs: The Hermes approach

    NASA Astrophysics Data System (ADS)

    Bernede, G.

    1991-08-01

    The increasing need for product assurance (PA) in space programs makes finding skilled and trained engineers willing to work in the PA field a top level difficulty. Few engineers are available and exchanging them from one project to another is not a solution. No reservoir of talent exists for the time being in Europe. Educational efforts have started in several countries to have product assurance techniques become part of basic engineering knowledge. These efforts will bring strong improvement compared to today's situation but not in time for programs such as Hermes. Peculiar solutions must be developed. Approaches used to solve this problem within the Hermes program are outlined.

  7. An Effective Vaccination Approach Augments anti-HIV Systemic and Vaginal Immunity in Mice with Decreased HIV-1 Susceptible α4β7high CD4+ T Cells

    PubMed Central

    Zhu, Wei; Shi, Guoping; Tang, Haijun; Lewis, Dorothy E; Song, Xiao-Tong

    2013-01-01

    HIV-1 preferentially infects activated CD4+ T cells expressing α4β7 integrin and conventional vaccination approaches non-selectively induce immune responses including α4β7high CD4+ T cells, suggesting that current candidate AIDS vaccines may produce more target cells for HIV-1 and paradoxically enhance HIV-1 infection. Thus it remains a challenge to selectively induce robust anti-HIV immunity without the unwanted HIV-1 susceptible α4β7high CD4+ T cells. Here we describe a vaccination strategy that targets ALDH1a2, a retinoic acid producing enzyme in dendritic cells (DCs). Silencing ALDH1a2 in DCs enhanced the maturation and production of proinflammatory cytokines of DCs and promoted Th1/Th2 differentiation while suppressing Treg. ALDH1a2-silenced DCs effectively downregulated the expression of guthoming receptors α4β7 and CCR9 on activated T and B lymphocytes. Consequently, intranasal immunization of a lentiviral vaccine encoding ALDH1a2 shRNA and HIV-1 gp140 redirected gp140-specific mucosal T cell and antibody responses from the gut to the vaginal tract, while dramatically enhancing systemic gp140-specific immune responses. We further demonstrated that silencing ALDH1a2 in human DCs resulted in downregulation of β7 expression on activated autologous CD4+ T cells. Hence this study provides a unique and effective strategy to induce α4β7low anti-HIV immune responses. PMID:23157585

  8. An effective vaccination approach augments anti-HIV systemic and vaginal immunity in mice with decreased HIV-1 susceptible α4β7high CD4+ T cells.

    PubMed

    Zhu, Wei; Shi, Guoping; Tang, Haijun; Lewis, Dorothy E; Song, Xiao-Tong

    2013-01-01

    HIV-1 preferentially infects activated CD4(+) T cells expressing α4β7 integrin and conventional vaccination approaches non-selectively induce immune responses including α4β7(high) CD4(+) T cells, suggesting that current candidate AIDS vaccines may produce more target cells for HIV-1 and paradoxically enhance HIV-1 infection. Thus it remains a challenge to selectively induce robust anti-HIV immunity without the unwanted HIV-1 susceptible α4β77(high) CD4(+)+ T cells. Here we describe a vaccination strategy that targets ALDH1a2, a retinoic acid producing enzyme in dendritic cells (DCs). Silencing ALDH1a2 in DCs enhanced the maturation and production of proinflammatory cytokines of DCs and promoted Th1/Th2 differentiation while suppressing Treg. ALDH1a2-silenced DCs effectively downregulated the expression of guthoming receptors α4β77 and CCR9 on activated T and B lymphocytes. Consequently, intranasal immunization of a lentiviral vaccine encoding ALDH1a2 shRNA and HIV-1 gp140 redirected gp140-specific mucosal T cell and antibody responses from the gut to the vaginal tract, while dramatically enhancing systemic gp140-specific immune responses. We further demonstrated that silencing ALDH1a2 in human DCs resulted in downregulation of β7 expression on activated autologous CD4(+) T cells. Hence this study provides a unique and effective strategy to induce α4β7(low) anti-HIV immune responses.

  9. An Advanced Orbiting Systems Approach to Quality of Service in Space-Based Intelligent Communication Networks

    NASA Technical Reports Server (NTRS)

    Riha, Andrew P.

    2005-01-01

    As humans and robotic technologies are deployed in future constellation systems, differing traffic services will arise, e.g., realtime and non-realtime. In order to provide a quality of service framework that would allow humans and robotic technologies to interoperate over a wide and dynamic range of interactions, a method of classifying data as realtime or non-realtime is needed. In our paper, we present an approach that leverages the Consultative Committee for Space Data Systems (CCSDS) Advanced Orbiting Systems (AOS) data link protocol. Specifically, we redefine the AOS Transfer Frame Replay Flag in order to provide an automated store-and-forward approach on a per-service basis for use in the next-generation Interplanetary Network. In addition to addressing the problem of intermittent connectivity and associated services, we propose a follow-on methodology for prioritizing data through further modification of the AOS Transfer Frame.

  10. A probabilistic fracture mechanics approach for structural reliability assessment of space flight systems

    NASA Technical Reports Server (NTRS)

    Sutharshana, S.; Creager, M.; Ebbeler, D.; Moore, N.

    1992-01-01

    A probabilistic fracture mechanics approach for predicting the failure life distribution due to subcritical crack growth is presented. A state-of-the-art crack propagation method is used in a Monte Carlo simulation to generate a distribution of failure lives. The crack growth failure model expresses failure life as a function of stochastic parameters including environment, loads, material properties, geometry, and model specification errors. A stochastic crack growth rate model that considers the uncertainties due to scatter in the data and mode misspecification is proposed. The rationale for choosing a particular type of probability distribution for each stochastic input parameter and for specifying the distribution parameters is presented. The approach is demonstrated through a probabilistic crack growth failure analysis of a welded tube in the Space Shuttle Main Engine. A discussion of the results from this application of the methodology is given.

  11. An innovative approach for distributed and integrated resources planning for the Space Station Freedom

    NASA Technical Reports Server (NTRS)

    Hornstein, Rhoda S.; Shinkle, Gerald L.; Weiler, Jerry D.; Willoughby, John K.

    1990-01-01

    This paper presents a planning approach to the Space Station Freedom program which takes into account the widely distributed nature of that program. The program management structure is organized into three major levels: a strategic level, a tactical level, and an execution level. For each level, resource availabilities are determined, the resources are distributed, schedules are built independently within the resource limits, the schedules are integrated into a single schedule, and conflicts are resolved by negotiating requirements and/or relaxing contraints. This approach distributes resources to multiple planning entities in such a way that when the multiple plans are collected, they fit together with minimal modification. The up-front distribution is planned in such a way and to a sufficient degree that a fit is virtually assured.

  12. An integrative approach to space-flight physiology using systems analysis and mathematical simulation

    NASA Technical Reports Server (NTRS)

    Leonard, J. I.; White, R. J.; Rummel, J. A.

    1980-01-01

    An approach was developed to aid in the integration of many of the biomedical findings of space flight, using systems analysis. The mathematical tools used in accomplishing this task include an automated data base, a biostatistical and data analysis system, and a wide variety of mathematical simulation models of physiological systems. A keystone of this effort was the evaluation of physiological hypotheses using the simulation models and the prediction of the consequences of these hypotheses on many physiological quantities, some of which were not amenable to direct measurement. This approach led to improvements in the model, refinements of the hypotheses, a tentative integrated hypothesis for adaptation to weightlessness, and specific recommendations for new flight experiments.

  13. The management approach to the NASA space station definition studies at the Manned Spacecraft Center

    NASA Technical Reports Server (NTRS)

    Heberlig, J. C.

    1972-01-01

    The overall management approach to the NASA Phase B definition studies for space stations, which were initiated in September 1969 and completed in July 1972, is reviewed with particular emphasis placed on the management approach used by the Manned Spacecraft Center. The internal working organizations of the Manned Spacecraft Center and its prime contractor, North American Rockwell, are delineated along with the interfacing techniques used for the joint Government and industry study. Working interfaces with other NASA centers, industry, and Government agencies are briefly highlighted. The controlling documentation for the study (such as guidelines and constraints, bibliography, and key personnel) is reviewed. The historical background and content of the experiment program prepared for use in this Phase B study are outlined and management concepts that may be considered for future programs are proposed.

  14. Implementation of an Open-Scenario, Long-Term Space Debris Simulation Approach

    NASA Technical Reports Server (NTRS)

    Nelson, Bron; Yang Yang, Fan; Carlino, Roberto; Dono Perez, Andres; Faber, Nicolas; Henze, Chris; Karacalioglu, Arif Goktug; O'Toole, Conor; Swenson, Jason; Stupl, Jan

    2015-01-01

    This paper provides a status update on the implementation of a flexible, long-term space debris simulation approach. The motivation is to build a tool that can assess the long-term impact of various options for debris-remediation, including the LightForce space debris collision avoidance concept that diverts objects using photon pressure [9]. State-of-the-art simulation approaches that assess the long-term development of the debris environment use either completely statistical approaches, or they rely on large time steps on the order of several days if they simulate the positions of single objects over time. They cannot be easily adapted to investigate the impact of specific collision avoidance schemes or de-orbit schemes, because the efficiency of a collision avoidance maneuver can depend on various input parameters, including ground station positions and orbital and physical parameters of the objects involved in close encounters (conjunctions). Furthermore, maneuvers take place on timescales much smaller than days. For example, LightForce only changes the orbit of a certain object (aiming to reduce the probability of collision), but it does not remove entire objects or groups of objects. In the same sense, it is also not straightforward to compare specific de-orbit methods in regard to potential collision risks during a de-orbit maneuver. To gain flexibility in assessing interactions with objects, we implement a simulation that includes every tracked space object in Low Earth Orbit (LEO) and propagates all objects with high precision and variable time-steps as small as one second. It allows the assessment of the (potential) impact of physical or orbital changes to any object. The final goal is to employ a Monte Carlo approach to assess the debris evolution during the simulation time-frame of 100 years and to compare a baseline scenario to debris remediation scenarios or other scenarios of interest. To populate the initial simulation, we use the entire space

  15. Augmented Reality Comes to Physics

    ERIC Educational Resources Information Center

    Buesing, Mark; Cook, Michael

    2013-01-01

    Augmented reality (AR) is a technology used on computing devices where processor-generated graphics are rendered over real objects to enhance the sensory experience in real time. In other words, what you are really seeing is augmented by the computer. Many AR games already exist for systems such as Kinect and Nintendo 3DS and mobile apps, such as…

  16. Study of space utilization and technical approaches to heating in buildings with irregular occupancy. Final report. Volume 1

    SciTech Connect

    Not Available

    1984-05-01

    The study objective was to review, identify and recommend technical approaches to the heating of buildings with irregular occupancy including physiological and psychological parameters affecting comfort. Numerous optimal room treatments have been identified for each space type and climate zone.

  17. OPC model space approach to in-line process monitoring structures

    NASA Astrophysics Data System (ADS)

    Sabatier, Romuald; Di Giacomo, Antonio; Fossati, Caroline; Bourennane, Salah

    2009-10-01

    With shrinking technology nodes and increasing geometries criticity, it has become more and more difficult to conceive fast and accurate in-line check to insure process quality for each lithography level. Time and costs limit metrology options. A commonly accepted solution consists in some CD measurement on high contrast structure for each critical level. However, the RET complexity of current layouts makes this solution no longer fully reliable and allows non-conform materials to pass through the check. The idea behind this article (patent pending) is to add a second verification by creating a set of small structures layouted to cover specific coordinates in the model parameters space. Extrapolated model parameters allow to layout geometries encircling the OPC space region occupied by the production device. Those structures shall bridge or pinch for litho or process deviations before any detectable impact on the most sensitive shapes present in the product. Total size of few square microns is required to stay within a single SEM picture. The use of image processing based on pattern recognition on SEM pictures to assess their sensitivity to process variations permits a fast analysis. As a matter of fact, this approach will allow getting reliability by watching the whole model space and economic compatibility as the procedure is fast and cost-effective.

  18. The systems approach for applying artificial intelligence to space station automation (Invited Paper)

    NASA Astrophysics Data System (ADS)

    Grose, Vernon L.

    1985-12-01

    The progress of technology is marked by fragmentation -- dividing research and development into ever narrower fields of specialization. Ultimately, specialists know everything about nothing. And hope for integrating those slender slivers of specialty into a whole fades. Without an integrated, all-encompassing perspective, technology becomes applied in a lopsided and often inefficient manner. A decisionary model, developed and applied for NASA's Chief Engineer toward establishment of commercial space operations, can be adapted to the identification, evaluation, and selection of optimum application of artificial intelligence for space station automation -- restoring wholeness to a situation that is otherwise chaotic due to increasing subdivision of effort. Issues such as functional assignments for space station task, domain, and symptom modules can be resolved in a manner understood by all parties rather than just the person with assigned responsibility -- and ranked by overall significance to mission accomplishment. Ranking is based on the three basic parameters of cost, performance, and schedule. This approach has successfully integrated many diverse specialties in situations like worldwide terrorism control, coal mining safety, medical malpractice risk, grain elevator explosion prevention, offshore drilling hazards, and criminal justice resource allocation -- all of which would have otherwise been subject to "squeaky wheel" emphasis and support of decision-makers.

  19. Fault-tolerant control of large space structures using the stable factorization approach

    NASA Technical Reports Server (NTRS)

    Razavi, H. C.; Mehra, R. K.; Vidyasagar, M.

    1986-01-01

    Large space structures are characterized by the following features: they are in general infinite-dimensional systems, and have large numbers of undamped or lightly damped poles. Any attempt to apply linear control theory to large space structures must therefore take into account these features. Phase I consisted of an attempt to apply the recently developed Stable Factorization (SF) design philosophy to problems of large space structures, with particular attention to the aspects of robustness and fault tolerance. The final report on the Phase I effort consists of four sections, each devoted to one task. The first three sections report theoretical results, while the last consists of a design example. Significant results were obtained in all four tasks of the project. More specifically, an innovative approach to order reduction was obtained, stabilizing controller structures for plants with an infinite number of unstable poles were determined under some conditions, conditions for simultaneous stabilizability of an infinite number of plants were explored, and a fault tolerance controller design that stabilizes a flexible structure model was obtained which is robust against one failure condition.

  20. A reciprocal space approach for locating symmetry elements in Patterson superposition maps

    SciTech Connect

    Hendrixson, T.

    1990-09-21

    A method for determining the location and possible existence of symmetry elements in Patterson superposition maps has been developed. A comparison of the original superposition map and a superposition map operated on by the symmetry element gives possible translations to the location of the symmetry element. A reciprocal space approach using structure factor-like quantities obtained from the Fourier transform of the superposition function is then used to determine the best'' location of the symmetry element. Constraints based upon the space group requirements are also used as a check on the locations. The locations of the symmetry elements are used to modify the Fourier transform coefficients of the superposition function to give an approximation of the structure factors, which are then refined using the EG relation. The analysis of several compounds using this method is presented. Reciprocal space techniques for locating multiple images in the superposition function are also presented, along with methods to remove the effect of multiple images in the Fourier transform coefficients of the superposition map. In addition, crystallographic studies of the extended chain structure of (NHC{sub 5}H{sub 5})SbI{sub 4} and of the twinning method of the orthorhombic form of the high-{Tc} superconductor YBa{sub 2}Cu{sub 3}O{sub 7-x} are presented. 54 refs.

  1. Design Space Approach in Optimization of Fluid Bed Granulation and Tablets Compression Process

    PubMed Central

    Djuriš, Jelena; Medarević, Djordje; Krstić, Marko; Vasiljević, Ivana; Mašić, Ivana; Ibrić, Svetlana

    2012-01-01

    The aim of this study was to optimize fluid bed granulation and tablets compression processes using design space approach. Type of diluent, binder concentration, temperature during mixing, granulation and drying, spray rate, and atomization pressure were recognized as critical formulation and process parameters. They were varied in the first set of experiments in order to estimate their influences on critical quality attributes, that is, granules characteristics (size distribution, flowability, bulk density, tapped density, Carr's index, Hausner's ratio, and moisture content) using Plackett-Burman experimental design. Type of diluent and atomization pressure were selected as the most important parameters. In the second set of experiments, design space for process parameters (atomization pressure and compression force) and its influence on tablets characteristics was developed. Percent of paracetamol released and tablets hardness were determined as critical quality attributes. Artificial neural networks (ANNs) were applied in order to determine design space. ANNs models showed that atomization pressure influences mostly on the dissolution profile, whereas compression force affects mainly the tablets hardness. Based on the obtained ANNs models, it is possible to predict tablet hardness and paracetamol release profile for any combination of analyzed factors. PMID:22919295

  2. A New Unified Approach to Determine Geocenter Motion Using Space Geodetic and GRACE Gravity Data

    NASA Astrophysics Data System (ADS)

    Wu, Xiaoping; Kusche, Jürgen; Landerer, Felix W.

    2017-03-01

    Geocenter motion between the center-of-mass of the Earth system (CM) and the center-of-figure of the solid Earth surface is a critical signature of degree-1 components of global surface mass transport process that includes sea level rise, ice mass imbalance, and continental-scale hydrological change. To complement GRACE data for complete-spectrum mass transport monitoring, geocenter motion needs to be measured accurately. However, current methods of geodetic translational approach and global inversions of various combinations of geodetic deformation, simulated ocean bottom pressure, and GRACE data contain substantial biases and systematic errors. Here, we demonstrate a new and more reliable unified approach to geocenter motion determination using a recently formed satellite laser ranging based geocentric displacement time series of an expanded geodetic network of all four space geodetic techniques and GRACE gravity data. The unified approach exploits both translational and deformational signatures of the displacement data, while the addition of GRACE's near global coverage significantly reduces biases found in the translational approach and spectral aliasing errors in the inversion.

  3. A state-based approach to trend recognition and failure prediction for the Space Station Freedom

    NASA Technical Reports Server (NTRS)

    Nelson, Kyle S.; Hadden, George D.

    1992-01-01

    A state-based reasoning approach to trend recognition and failure prediction for the Altitude Determination, and Control System (ADCS) of the Space Station Freedom (SSF) is described. The problem domain is characterized by features (e.g., trends and impending failures) that develop over a variety of time spans, anywhere from several minutes to several years. Our state-based reasoning approach, coupled with intelligent data screening, allows features to be tracked as they develop in a time-dependent manner. That is, each state machine has the ability to encode a time frame for the feature it detects. As features are detected, they are recorded and can be used as input to other state machines, creating a hierarchical feature recognition scheme. Furthermore, each machine can operate independently of the others, allowing simultaneous tracking of features. State-based reasoning was implemented in the trend recognition and the prognostic modules of a prototype Space Station Freedom Maintenance and Diagnostic System (SSFMDS) developed at Honeywell's Systems and Research Center.

  4. An automatic approach and grip method of micro-particle in 3D space

    NASA Astrophysics Data System (ADS)

    Zhang, Juan; Wu, Wenrong; Bi, Lie

    2017-03-01

    Micro-particle is hard to be observed as small scale and hard to be gripped as micro-force from substrate, an automatic approach and grip method of micro-particle in the guide of microscopic vision systems is proposed in the paper to grip micro-particle. First, the micro-gripper driven by electrostatic force is introduced and forces in gripping process are analyzed. Second, a micro-assembly robot composed of two microscopic vision systems is established to monitor micro-operation process and to operate micro-particle. Image features of micro-particle and micro-gripper end-effector are extracted by image feature extraction method to calculate relative position of micro-particle and micro-gripper in image space. Last, a movement control strategy in 3D space based on image Jacobian matrix is studied to control micro-gripper approach and align with micro-particle. Experimental results verified the effectiveness of proposed methods.

  5. An integrated and modular digital modeling approach for the space station electrical power system development

    NASA Technical Reports Server (NTRS)

    Gombos, Frank J.; Dravid, Narayan

    1988-01-01

    An electrical power system for the Space Station was designed, developed and built. This system provides for electrical power generation, conditioning, storage, and distribution. The initial configuration uses photovoltaic power generation. The power system control is based on a hierarchical architecture to support the requirements of automation. In the preliminary design and technology development phase of the program, various modeling techniques and software tools were evaluated for the purpose of meeting the Space Station power system modeling requirements. Rocketdyne and LeRC jointly selected the EASY5 simulation software, developed by Boeing Computer Services, as a system level modeling tool. The application of the selected analytical modeling approach to represent the entire power system is described. Typical results of model predictions are also summarized. The equipment modeled includes solar arrays, dc to ac converters, resonant inverters, battery storage system, alternator, transmission line, switch gear, and system level microprocessor controls. During the advanced development phase of this program, several models were developed using this approach.

  6. An integrated and modular digital modeling approach for the Space Station electrical power system development

    NASA Technical Reports Server (NTRS)

    Gombos, Frank J.; Dravid, Narayan

    1988-01-01

    An electrical power system for the Space Station was designed, developed and built. This system provides for electrical power generation, conditioning, storage, and distribution. The initial configuration uses photovoltaic power generation. The power system control is based on a hierarchical architecture to support the requirements of automation. In the preliminary design and technology development phase of the program, various modeling techniques and software tools were evaluated for the purpose of meeting the Space Station power system modeling requirements. Rocketdyne and LeRC jointly selected the EASY5 simulation software, developed by Boeing Computer Services, as a system level modeling tool. The application of the selected analytical modeling approach to represent the entire power system is described. Typical results of model predictions are also summarized. The equipment modeled includes solar arrays, dc to ac converters, resonant inverters, battery storage system, alternator, transmission line, switch gear, and system level microprocessor controls. During the advanced development phase of this program, several models were developed using this approach.

  7. Evaluation of a Tool for Airborne-Managed In-Trail Approach Spacing

    NASA Technical Reports Server (NTRS)

    Oseguera-Lohr, Rosa M.; Lohr, Gary W.; Abbott, Terence S.; Nadler, Eric D.; Eischeid, Todd

    2005-01-01

    The Advanced Terminal Area Approach Spacing (ATAAS) tool uses Automatic Dependent Surveillance-Broadcast aircraft state data to compute a speed command for an ATAAS-equipped aircraft to follow and obtain a required time interval behind another aircraft. The ATAAS tool and candidate operational procedures were tested in a high-fidelity, full mission simulator with active airline subject pilots flying an arrival scenario to obtain pilot perceptions of acceptability and workload for the concept. The aircraft consistently achieved the target spacing interval within 1 s when the ATAAS speed guidance was autothrottle-coupled and a slightly greater (4 - 5 s) but consistent interval with pilot-controlled speed changes. The subject pilots rated the ATAAS workload as similar to one with standard procedures for a nominal Instrument Landing System (ILS) approach. They also rated highly various procedural aspects (including amount of head-down time required). Eyetracker data showed only slight changes in instrument scan patterns for ATAAS versus standard ILS procedures.

  8. A real space auxiliary field approach to the BCS-BEC crossover

    NASA Astrophysics Data System (ADS)

    Tarat, Sabyasachi; Majumdar, Pinaki

    2015-03-01

    The BCS to BEC crossover in attractive Fermi systems is a prototype of weak to strong coupling evolution in many body physics. While extensive numerical results are available, and several approximate methods have been developed, most of these schemes are unsuccessful in the presence of spatial inhomogeneity. Such situations call for a real space approach that can handle large spatial scales and retain the crucial thermal fluctuations. With this in mind we present comprehensive results of a real space auxiliary field approach to the BCS to BEC crossover in the attractive Hubbard model in two dimensions. The scheme reproduces the Hartree-Fock-Bogoliubov ground state, and leads to a T c scale that agrees with quantum Monte Carlo estimates to within a few percent. We provide results on the T c , amplitude and phase fluctuations, density of states, and the momentum resolved spectral function, over the entire interaction and temperature window. We suggest how the method generalises successfully to the presence of disorder, trapping, and population imbalance.

  9. Mentoring SFRM: A New Approach to International Space Station Flight Controller Training

    NASA Technical Reports Server (NTRS)

    Huning, Therese; Barshi, Immanuel; Schmidt, Lacey

    2008-01-01

    The Mission Operations Directorate (MOD) of the Johnson Space Center is responsible for providing continuous operations support for the International Space Station (ISS). Operations support requires flight controllers who are skilled in team performance as well as the technical operations of the ISS. Space Flight Resource Management (SFRM), a NASA adapted variant of Crew Resource Management (CRM), is the competency model used in the MOD. ISS flight controller certification has evolved to include a balanced focus on development of SFRM and technical expertise. The latest challenge the MOD faces is how to certify an ISS flight controller (operator) to a basic level of effectiveness in 1 year. SFRM training uses a two-pronged approach to expediting operator certification: 1) imbed SFRM skills training into all operator technical training and 2) use senior flight controllers as mentors. This paper focuses on how the MOD uses senior flight controllers as mentors to train SFRM skills. Methods: A mentor works with an operator throughout the training flow. Inserted into the training flow are guided-discussion sessions and on-the-job observation opportunities focusing on specific SFRM skills, including: situational leadership, conflict management, stress management, cross-cultural awareness, self care and team care while on-console, communication, workload management, and situation awareness. The mentor and operator discuss the science and art behind the skills, cultural effects on skills applications, recognition of good and bad skills applications, recognition of how skills application changes subtly in different situations, and individual goals and techniques for improving skills. Discussion: This mentoring program provides an additional means of transferring SFRM knowledge compared to traditional CRM training programs. Our future endeavors in training SFRM skills (as well as other organization s) may benefit from adding team performance skills mentoring. This paper

  10. A metamodeling approach for studying ignition target robustness in a highly dimensional parameter space

    SciTech Connect

    Giorla, Jean; Masson, Annie; Poggi, Francoise; Quach, Robert; Seytor, Patricia; Garnier, Josselin

    2009-03-15

    Inertial confinement fusion targets must be carefully designed to ignite their central hot spots and burn. Changes in the optimal implosion could reduce the fusion energy or even prevent ignition. Since there are unavoidable uncertainties due to technological defects and not perfect reproducibility from shot to shot, the fusion energy will remain uncertain. The degree with which a target can tolerate larger specifications than specified, and the probability with which a particular yield is exceeded, are possible measures of the robustness of that design. This robustness must be assessed in a very high-dimensional parameter space whose variables include every characteristics of the given target and of the associated laser pulse shape, using high-fidelity simulations. Therefore, these studies would remain computationally very intensive. In this paper we propose an approach which consist first of constructing an accurate metamodel of the yield on the whole parameter space with a reasonable data set of simulations. Then the robustness is very quickly assessed for any set of specifications with this surrogate. The yield is approximated by a neural network, and an iterative method adds new points in the data set by means of D-optimal experimental designs. The robustness study of the baseline Laser Megajoule target against one-dimensional defects illustrates this approach. A set of 2000 simulations is sufficient to metamodel the fusion energy on a large 22-dimensional parameter space around the nominal point. Furthermore, a metamodel of the robustness margin against all specifications has been obtained, providing guidance for target fabrication research and development.

  11. Metric-space approach to potentials and its relevance to density-functional theory

    NASA Astrophysics Data System (ADS)

    Sharp, P. M.; D'Amico, I.

    2016-12-01

    External potentials play a crucial role in modeling quantum systems, since, for a given interparticle interaction, they define the system Hamiltonian. We use the metric-space approach to quantum mechanics to derive, from the energy conservation law, two natural metrics for potentials. We show that these metrics are well defined for physical potentials, regardless of whether the system is in an eigenstate or if the potential is bounded. In addition, we discuss the gauge freedom of potentials and how to ensure that the metrics preserve physical relevance. Our metrics for potentials, together with the metrics for wave functions and densities from I. D'Amico et al. [Phys. Rev. Lett. 106, 050401 (2011), 10.1103/PhysRevLett.106.050401] paves the way for a comprehensive study of the two fundamental theorems of density-functional theory. We explore these by analyzing two many-body systems for which the related exact Kohn-Sham systems can be derived. First we consider the information provided by each of the metrics, and we find that the density metric performs best in distinguishing two many-body systems. Next we study for the systems at hand the one-to-one relationships among potentials, ground-state wave functions, and ground-state densities defined by the Hohenberg-Kohn theorem as relationships in metric spaces. We find that, in metric space, these relationships are monotonic and incorporate regions of linearity, at least for the systems considered. Finally, we use the metrics for wave functions and potentials in order to assess quantitatively how close the many-body and Kohn-Sham systems are: We show that, at least for the systems analyzed, both metrics provide a consistent picture, and for large regions of the parameter space the error in approximating the many-body wave function with the Kohn-Sham wave function lies under a threshold of 10%.

  12. Task-space separation principle: a force-field approach to motion planning for redundant manipulators.

    PubMed

    Tommasino, Paolo; Campolo, Domenico

    2017-02-03

    In this work, we address human-like motor planning in redundant manipulators. Specifically, we want to capture postural synergies such as Donders' law, experimentally observed in humans during kinematically redundant tasks, and infer a minimal set of parameters to implement similar postural synergies in a kinematic model. For the model itself, although the focus of this paper is to solve redundancy by implementing postural strategies derived from experimental data, we also want to ensure that such postural control strategies do not interfere with other possible forms of motion control (in the task-space), i.e. solving the posture/movement problem. The redundancy problem is framed as a constrained optimization problem, traditionally solved via the method of Lagrange multipliers. The posture/movement problem can be tackled via the separation principle which, derived from experimental evidence, posits that the brain processes static torques (i.e. posture-dependent, such as gravitational torques) separately from dynamic torques (i.e. velocity-dependent). The separation principle has traditionally been applied at a joint torque level. Our main contribution is to apply the separation principle to Lagrange multipliers, which act as task-space force fields, leading to a task-space separation principle. In this way, we can separate postural control (implementing Donders' law) from various types of tasks-space movement planners. As an example, the proposed framework is applied to the (redundant) task of pointing with the human wrist. Nonlinear inverse optimization (NIO) is used to fit the model parameters and to capture motor strategies displayed by six human subjects during pointing tasks. The novelty of our NIO approach is that (i) the fitted motor strategy, rather than raw data, is used to filter and down-sample human behaviours; (ii) our framework is used to efficiently simulate model behaviour iteratively, until it converges towards the experimental human strategies.

  13. Extending peripersonal space representation without tool-use: evidence from a combined behavioral-computational approach

    PubMed Central

    Serino, Andrea; Canzoneri, Elisa; Marzolla, Marilena; di Pellegrino, Giuseppe; Magosso, Elisa

    2015-01-01

    Stimuli from different sensory modalities occurring on or close to the body are integrated in a multisensory representation of the space surrounding the body, i.e., peripersonal space (PPS). PPS dynamically modifies depending on experience, e.g., it extends after using a tool to reach far objects. However, the neural mechanism underlying PPS plasticity after tool use is largely unknown. Here we use a combined computational-behavioral approach to propose and test a possible mechanism accounting for PPS extension. We first present a neural network model simulating audio-tactile representation in the PPS around one hand. Simulation experiments showed that our model reproduced the main property of PPS neurons, i.e., selective multisensory response for stimuli occurring close to the hand. We used the neural network model to simulate the effects of a tool-use training. In terms of sensory inputs, tool use was conceptualized as a concurrent tactile stimulation from the hand, due to holding the tool, and an auditory stimulation from the far space, due to tool-mediated action. Results showed that after exposure to those inputs, PPS neurons responded also to multisensory stimuli far from the hand. The model thus suggests that synchronous pairing of tactile hand stimulation and auditory stimulation from the far space is sufficient to extend PPS, such as after tool-use. Such prediction was confirmed by a behavioral experiment, where we used an audio-tactile interaction paradigm to measure the boundaries of PPS representation. We found that PPS extended after synchronous tactile-hand stimulation and auditory-far stimulation in a group of healthy volunteers. Control experiments both in simulation and behavioral settings showed that the same amount of tactile and auditory inputs administered out of synchrony did not change PPS representation. We conclude by proposing a simple, biological-plausible model to explain plasticity in PPS representation after tool-use, which is

  14. Extending peripersonal space representation without tool-use: evidence from a combined behavioral-computational approach.

    PubMed

    Serino, Andrea; Canzoneri, Elisa; Marzolla, Marilena; di Pellegrino, Giuseppe; Magosso, Elisa

    2015-01-01

    Stimuli from different sensory modalities occurring on or close to the body are integrated in a multisensory representation of the space surrounding the body, i.e., peripersonal space (PPS). PPS dynamically modifies depending on experience, e.g., it extends after using a tool to reach far objects. However, the neural mechanism underlying PPS plasticity after tool use is largely unknown. Here we use a combined computational-behavioral approach to propose and test a possible mechanism accounting for PPS extension. We first present a neural network model simulating audio-tactile representation in the PPS around one hand. Simulation experiments showed that our model reproduced the main property of PPS neurons, i.e., selective multisensory response for stimuli occurring close to the hand. We used the neural network model to simulate the effects of a tool-use training. In terms of sensory inputs, tool use was conceptualized as a concurrent tactile stimulation from the hand, due to holding the tool, and an auditory stimulation from the far space, due to tool-mediated action. Results showed that after exposure to those inputs, PPS neurons responded also to multisensory stimuli far from the hand. The model thus suggests that synchronous pairing of tactile hand stimulation and auditory stimulation from the far space is sufficient to extend PPS, such as after tool-use. Such prediction was confirmed by a behavioral experiment, where we used an audio-tactile interaction paradigm to measure the boundaries of PPS representation. We found that PPS extended after synchronous tactile-hand stimulation and auditory-far stimulation in a group of healthy volunteers. Control experiments both in simulation and behavioral settings showed that the same amount of tactile and auditory inputs administered out of synchrony did not change PPS representation. We conclude by proposing a simple, biological-plausible model to explain plasticity in PPS representation after tool-use, which is

  15. An Alternative and Validated Injection Method for Accessing the Subretinal Space via a Transcleral Posterior Approach.

    PubMed

    Parikh, Sachin; Le, Andrew; Davenport, Julian; Gorin, Michael B; Nusinowitz, Steven; Matynia, Anna

    2016-12-07

    Subretinal injections have been successfully used in both humans and rodents to deliver therapeutic interventions of proteins, viral agents, and cells to the interphotoreceptor/subretinal compartment that has direct exposure to photoreceptors and the retinal pigment epithelium (RPE). Subretinal injections of plasminogen as well as recent preclinical and clinical trials have demonstrated safety and/or efficacy of delivering viral vectors and stem cells to individuals with advanced retinal disease. Mouse models of retinal disease, particularly hereditary retinal dystrophies, are essential for testing these therapies. The most common injection procedure in rodents is to use small transcorneal or transcleral incisions with an anterior approach to the retina. With this approach, the injection needle penetrates the neurosensory retina disrupting the underlying RPE and on insertion can easily nick the lens, causing lens opacification and impairment of noninvasive imaging. Accessing the subretinal space via a transcleral, posterior approach avoids these problems: the needle crosses the sclera approximately 0.5 mm from the optic nerve, without retinal penetration and avoids disrupting the vitreous. Collateral damage is limited to that associated with the focal sclerotomy and the effects of a transient, serous retinal detachment. The simplicity of the method minimizes ocular injury, ensures rapid retinal reattachment and recovery, and has a low failure rate. The minimal damage to the retina and RPE allows for clear assessment of the efficacy and direct effects of the therapeutic agents themselves. This manuscript describes a novel subretinal injection technique that can be used to target viral vectors, pharmacological agents, stem cells or induced pluripotent stem (iPS) cells to the subretinal space in mice with high efficacy, minimal damage, and fast recovery.

  16. Gradual approach to realize lightning monitoring from space by means of VHF observations

    NASA Astrophysics Data System (ADS)

    Morimoto, T.; Kikuchi, H.; Ushio, T.; Kawasaki, Z.

    2010-12-01

    Lightning Research Group of Osaka University (LRG-OU) has been developing VHF Broadband Digital Interferometer (DITF) to image precise lightning channels and monitor lightning activity widely. DITF is an equipment to locate sources of impulsive VHF radiation based on the digital interferometric technique. In other words, DITF is a system to visualize lightning channel by VHF radio observations. The feature of DITF is its ultra-wide bandwidth (from 25 MHz to 100 MHz) and implicit redundancy for the direction-of-arrival (DOA) estimation. LRG-OU considers an application of the broadband DITF to the spaceborne measurement system because its fairly high resolutions and the compactness of the system are great advantages to be the space-borne one. To realize space-borne DITF, LRG-OU intends to have gradual approach for the development. As their first step, a VHF sensor on Maido-1 satellite is proposed to examine the feasibility of receiving VHF lightning impulses in space. Maido-1 is a small satellite manufactured by factory members of SOHLA (Space Oriented Higashi-Osaka Leading Associate). The SOHLA project represents a technology transfer program to expand the range of the space development community in Japan. The objective is to get SMEs (Small and Medium sized manufacturing Enterprises) involved in small space projects and new space technologies. Under the cooperative agreement, JAXA (Japan Aerospace Exploration Agency) intends to contribute to socio-economic development by returning its R&D results to the society, and SOHLA tries to revitalize the local economy through the commercialization of versatile small satellites. Maido-1 is in sun-synchronous polar orbit at an altitude of 660 kilometers. The VHF sensor comprises a single pair of an antenna, a band-pass filter with a pass band of 30-100MHz, an amplifier with a gain of 45dB and an analog-to-digital converter with a sampling rate of 200MS/s and 8-bit resolution to record broadband VHF signals. The 100 waveforms

  17. Abstraction Augmented Markov Models.

    PubMed

    Caragea, Cornelia; Silvescu, Adrian; Caragea, Doina; Honavar, Vasant

    2010-12-13

    High accuracy sequence classification often requires the use of higher order Markov models (MMs). However, the number of MM parameters increases exponentially with the range of direct dependencies between sequence elements, thereby increasing the risk of overfitting when the data set is limited in size. We present abstraction augmented Markov models (AAMMs) that effectively reduce the number of numeric parameters of k(th) order MMs by successively grouping strings of length k (i.e., k-grams) into abstraction hierarchies. We evaluate AAMMs on three protein subcellular localization prediction tasks. The results of our experiments show that abstraction makes it possible to construct predictive models that use significantly smaller number of features (by one to three orders of magnitude) as compared to MMs. AAMMs are competitive with and, in some cases, significantly outperform MMs. Moreover, the results show that AAMMs often perform significantly better than variable order Markov models, such as decomposed context tree weighting, prediction by partial match, and probabilistic suffix trees.

  18. Augmenting Probabilistic Risk Assesment with Malevolent Initiators

    SciTech Connect

    Curtis Smith; David Schwieder

    2011-11-01

    As commonly practiced, the use of probabilistic risk assessment (PRA) in nuclear power plants only considers accident initiators such as natural hazards, equipment failures, and human error. Malevolent initiators are ignored in PRA, but are considered the domain of physical security, which uses vulnerability assessment based on an officially specified threat (design basis threat). This paper explores the implications of augmenting and extending existing PRA models by considering new and modified scenarios resulting from malevolent initiators. Teaming the augmented PRA models with conventional vulnerability assessments can cost-effectively enhance security of a nuclear power plant. This methodology is useful for operating plants, as well as in the design of new plants. For the methodology, we have proposed an approach that builds on and extends the practice of PRA for nuclear power plants for security-related issues. Rather than only considering 'random' failures, we demonstrated a framework that is able to represent and model malevolent initiating events and associated plant impacts.

  19. On the Development of an Integrated Hydrologic, Hydraulic, and Inverse Modeling Approach for Estimating Discharges and Water Depths for Ungauged Rivers from Space

    NASA Astrophysics Data System (ADS)

    LIU, G.; Schwartz, F. W.; Tseng, K. H.; Shum, C. K.

    2015-12-01

    The characterization of hydrologic processes in large river basins has been benefitting from a variety of remotely sensed data. These are useful in augmenting the conventional ground-surface and gage data that have long been available, or in providing what is often the only available information for ungauged river basins. The goal of this study is to demonstrate an innovative modeling approach that uses satellite data to enhance understanding of rivers, particularly ungauged rivers. The paper describes a prototype system - SWAT-XG, coupling SWAT and XSECT models in a Genetic Algorithm framework, for estimating discharge and depth for ungauged rivers from space. SWAT-XG was rigorously tested in the Red River of the North basin by validating discharge and depth products from 2006 to 2010 using in-situ observations across the basin. Results show that SWAT-XG, calibrated against remotely sensed data alone (i.e., water levels from ENVISAT altimetry and water extents from LANDSAT), was able to provide estimates of daily and monthly river discharge with mean R2 values of 0.822 and 0.924, respectively, against data from three gaging stations on the main stem. SWAT-XG also simulated the discharges of smaller tributaries well (yielding a mean R2 of 0.809 over seven gaging stations), suggesting that the SWAT-XG is a powerful estimator of river discharge at a basin scale. Results also show that the SWAT-XG simulated river's vertical dynamics quite well, providing water-depth estimates with an average R2 of 0.831. We conclude that the SWAT-XG advances the ability to estimate discharge and water depth from space for ungauged rivers. SWAT-XG would help to solve global big data problem for river studies and offer potential for understanding and quantifying the global water cycles. This study also implies that in-situ discharge data may not be necessary for a successful hydrologic model calibration.

  20. Distribution function approach to redshift space distortions. Part III: halos and galaxies

    SciTech Connect

    Okumura, Teppei; Seljak, Uroš; Desjacques, Vincent E-mail: useljak@berkeley.edu

    2012-11-01

    It was recently shown that the power spectrum in redshift space can be written as a sum of cross-power spectra between number weighted velocity moments, of which the lowest are density and momentum density. We investigate numerically the properties of these power spectra for simulated galaxies and dark matter halos and compare them to the dark matter power spectra, generalizing the concept of the bias in density-density power spectra. Because all of the quantities are number weighted this approach is well defined even for sparse systems such as massive halos. This contrasts to the previous approaches to RSD where velocity correlations have been explored, but velocity field is a poorly defined concept for sparse systems. We find that the number density weighting leads to a strong scale dependence of the bias terms for momentum density auto-correlation and cross-correlation with density. This trend becomes more significant for the more biased halos and leads to an enhancement of RSD power relative to the linear theory. Fingers-of-god effects, which in this formalism come from the correlations of the higher order moments beyond the momentum density, lead to smoothing of the power spectrum and can reduce this enhancement of power from the scale dependent bias, but are relatively small for halos with no small scale velocity dispersion. In comparison, for a more realistic galaxy sample with satellites the small scale velocity dispersion generated by satellite motions inside the halos leads to a larger power suppression on small scales, but this depends on the satellite fraction and on the details of how the satellites are distributed inside the halo. We investigate several statistics such as the two-dimensional power spectrum P(k,μ), where μ is the angle between the Fourier mode and line of sight, its multipole moments, its powers of μ{sup 2}, and configuration space statistics. Overall we find that the nonlinear effects in realistic galaxy samples such as luminous

  1. An approach to ground based space surveillance of geostationary on-orbit servicing operations

    NASA Astrophysics Data System (ADS)

    Scott, Robert (Lauchie); Ellery, Alex

    2015-07-01

    On Orbit Servicing (OOS) is a class of dual-use robotic space missions that could potentially extend the life of orbiting satellites by fuel replenishment, repair, inspection, orbital maintenance or satellite repurposing, and possibly reduce the rate of space debris generation. OOS performed in geostationary orbit poses a unique challenge for the optical space surveillance community. Both satellites would be performing proximity operations in tight formation flight with separations less than 500 m making atmospheric seeing (turbulence) a challenge to resolving a geostationary satellite pair when viewed from the ground. The two objects would appear merged in an image as the resolving power of the telescope and detector, coupled with atmospheric seeing, limits the ability to resolve the two objects. This poses an issue for obtaining orbital data for conjunction flight safety or, in matters pertaining to space security, inferring the intent and trajectory of an unexpected object perched very close to one's satellite asset on orbit. In order to overcome this problem speckle interferometry using a cross spectrum approach is examined as a means to optically resolve the client and servicer's relative positions to enable a means to perform relative orbit determination of the two spacecraft. This paper explores cases where client and servicing satellites are in unforced relative motion flight and examines the observability of the objects. Tools are described that exploit cross-spectrum speckle interferometry to (1) determine the presence of a secondary in the vicinity of the client satellite and (2) estimate the servicing satellite's motion relative to the client. Experimental observations performed with the Mont Mégantic 1.6 m telescope on co-located geostationary satellites (acting as OOS proxy objects) are described. Apparent angular separations between Anik G1 and Anik F1R from 5 to 1 arcsec were observed as the two satellites appeared to graze one another. Data

  2. Coherent optical system of modular imaging collectors (COSMIC) - An approach for a large aperture high angular resolution telescope in space

    NASA Technical Reports Server (NTRS)

    Davis, B.; Hunt, G.; Nein, M.; Korsch, D.

    1984-01-01

    Very high angular resolution can be achieved in UV/optical astronomy through interferometers in space. A concept analysis of COSMIC, which may be placed into orbit by the Space Shuttle in the late 1990's, is discussed. The photon-collecting area is three times larger than that of Space Telescope (ST), and exceeds its resolution by approximately an order of magnitude. Several alternative configurations are presented to scope the extent of design approaches which may be achievable within the transportation capability of the Space Shuttle.

  3. Augmented reality in surgical procedures

    NASA Astrophysics Data System (ADS)

    Samset, E.; Schmalstieg, D.; Vander Sloten, J.; Freudenthal, A.; Declerck, J.; Casciaro, S.; Rideng, Ø.; Gersak, B.

    2008-02-01

    Minimally invasive therapy (MIT) is one of the most important trends in modern medicine. It includes a wide range of therapies in videoscopic surgery and interventional radiology and is performed through small incisions. It reduces hospital stay-time by allowing faster recovery and offers substantially improved cost-effectiveness for the hospital and the society. However, the introduction of MIT has also led to new problems. The manipulation of structures within the body through small incisions reduces dexterity and tactile feedback. It requires a different approach than conventional surgical procedures, since eye-hand co-ordination is not based on direct vision, but more predominantly on image guidance via endoscopes or radiological imaging modalities. ARIS*ER is a multidisciplinary consortium developing a new generation of decision support tools for MIT by augmenting visual and sensorial feedback. We will present tools based on novel concepts in visualization, robotics and haptics providing tailored solutions for a range of clinical applications. Examples from radio-frequency ablation of liver-tumors, laparoscopic liver surgery and minimally invasive cardiac surgery will be presented. Demonstrators were developed with the aim to provide a seamless workflow for the clinical user conducting image-guided therapy.

  4. Augmented reality visualization for thoracoscopic spine surgery

    NASA Astrophysics Data System (ADS)

    Sauer, Frank; Vogt, Sebastian; Khamene, Ali; Heining, Sandro; Euler, Ekkehard; Schneberger, Marc; Zuerl, Konrad; Mutschler, Wolf

    2006-03-01

    We are developing an augmented reality (AR) image guidance system in which information derived from medical images is overlaid onto a video view of the patient. The centerpiece of the system is a head-mounted display custom fitted with two miniature color video cameras that capture the stereo view of the scene. Medical graphics is overlaid onto the video view and appears firmly anchored in the scene, without perceivable time lag or jitter. We have been testing the system for different clinical applications. In this paper we discuss minimally invasive thoracoscopic spine surgery as a promising new orthopedic application. In the standard approach, the thoracoscope - a rigid endoscope - provides visual feedback for the minimally invasive procedure of removing a damaged disc and fusing the two neighboring vertebrae. The navigation challenges are twofold. From a global perspective, the correct vertebrae on the spine have to be located with the inserted instruments. From a local perspective, the actual spine procedure has to be performed precisely. Visual feedback from the thoracoscope provides only limited support for both of these tasks. In the augmented reality approach, we give the surgeon additional anatomical context for the navigation. Before the surgery, we derive a model of the patient's anatomy from a CT scan, and during surgery we track the location of the surgical instruments in relation to patient and model. With this information, we can help the surgeon in both the global and local navigation, providing a global map and 3D information beyond the local 2D view of the thoracoscope. Augmented reality visualization is a particularly intuitive method of displaying this information to the surgeon. To adapt our augmented reality system to this application, we had to add an external optical tracking system, which works now in combination with our head-mounted tracking camera. The surgeon's feedback to the initial phantom experiments is very positive.

  5. Augmented Reality Comes to Physics

    NASA Astrophysics Data System (ADS)

    Buesing, Mark; Cook, Michael

    2013-04-01

    Augmented reality (AR) is a technology used on computing devices where processor-generated graphics are rendered over real objects to enhance the sensory experience in real time. In other words, what you are really seeing is augmented by the computer. Many AR games already exist for systems such as Kinect and Nintendo 3DS and mobile apps, such as Tagwhat and Star Chart (a must for astronomy class). The yellow line marking first downs in a televised football game2 and the enhanced puck that makes televised hockey easier to follow3 both use augmented reality to do the job.

  6. Infinite-mode squeezed coherent states and non-equilibrium statistical mechanics (phase-space-picture approach)

    NASA Technical Reports Server (NTRS)

    Yeh, Leehwa

    1993-01-01

    The phase-space-picture approach to quantum non-equilibrium statistical mechanics via the characteristic function of infinite-mode squeezed coherent states is introduced. We use quantum Brownian motion as an example to show how this approach provides an interesting geometrical interpretation of quantum non-equilibrium phenomena.

  7. High-Payoff Space Transportation Design Approach with a Technology Integration Strategy

    NASA Technical Reports Server (NTRS)

    McCleskey, C. M.; Rhodes, R. E.; Chen, T.; Robinson, J.

    2011-01-01

    A general architectural design sequence is described to create a highly efficient, operable, and supportable design that achieves an affordable, repeatable, and sustainable transportation function. The paper covers the following aspects of this approach in more detail: (1) vehicle architectural concept considerations (including important strategies for greater reusability); (2) vehicle element propulsion system packaging considerations; (3) vehicle element functional definition; (4) external ground servicing and access considerations; and, (5) simplified guidance, navigation, flight control and avionics communications considerations. Additionally, a technology integration strategy is forwarded that includes: (a) ground and flight test prior to production commitments; (b) parallel stage propellant storage, such as concentric-nested tanks; (c) high thrust, LOX-rich, LOX-cooled first stage earth-to-orbit main engine; (d) non-toxic, day-of-launch-loaded propellants for upper stages and in-space propulsion; (e) electric propulsion and aero stage control.

  8. Truncated conformal space approach for 2D Landau–Ginzburg theories

    DOE PAGES

    Coser, A.; Beria, M.; Brandino, G. P.; ...

    2014-12-10

    In this study, We examine the spectrum of Landau–Ginzburg theories in 1 + 1 dimensions using the truncated conformal space approach employing a compactified boson. We study these theories both in their broken and unbroken phases. We first demonstrate that we can reproduce the expected spectrum of a Φ² theory (i.e. a free massive boson) in this framework. We then turn to Φ⁴ in its unbroken phase and compare our numerical results with the predictions of two-loop perturbation theory, finding excellent agreement. We then analyze the broken phase of Φ⁴ where kink excitations together with their bound states are present.more » We confirm the semiclassical predictions for this model on the number of stable kink-antikink bound states. We also test the semiclassics in the double well phase of Φ⁶ Landau-Ginzburg theory, again finding agreement.« less

  9. Sonic booms of space shuttles approaching Edwards Air Force Base, 1988-1993.

    PubMed

    Young, Robert W

    2002-01-01

    From 1988 to 1993 13 sonic booms of space shuttles approaching Edwards Air Force Base were measured at a site 10 miles west of EAFB, with one to seven different sound level meters for each measurement. Results from five of these measurements are here presented. Maximum differences in measured levels between instruments for the same flight varied from 0 to 6 dB depending on the measurement descriptor and model of sound level meter. The average difference between predicted and measured values was 0.7+/-1.5 dB. For sound level meters with adequate bandwidth the waveforms measured varied from a near perfect N-wave to a more distorted form reflecting the influence of the varying condition of the atmosphere during propagation to the ground.

  10. A computational approach for hypersonic nonequilibrium radiation utilizing space partition algorithm and Gauss quadrature

    NASA Astrophysics Data System (ADS)

    Shang, J. S.; Andrienko, D. A.; Huang, P. G.; Surzhikov, S. T.

    2014-06-01

    An efficient computational capability for nonequilibrium radiation simulation via the ray tracing technique has been accomplished. The radiative rate equation is iteratively coupled with the aerodynamic conservation laws including nonequilibrium chemical and chemical-physical kinetic models. The spectral properties along tracing rays are determined by a space partition algorithm of the nearest neighbor search process, and the numerical accuracy is further enhanced by a local resolution refinement using the Gauss-Lobatto polynomial. The interdisciplinary governing equations are solved by an implicit delta formulation through the diminishing residual approach. The axisymmetric radiating flow fields over the reentry RAM-CII probe have been simulated and verified with flight data and previous solutions by traditional methods. A computational efficiency gain nearly forty times is realized over that of the existing simulation procedures.

  11. A computational approach for hypersonic nonequilibrium radiation utilizing space partition algorithm and Gauss quadrature

    SciTech Connect

    Shang, J.S.; Andrienko, D.A.; Huang, P.G.; Surzhikov, S.T.

    2014-06-01

    An efficient computational capability for nonequilibrium radiation simulation via the ray tracing technique has been accomplished. The radiative rate equation is iteratively coupled with the aerodynamic conservation laws including nonequilibrium chemical and chemical–physical kinetic models. The spectral properties along tracing rays are determined by a space partition algorithm of the nearest neighbor search process, and the numerical accuracy is further enhanced by a local resolution refinement using the Gauss–Lobatto polynomial. The interdisciplinary governing equations are solved by an implicit delta formulation through the diminishing residual approach. The axisymmetric radiating flow fields over the reentry RAM-CII probe have been simulated and verified with flight data and previous solutions by traditional methods. A computational efficiency gain nearly forty times is realized over that of the existing simulation procedures.

  12. Truncated conformal space approach for 2D Landau–Ginzburg theories

    SciTech Connect

    Coser, A.; Beria, M.; Brandino, G. P.; Konik, R. M.; Mussardo, G.

    2014-12-10

    In this study, We examine the spectrum of Landau–Ginzburg theories in 1 + 1 dimensions using the truncated conformal space approach employing a compactified boson. We study these theories both in their broken and unbroken phases. We first demonstrate that we can reproduce the expected spectrum of a Φ² theory (i.e. a free massive boson) in this framework. We then turn to Φ⁴ in its unbroken phase and compare our numerical results with the predictions of two-loop perturbation theory, finding excellent agreement. We then analyze the broken phase of Φ⁴ where kink excitations together with their bound states are present. We confirm the semiclassical predictions for this model on the number of stable kink-antikink bound states. We also test the semiclassics in the double well phase of Φ⁶ Landau-Ginzburg theory, again finding agreement.

  13. Space Shuttle Stiffener Ring Foam Failure, a Non-Conventional Approach

    NASA Technical Reports Server (NTRS)

    Howard, Philip M.

    2007-01-01

    The Space Shuttle makes use of the excellent properties of rigid polyurethane foam for cryogenic tank insulation and as structural protection on the solid rocket boosters. When foam applications debond, classical methods of analysis do not always provide root cause of the failure of the foam. Realizing that foam is the ideal media to document and preserve its own mode of failure, thin sectioning was seen as a logical approach for foam failure analysis. Thin sectioning in two directions, both horizontal and vertical to the application, was chosen to observe the three dimensional morphology of the foam cells. The cell foam morphology provided a much greater understanding of the failure modes than previously achieved.

  14. Legacy Making Through Illness Blogs: Online Spaces for Young Adults Approaching the End-of-Life

    PubMed Central

    Adelstein, Katharine; Kavalieratos, Dio

    2015-01-01

    Little is known about young adults with cancer at the end-of-life, but life review and legacy making may be important modalities to process the emotions associated with anticipatory grief. The study analyzed the illness blogs of five young women (aged 25–39 years) at the end-of-life using a narrative approach. Key elements of legacy making and grief processing were explored. The women had varying experiences before their death, but uniform posthumous occurrences with the use of the blog for a space of grief for loved ones. The use of online blogs among adolescents and young adults with advanced cancer is an area of needed further study. PMID:26697270

  15. Application of a computationally efficient geostatistical approach to characterizing variably spaced water-table data

    SciTech Connect

    Quinn, J.J.

    1996-02-01

    Geostatistical analysis of hydraulic head data is useful in producing unbiased contour plots of head estimates and relative errors. However, at most sites being characterized, monitoring wells are generally present at different densities, with clusters of wells in some areas and few wells elsewhere. The problem that arises when kriging data at different densities is in achieving adequate resolution of the grid while maintaining computational efficiency and working within software limitations. For the site considered, 113 data points were available over a 14-mi{sup 2} study area, including 57 monitoring wells within an area of concern of 1.5 mi{sup 2}. Variogram analyses of the data indicate a linear model with a negligible nugget effect. The geostatistical package used in the study allows a maximum grid of 100 by 100 cells. Two-dimensional kriging was performed for the entire study area with a 500-ft grid spacing, while the smaller zone was modeled separately with a 100-ft spacing. In this manner, grid cells for the dense area and the sparse area remained small relative to the well separation distances, and the maximum dimensions of the program were not exceeded. The spatial head results for the detailed zone were then nested into the regional output by use of a graphical, object-oriented database that performed the contouring of the geostatistical output. This study benefitted from the two-scale approach and from very fine geostatistical grid spacings relative to typical data separation distances. The combining of the sparse, regional results with those from the finer-resolution area of concern yielded contours that honored the actual data at every measurement location. The method applied in this study can also be used to generate reproducible, unbiased representations of other types of spatial data.

  16. A multifractal approach to space-filling recovery for PET quantification

    SciTech Connect

    Willaime, Julien M. Y. Aboagye, Eric O.; Tsoumpas, Charalampos; Turkheimer, Federico E.

    2014-11-01

    Purpose: A new image-based methodology is developed for estimating the apparent space-filling properties of an object of interest in PET imaging without need for a robust segmentation step and used to recover accurate estimates of total lesion activity (TLA). Methods: A multifractal approach and the fractal dimension are proposed to recover the apparent space-filling index of a lesion (tumor volume, TV) embedded in nonzero background. A practical implementation is proposed, and the index is subsequently used with mean standardized uptake value (SUV {sub mean}) to correct TLA estimates obtained from approximate lesion contours. The methodology is illustrated on fractal and synthetic objects contaminated by partial volume effects (PVEs), validated on realistic {sup 18}F-fluorodeoxyglucose PET simulations and tested for its robustness using a clinical {sup 18}F-fluorothymidine PET test–retest dataset. Results: TLA estimates were stable for a range of resolutions typical in PET oncology (4–6 mm). By contrast, the space-filling index and intensity estimates were resolution dependent. TLA was generally recovered within 15% of ground truth on postfiltered PET images affected by PVEs. Volumes were recovered within 15% variability in the repeatability study. Results indicated that TLA is a more robust index than other traditional metrics such as SUV {sub mean} or TV measurements across imaging protocols. Conclusions: The fractal procedure reported here is proposed as a simple and effective computational alternative to existing methodologies which require the incorporation of image preprocessing steps (i.e., partial volume correction and automatic segmentation) prior to quantification.

  17. Optimization of the Ethanol Recycling Reflux Extraction Process for Saponins Using a Design Space Approach

    PubMed Central

    Gong, Xingchu; Zhang, Ying; Pan, Jianyang; Qu, Haibin

    2014-01-01

    A solvent recycling reflux extraction process for Panax notoginseng was optimized using a design space approach to improve the batch-to-batch consistency of the extract. Saponin yields, total saponin purity, and pigment yield were defined as the process critical quality attributes (CQAs). Ethanol content, extraction time, and the ratio of the recycling ethanol flow rate and initial solvent volume in the extraction tank (RES) were identified as the critical process parameters (CPPs) via quantitative risk assessment. Box-Behnken design experiments were performed. Quadratic models between CPPs and process CQAs were developed, with determination coefficients higher than 0.88. As the ethanol concentration decreases, saponin yields first increase and then decrease. A longer extraction time leads to higher yields of the ginsenosides Rb1 and Rd. The total saponin purity increases as the ethanol concentration increases. The pigment yield increases as the ethanol concentration decreases or extraction time increases. The design space was calculated using a Monte-Carlo simulation method with an acceptable probability of 0.90. Normal operation ranges to attain process CQA criteria with a probability of more than 0.914 are recommended as follows: ethanol content of 79–82%, extraction time of 6.1–7.1 h, and RES of 0.039–0.040 min−1. Most of the results of the verification experiments agreed well with the predictions. The verification experiment results showed that the selection of proper operating ethanol content, extraction time, and RES within the design space can ensure that the CQA criteria are met. PMID:25470598

  18. Optimization of the ethanol recycling reflux extraction process for saponins using a design space approach.

    PubMed

    Gong, Xingchu; Zhang, Ying; Pan, Jianyang; Qu, Haibin

    2014-01-01

    A solvent recycling reflux extraction process for Panax notoginseng was optimized using a design space approach to improve the batch-to-batch consistency of the extract. Saponin yields, total saponin purity, and pigment yield were defined as the process critical quality attributes (CQAs). Ethanol content, extraction time, and the ratio of the recycling ethanol flow rate and initial solvent volume in the extraction tank (RES) were identified as the critical process parameters (CPPs) via quantitative risk assessment. Box-Behnken design experiments were performed. Quadratic models between CPPs and process CQAs were developed, with determination coefficients higher than 0.88. As the ethanol concentration decreases, saponin yields first increase and then decrease. A longer extraction time leads to higher yields of the ginsenosides Rb1 and Rd. The total saponin purity increases as the ethanol concentration increases. The pigment yield increases as the ethanol concentration decreases or extraction time increases. The design space was calculated using a Monte-Carlo simulation method with an acceptable probability of 0.90. Normal operation ranges to attain process CQA criteria with a probability of more than 0.914 are recommended as follows: ethanol content of 79-82%, extraction time of 6.1-7.1 h, and RES of 0.039-0.040 min-1. Most of the results of the verification experiments agreed well with the predictions. The verification experiment results showed that the selection of proper operating ethanol content, extraction time, and RES within the design space can ensure that the CQA criteria are met.

  19. Quantum harmonic Brownian motion in a general environment: A modified phase-space approach

    SciTech Connect

    Yeh, L. |

    1993-06-23

    After extensive investigations over three decades, the linear-coupling model and its equivalents have become the standard microscopic models for quantum harmonic Brownian motion, in which a harmonically bound Brownian particle is coupled to a quantum dissipative heat bath of general type modeled by infinitely many harmonic oscillators. The dynamics of these models have been studied by many authors using the quantum Langevin equation, the path-integral approach, quasi-probability distribution functions (e.g., the Wigner function), etc. However, the quantum Langevin equation is only applicable to some special problems, while other approaches all involve complicated calculations due to the inevitable reduction (i.e., contraction) operation for ignoring/eliminating the degrees of freedom of the heat bath. In this dissertation, the author proposes an improved methodology via a modified phase-space approach which employs the characteristic function (the symplectic Fourier transform of the Wigner function) as the representative of the density operator. This representative is claimed to be the most natural one for performing the reduction, not only because of its simplicity but also because of its manifestation of geometric meaning. Accordingly, it is particularly convenient for studying the time evolution of the Brownian particle with an arbitrary initial state. The power of this characteristic function is illuminated through a detailed study of several physically interesting problems, including the environment-induced damping of quantum interference, the exact quantum Fokker-Planck equations, and the relaxation of non-factorizable initial states. All derivations and calculations axe shown to be much simplified in comparison with other approaches. In addition to dynamical problems, a novel derivation of the fluctuation-dissipation theorem which is valid for all quantum linear systems is presented.

  20. Augmenter of liver regeneration.

    PubMed

    Gandhi, Chandrashekhar R

    2012-07-09

    'Augmenter of liver regeneration' (ALR) (also known as hepatic stimulatory substance or hepatopoietin) was originally found to promote growth of hepatocytes in the regenerating or injured liver. ALR is expressed ubiquitously in all organs, and exclusively in hepatocytes in the liver. ALR, a survival factor for hepatocytes, exhibits significant homology with ERV1 (essential for respiration and viability) protein that is essential for the survival of the yeast, Saccharomyces cerevisiae. ALR comprises 198 to 205 amino acids (approximately 22 kDa), but is post-translationally modified to three high molecular weight species (approximately 38 to 42 kDa) found in hepatocytes. ALR is present in mitochondria, cytosol, endoplasmic reticulum, and nucleus. Mitochondrial ALR may be involved in oxidative phosphorylation, but also functions as sulfhydryl oxidase and cytochrome c reductase, and causes Fe/S maturation of proteins. ALR, secreted by hepatocytes, stimulates synthesis of TNF-α, IL-6, and nitric oxide in Kupffer cells via a G-protein coupled receptor. While the 22 kDa rat recombinant ALR does not stimulate DNA synthesis in hepatocytes, the short form (15 kDa) of human recombinant ALR was reported to be equipotent as or even stronger than TGF-α or HGF as a mitogen for hepatocytes. Altered serum ALR levels in certain pathological conditions suggest that it may be a diagnostic marker for liver injury/disease. Although ALR appears to have multiple functions, the knowledge of its role in various organs, including the liver, is extremely inadequate, and it is not known whether different ALR species have distinct functions. Future research should provide better understanding of the expression and functions of this enigmatic molecule.

  1. Approach to establishing the effect of aeroelasticity on aerodynamic characteristics of the space shuttle orbiter

    NASA Technical Reports Server (NTRS)

    Schlosser, D. C.; Dominik, D. F.

    1983-01-01

    The static aeroelastic effects on the longitudinal stability and elevon/aileron effectiveness of the space transportation system (STS) Space Shuttle orbiter were estimated by a simplified approach called the elevon torsional stiffness (ETS) method. This method employs rigid model wind tunnel test results to predict aeroelastic effects. Lateral/directional stability and rudder effectiveness were based on results of a wind tunnel test in which a flexible tail model was used. Comparisons with selective flight data are made in this paper. Results of correlations with flight data (although limited at the present time) verify the predicted aeroelastic effects for the orbiter. The orbiter's structural characteristics are such that the effects of aeroelasticity, whether estimated using analytical techniques or simplified methods, do not appear to affect the vehicle performance to any great extent. The large amount of scatter in the flight-extracted data made verification of the aeroelastic corrections very difficult. Generally, the simplified elevon torsional stiffness method provided better correlation with flight test results than he analytical method and reduced the verification effort and cost.

  2. Modeling solvation effects in real-space and real-time within density functional approaches.

    PubMed

    Delgado, Alain; Corni, Stefano; Pittalis, Stefano; Rozzi, Carlo Andrea

    2015-10-14

    The Polarizable Continuum Model (PCM) can be used in conjunction with Density Functional Theory (DFT) and its time-dependent extension (TDDFT) to simulate the electronic and optical properties of molecules and nanoparticles immersed in a dielectric environment, typically liquid solvents. In this contribution, we develop a methodology to account for solvation effects in real-space (and real-time) (TD)DFT calculations. The boundary elements method is used to calculate the solvent reaction potential in terms of the apparent charges that spread over the van der Waals solute surface. In a real-space representation, this potential may exhibit a Coulomb singularity at grid points that are close to the cavity surface. We propose a simple approach to regularize such singularity by using a set of spherical Gaussian functions to distribute the apparent charges. We have implemented the proposed method in the Octopus code and present results for the solvation free energies and solvatochromic shifts for a representative set of organic molecules in water.

  3. Space station electrical power distribution analysis using a load flow approach

    NASA Technical Reports Server (NTRS)

    Emanuel, Ervin M.

    1987-01-01

    The space station's electrical power system will evolve and grow in a manner much similar to the present terrestrial electrical power system utilities. The initial baseline reference configuration will contain more than 50 nodes or busses, inverters, transformers, overcurrent protection devices, distribution lines, solar arrays, and/or solar dynamic power generating sources. The system is designed to manage and distribute 75 KW of power single phase or three phase at 20 KHz, and grow to a level of 300 KW steady state, and must be capable of operating at a peak of 450 KW for 5 to 10 min. In order to plan far into the future and keep pace with load growth, a load flow power system analysis approach must be developed and utilized. This method is a well known energy assessment and management tool that is widely used throughout the Electrical Power Utility Industry. The results of a comprehensive evaluation and assessment of an Electrical Distribution System Analysis Program (EDSA) is discussed. Its potential use as an analysis and design tool for the 20 KHz space station electrical power system is addressed.

  4. Modeling solvation effects in real-space and real-time within density functional approaches

    SciTech Connect

    Delgado, Alain; Corni, Stefano; Pittalis, Stefano; Rozzi, Carlo Andrea

    2015-10-14

    The Polarizable Continuum Model (PCM) can be used in conjunction with Density Functional Theory (DFT) and its time-dependent extension (TDDFT) to simulate the electronic and optical properties of molecules and nanoparticles immersed in a dielectric environment, typically liquid solvents. In this contribution, we develop a methodology to account for solvation effects in real-space (and real-time) (TD)DFT calculations. The boundary elements method is used to calculate the solvent reaction potential in terms of the apparent charges that spread over the van der Waals solute surface. In a real-space representation, this potential may exhibit a Coulomb singularity at grid points that are close to the cavity surface. We propose a simple approach to regularize such singularity by using a set of spherical Gaussian functions to distribute the apparent charges. We have implemented the proposed method in the OCTOPUS code and present results for the solvation free energies and solvatochromic shifts for a representative set of organic molecules in water.

  5. Modeling solvation effects in real-space and real-time within density functional approaches

    NASA Astrophysics Data System (ADS)

    Delgado, Alain; Corni, Stefano; Pittalis, Stefano; Rozzi, Carlo Andrea

    2015-10-01

    The Polarizable Continuum Model (PCM) can be used in conjunction with Density Functional Theory (DFT) and its time-dependent extension (TDDFT) to simulate the electronic and optical properties of molecules and nanoparticles immersed in a dielectric environment, typically liquid solvents. In this contribution, we develop a methodology to account for solvation effects in real-space (and real-time) (TD)DFT calculations. The boundary elements method is used to calculate the solvent reaction potential in terms of the apparent charges that spread over the van der Waals solute surface. In a real-space representation, this potential may exhibit a Coulomb singularity at grid points that are close to the cavity surface. We propose a simple approach to regularize such singularity by using a set of spherical Gaussian functions to distribute the apparent charges. We have implemented the proposed method in the Octopus code and present results for the solvation free energies and solvatochromic shifts for a representative set of organic molecules in water.

  6. Design Space Approach for Preservative System Optimization of an Anti-Aging Eye Fluid Emulsion.

    PubMed

    Lourenço, Felipe Rebello; Francisco, Fabiane Lacerda; Ferreira, Márcia Regina Spuri; Andreoli, Terezinha De Jesus; Löbenberg, Raimar; Bou-Chacra, Nádia

    2015-01-01

    The use of preservatives must be optimized in order to ensure the efficacy of an antimicrobial system as well as the product safety. Despite the wide variety of preservatives, the synergistic or antagonistic effects of their combinations are not well established and it is still an issue in the development of pharmaceutical and cosmetic products. The purpose of this paper was to establish a space design using a simplex-centroid approach to achieve the lowest effective concentration of 3 preservatives (methylparaben, propylparaben, and imidazolidinyl urea) and EDTA for an emulsion cosmetic product. Twenty-two formulae of emulsion differing only by imidazolidinyl urea (A: 0.00 to 0.30% w/w), methylparaben (B: 0.00 to 0.20% w/w), propylparaben (C: 0.00 to 0.10% w/w) and EDTA (D: 0.00 to 0.10% w/w) concentrations were prepared. They were tested alone and in binary, ternary and quaternary combinations. Aliquots of these formulae were inoculated with several microorganisms. An electrochemical method was used to determine microbial burden immediately after inoculation and after 2, 4, 8, 12, 24, 48, and 168 h. An optimization strategy was used to obtain the concentrations of preservatives and EDTA resulting in a most effective preservative system of all microorganisms simultaneously. The use of preservatives and EDTA in combination has the advantage of exhibiting a potential synergistic effect against a wider spectrum of microorganisms. Based on graphic and optimization strategies, we proposed a new formula containing a quaternary combination (A: 55%; B: 30%; C: 5% and D: 10% w/w), which complies with the specification of a conventional challenge test. A design space approach was successfully employed in the optimization of concentrations of preservatives and EDTA in an emulsion cosmetic product.

  7. Mersiline mesh in premaxillary augmentation.

    PubMed

    Foda, Hossam M T

    2005-01-01

    Premaxillary retrusion may distort the aesthetic appearance of the columella, lip, and nasal tip. This defect is characteristically seen in, but not limited to, patients with cleft lip nasal deformity. This study investigated 60 patients presenting with premaxillary deficiencies in which Mersiline mesh was used to augment the premaxilla. All the cases had surgery using the external rhinoplasty technique. Two methods of augmentation with Mersiline mesh were used: the Mersiline roll technique, for the cases with central symmetric deficiencies, and the Mersiline packing technique, for the cases with asymmetric deficiencies. Premaxillary augmentation with Mersiline mesh proved to be simple technically, easy to perform, and not associated with any complications. Periodic follow-up evaluation for a mean period of 32 months (range, 12-98 months) showed that an adequate degree of premaxillary augmentation was maintained with no clinically detectable resorption of the mesh implant.

  8. A Collaborative Approach for Providing Low-Cost ELF Monitoring from Ground and Space

    NASA Astrophysics Data System (ADS)

    Bleier, T. E.; Franklin, L.

    2003-12-01

    This paper describes a collaborative effort among several groups, including a small business (QuakeFinder,LLC), dozens of high schools in northern California, several universities (Stanford and Cal Poly SLO), and Lockheed Martin in Sunnyvale to build a combined ground-based and space-based ELF monitoring system. The goal is to monitor and characterize the raw RF spectrum in the ELF band, and to look for pre- and post-earthquake signatures. Previous attempts at monitoring ELF signals associated with earthquakes have always been summarized with the statement, more data is needed. QuakeFinder is a small business that approached the problem with a different strategy. Rather than deploy a few, expensive, commercial high sensitivity, AC magnetometers on the ground, a collaboration was formed with high school physics classes to build a large number of medium sensitivity magnetometers from partially-assembled kits, and to deploy these sensors in a close spacing along the major California earthquake faults. The strategy was to have a 3-axis ELF ground monitor within 15 km of any large (>M5) quake-- before, during, and after the event. To date, 34 sites have been deployed (out of 50 planned), and they now collect and display daily averages from these 3-axis monitors on a web site (www.earthquaketracker.com). Likewise, satellite-based monitoring is severely restricted by the high cost of building and flying space-based ELF monitors. QuakeFinder formed a collaboration between Stanford Space System Development Laboratory and Lockheed Martin to design and build a nano-satellite (4.5 kg) whose mission was to collect ELF background signatures. QuakeFinder built and donated a single axis ELF (1-1000Hz) magnetometer payload and provided integration and a launch opportunity for "QuakeSat I". The satellite was launched on June 30, 2003 into a 820 km circular polar orbit, and has recorded natural signals (lightning, whistlers, auroral noise, and several unidentified signatures) as well

  9. Orion MPCV Continuum RCS Heating Augmentation Model Development

    NASA Technical Reports Server (NTRS)

    Hyatt, Andrew J.; White, Molly E.

    2014-01-01

    The reaction control system jets of the Orion Multi Purpose Crew Vehicle can have a significant impact on the magnitude and distribution of the surface heat flux on the leeside of the aft-body, when they are fired. Changes in surface heating are expressed in terms of augmentation factor over the baseline smooth body heating. Wind tunnel tests revealed heating augmentation factors as high as 13.0, 7.6, 2.8, and 5.8 for the roll, pitch down, pitch up, and yaw jets respectively. Heating augmentation factor models, based almost exclusively on data from a series of wind tunnel tests have been developed, for the purposes of thermal protection system design. The wind tunnel tests investigated several potential jet-to-freestream similarity parameters, and heating augmentation factors derived from the data showed correlation with the jet-to-freestream momentum ratio. However, this correlation was not utilized in the developed models. Instead augmentation factors were held constant throughout the potential trajectory space. This simplification was driven by the fact that ground to flight traceability and sting effects are not well understood. Given the sensitivity of the reaction control system jet heating augmentation to configuration, geometry, and orientation the focus in the present paper is on the methodology used to develop the models and the lessons learned from the data. The models that are outlined in the present work are specific to the aerothermal database used to design the thermal protection system for the Exploration Flight Test 1 vehicle.

  10. Augmented reality based real-time subcutaneous vein imaging system

    PubMed Central

    Ai, Danni; Yang, Jian; Fan, Jingfan; Zhao, Yitian; Song, Xianzheng; Shen, Jianbing; Shao, Ling; Wang, Yongtian

    2016-01-01

    A novel 3D reconstruction and fast imaging system for subcutaneous veins by augmented reality is presented. The study was performed to reduce the failure rate and time required in intravenous injection by providing augmented vein structures that back-project superimposed veins on the skin surface of the hand. Images of the subcutaneous vein are captured by two industrial cameras with extra reflective near-infrared lights. The veins are then segmented by a multiple-feature clustering method. Vein structures captured by the two cameras are matched and reconstructed based on the epipolar constraint and homographic property. The skin surface is reconstructed by active structured light with spatial encoding values and fusion displayed with the reconstructed vein. The vein and skin surface are both reconstructed in the 3D space. Results show that the structures can be precisely back-projected to the back of the hand for further augmented display and visualization. The overall system performance is evaluated in terms of vein segmentation, accuracy of vein matching, feature points distance error, duration times, accuracy of skin reconstruction, and augmented display. All experiments are validated with sets of real vein data. The imaging and augmented system produces good imaging and augmented reality results with high speed. PMID:27446690

  11. Augmented reality based real-time subcutaneous vein imaging system.

    PubMed

    Ai, Danni; Yang, Jian; Fan, Jingfan; Zhao, Yitian; Song, Xianzheng; Shen, Jianbing; Shao, Ling; Wang, Yongtian

    2016-07-01

    A novel 3D reconstruction and fast imaging system for subcutaneous veins by augmented reality is presented. The study was performed to reduce the failure rate and time required in intravenous injection by providing augmented vein structures that back-project superimposed veins on the skin surface of the hand. Images of the subcutaneous vein are captured by two industrial cameras with extra reflective near-infrared lights. The veins are then segmented by a multiple-feature clustering method. Vein structures captured by the two cameras are matched and reconstructed based on the epipolar constraint and homographic property. The skin surface is reconstructed by active structured light with spatial encoding values and fusion displayed with the reconstructed vein. The vein and skin surface are both reconstructed in the 3D space. Results show that the structures can be precisely back-projected to the back of the hand for further augmented display and visualization. The overall system performance is evaluated in terms of vein segmentation, accuracy of vein matching, feature points distance error, duration times, accuracy of skin reconstruction, and augmented display. All experiments are validated with sets of real vein data. The imaging and augmented system produces good imaging and augmented reality results with high speed.

  12. Augmentative and Alternative Communication. Tech Use Guide: Using Computer Technology.

    ERIC Educational Resources Information Center

    Mineo, Beth

    This guide outlines who may benefit from augmentative and alternative communication (AAC) approaches, such as individuals with speech handicaps, visual impairments, physical disabilities, and cognitive impairments. The guide distinguishes between "low tech" approaches such as signal systems and communication boards and "high…

  13. Simulating the Generalized Gibbs Ensemble (GGE): A Hilbert space Monte Carlo approach

    NASA Astrophysics Data System (ADS)

    Alba, Vincenzo

    By combining classical Monte Carlo and Bethe ansatz techniques we devise a numerical method to construct the Truncated Generalized Gibbs Ensemble (TGGE) for the spin-1/2 isotropic Heisenberg (XXX) chain. The key idea is to sample the Hilbert space of the model with the appropriate GGE probability measure. The method can be extended to other integrable systems, such as the Lieb-Liniger model. We benchmark the approach focusing on GGE expectation values of several local observables. As finite-size effects decay exponentially with system size, moderately large chains are sufficient to extract thermodynamic quantities. The Monte Carlo results are in agreement with both the Thermodynamic Bethe Ansatz (TBA) and the Quantum Transfer Matrix approach (QTM). Remarkably, it is possible to extract in a simple way the steady-state Bethe-Gaudin-Takahashi (BGT) roots distributions, which encode complete information about the GGE expectation values in the thermodynamic limit. Finally, it is straightforward to simulate extensions of the GGE, in which, besides the local integral of motion (local charges), one includes arbitrary functions of the BGT roots. As an example, we include in the GGE the first non-trivial quasi-local integral of motion.

  14. A minimum state multibody/FEM approach for modeling flexible orbiting space systems

    NASA Astrophysics Data System (ADS)

    Pisculli, A.; Gasbarri, P.

    2015-05-01

    In the past the deployment of space structures has widely been analyzed by using multibody formulations. The two leading approaches are usually based on the Newton-Euler (NE) formulation and Euler-Lagrange (EL) formulation. Both of them present advantages and drawbacks. The ideal approach for describing multi-body systems can be represented by a combination between NE and EL formulations. This can be obtained by considering the NE formulation for assembling the equation of motion and then by defining the ODE governing equations with the use of a minimum set of variables. In this paper the authors present a mixed NE/EL formulation suitable for synthesizing optimal control strategies during the deploying maneuvers of robotic arms or solar arrays. The proposed method has two main characteristics: (i) the reference frame, which all the bodies motions are referred to, is a floating reference frame attached to the orbiting base platform body; (ii) it leads to a more organic formulation which makes a shifting from the NE to the EL formulations possible, through the use of a Jacobian matrix. In the present work this mixed formulation is derived to describe a fully elastic multi-body spacecraft. Furthermore the presented formulation, complemented with gravity, gravity gradient and generalized gravitational modal forces, will be used to study the dynamic behavior of an orbiting manipulator with flexible appendages. Finally a Reaction Null/Jacobian Transpose control strategy will be applied to control and deploy the robotic arms to grasp an orbiting flexible spacecraft.

  15. Human Factors Assessment: The Passive Final Approach Spacing Tool (pFAST) Operational Evaluation

    NASA Technical Reports Server (NTRS)

    Lee, Katharine K.; Sanford, Beverly D.

    1998-01-01

    Automation to assist air traffic controllers in the current terminal and en route air traff ic environments is being developed at Ames Research Center in conjunction with the Federal Aviation Administration. This automation, known collectively as the Center-TRACON Automation System (CTAS), provides decision- making assistance to air traffic controllers through computer-generated advisories. One of the CTAS tools developed specifically to assist terminal area air traffic controllers is the Passive Final Approach Spacing Tool (pFAST). An operational evaluation of PFAST was conducted at the Dallas/Ft. Worth, Texas, Terminal Radar Approach Control (TRACON) facility. Human factors data collected during the test describe the impact of the automation upon the air traffic controller in terms of perceived workload and acceptance. Results showed that controller self-reported workload was not significantly increased or reduced by the PFAST automation; rather, controllers reported that the levels of workload remained primarily the same. Controller coordination and communication data were analyzed, and significant differences in the nature of controller coordination were found. Controller acceptance ratings indicated that PFAST was acceptable. This report describes the human factors data and results from the 1996 Operational Field Evaluation of Passive FAST.

  16. A multi-objective approach to the design of low thrust space trajectories using optimal control

    NASA Astrophysics Data System (ADS)

    Dellnitz, Michael; Ober-Blöbaum, Sina; Post, Marcus; Schütze, Oliver; Thiere, Bianca

    2009-11-01

    In this article, we introduce a novel three-step approach for solving optimal control problems in space mission design. We demonstrate its potential by the example task of sending a group of spacecraft to a specific Earth L 2 halo orbit. In each of the three steps we make use of recently developed optimization methods and the result of one step serves as input data for the subsequent one. Firstly, we perform a global and multi-objective optimization on a restricted class of control functions. The solutions of this problem are (Pareto-)optimal with respect to Δ V and flight time. Based on the solution set, a compromise trajectory can be chosen suited to the mission goals. In the second step, this selected trajectory serves as initial guess for a direct local optimization. We construct a trajectory using a more flexible control law and, hence, the obtained solutions are improved with respect to control effort. Finally, we consider the improved result as a reference trajectory for a formation flight task and compute trajectories for several spacecraft such that these arrive at the halo orbit in a prescribed relative configuration. The strong points of our three-step approach are that the challenging design of good initial guesses is handled numerically by the global optimization tool and afterwards, the last two steps only have to be performed for one reference trajectory.

  17. TRACER. A new approach to comparative modeling that combines threading with free-space conformational sampling.

    PubMed

    Trojanowski, Sebastian; Rutkowska, Aleksandra; Kolinski, Andrzej

    2010-01-01

    A new approach to comparative modeling of proteins, TRACER, is described and benchmarked against classical modeling procedures. The new method unifies true three-dimensional threading with coarse-grained sampling of query protein conformational space. The initial sequence alignment of a query protein with a template is not required, although a template needs to be somehow identified. The template is used as a multi-featured fuzzy three-dimensional scaffold. The conformational search for the query protein is guided by intrinsic force field of the coarse-grained modeling engine CABS and by compatibility with the template scaffold. During Replica Exchange Monte Carlo simulations the model chain representing the query protein finds the best possible structural alignment with the template chain, that also optimizes the intra-protein interactions as approximated by the knowledge based force field of CABS. The benchmark done for a representative set of query/template pairs of various degrees of sequence similarity showed that the new method allows meaningful comparative modeling also for the region of marginal, or non-existing, sequence similarity. Thus, the new approach significantly extends the applicability of comparative modeling.

  18. A simulation-based approach towards automatic target recognition of high resolution space borne radar signatures

    NASA Astrophysics Data System (ADS)

    Anglberger, H.; Kempf, T.

    2016-10-01

    Specific imaging effects that are caused mainly by the range measurement principle of a radar device, its much lower frequency range as compared to the optical spectrum, the slanted imaging geometry and certainly the limited spatial resolution complicates the interpretation of radar signatures decisively. Especially the coherent image formation which causes unwanted speckle noise aggravates the problem of visually recognizing target objects. Fully automatic approaches with acceptable false alarm rates are therefore an even harder challenge. At the Microwaves and Radar Institute of the German Aerospace Center (DLR) the development of methods to implement a robust overall processing workflow for automatic target recognition (ATR) out of high resolution synthetic aperture radar (SAR) image data is under progress. The heart of the general approach is to use time series exploitation for the former detection step and simulation-based signature matching for the subsequent recognition. This paper will show the overall ATR chain as a proof of concept for the special case of airplane recognition on image data from the space borne SAR sensor TerraSAR-X.

  19. Application of a Systems Engineering Approach to Support Space Reactor Development

    SciTech Connect

    Wold, Scott

    2005-02-06

    In 1992, approximately 25 Russian and 12 U.S. engineers and technicians were involved in the transport, assembly, inspection, and testing of over 90 tons of Russian equipment associated with the Thermionic System Evaluation Test (TSET) Facility. The entire Russian Baikal Test Stand, consisting of a 5.79 m tall vacuum chamber and related support equipment, was reassembled and tested at the TSET facility in less than four months. In November 1992, the first non-nuclear operational test of a complete thermionic power reactor system in the U.S. was accomplished three months ahead of schedule and under budget. A major factor in this accomplishment was the application of a disciplined top-down systems engineering approach and application of a spiral development model to achieve the desired objectives of the TOPAZ International Program (TIP). Systems Engineering is a structured discipline that helps programs and projects conceive, develop, integrate, test and deliver products and services that meet customer requirements within cost and schedule. This paper discusses the impact of Systems Engineering and a spiral development model on the success of the TOPAZ International Program and how the application of a similar approach could help ensure the success of future space reactor development projects.

  20. Projector Augmented Wave (PAW) Datasets for Multi-Mbar Simulations: An Evolutionary Algorithm Based Recipe

    NASA Astrophysics Data System (ADS)

    Sarkar, K.; Topsakal, M.; Wentzcovitch, R. M.

    2015-12-01

    We attempt to achieve the accuracy of full-potential linearized augmented-plane-wave (FLAPW) method, as implemented in the WIEN2k code, at the favorable computational efficiency of the projector augmented wave (PAW) method for ab initio calculations of solids. For decades, PAW datasets have been generated by manually choosing its parameters and by visually inspecting its logarithmic derivatives, partial wave, and projector basis set. In addition to being tedious and error-prone, this procedure is inadequate because it is impractical to manually explore the full parameter space, as an infinite number of PAW parameter sets for a given augmentation radius can be generated maintaining all the constraints on logarithmic derivatives and basis sets. Performance verification of all plausible solutions against FLAPW is also impractical. Here we report the development of a hybrid algorithm to construct optimized PAW basis sets that can closely reproduce FLAPW results from zero to ultra-high pressures. The approach applies evolutionary computing (EC) to generate optimum PAW parameter sets using the ATOMPAW code. We have the Quantum ESPRESSO distribution to generate equation of state (EOS) to be compared with WIEN2k EOSs set as target. Softer PAW potentials reproducing yet more closely FLAPW EOSs can be found with this method. We demonstrate its working principles and workability by optimizing PAW basis functions for carbon, magnesium, aluminum, silicon, calcium, and iron atoms. The algorithm requires minimal user intervention in a sense that there is no requirement of visual inspection of logarithmic derivatives or of projector functions.

  1. MetaTree: augmented reality narrative explorations of urban forests

    NASA Astrophysics Data System (ADS)

    West, Ruth; Margolis, Todd; O'Neil-Dunne, Jarlath; Mendelowitz, Eitan

    2012-03-01

    As cities world-wide adopt and implement reforestation initiatives to plant millions of trees in urban areas, they are engaging in what is essentially a massive ecological and social experiment. Existing air-borne, space-borne, and fieldbased imaging and inventory mechanisms fail to provide key information on urban tree ecology that is crucial to informing management, policy, and supporting citizen initiatives for the planting and stewardship of trees. The shortcomings of the current approaches include: spatial and temporal resolution, poor vantage point, cost constraints and biological metric limitations. Collectively, this limits their effectiveness as real-time inventory and monitoring tools. Novel methods for imaging and monitoring the status of these emerging urban forests and encouraging their ongoing stewardship by the public are required to ensure their success. This art-science collaboration proposes to re-envision citizens' relationship with urban spaces by foregrounding urban trees in relation to local architectural features and simultaneously creating new methods for urban forest monitoring. We explore creating a shift from overhead imaging or field-based tree survey data acquisition methods to continuous, ongoing monitoring by citizen scientists as part of a mobile augmented reality experience. We consider the possibilities of this experience as a medium for interacting with and visualizing urban forestry data and for creating cultural engagement with urban ecology.

  2. 14 CFR 29.672 - Stability augmentation, automatic, and power-operated systems.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... power-operated systems. 29.672 Section 29.672 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... Construction Control Systems § 29.672 Stability augmentation, automatic, and power-operated systems. If the functioning of stability augmentation or other automatic or power-operated system is necessary to...

  3. 14 CFR 25.672 - Stability augmentation and automatic and power-operated systems.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... power-operated systems. 25.672 Section 25.672 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... Construction Control Systems § 25.672 Stability augmentation and automatic and power-operated systems. If the functioning of stability augmentation or other automatic or power-operated systems is necessary to...

  4. 14 CFR 27.672 - Stability augmentation, automatic, and power-operated systems.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... power-operated systems. 27.672 Section 27.672 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... Construction Control Systems § 27.672 Stability augmentation, automatic, and power-operated systems. If the functioning of stability augmentation or other automatic or power-operated systems is necessary to...

  5. Asian Breast Augmentation: A Systematic Review

    PubMed Central

    Zelken, Jonathan

    2015-01-01

    Background: Economic, cultural, and regulatory phenomena may explain recent popularization of implant-based augmentation in Asia; but the collective Eastern experience remains limited. Asian surgeons and their patients rely on evidence-based medicine that originates elsewhere and may not be entirely relevant. Distinct anatomic and cultural features of Asian women warrant a tailored approach to breast augmentation. We explore the Asian experience with a thorough exploration of the recent literature. Methods: A literature search was performed for articles written after 2000, of Asian women who underwent augmentation mammoplasty using MEDLINE, Embase, and Pubmed Databases. Technique and outcomes data were summarized. Results: Twelve articles reported outcomes of 2089 women. Korea contributed most series (English language, 7), followed by China (3), Taiwan (1), and Japan (1). Silicone implants were used in 82.1% of women studied, and almost exclusively after 2009. More round (68.9%) than anatomic implants (31.1%) were placed. Non-inframammary (axillary, areolar, and umbilical) incisions were used in 96.9% of cases. Nearly all implants were positioned below the muscle or fascia; subglandular placement accounted for 1.1% of cases. Implant/nipple malposition (1.3%), capsular contracture (1.9%), hematoma (0.6%), and infection (0.2%) rates were reported in most series. Undesirable scarring was the most frequent complication (7.3%), but was reported only in 4 of 12 series. Conclusions: Studies of Asian women undergoing augmentation mammoplasty are limited, often with ill-defined outcomes and inadequate follow-up. As experience accumulates, an expanding literature relevant to Asian women will provide evidence-based guidelines that improve outcomes and patient satisfaction, and foster innovation. PMID:26893980

  6. Experimental Study of Collision Detection Schema Used by Pilots During Closely Spaced Parallel Approaches

    NASA Technical Reports Server (NTRS)

    Pritchett, Amy R.; Hansman, R. John

    1996-01-01

    An experimental flight simulator study was conducted to examine the mental alerting logic and thresholds used by subjects to issue an alert and execute an avoidance maneuver. Subjects flew a series of autopilot landing approaches with traffic on a closely-spaced parallel approach; during some runs, the traffic would deviate towards the subject and the subject was to indicate the point when they recognized the potential traffic conflict, and then indicate a direction of flight for an avoidance maneuver. A variety of subjects, including graduate students, general aviation pilots and airline pilots, were tested. Five traffic displays were evaluated, with a moving map TCAS-type traffic display as a baseline. A side-task created both high and low workload situations. Subjects appeared to use the lateral deviation of the intruder aircraft from its approach path as the criteria for an alert regardless of the display available. However, with displays showing heading and/or trend information, their alerting thresholds were significantly lowered. This type of range-only schema still resulted in many near misses, as a high convergence rate was often established by the time of the subject's alert. Therefore, the properties of the intruder's trajectory had the greatest effect on the resultant near miss rate; no display system reliably caused alerts timely enough for certain collision avoidance. Subjects' performance dropped significantly on a side-task while they analyzed the need for an alert, showing alert generation can be a high workload situation at critical times. No variation was found between subjects with and with out piloting experience. These results suggest the design of automatic alerting systems should take into account the range-type alerting schema used by the human, such that the rationale for the automatic alert should be obvious to, and trusted by, the operator. Although careful display design may help generate pilot/automation trust, issues such as user non

  7. Applying the system engineering approach to devise a master’s degree program in space technology in developing countries

    NASA Astrophysics Data System (ADS)

    Jazebizadeh, Hooman; Tabeshian, Maryam; Taheran Vernoosfaderani, Mahsa

    2010-11-01

    Although more than half a century is passed since space technology was first developed, developing countries are just beginning to enter the arena, focusing mainly on educating professionals. Space technology by itself is an interdisciplinary science, is costly, and developing at a fast pace. Moreover, a fruitful education system needs to remain dynamic if the quality of education is the main concern, making it a complicated system. This paper makes use of the System Engineering Approach and the experiences of developed countries in this area while incorporating the needs of the developing countries to devise a comprehensive program in space engineering at the Master's level. The needs of the developing countries as regards space technology education may broadly be put into two categories: to raise their knowledge of space technology which requires hard work and teamwork skills, and to transfer and domesticate space technology while minimizing the costs and maximizing its effectiveness. The requirements of such space education system, which include research facilities, courses, and student projects are then defined using a model drawn from the space education systems in universities in North America and Europe that has been modified to include the above-mentioned needs. Three design concepts have been considered and synthesized through functional analysis. The first one is Modular and Detail Study which helps students specialize in a particular area in space technology. Second is referred to as Integrated and Interdisciplinary Study which focuses on understanding and development of space systems. Finally, the third concept which has been chosen for the purpose of this study, is a combination of the other two, categorizing the required curriculum into seven modules, setting aside space applications. This helps students to not only specialize in one of these modules but also to get hands-on experience in a real space project through participation in summer group

  8. An approach for automated fault diagnosis based on a fuzzy decision tree and boundary analysis of a reconstructed phase space.

    PubMed

    Aydin, Ilhan; Karakose, Mehmet; Akin, Erhan

    2014-03-01

    Although reconstructed phase space is one of the most powerful methods for analyzing a time series, it can fail in fault diagnosis of an induction motor when the appropriate pre-processing is not performed. Therefore, boundary analysis based a new feature extraction method in phase space is proposed for diagnosis of induction motor faults. The proposed approach requires the measurement of one phase current signal to construct the phase space representation. Each phase space is converted into an image, and the boundary of each image is extracted by a boundary detection algorithm. A fuzzy decision tree has been designed to detect broken rotor bars and broken connector faults. The results indicate that the proposed approach has a higher recognition rate than other methods on the same dataset.

  9. Active member bridge feedback control for damping augmentation

    NASA Technical Reports Server (NTRS)

    Chen, Gun-Shing; Lurie, Boris J.

    1992-01-01

    An active damping augmentation approach using active members in a structural system is described. The problem of maximizing the vibration damping in a lightly damped structural system is considered using the analogy of impedance matching between the load and source impedances in an electrical network. The proposed active damping augmentation approach therefore consists of finding the desired active member impedances that maximize the vibration damping, and designing a feedback control in order to achieve desired active member impedances. This study uses a bridge feedback concept that feeds back a combination of signals from sensors of the axial force and relative velocity across the active member to realize the desired active member impedance. The proposed active damping augmentation approach and bridge feedback concept were demonstrated on a three-longeron softly suspended truss structure.

  10. An innovative approach to supplying an environment for the integration and test of the Space Station distributed avionics systems

    NASA Technical Reports Server (NTRS)

    Barry, Thomas; Scheffer, Terrance; Small, L. R.

    1988-01-01

    This paper describes an innovative approach to supplying an environment for the integration and testing of the Space Station distributed avionics systems. The environment's relationship to the process flow of the Space Station verification from systems development to on-orbit verification is presented. This paper also describes the uses of the environment's hardware implementation called Data Management System (DMS) kits. The way in which this environment allows system developers to independently verify their system's performance, fault detection, and recovery capability is explained.

  11. Real-space grids and the Octopus code as tools for the development of new simulation approaches for electronic systems

    NASA Astrophysics Data System (ADS)

    Andrade, Xavier; Strubbe, David; De Giovannini, Umberto; Larsen, Ask Hjorth; Oliveira, Micael J. T.; Alberdi-Rodriguez, Joseba; Varas, Alejandro; Theophilou, Iris; Helbig, Nicole; Verstraete, Matthieu J.; Stella, Lorenzo; Nogueira, Fernando; Aspuru-Guzik, Alán; Castro, Alberto; Marques, Miguel A. L.; Rubio, Angel

    Real-space grids are a powerful alternative for the simulation of electronic systems. One of the main advantages of the approach is the flexibility and simplicity of working directly in real space where the different fields are discretized on a grid, combined with competitive numerical performance and great potential for parallelization. These properties constitute a great advantage at the time of implementing and testing new physical models. Based on our experience with the Octopus code, in this article we discuss how the real-space approach has allowed for the recent development of new ideas for the simulation of electronic systems. Among these applications are approaches to calculate response properties, modeling of photoemission, optimal control of quantum systems, simulation of plasmonic systems, and the exact solution of the Schr\\"odinger equation for low-dimensionality systems.

  12. Phase-space densities and effects of resonance decays in a hydrodynamic approach to heavy ion collisions

    SciTech Connect

    Akkelin, S.V.; Sinyukov, Yu.M.

    2004-12-01

    A method allowing analysis of the overpopulation of phase space in heavy ion collisions in a model-independent way is proposed within the hydrodynamic approach. It makes it possible to extract a chemical potential of thermal pions at freeze-out, irrespective of the form of freeze-out (isothermal) hypersurface in Minkowski space and transverse flows on it. The contributions of resonance (with masses up to 2 GeV) decays to spectra, interferometry volumes, and phase-space densities are calculated and discussed in detail. The estimates of average phase-space densities and chemical potentials of thermal pions are obtained for SPS and RHIC energies. They demonstrate that multibosonic phenomena at those energies might be considered as a correction factor rather than as a significant physical effect. The analysis of the evolution of the pion average phase-space density in chemically frozen hadron systems shows that it is almost constant or slightly increases with time while the particle density and phase-space density at each space point decreases rapidly during the system's expansion. We found that, unlike the particle density, the average phase-space density has no direct link to the freeze-out criterion and final thermodynamic parameters, being connected rather to the initial phase-space density of hadronic matter formed in relativistic nucleus-nucleus collisions.

  13. Coral growth on three reefs: development of recovery benchmarks using a space for time approach

    NASA Astrophysics Data System (ADS)

    Done, T. J.; Devantier, L. M.; Turak, E.; Fisk, D. A.; Wakeford, M.; van Woesik, R.

    2010-12-01

    This 14-year study (1989-2003) develops recovery benchmarks based on a period of very strong coral recovery in Acropora-dominated assemblages on the Great Barrier Reef (GBR) following major setbacks from the predatory sea-star Acanthaster planci in the early 1980s. A space for time approach was used in developing the benchmarks, made possible by the choice of three study reefs (Green Island, Feather Reef and Rib Reef), spread along 3 degrees of latitude (300 km) of the GBR. The sea-star outbreaks progressed north to south, causing death of corals that reached maximum levels in the years 1980 (Green), 1982 (Feather) and 1984 (Rib). The reefs were initially surveyed in 1989, 1990, 1993 and 1994, which represent recovery years 5-14 in the space for time protocol. Benchmark trajectories for coral abundance, colony sizes, coral cover and diversity were plotted against nominal recovery time (years 5-14) and defined as non-linear functions. A single survey of the same three reefs was conducted in 2003, when the reefs were nominally 1, 3 and 5 years into a second recovery period, following further Acanthaster impacts and coincident coral bleaching events around the turn of the century. The 2003 coral cover was marginally above the benchmark trajectory, but colony density (colonies.m-2) was an order of magnitude lower than the benchmark, and size structure was biased toward larger colonies that survived the turn of the century disturbances. The under-representation of small size classes in 2003 suggests that mass recruitment of corals had been suppressed, reflecting low regional coral abundance and depression of coral fecundity by recent bleaching events. The marginally higher cover and large colonies of 2003 were thus indicative of a depleted and aging assemblage not yet rejuvenated by a strong cohort of recruits.

  14. Summer school in the field of Space Technologies: A novel approach for teenage education

    NASA Astrophysics Data System (ADS)

    Dolea, Paul; Vladut Dascal, Paul

    2014-05-01

    This paper presents the main practical aspects regarding the organization of a summer school in the field of Space Technologies and Radio Science. This one-week summer school is aimed for education of teenagers between 12 and 16 years. Currently, the summer school reached its third edition. During this educational activities some especially designed prototype equipments were used with the main purpose of educating adolescents towards a scientific career in the field of Space Technologies and Radio Science. The main equipments and associated experiments are presented as follows: 1. A teaching purpose radio telescope emphasizing the working principle of professional radio telescopes. The experiments were focused on scanning the sky for identifying the positions of geostationary satellites and the Sun. 2. A weather satellite reception equipment used for downloading real-time APT (Automatic Picture Transmission) weather data from NOAA (National Oceanic and Atmospheric Administration) weather satellite fleet. The visual images were used for emphasizing the clouds and cloud systems over Europe. 3. A prototype equipment for receiving electromagnetic waves in the field of VLF (Very Low Frequency) with the purpose of analyzing the electromagnetic radio frequency spectrum. The main emphasized phenomenons in the VLF band (3 kHz - 30 kHz) are related to radio transmitters, electrical discharges in the atmosphere (lightning) and the electromagnetic pollution. 4. An equipment designed for initiating teenagers in the field of radio communication. This equipment was used for transmission and reception of images and sound over a distance of few kilometers, by using high-gain directional antennas. 5. Other sets of experiments were undertaken with the main purpose of mapping the countryside area in which the experiments had taken place. For this activity GPS devices were used. This paper may be considered a practical guideline for those who want to attract young students towards a

  15. Latin-American Regional Developments in Space Technology and International Cooperation - Columbian Space Policy: An Approach to Create a National Space Agency

    NASA Astrophysics Data System (ADS)

    Arenales-Vergara, Oscar A.

    2002-01-01

    Space exploration is a great human adventure: culturally, scientifically, technologically and industrially. Since the earliest of times, civilizations have been united in their awe of, and inspiration by, the cosmos, as testified in particularly by the peoples and cultures of the Central and South American continent in pre-Columbian times. Today, space systems have become an essential tool for the scientific disciplines related to the knowledge of the universe, including our own planet and its close or its remote environment. The main objective of this research is to explain the way in which Colombia, rich in myths and secular legends connecting mankind to the universe, must in the present tackle the issue of its development of space activities. The context in which it could be carried out is also described, along with a perspective of the current state of science and technology in the space sector on a global scale. Any modern nation is concerned with its independence, whether political, economic, or intellectual. That is why we support the concept of countries in the process of development becoming actively involved in the international space scene. Indeed, having limitations in industrial and technological exchange, we feel excluded today from key fields for our tomorrow. This research thus proposes to demonstrate how in a time that can be regarded as one of the most serious crises in its history, Colombia could, in an atmosphere free from fratricidal conflicts, exploit its space matter capabilities. We do not limit our focus to the scientific field, but also consider the social, economic and cultural aspects. The results of this research delineate how Colombia could start a new optimistic phase of its development, joining the international space programs within the framework of agreements among the regional governments in Latin America.

  16. Real-Space Renormalization-Group Approach to the Integer Quantum Hall Effect

    NASA Astrophysics Data System (ADS)

    Cain, Philipp; Römer, Rudolf A.

    We review recent results based on an application of the real-space renormalization group (RG) approach to a network model for the integer quantum Hall (QH) transition. We demonstrate that this RG approach reproduces the critical distribution of the power transmission coefficients, i.e., two-terminal conductances, Pc(G), with very high accuracy. The RG flow of P(G) at energies away from the transition yields a value of the critical exponent ν that agrees with most accurate large-size lattice simulations. A description of how to obtain other relevant transport coefficients such as RL and RH is given. From the non-trivial fixed point of the RG flow we extract the critical level-spacing distribution (LSD). This distribution is close, but distinctively different from the earlier large-scale simulations. We find that the LSD obeys scaling behavior around the QH transition with ν = 2.37±0.02. Away from the transition it crosses over towards the Poisson distribution. We next investigate the plateau-to-insulator transition at strong magnetic fields. For a fully quantum coherent situation, we find a quantized Hall insulator with RH≈h/e2 up to RL 20h/e2 when interpreting the results in terms of most probable value of the distribution function P(RH). Upon further increasing RL→∞, the Hall insulator with diverging Hall resistance R H∝ R Lκ is seen. The crossover between these two regimes depends on the precise nature of the averaging procedure for the distributions P(RL) and P(RH). We also study the effect of long-ranged inhomogeneities on the critical properties of the QH transition. Inhomogeneities are modeled by a smooth random potential with a correlator which falls off with distance as a power law r-α. Similar to the classical percolation, we observe an enhancement of ν with decreasing α. These results exemplify the surprising fact that a small RG unit, containing only five nodes, accurately captures most of the correlations responsible for the localization

  17. Using Laser Scanners to Augment the Systematic Error Pointing Model

    NASA Astrophysics Data System (ADS)

    Wernicke, D. R.

    2016-08-01

    The antennas of the Deep Space Network (DSN) rely on precise pointing algorithms to communicate with spacecraft that are billions of miles away. Although the existing systematic error pointing model is effective at reducing blind pointing errors due to static misalignments, several of its terms have a strong dependence on seasonal and even daily thermal variation and are thus not easily modeled. Changes in the thermal state of the structure create a separation from the model and introduce a varying pointing offset. Compensating for this varying offset is possible by augmenting the pointing model with laser scanners. In this approach, laser scanners mounted to the alidade measure structural displacements while a series of transformations generate correction angles. Two sets of experiments were conducted in August 2015 using commercially available laser scanners. When compared with historical monopulse corrections under similar conditions, the computed corrections are within 3 mdeg of the mean. However, although the results show promise, several key challenges relating to the sensitivity of the optical equipment to sunlight render an implementation of this approach impractical. Other measurement devices such as inclinometers may be implementable at a significantly lower cost.

  18. Bayesian Alternation during Tactile Augmentation

    PubMed Central

    Goeke, Caspar M.; Planera, Serena; Finger, Holger; König, Peter

    2016-01-01

    A large number of studies suggest that the integration of multisensory signals by humans is well-described by Bayesian principles. However, there are very few reports about cue combination between a native and an augmented sense. In particular, we asked the question whether adult participants are able to integrate an augmented sensory cue with existing native sensory information. Hence for the purpose of this study, we build a tactile augmentation device. Consequently, we compared different hypotheses of how untrained adult participants combine information from a native and an augmented sense. In a two-interval forced choice (2 IFC) task, while subjects were blindfolded and seated on a rotating platform, our sensory augmentation device translated information on whole body yaw rotation to tactile stimulation. Three conditions were realized: tactile stimulation only (augmented condition), rotation only (native condition), and both augmented and native information (bimodal condition). Participants had to choose one out of two consecutive rotations with higher angular rotation. For the analysis, we fitted the participants' responses with a probit model and calculated the just notable difference (JND). Then, we compared several models for predicting bimodal from unimodal responses. An objective Bayesian alternation model yielded a better prediction (χred2 = 1.67) than the Bayesian integration model (χred2 = 4.34). Slightly higher accuracy showed a non-Bayesian winner takes all (WTA) model (χred2 = 1.64), which either used only native or only augmented values per subject for prediction. However, the performance of the Bayesian alternation model could be substantially improved (χred2 = 1.09) utilizing subjective weights obtained by a questionnaire. As a result, the subjective Bayesian alternation model predicted bimodal performance most accurately among all tested models. These results suggest that information from augmented and existing sensory modalities in

  19. Long-term prospects for developments in space: A scenario approach

    NASA Technical Reports Server (NTRS)

    Brown, W. M.; Kahn, H. D.

    1977-01-01

    Long-term plans for future NASA programs are reported, and some of the following topics are discussed in detail: (1) systematic formulation of space scenarios; (2) the basic international context; (3) potential 21st century space developments; (4) space vehicle developments; and (5) future exploration.

  20. International Space Station Centrifuge Rotor Models A Comparison of the Euler-Lagrange and the Bond Graph Modeling Approach

    NASA Technical Reports Server (NTRS)

    Nguyen, Louis H.; Ramakrishnan, Jayant; Granda, Jose J.

    2006-01-01

    The assembly and operation of the International Space Station (ISS) require extensive testing and engineering analysis to verify that the Space Station system of systems would work together without any adverse interactions. Since the dynamic behavior of an entire Space Station cannot be tested on earth, math models of the Space Station structures and mechanical systems have to be built and integrated in computer simulations and analysis tools to analyze and predict what will happen in space. The ISS Centrifuge Rotor (CR) is one of many mechanical systems that need to be modeled and analyzed to verify the ISS integrated system performance on-orbit. This study investigates using Bond Graph modeling techniques as quick and simplified ways to generate models of the ISS Centrifuge Rotor. This paper outlines the steps used to generate simple and more complex models of the CR using Bond Graph Computer Aided Modeling Program with Graphical Input (CAMP-G). Comparisons of the Bond Graph CR models with those derived from Euler-Lagrange equations in MATLAB and those developed using multibody dynamic simulation at the National Aeronautics and Space Administration (NASA) Johnson Space Center (JSC) are presented to demonstrate the usefulness of the Bond Graph modeling approach for aeronautics and space applications.

  1. Motion planning for mobile manipulators using the FSP (full space parameterization) approach

    SciTech Connect

    Pin, F.G.; Morgansen, K.A.; Tulloch, F.A.; Hacker, C.J.

    1996-05-01

    The efficient utilization of the motion capabilities of mobile manipulators, i.e., manipulators mounted on mobile platforms, requires the resolution of the kinematically redundant system formed by the addition of the degrees of freedom (d.o.f.) of the platform to those of the manipulator. At the velocity level, the linearized Jacobian equation for such a redundant system represents an underspecified system of algebraic equations. In addition, constraints such as obstacle avoidance or joint limits may appear at any time during the trajectory of the system. A method, which we named the FSP (Full Space Parameterization), has recently been developed to resolve such underspecified systems with constraints that may vary in time and in number during a single trajectory. In this paper, we review the principles of the FSP and give analytical solutions for the constrained motion case, with a general optimization criterion for resolving the redundancy. We then focus on a solution to the problem introduced by the combined use of prismatic and revolute joints (a common occurrence in practical mobile manipulators) which makes the dimensions of the joint displacement vector components non-homogeneous. Successful applications to the motion planning of several large-payload mobile manipulators with up to 11 d.o.f. are discussed. Sample trajectories involving combined motions of the platform and manipulator under the time-varying occurrence of obstacle and joint limit constraints are presented to illustrate the use and efficiency of the FSP approach in complex motion planning problems.

  2. Runoff modelling using radar data and flow measurements in a stochastic state space approach.

    PubMed

    Krämer, S; Grum, M; Verworn, H R; Redder, A

    2005-01-01

    In urban drainage the estimation of runoff with the help of models is a complex task. This is in part due to the fact that rainfall, the most important input to urban drainage modelling, is highly uncertain. Added to the uncertainty of rainfall is the complexity of performing accurate flow measurements. In terms of deterministic modelling techniques these are needed for calibration and evaluation of the applied model. Therefore, the uncertainties of rainfall and flow measurements have a severe impact on the model parameters and results. To overcome these problems a new methodology has been developed which is based on simple rain plane and runoff models that are incorporated into a stochastic state space model approach. The state estimation is done by using the extended Kalman filter in combination with a maximum likelihood criterion and an off-line optimization routine. This paper presents the results of this new methodology with respect to the combined consideration of uncertainties in distributed rainfall derived from radar data and uncertainties in measured flows in an urban catchment within the Emscher river basin, Germany.

  3. A space-for-time (SFT) substitution approach to studying historical phenological changes in urban environment.

    PubMed

    Buyantuyev, Alexander; Xu, Pengyan; Wu, Jianguo; Piao, Shunji; Wang, Dachuan

    2012-01-01

    Plant phenological records are crucial for predicting plant responses to global warming. However, many historical records are either short or replete with data gaps, which pose limitations and may lead to erroneous conclusions about the direction and magnitude of change. In addition to uninterrupted monitoring, missing observations may be substituted via modeling, experimentation, or gradient analysis. Here we have developed a space-for-time (SFT) substitution method that uses spatial phenology and temperature data to fill gaps in historical records. To do this, we combined historical data for several tree species from a single location with spatial data for the same species and used linear regression and Analysis of Covariance (ANCOVA) to build complementary spring phenology models and assess improvements achieved by the approach. SFT substitution allowed increasing the sample size and developing more robust phenology models for some of the species studied. Testing models with reduced historical data size revealed thresholds at which SFT improved historical trend estimation. We conclude that under certain circumstances both the robustness of models and accuracy of phenological trends can be enhanced although some limitations and assumptions still need to be resolved. There is considerable potential for exploring SFT analyses in phenology studies, especially those conducted in urban environments and those dealing with non-linearities in phenology modeling.

  4. Relative position and pose measurement approach of specific operation site of space non-cooperative target

    NASA Astrophysics Data System (ADS)

    Chen, Feng; Zhou, Ying; Li, Ronghua; Huang, Jianming

    2015-12-01

    In order to achieve the rendezvous and capture of the space non-cooperative target, the relative position and pose measurement of non-cooperative target must be resolved. Since the marker is not installed into the non-cooperative target and there is no inter satellite link to transfer the information, so it is very difficult to measure the relative position and pose measurement of non-cooperative target. The solar array connecting frame of non-cooperative targets have their characters and are easy to capture, so the position and pose measurement of specific operation site of non-cooperative target based on stereo vision has been studied in this paper. The method composed of image acquiring, image filtering, edge detection, feature extraction and relative pose measurement. Finally, the relative position and attitude parameters of the solar wing connection were obtained and provided to the control system. The results of simulation and ground verification show that the algorithm is accurate and effective, and can satisfy the technical requirements of the on orbit operation. The measurement approach can be used for engineering implementation.

  5. Cryogenic stray light testing of the James Webb Space Telescope: an easy approach

    NASA Astrophysics Data System (ADS)

    Liepmann, Till W.

    2009-08-01

    A practical method for introducing stray light for testing the James Webb Space Telescope (JWST) at cryogenic temperatures using hollow shell spherical reflectors is described. Several alternate approaches to stray light testing are compared, including fiber sources, diffuse panels, and curved specular reflectors. Alignment of the sources can pose special difficulties when cooling to cryogenic temperatures, since the shape of the reflector, mounts, and support structure can all change. The hollow shell spherical reflectors do not have any of these difficulties, and can be mounted so that they are automatically aligned by gravity. This also makes them insensitive to vibration, so they can be used with long detector integration times to provide adequate stray light signal to noise without interfering with other optical tests. The reflectors are positioned so as to work with test source(s) already in the cryo-vac chamber. The spherical reflectors operate at all wavelengths, reducing the number of reflectors required and providing operational flexibility in reflector placement. Electroplated stainless steel hollow shell reflectors are inherently compatible with cryogenic and vacuum environments. The reflectors are passive and have no thermal dissipation, eliminating impact on sensitive thermal tests. Their light weight and single point suspension mounting minimize the dynamic and static loads. Finally, the reflector's simple geometry is inherently compatible with optical alignment metrology (e.g. LIDAR), making position measurements both more accurate and simpler to document.

  6. Different Approaches for Ensuring Performance/Reliability of Plastic Encapsulated Microcircuits (PEMs) in Space Applications

    NASA Technical Reports Server (NTRS)

    Gerke, R. David; Sandor, Mike; Agarwal, Shri; Moor, Andrew F.; Cooper, Kim A.

    2000-01-01

    Engineers within the commercial and aerospace industries are using trade-off and risk analysis to aid in reducing spacecraft system cost while increasing performance and maintaining high reliability. In many cases, Commercial Off-The-Shelf (COTS) components, which include Plastic Encapsulated Microcircuits (PEMs), are candidate packaging technologies for spacecrafts due to their lower cost, lower weight and enhanced functionality. Establishing and implementing a parts program that effectively and reliably makes use of these potentially less reliable, but state-of-the-art devices, has become a significant portion of the job for the parts engineer. Assembling a reliable high performance electronic system, which includes COTS components, requires that the end user assume a risk. To minimize the risk involved, companies have developed methodologies by which they use accelerated stress testing to assess the product and reduce the risk involved to the total system. Currently, there are no industry standard procedures for accomplishing this risk mitigation. This paper will present the approaches for reducing the risk of using PEMs devices in space flight systems as developed by two independent Laboratories. The JPL procedure involves primarily a tailored screening with accelerated stress philosophy while the APL procedure is primarily, a lot qualification procedure. Both Laboratories successfully have reduced the risk of using the particular devices for their respective systems and mission requirements.

  7. A Space-For-Time (SFT) Substitution Approach to Studying Historical Phenological Changes in Urban Environment

    PubMed Central

    Buyantuyev, Alexander; Xu, Pengyan; Wu, Jianguo; Piao, Shunji; Wang, Dachuan

    2012-01-01

    Plant phenological records are crucial for predicting plant responses to global warming. However, many historical records are either short or replete with data gaps, which pose limitations and may lead to erroneous conclusions about the direction and magnitude of change. In addition to uninterrupted monitoring, missing observations may be substituted via modeling, experimentation, or gradient analysis. Here we have developed a space-for-time (SFT) substitution method that uses spatial phenology and temperature data to fill gaps in historical records. To do this, we combined historical data for several tree species from a single location with spatial data for the same species and used linear regression and Analysis of Covariance (ANCOVA) to build complementary spring phenology models and assess improvements achieved by the approach. SFT substitution allowed increasing the sample size and developing more robust phenology models for some of the species studied. Testing models with reduced historical data size revealed thresholds at which SFT improved historical trend estimation. We conclude that under certain circumstances both the robustness of models and accuracy of phenological trends can be enhanced although some limitations and assumptions still need to be resolved. There is considerable potential for exploring SFT analyses in phenology studies, especially those conducted in urban environments and those dealing with non-linearities in phenology modeling. PMID:23236460

  8. Distribution function approach to redshift space distortions. Part V: perturbation theory applied to dark matter halos

    SciTech Connect

    Vlah, Zvonimir; Seljak, Uroš; Okumura, Teppei; Desjacques, Vincent E-mail: seljak@physik.uzh.ch E-mail: Vincent.Desjacques@unige.ch

    2013-10-01

    Numerical simulations show that redshift space distortions (RSD) introduce strong scale dependence in the power spectra of halos, with ten percent deviations relative to linear theory predictions even on relatively large scales (k < 0.1h/Mpc) and even in the absence of satellites (which induce Fingers-of-God, FoG, effects). If unmodeled these effects prevent one from extracting cosmological information from RSD surveys. In this paper we use Eulerian perturbation theory (PT) and Eulerian halo biasing model and apply it to the distribution function approach to RSD, in which RSD is decomposed into several correlators of density weighted velocity moments. We model each of these correlators using PT and compare the results to simulations over a wide range of halo masses and redshifts. We find that with an introduction of a physically motivated halo biasing, and using dark matter power spectra from simulations, we can reproduce the simulation results at a percent level on scales up to k ∼ 0.15h/Mpc at z = 0, without the need to have free FoG parameters in the model.

  9. A nonlinear optimization approach for disturbance rejection in flexible space structures

    NASA Technical Reports Server (NTRS)

    Parlos, Alexander G.; Sunkel, John W.

    1990-01-01

    In this paper the design of an active control law for the rejection of persistent disturbances in large space structures is presented. The control system design approach is based on a deterministic model of the disturbances, with a model-based-compensator (MBC) structure, optimizing the magnitude of the disturbance that the structure can tolerate without violating certain predetermined constraints. In addition to closed-loop stability, the explicit treatment of state, control and control rate constraints, such as structural displacement, control actuator effort, and compensator time guarantees that the final design will exhibit desired performance characteristics. The technique is applied for the vibration damping of a simple two bay truss structure which is subjected to persistent disturbances, such as shuttle docking. Preliminary results indicate that the proposed control system can reject considerable persistent disturbances by utilizing most of the available control, while limiting the structural displacements to within desired tolerances. Further work, however, for incorporating additional design criteria, such as compensator robustness to be traded-off against performance specifications, is warranted.

  10. On energy harvesting for augmented tags

    NASA Astrophysics Data System (ADS)

    Allane, Dahmane; Duroc, Yvan; Andia Vera, Gianfranco; Touhami, Rachida; Tedjini, Smail

    2017-02-01

    In this paper, the harmonic signals generated by UHF RFID chips, usually considered as spurious effects and unused, are exploited. Indeed, the harmonic signals are harvested to feed a supplementary circuitry associated with a passive RFID tag. Two approaches are presented and compared. In the first one, the third-harmonic signal is combined with an external 2.45-GHz Wi-Fi signal. The integration is done in such a way that the composite signal boosts the conversion efficiency of the energy harvester. In the second approach, the third-harmonic signal is used as the only source of a harvester that energizes a commercial temperature sensor associated with the tag. The design procedures of the two "augmented-tag" approaches are presented. The performance of each system is simulated with ADS software, and using Harmonic Balance tool (HB), the results obtained in simulation and measurements are compared also. xml:lang="fr"

  11. Augmented Reality Tower Technology Assessment

    NASA Technical Reports Server (NTRS)

    Reisman, Ronald J.; Brown, David M.

    2009-01-01

    Augmented Reality technology may help improve Air Traffic Control Tower efficiency and safety during low-visibility conditions. This paper presents the assessments of five off-duty controllers who shadow-controlled' with an augmented reality prototype in their own facility. Initial studies indicated unanimous agreement that this technology is potentially beneficial, though the prototype used in the study was not adequate for operational use. Some controllers agreed that augmented reality technology improved situational awareness, had potential to benefit clearance, control, and coordination tasks and duties and could be very useful for acquiring aircraft and weather information, particularly aircraft location, heading, and identification. The strongest objections to the prototype used in this study were directed at aircraft registration errors, unacceptable optical transparency, insufficient display performance in sunlight, inadequate representation of the static environment and insufficient symbology.

  12. Therapeutic options for lip augmentation.

    PubMed

    Segall, Lorne; Ellis, David A F

    2007-11-01

    Aesthetic ideals vary with emerging fashion trends and within different cultures. However, over the past few decades, fuller lips have been considered a desirable trait. Many younger patients are presenting for lip augmentation to achieve the sought-after look commonly seen in many fashion magazines. In addition, as individuals age, they lose lip volume, with a thinning of the red lip, some effacement of the vermillion border, and elongation and flattening of the white portion of the lip. Rejuvenation of the lips plays a key role in restoring a more youthful appearance. As a result, lip augmentation appeals to a wide spectrum of patients who present with various different aesthetic goals and expectations. Numerous therapeutic options exist for aesthetic lip augmentation, ranging from temporary and permanent injectable fillers to implants and other surgical techniques.

  13. Augmentation-related brain plasticity

    PubMed Central

    Di Pino, Giovanni; Maravita, Angelo; Zollo, Loredana; Guglielmelli, Eugenio; Di Lazzaro, Vincenzo

    2014-01-01

    Today, the anthropomorphism of the tools and the development of neural interfaces require reconsidering the concept of human-tools interaction in the framework of human augmentation. This review analyses the plastic process that the brain undergoes when it comes into contact with augmenting artificial sensors and effectors and, on the other hand, the changes that the use of external augmenting devices produces in the brain. Hitherto, few studies investigated the neural correlates of augmentation, but clues on it can be borrowed from logically-related paradigms: sensorimotor training, cognitive enhancement, cross-modal plasticity, sensorimotor functional substitution, use and embodiment of tools. Augmentation modifies function and structure of a number of areas, i.e., primary sensory cortices shape their receptive fields to become sensitive to novel inputs. Motor areas adapt the neuroprosthesis representation firing-rate to refine kinematics. As for normal motor outputs, the learning process recruits motor and premotor cortices and the acquisition of proficiency decreases attentional recruitment, focuses the activity on sensorimotor areas and increases the basal ganglia drive on the cortex. Augmentation deeply relies on the frontoparietal network. In particular, premotor cortex is involved in learning the control of an external effector and owns the tool motor representation, while the intraparietal sulcus extracts its visual features. In these areas, multisensory integration neurons enlarge their receptive fields to embody supernumerary limbs. For operating an anthropomorphic neuroprosthesis, the mirror system is required to understand the meaning of the action, the cerebellum for the formation of its internal model and the insula for its interoception. In conclusion, anthropomorphic sensorized devices can provide the critical sensory afferences to evolve the exploitation of tools through their embodiment, reshaping the body representation and the sense of the self

  14. Combustion-augmented laser ramjets

    NASA Astrophysics Data System (ADS)

    Horisawa, Hideyuki; Tamada, Kazunobu; Kimura, Itsuro

    2006-05-01

    A preliminary study of combustion-augmented laser-ramjets was conducted, in which chemical propellant such as a gaseous hydrogen/air mixture was utilized and detonated with a focused laser beam in order to obtain a higher impulse compared to the case only using lasers. CFD analysis of internal conical-nozzle flows and experimental measurements including impulse measurement were conducted to evaluate effects of chemical reaction on thrust performance improvement. From the results, a significant improvement in the thrust performances was confirmed with addition of a small amount of hydrogen to propellant air, or in combustion-augmented operation.

  15. Space commerce in a global economy: Comparison of US and Australian approaches

    NASA Technical Reports Server (NTRS)

    Stone, Barbara A.; Page, John R.

    1993-01-01

    The United States and Australia are among the 20 or more nations of the world having industries currently engaging in some form of space commerce. As a matter of national policy, the United States has encouraged private investment and involvement in space activities since 1984, when the Congress declared it in the best interest of the Nation that NASA '...seek and encourage to the maximum extent possible, the fullest commercial use of space.' Australia's space policy, announced in 1986, has the objective of encouraging greater involvement by industry in space research and development, and the development of commercial space activities. This paper discusses the underlying policies, current status, and prospects for the future of commercial space business activities in the two countries.

  16. Lean Stability augmentation study

    NASA Technical Reports Server (NTRS)

    Mcvey, J. B.; Kennedy, J. B.

    1979-01-01

    An analytical and experimental program was conducted to investigate techniques and develop technology for improving the lean combustion limits of premixing, prevaporizing combustors applicable to gas turbine engine main burners. Three concepts for improving lean stability limits were selected for experimental evaluation among twelve approaches considered. Concepts were selected on the basis of the potential for improving stability limits and achieving emission goals, the technological risks associated with development of practical burners employing the concepts, and the penalties to airline direct operating costs resulting from decreased combustor performance, increased engine cost, increased maintenance cost and increased engine weight associated with implementation of the concepts. Tests of flameholders embodying the selected concepts were conducted.

  17. HDF Augmentation: Interoperability in the Last Mile

    NASA Astrophysics Data System (ADS)

    Plutchak, J.; Folk, M. J.; Habermann, T.; Knox, L.

    2014-12-01

    Science data files are generally written to serve well-defined purposes for a small science teams. In many cases, the organization of the data and the metadata are designed for custom tools developed and maintained by and for the team. Using these data outside of this context many times involves restructuring, re-documenting, or reformatting the data. This expensive and time-consuming process usually prevents data reuse and thus decreases the total life-cycle value of the data considerably. If the data are unique or critically important to solving a particular problem, they can be modified into a more generally usable form or metadata can be added in order to enable reuse. This augmentation process can be done to enhance data for the intended purpose or for a new purpose, to make the data available to new tools and applications, to make the data more conventional or standard, or to simplify preservation of the data. The HDF Group has addressed augmentation needs in many ways: by adding extra information, by renaming objects or moving them around in the file, by reducing complexity of the organization, and sometimes by hiding data objects that are not understood by specific applications. In some cases these approaches require re-writing the data into new files and in some cases it can be done externally, without affecting the original file. We will describe and compare several examples of each approach.

  18. Flow interaction of diffuser augmented wind turbines

    NASA Astrophysics Data System (ADS)

    Göltenbott, U.; Ohya, Y.; Yoshida, S.; Jamieson, P.

    2016-09-01

    Up-scaling of wind turbines has been a major trend in order to reduce the cost of energy generation from the wind. Recent studies however show that for a given technology, the cost always rises with upscaling, notably due to the increased mass of the system. To reach capacities beyond 10 MW, multi-rotor systems (MRS) have promising advantages. On the other hand, diffuser augmented wind turbines (DAWTs) can significantly increase the performance of the rotor. Up to now, diffuser augmentation has only been applied to single small wind turbines. In the present research, DAWTs are used in a multi-rotor system. In wind tunnel experiments, the aerodynamics of two and three DAWTs, spaced in close vicinity in the same plane normal to a uniform flow, have been analysed. Power increases of up to 5% and 9% for the two and three rotor configurations are respectively achieved in comparison to a stand-alone turbine. The physical dynamics of the flows are analysed on the basis of the results obtained with a stand-alone turbine.

  19. A new calculation approach for dielectric space charge characterization from nano to macro-scales by the thermal step method

    NASA Astrophysics Data System (ADS)

    Belgaroui, E.; Kallel, A.

    2010-09-01

    In this paper, a new calculation approach is developed and applied, for the first time, to different dielectric scales using the thermal step method (TSM). The thermal aspect of the approach concerns insulating materials from nano to macro-scales. The theoretical approach is based on the ballistic-diffuse transport taking into account the relaxation time of heat phonons and their effects on the trapped space charges. These effects are revealed on the temporal evolution of the induced image charges that constitute the electrical signal of the thermal step method. The temperature distributions and the TSM induced image charges are obtained by applying the numerical finite element method, the Newmark direct integration, the mean value theorem and the composite Simpson approximation. In a first step, the results of the temperature distributions are validated with those obtained by Boltzmann and Chen models for nano-polyethylene sample. In a second step, our approach is validated with TSM previous works using the Fourier's model for space charge characterizations in the micro and macro-dielectrics. The validated results of the TSM induced image charges for micro and macro-scales show good agreements, and prove that our approach is a consistent tool to be applied in space charge characterizations for different dielectric scales.

  20. Modern approach to an old technique: Narrative revision of techniques used to locate the epidural space.

    PubMed

    Brogly, N; Guasch Arévalo, E; Kollmann Camaiora, A; Alsina Marcos, E; García García, C; Gilsanz Rodríguez, F

    2017-03-16

    Since the first description of the epidural technique during the 1920s, the continuous progress of knowledge of the anatomy and physiology of the epidural space has allowed the development of different techniques to locate this space while increasing both the safety and efficacy of the procedure. The most common techniques used today are based on the two main characteristics of the epidural space: the difference in distensibility between the ligamentum flavum and the epidural space, and the existence of negative pressure within the epidural space. However, over recent years, technological advances have allowed the development of new techniques to locate the epidural space based on other physical properties of tissues. Some are still in the experimental phase, but others, like ultrasound-location have reached a clinical phase and are being used increasingly in daily practice.