Sample records for trajectory boost part
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NASA Astrophysics Data System (ADS)
Latypov, A. F.
2009-03-01
The fuel economy was estimated at boost trajectory of aerospace plane during energy supply to the free stream. Initial and final velocities of the flight were given. A model of planning flight above cold air in infinite isobaric thermal wake was used. The comparison of fuel consumption was done at optimal trajectories. The calculations were done using a combined power plant consisting of ramjet and liquid-propellant engine. An exergy model was constructed in the first part of the paper for estimating the ramjet thrust and specific impulse. To estimate the aerodynamic drag of aircraft a quadratic dependence on aerodynamic lift is used. The energy for flow heating is obtained at the sacrifice of an equivalent decrease of exergy of combustion products. The dependencies are obtained for increasing the range coefficient of cruise flight at different Mach numbers. In the second part of the paper, a mathematical model is presented for the boost part of the flight trajectory of the flying vehicle and computational results for reducing the fuel expenses at the boost trajectory at a given value of the energy supplied in front of the aircraft.
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Research on motion model for the hypersonic boost-glide aircraft
NASA Astrophysics Data System (ADS)
Xu, Shenda; Wu, Jing; Wang, Xueying
2015-11-01
A motion model for the hypersonic boost-glide aircraft(HBG) was proposed in this paper, which also analyzed the precision of model through simulation. Firstly the trajectory of HBG was analyzed, and a scheme which divide the trajectory into two parts then build the motion model on each part. Secondly a restrained model of boosting stage and a restrained model of J2 perturbation were established, and set up the observe model. Finally the analysis of simulation results show the feasible and high-accuracy of the model, and raise a expectation for intensive research.
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NASA Astrophysics Data System (ADS)
Latypov, A. F.
2008-12-01
Fuel economy at boost trajectory of the aerospace plane was estimated during energy supply to the free stream. Initial and final flight velocities were specified. The model of a gliding flight above cold air in an infinite isobaric thermal wake was used. The fuel consumption rates were compared at optimal trajectory. The calculations were carried out using a combined power plant consisting of ramjet and liquid-propellant engine. An exergy model was built in the first part of the paper to estimate the ramjet thrust and specific impulse. A quadratic dependence on aerodynamic lift was used to estimate the aerodynamic drag of aircraft. The energy for flow heating was obtained at the expense of an equivalent reduction of the exergy of combustion products. The dependencies were obtained for increasing the range coefficient of cruise flight for different Mach numbers. The second part of the paper presents a mathematical model for the boost interval of the aircraft flight trajectory and the computational results for the reduction of fuel consumption at the boost trajectory for a given value of the energy supplied in front of the aircraft.
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Earth-to-Orbit Laser Launch Simulation for a Lightcraft Technology Demonstrator
NASA Astrophysics Data System (ADS)
Richard, J. C.; Morales, C.; Smith, W. L.; Myrabo, L. N.
2006-05-01
Optimized laser launch trajectories have been developed for a 1.4 m diameter, 120 kg (empty mass) Lightcraft Technology Demonstrator (LTD). The lightcraft's combined-cycle airbreathing/rocket engine is designed for single-stage-to-orbit flights with a mass ratio of 2 propelled by a 100 MW class ground-based laser built on a 3 km mountain peak. Once in orbit, the vehicle becomes an autonomous micro-satellite. Two types of trajectories were simulated with the SORT (Simulation and Optimization of Rocket Trajectories) software package: a) direct GBL boost to orbit, and b) GBL boost aided by laser relay satellite. Several new subroutines were constructed for SORT to input engine performance (as a function of Mach number and altitude), vehicle aerodynamics, guidance algorithms, and mass history. A new guidance/steering option required the lightcraft to always point at the GBL or laser relay satellite. SORT iterates on trajectory parameters to optimize vehicle performance, achieve a desired criteria, or constrain the solution to avoid some specific limit. The predicted laser-boost performance for the LTD is undoubtedly revolutionary, and SORT simulations have helped to define this new frontier.
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2009-04-21
CAPE CANAVERAL, Fla. – On Launch Pad 17-B at Cape Canaveral Air Force Station, a worker attaches solid rocket boosters to a Delta II rocket for launch of the STSS Demonstrator spacecraft. The spacecraft is a midcourse tracking technology demonstrator, part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency on July 29. Photo credit: NASA/Kim Shiflett
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2009-05-01
CAPE CANAVERAL, Fla. – The STSS Demonstrator SV-2spacecraft arrives at the Astrotech payload processing facility in Titusville, Fla. The spacecraft is a midcourse tracking technology demonstrator, part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency in late summer. Photo credit: NASA/Jack Pfaller (Approved for Public Release 09-MDA-4616 [27 May 09])
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2009-04-21
CAPE CANAVERAL, Fla. – On Launch Pad 17-B at Cape Canaveral Air Force Station, solid rocket boosters are attached to a Delta II rocket for launch of the STSS Demonstrator spacecraft. The spacecraft is a midcourse tracking technology demonstrator, part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency on July 29. Photo credit: NASA/Kim Shiflett
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2009-04-21
CAPE CANAVERAL, Fla. – On Launch Pad 17-B at Cape Canaveral Air Force Station, solid rocket boosters are installed on a Delta II rocket for launch of the STSS Demonstrator spacecraft. The spacecraft is a midcourse tracking technology demonstrator, part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency on July 29. Photo credit: NASA/Kim Shiflett
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Ascent Guidance for a Winged Boost Vehicle. M.S. Thesis
NASA Technical Reports Server (NTRS)
Corvin, Michael Alexander
1988-01-01
The objective of the advanced ascent guidance study was to investigate guidance concepts which could contribute to increased autonomy during ascent operations in a winged boost vehicle such as the proposed Shuttle II. The guidance scheme was required to yield near a full-optimal ascent in the presence of vehicle system and environmental dispersions. The study included consideration of trajectory shaping issues, trajectory design, closed loop and predictive adaptive guidance techniques and control of dynamic pressure by throttling. An extensive ascent vehicle simulation capability was developed for use in the study.
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The Meteor and Fireball Network of the Sociedad Malagueña de Astronomía
NASA Astrophysics Data System (ADS)
Aznar, J. C.; Castellón, A.; Gálvez, F.; Martínez, E.; Troughton, B.; Núñez, J. M.; Villalba, F.
2016-12-01
One of the most active fields in which has been dedicated the Málaga Astronomical Society (SMA) is the meteors and meteor showers. Since 2006 the SMA refers parts of visual observations and photographic detections from El Pinillo station (Torremolinos, Spain). In 2013 it was decided to give an extra boost to get a camera network that allowed the calculation of the atmospheric trajectory of a meteoroid and, where possible, obtaining the orbital elements.
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2009-07-23
CAPE CANAVERAL, Fla. – In the Astrotech payload processing facility in Titusville, Fla. , technicians monitor the STSS Demonstrator SV-1 spacecraft as it is lowered to the orbital insertion system. The spacecraft is a midcourse tracking technology demonstrator, part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency in late summer. Photo credit: NASA/Tim Jacobs (Approved for Public Release 09-MDA-4800 [30 July 09] )
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2009-04-21
CAPE CANAVERAL, Fla. – On Launch Pad 17-B at Cape Canaveral Air Force Station, workers monitor the placement of a solid rocket booster on a Delta II rocket for launch of the STSS Demonstrator spacecraft. The spacecraft is a midcourse tracking technology demonstrator, part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency on July 29. Photo credit: NASA/Kim Shiflett
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2009-05-01
CAPE CANAVERAL, Fla. – A flatbed truck carrying the STSS Demonstrator SV-2spacecraft arrives at the Astrotech payload processing facility in Titusville, Fla. The spacecraft is a midcourse tracking technology demonstrator, part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency in late summer. Photo credit: NASA/Jack Pfaller (Approved for Public Release 09-MDA-4616 [27 May 09])
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2009-07-23
CAPE CANAVERAL, Fla. – In the Astrotech payload processing facility in Titusville, Fla. , the STSS Demonstrator SV-1 spacecraft is lowered toward the orbital insertion system. The spacecraft is a midcourse tracking technology demonstrator, part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency in late summer. Photo credit: NASA/Tim Jacobs (Approved for Public Release 09-MDA-4800 [30 July 09] )
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2009-06-25
CAPE CANAVERAL, Fla. – The flatbed truck with the SV-1 cargo of the STSS Demonstrator spacecraft arrives at the Astrotech payload processing facility in Titusville, Fla. The spacecraft is a midcourse tracking technology demonstrator, part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency in late summer. Photo credit: NASA/Kim Shiflett (Approved for Public Release 09-MDA-4804 [4 Aug 09] )
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2009-07-23
CAPE CANAVERAL, Fla. – In the Astrotech payload processing facility in Titusville, Fla. , technicians monitor the STSS Demonstrator SV-1 spacecraft as it is lowered to the orbital insertion system. The spacecraft is a midcourse tracking technology demonstrator, part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency in late summer. Photo credit: NASA/Tim Jacobs (Approved for Public Release 09-MDA-4800 [30 July 09] )
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2009-07-23
CAPE CANAVERAL, Fla. – In the Astrotech payload processing facility in Titusville, Fla. , the STSS Demonstrator SV-1 spacecraft is being moved to a stand. The spacecraft is a midcourse tracking technology demonstrator, part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency in late summer. Photo credit: NASA/Tim Jacobs (Approved for Public Release 09-MDA-4800 [30 July 09] )
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2009-05-01
CAPE CANAVERAL, Fla. – The STSS Demonstrator SV-2spacecraft is moved inside a building at the Astrotech payload processing facility in Titusville, Fla. The spacecraft is a midcourse tracking technology demonstrator, part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency in late summer. Photo credit: NASA/Jack Pfaller (Approved for Public Release 09-MDA-4616 [27 May 09])
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2009-06-25
CAPE CANAVERAL, Fla. – The SV-1 cargo of the STSS Demonstrator spacecraft is moved into the Astrotech payload processing facility in Titusville, Fla. The spacecraft is a midcourse tracking technology demonstrator, part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency in late summer. Photo credit: NASA/Kim Shiflett (Approved for Public Release 09-MDA-4804 [4 Aug 09] )
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2009-07-23
CAPE CANAVERAL, Fla. – In the Astrotech payload processing facility in Titusville, Fla. , the STSS Demonstrator SV-1 spacecraft is lowered to the orbital insertion system. The spacecraft is a midcourse tracking technology demonstrator, part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency in late summer. Photo credit: NASA/Tim Jacobs (Approved for Public Release 09-MDA-4800 [30 July 09] )
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2009-07-23
CAPE CANAVERAL, Fla. – In the Astrotech payload processing facility in Titusville, Fla. , the STSS Demonstrator SV-1 spacecraft is moved toward the orbital insertion system. The spacecraft is a midcourse tracking technology demonstrator, part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency in late summer. Photo credit: NASA/Tim Jacobs (Approved for Public Release 09-MDA-4800 [30 July 09] )
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2009-07-23
CAPE CANAVERAL, Fla. – The shipping crate is being removed from the STSS Demonstrator SV-1 spacecraft in the Astrotech payload processing facility in Titusville, Fla. The spacecraft is a midcourse tracking technology demonstrator, part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency in late summer. Photo credit: NASA/Tim Jacobs (Approved for Public Release 09-MDA-4800 [30 July 09] )
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2009-04-21
CAPE CANAVERAL, Fla. – On Launch Pad 17-B at Cape Canaveral Air Force Station, a worker monitors the placement of a solid rocket booster on a Delta II rocket for launch of the STSS Demonstrator spacecraft. The spacecraft is a midcourse tracking technology demonstrator, part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency on July 29. Photo credit: NASA/Kim Shiflett
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2009-07-23
CAPE CANAVERAL, Fla. – In the Astrotech payload processing facility in Titusville, Fla. , the STSS Demonstrator SV-1 spacecraft is lowered onto a stand. The spacecraft is a midcourse tracking technology demonstrator, part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency in late summer. Photo credit: NASA/Tim Jacobs (Approved for Public Release 09-MDA-4800 [30 July 09] )
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2009-04-16
CAPE CANAVERAL, Fla. – On Launch Complex 17-B at Cape Canaveral Air Force Station, the first stage of the Delta II rocket waits on the gantry for the solid rocket boosters. The STSS Demonstrators is a midcourse tracking technology demonstrator and is part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency on July 29. Photo credit: NASA/Kim Shiflett
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2009-06-25
CAPE CANAVERAL, Fla. – The flatbed truck with the SV-1 cargo of the STSS Demonstrator spacecraft arrives at the Astrotech payload processing facility in Titusville, Fla. The spacecraft is a midcourse tracking technology demonstrator, part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency in late summer. Photo credit: NASA/Kim Shiflett (Approved for Public Release 09-MDA-4804 [4 Aug 09] )
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2009-07-23
CAPE CANAVERAL, Fla. – In the Astrotech payload processing facility in Titusville, Fla. , the STSS Demonstrator SV-1 spacecraft is lifted from its shipping crate. The spacecraft is a midcourse tracking technology demonstrator, part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency in late summer. Photo credit: NASA/Tim Jacobs (Approved for Public Release 09-MDA-4800 [30 July 09] )
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2009-07-23
CAPE CANAVERAL, Fla. – In the Astrotech payload processing facility in Titusville, Fla. , the STSS Demonstrator SV-1 spacecraft is lifted clear from its shipping crate. The spacecraft is a midcourse tracking technology demonstrator, part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency in late summer. Photo credit: NASA/Tim Jacobs (Approved for Public Release 09-MDA-4800 [30 July 09] )
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2009-07-23
CAPE CANAVERAL, Fla. – In the Astrotech payload processing facility in Titusville, Fla. , technicians get ready to remove the overhead crane from the STSS Demonstrator SV-1 spacecraft. The spacecraft is a midcourse tracking technology demonstrator, part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency in late summer. Photo credit: NASA/Tim Jacobs (Approved for Public Release 09-MDA-4800 [30 July 09] )
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2009-04-16
CAPE CANAVERAL, Fla. – On Launch Complex 17-B at Cape Canaveral Air Force Station, the mobile service tower encloses the first stage of the Delta II rocket. The boosters in the tower will be attached to the rocket for launch of the STSS Demonstrator spacecraft. The STSS Demonstrators is a midcourse tracking technology demonstrator and is part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency on July 29. Photo credit: NASA/Kim Shiflett
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2009-04-16
CAPE CANAVERAL, Fla. – On Launch Complex 17-B at Cape Canaveral Air Force Station, solid rocket boosters are lifted into the mobile service tower. The boosters will be attached to the Delta II rocket that will launch the STSS Demonstrator spacecraft. The STSS Demonstrators is a midcourse tracking technology demonstrator and is part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency on July 29. Photo credit: NASA/Kim Shiflett
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2009-04-16
CAPE CANAVERAL, Fla. – On Launch Complex 17-B at Cape Canaveral Air Force Station, solid rocket boosters are lifted into the mobile service tower. The boosters will be attached to the Delta II rocket that will launch the STSS Demonstrator spacecraft. The STSS Demonstrators is a midcourse tracking technology demonstrator and is part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency on July 29. Photo credit: NASA/Kim Shiflett
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2009-05-01
CAPE CANAVERAL, Fla. – At NASA Kennedy Space Center's Shuttle Landing Facility, the shipping container with the STSS Demonstrator SV-2spacecraft is secured on a trailer for transfer to the Astrotech payload processing facility in Titusville, Fla. The spacecraft is a midcourse tracking technology demonstrator, part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency in late summer. Photo credit: NASA/Jack Pfaller (Approved for Public Release 09-MDA-4616 [27 May 09])
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2009-05-01
CAPE CANAVERAL, Fla. – At NASA Kennedy Space Center's Shuttle Landing Facility, the shipping container with the STSS Demonstrator SV-2spacecraft is secured on a trailer for transfer to the Astrotech payload processing facility in Titusville, Fla. The spacecraft is a midcourse tracking technology demonstrator, part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency in late summer. Photo credit: NASA/Jack Pfaller (Approved for Public Release 09-MDA-4616 [27 May 09])
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2009-07-23
CAPE CANAVERAL, Fla. – In the Astrotech payload processing facility in Titusville, Fla. , technicians check equipment on the STSS Demonstrator SV-1 spacecraft after it was lowered onto the orbital insertion system. The spacecraft is a midcourse tracking technology demonstrator, part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency in late summer. Photo credit: NASA/Tim Jacobs (Approved for Public Release 09-MDA-4800 [30 July 09] )
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2009-06-25
CAPE CANAVERAL, Fla. – At NASA Kennedy Space Center's Shuttle Landing Facility, the SV-1 cargo of the STSS Demonstrator spacecraft is moved onto a flatbed truck for transfer to the Astrotech payload processing facility in Titusville, Fla. The spacecraft is a midcourse tracking technology demonstrator, part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency in late summer. Photo credit: NASA/Kim Shiflett (Approved for Public Release 09-MDA-4804 [4 Aug 09] )
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2009-04-15
CAPE CANAVERAL, Fla. – On Cape Canaveral Air Force Station's Launch Complex 17-B in Florida, the first stage of a Delta II rocket is lifted into the mobile service tower. The rocket is the launch vehicle for the STSS Demonstrators Program. STSS Demonstrators Program is a midcourse tracking technology demonstrator and is part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency on July 29. Photo credit: NASA/Jack Pfaller
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2009-06-25
CAPE CANAVERAL, Fla. – At NASA Kennedy Space Center's Shuttle Landing Facility, the flatbed truck with the SV-1 cargo of the STSS Demonstrator spacecraft begins moving to the Astrotech payload processing facility in Titusville, Fla. The spacecraft is a midcourse tracking technology demonstrator, part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency in late summer. Photo credit: NASA/Kim Shiflett (Approved for Public Release 09-MDA-4804 [4 Aug 09] )
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2009-04-15
CAPE CANAVERAL, Fla. – On Cape Canaveral Air Force Station's Launch Complex 17-B in Florida, workers check the first stage of a Delta II rocket before it is lifted into the mobile service tower. The rocket is the launch vehicle for the STSS Demonstrators Program. STSS Demonstrators Program is a midcourse tracking technology demonstrator and is part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency on July 29. Photo credit: NASA/Jack Pfaller
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2009-04-15
CAPE CANAVERAL, Fla. – On Cape Canaveral Air Force Station's Launch Complex 17-B in Florida, the first stage of a Delta II rocket is ready to be lifted into the mobile service tower. The rocket is the launch vehicle for the STSS Demonstrators Program. STSS Demonstrators Program is a midcourse tracking technology demonstrator and is part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency on July 29. Photo credit: NASA/Jack Pfaller
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2009-04-16
CAPE CANAVERAL, Fla. – On Launch Complex 17-B at Cape Canaveral Air Force Station, the mobile service tower at right moves toward the first stage of the Delta II rocket. The boosters in the tower will be attached to the rocket for launch of the STSS Demonstrator spacecraft. The STSS Demonstrators is a midcourse tracking technology demonstrator and is part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency on July 29. Photo credit: NASA/Kim Shiflett
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2009-04-16
CAPE CANAVERAL, Fla. – On Launch Complex 17-B at Cape Canaveral Air Force Station, the mobile service tower at right moves closer to the first stage of the Delta II rocket. The boosters in the tower will be attached to the rocket for launch of the STSS Demonstrator spacecraft. The STSS Demonstrators is a midcourse tracking technology demonstrator and is part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency on July 29. Photo credit: NASA/Kim Shiflett
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2009-04-16
CAPE CANAVERAL, Fla. – On Launch Complex 17-B at Cape Canaveral Air Force Station, a third solid rocket booster is raised from the transporter. It will join the others in the mobile service tower for attachment to the Delta II rocket that will launch the STSS Demonstrator spacecraft. The STSS Demonstrators is a midcourse tracking technology demonstrator and is part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency on July 29. Photo credit: NASA/Kim Shiflett
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2009-04-16
CAPE CANAVERAL, Fla. – On Launch Complex 17-B at Cape Canaveral Air Force Station, a third solid rocket booster is raised from the transporter. It will join the others in the mobile service tower for attachment to the Delta II rocket that will launch the STSS Demonstrator spacecraft. The STSS Demonstrators is a midcourse tracking technology demonstrator and is part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency on July 29. Photo credit: NASA/Kim Shiflett
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2009-04-16
CAPE CANAVERAL, Fla. – On Launch Complex 17-B at Cape Canaveral Air Force Station, a third solid rocket booster is lifted into the mobile service tower next to the other two. The boosters will be attached to the Delta II rocket that will launch the STSS Demonstrator spacecraft. The STSS Demonstrators is a midcourse tracking technology demonstrator and is part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency on July 29. Photo credit: NASA/Kim Shiflett
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2009-05-01
CAPE CANAVERAL, Fla. – At NASA Kennedy Space Center's Shuttle Landing Facility, the shipping container with the STSS Demonstrator SV-2spacecraft moves out of the U.S. Air Force C-17 aircraft. The spacecraft will be transferred to the Astrotech payload processing facility in Titusville, Fla. The spacecraft is a midcourse tracking technology demonstrator, part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency in late summer. Photo credit: NASA/Jack Pfaller (Approved for Public Release 09-MDA-4616 [27 May 09])
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2009-04-15
CAPE CANAVERAL, Fla. – On Cape Canaveral Air Force Station's Launch Complex 17-B in Florida, the first stage of a Delta II rocket is raised to vertical before it can be moved into the mobile service tower for processing. The rocket is the launch vehicle for the STSS Demonstrators Program. STSS Demonstrators Program is a midcourse tracking technology demonstrator and is part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency on July 29. Photo credit: NASA/Jack Pfaller
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2009-04-15
CAPE CANAVERAL, Fla. – The first stage of a Delta II rocket arrives on Cape Canaveral Air Force Station's Launch Complex 17-B in Florida. The rocket is the launch vehicle for the STSS Demonstrators Program and will be raised and lifted into the mobile service tower for processing. STSS Demonstrators Program is a midcourse tracking technology demonstrator and is part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency on July 29. Photo credit: NASA/Jack Pfaller
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2009-04-15
CAPE CANAVERAL, Fla. – The first stage of a Delta II rocket arrives on Cape Canaveral Air Force Station's Launch Complex 17-B in Florida. The rocket is the launch vehicle for the STSS Demonstrators Program and will be raised and lifted into the mobile service tower for processing. STSS Demonstrators Program is a midcourse tracking technology demonstrator and is part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency on July 29. Photo credit: NASA/Jack Pfaller
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2009-04-15
CAPE CANAVERAL, Fla. – On Cape Canaveral Air Force Station's Launch Complex 17-B in Florida, after being raised to vertical, the first stage of a Delta II rocket will be lifted into the mobile service tower on for processing. The rocket is the launch vehicle for the STSS Demonstrators Program. STSS Demonstrators Program is a midcourse tracking technology demonstrator and is part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency on July 29. Photo credit: NASA/Jack Pfaller
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2009-05-01
CAPE CANAVERAL, Fla. – The U.S. Air Force C-17 aircraft arrives at NASA Kennedy Space Center's Shuttle Landing Facility with its cargo of the STSS Demonstrator SV-2 spacecraft. The spacecraft will be transferred to the Astrotech payload processing facility in Titusville, Fla. The spacecraft is a midcourse tracking technology demonstrator, part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency in late summer. Photo credit: NASA/Jack Pfaller (Approved for Public Release 09-MDA-4616 [27 May 09])
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2009-06-25
CAPE CANAVERAL, Fla. – The U.S. Air Force C-17 aircraft arrives at NASA Kennedy Space Center's Shuttle Landing Facility with its SV-1 cargo of the STSS Demonstrator spacecraft. The cargo will be transferred to the Astrotech payload processing facility in Titusville, Fla. The spacecraft is a midcourse tracking technology demonstrator, part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency in late summer. Photo credit: NASA/Kim Shiflett (Approved for Public Release 09-MDA-4804 [4 Aug 09] )
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2009-06-25
CAPE CANAVERAL, Fla. – At NASA Kennedy Space Center's Shuttle Landing Facility, the SV-1 cargo of the STSS Demonstrator spacecraft moves out of the U.S. Air Force C-17. The cargo will be transferred to the Astrotech payload processing facility in Titusville, Fla. The spacecraft is a midcourse tracking technology demonstrator, part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency in late summer. Photo credit: NASA/Kim Shiflett (Approved for Public Release 09-MDA-4804 [4 Aug 09] )
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2009-04-15
CAPE CANAVERAL, Fla. – On Cape Canaveral Air Force Station's Launch Complex 17-B in Florida, the first stage of a Delta II rocket is prepared to lift it into the mobile service tower for processing. The rocket is the launch vehicle for the STSS Demonstrators Program . STSS Demonstrators Program is a midcourse tracking technology demonstrator and is part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency on July 29. Photo credit: NASA/Jack Pfaller
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2009-04-15
CAPE CANAVERAL, Fla. – On Cape Canaveral Air Force Station's Launch Complex 17-B in Florida, the first stage of a Delta II rocket is raised to vertical before it can be moved into the mobile service tower for processing. The rocket is the launch vehicle for the STSS Demonstrators Program. STSS Demonstrators Program is a midcourse tracking technology demonstrator and is part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency on July 29. Photo credit: NASA/Jack Pfaller
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2009-05-01
CAPE CANAVERAL, Fla. – At NASA Kennedy Space Center's Shuttle Landing Facility, more equipment for the STSS Demonstrator SV-2 spacecraft is offloaded from the U.S. Air Force C-17 aircraft. The spacecraft will be transferred to the Astrotech payload processing facility in Titusville, Fla.The spacecraft is a midcourse tracking technology demonstrator, part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency in late summer. Photo credit: NASA/Jack Pfaller (Approved for Public Release 09-MDA-4616 [27 May 09])
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2009-06-25
CAPE CANAVERAL, Fla. – At NASA Kennedy Space Center's Shuttle Landing Facility, the SV-1 cargo of the STSS Demonstrator spacecraft moves out of the U.S. Air Force C-17. The cargo will be transferred to the Astrotech payload processing facility in Titusville, Fla. The spacecraft is a midcourse tracking technology demonstrator, part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency in late summer. Photo credit: NASA/Kim Shiflett (Approved for Public Release 09-MDA-4804 [4 Aug 09] )
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2009-04-16
CAPE CANAVERAL, Fla. – On Launch Complex 17-B at Cape Canaveral Air Force Station, the first stage of the Delta II rocket in the background waits for the mobile service tower and the solid rocket boosters (top foreground) that will be attached. The Delta II is the launch vehicle for the STSS Demonstrator spacecraft. The STSS Demonstrators is a midcourse tracking technology demonstrator and is part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency on July 29. Photo credit: NASA/Kim Shiflett
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2009-05-01
CAPE CANAVERAL, Fla. – At NASA Kennedy Space Center's Shuttle Landing Facility, the shipping container with the STSS Demonstrator SV-2spacecraft has been moved out of the U.S. Air Force C-17 aircraft. The spacecraft will be transferred to the Astrotech payload processing facility in Titusville, Fla. The spacecraft is a midcourse tracking technology demonstrator, part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency in late summer. Photo credit: NASA/Jack Pfaller (Approved for Public Release 09-MDA-4616 [27 May 09])
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2009-05-01
CAPE CANAVERAL, Fla. – At NASA Kennedy Space Center's Shuttle Landing Facility, the shipping container with the STSS Demonstrator SV-2spacecraft waits to be offloaded from the U.S. Air Force C-17 aircraft. The spacecraft will be transferred to the Astrotech payload processing facility in Titusville, Fla. The spacecraft is a midcourse tracking technology demonstrator, part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency in late summer. Photo credit: NASA/Jack Pfaller (Approved for Public Release 09-MDA-4616 [27 May 09])
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2009-04-15
CAPE CANAVERAL, Fla. – On Cape Canaveral Air Force Station's Launch Complex 17-B in Florida, the first stage of a Delta II rocket is lifted off its transporter. It will be raised to vertical and lifted into the mobile service tower for processing. The rocket is the launch vehicle for the STSS Demonstrators Program. STSS Demonstrators Program is a midcourse tracking technology demonstrator and is part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency on July 29. Photo credit: NASA/Jack Pfaller
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2009-05-01
CAPE CANAVERAL, Fla. – At NASA Kennedy Space Center's Shuttle Landing Facility, workers move STSS Demonstrator SV-2 spacecraft equipment out of the cargo hold of the U.S. Air Force C-17 aircraft. The spacecraft will be transferred to the Astrotech payload processing facility in Titusville, Fla. The spacecraft is a midcourse tracking technology demonstrator, part of an evolving ballistic missile defense system. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency in late summer. Photo credit: NASA/Jack Pfaller (Approved for Public Release 09-MDA-4616 [27 May 09])
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Moser, Stephanie E.; West, Stephen G.; Hughes, Jan N.
2012-01-01
This study investigated the effects of retention or promotion in first grade on growth trajectories in mathematics and reading achievement over the elementary school years (grades 1–5). From a large multiethnic sample (n = 784) of children who were below the median in literacy at school entrance, 363 children who were either promoted (n = 251) or retained (n = 112) in first grade could be successfully matched on 72 background variables. Achievement was measured annually using Woodcock-Johnson W scores; scores of retained children were shifted back one year to permit same-grade comparisons. Using longitudinal growth curve analysis, trajectories of math and reading scores for promoted and retained children were compared. Retained children received a one year boost in achievement; this boost fully dissipated by the end of elementary school. The pattern of subsequent retention in grades 2, 3 and 4 and placement in special education of the sample during the elementary school years is also described and their effects are explored. Policy implications for interventions for low achieving children are considered. PMID:23335818
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Unified description of Bjorken and Landau 1+1 hydrodynamics
NASA Astrophysics Data System (ADS)
Bialas, A.; Janik, R. A.; Peschanski, R.
2007-11-01
We propose a generalization of the Bjorken in-out Ansatz for fluid trajectories, which, when applied to the 1+1 hydrodynamic equations, generates a one-parameter family of analytic solutions interpolating between the boost-invariant Bjorken picture and the non-boost-invariant one by Landau. This parameter characterizes the proper-time scale when the fluid velocities approach the in-out Ansatz. We discuss the resulting rapidity distribution of entropy for various freeze-out conditions and compare it with the original Bjorken and Landau results.
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2009-08-03
CAPE CANAVERAL, Fla. –At the Astrotech payload processing facility in Titusville, Fla., the SV1 spacecraft is lowered onto the SV2 for mating. The two spacecraft are part of the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, Program. The STSS Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Jim Grossmann
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2009-08-03
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., the SV1 spacecraft is lowered onto the SV2 for mating. The two spacecraft are part of the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, Program. The STSS Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Jim Grossmann
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2009-08-03
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., the SV1 spacecraft is lowered toward the SV2 for mating. The two spacecraft are part of the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, Program. The STSS Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Jim Grossmann
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2009-08-03
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., workers check the mating of the SV1 spacecraft onto the SV2. The two spacecraft are part of the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, Program. The STSS Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Jim Grossmann
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2009-08-03
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., the SV1 and SV2 spacecraft are ready for mating for launch. The two spacecraft are part of the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, Program. STSS-Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. The spacecraft is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Jim Grossmann
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Lunar Orbiter 4 - Photographic Mission Summary. Volume 1
NASA Technical Reports Server (NTRS)
1968-01-01
Photographic summary report of Lunar Orbiter 4 mission. The fourth of five Lunar Orbiter spacecraft was successfully launched from Launch Complex 13 at the Air Force Eastern Test Range by an Atlas-Agena launch vehicle at 22:25 GMT on May 4, 1967. Tracking data from the Cape Kennedy and Grand Bahama tracking stations were used to control and guide the launch vehicle during Atlas powered flight. The Agena-spacecraft combination was boosted to the proper coast ellipse by the Atlas booster prior to separation. Final maneuvering and acceleration to the velocity required to maintain the 100-nauticalmile- altitude Earth orbit was controlled by the preset on-board Agena computer. In addition, the Agena computer determined the maneuver and engine-burn period required to inject the spacecraft on the cislunar trajectory 20 minutes after launch. Tracking data from the downrange stations and the Johannesburg, South Africa station were used to monitor the boost trajectory.
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Lunar Orbiter 5. Photographic Mission Summary. Volume 1
NASA Technical Reports Server (NTRS)
1968-01-01
Selected photographs and mission summary of Lunar Orbiter 5. The last of five Lunar Orbiter spacecraft was successfully launched from Launch Complex 13 at the Air Force Eastern Test Range by an Atlas-Agena launch vehicle at 22:33 GMT on August 1, 1967. Tracking data from the Cape Kennedy and Grand Bahama tracking stations were used to control and guide the launch vehicle during Atlas powered flight. The Agena-spacecraft combination was boosted to the proper coast ellipse by the Atlas booster prior to separation. Final maneuvering and acceleration to the velocity required to maintain the 100-nautical-mile-altitude Earth orbit were controlled by the preset on-board Agena computer. In addition, the Agena computer determined the maneuver and engine-bum period required to inject the spacecraft on the cislunar trajectory about 33 minutes after launch. Tracking data from the downrange stations and the Johannesburg, South Africa station were used to monitor the boost trajectory.
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Lunar Orbiter 3 - Photographic Mission Summary
NASA Technical Reports Server (NTRS)
1968-01-01
Systems performance, lunar photography, and launch operations of Lunar Orbiter 3 photographic mission. The third of five Lunar Orbiter spacecraft was successfully launched from Launch Complex 13 at the Air Force Eastern Test Range by an Atlas-Agena launch vehicle at 01:17 GMT on February 5,1967. Tracking data from the Cape Kennedy and Grand Bahama tracking stations were used to control and guide the launch vehicle during Atlas powered flight. The Agena-spacecraft combination was boosted to the proper coast ellipse by the Atlas booster prior to separation. Final 1 maneuvering and acceleration to the velocity required to maintain the 100-nautical-milealtitude Earth orbit was controlled by the preset on-board Agena computer. In addition, the Agena computer determined the maneuver and engine-burn period required to inject the spacecraft on the cislunar trajectory 20 minutes after launch. Tracking data from the downrange stations and the Johannesburg, South Africa station were used to monitor the entire boost trajectory.
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Automated Transfer Vehicle (ATV) Critical Safety Software Overview
NASA Astrophysics Data System (ADS)
Berthelier, D.
2002-01-01
The European Automated Transfer Vehicle is an unmanned transportation system designed to dock to International Space Station (ISS) and to contribute to the logistic servicing of the ISS. Concisely, ATV control is realized by a nominal flight control function (using computers, softwares, sensors, actuators). In order to cover the extreme situations where this nominal chain can not ensure safe trajectory with respect to ISS, a segregated proximity flight safety function is activated, where unsafe free drift trajectories can be encountered. This function relies notably on a segregated computer, the Monitoring and Safing Unit (MSU) ; in case of major ATV malfunction detection, ATV is then controlled by MSU software. Therefore, this software is critical because a MSU software failure could result in catastrophic consequences. This paper provides an overview both of this software functions and of the software development and validation method which is specific considering its criticality. First part of the paper describes briefly the proximity flight safety chain. Second part deals with the software functions. Indeed, MSU software is in charge of monitoring nominal computers and ATV corridors, using its own navigation algorithms, and, if an abnormal situation is detected, it is in charge of the ATV control during the Collision Avoidance Manoeuvre (CAM) consisting in an attitude controlled braking boost, followed by a Post-CAM manoeuvre : a Sun-pointed ATV attitude control during up to 24 hours on a safe trajectory. Monitoring, navigation and control algorithms principles are presented. Third part of this paper describes the development and validation process : algorithms functional studies , ADA coding and unit validations ; algorithms ADA code integration and validation on a specific non real-time MATLAB/SIMULINK simulator ; global software functional engineering phase, architectural design, unit testing, integration and validation on target computer.
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2009-08-03
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., a crane moves the SV1 spacecraft, which will be mated with the SV2 at right. The two spacecraft are part of the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, Program. STSS-Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. The spacecraft is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Jim Grossmann
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2009-08-03
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., a crane moves the SV1 spacecraft, toward the SV2 at right. The two spacecraft , which will be mated, are part of the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, Program. The STSS Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Jim Grossmann
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2009-09-12
CAPE CANAVERAL, Fla. – The two halves of the fairing are moved into the mobile service tower on Launch Pad 17-B at Cape Canaveral Air Force Station in Florida. The two-part fairing will be placed around the Space Tracking and Surveillance System – Demonstrator spacecraft for protection during launch. STSS Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detection, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-4934 (09-22-09) Photo credit: NASA/Cory Huston
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2009-08-03
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., workers help guide the movement of the SV1 spacecraft as it is moved toward the SV2 at right. The two spacecraft are part of the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, Program. The STSS Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Jim Grossmann
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2009-08-03
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., workers help guide the movement of the SV1 spacecraft as it is moved toward the SV2 behind it. The two spacecraft are part of the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, Program. The STSS Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Jim Grossmann
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2009-08-03
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., workers observe as the SV1 spacecraft is lowered onto the SV2 for mating. The two spacecraft are part of the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, Program. The STSS Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Jim Grossmann
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2009-08-03
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., a worker checks the mating of the SV1 spacecraft onto the SV2. The two spacecraft are part of the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, Program. The STSS Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Jim Grossmann
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2009-08-03
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., workers help guide the movement of the SV1 spacecraft as it is moved toward the SV2 at right. The two spacecraft are part of the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, Program. The STSS Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Jim Grossmann
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LOKI WIND CORRECTION COMPUTER AND WIND STUDIES FOR LOKI
which relates burnout deviation of flight path with the distributed wind along the boost trajectory. The wind influence function was applied to...electrical outputs. A complete wind correction computer system based on the influence function and the results of wind studies was designed.
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Ares I-X Test Flight Reference Trajectory Development
NASA Technical Reports Server (NTRS)
Starr, Brett R.; Gumbert, Clyde R.; Tartabini, Paul V.
2011-01-01
Ares I-X was the first test flight of NASA's Constellation Program's Ares I crew launch vehicle. Ares I is a two stage to orbit launch vehicle that provides crew access to low Earth orbit for NASA's future manned exploration missions. The Ares I first stage consists of a Shuttle solid rocket motor (SRM) modified to include an additional propellant segment and a liquid propellant upper stage with an Apollo J2X engine modified to increase its thrust capability. The modified propulsion systems were not available for the first test flight, thus the test had to be conducted with an existing Shuttle 4 segment reusable solid rocket motor (RSRM) and an inert Upper Stage. The test flight's primary objective was to demonstrate controllability of an Ares I vehicle during first stage boost and the ability to perform a successful separation. In order to demonstrate controllability, the Ares I-X ascent control algorithms had to maintain stable flight throughout a flight environment equivalent to Ares I. The goal of the test flight reference trajectory development was to design a boost trajectory using the existing RSRM that results in a flight environment equivalent to Ares I. A trajectory similarity metric was defined as the integrated difference between the Ares I and Ares I-X Mach versus dynamic pressure relationships. Optimization analyses were performed that minimized the metric by adjusting the inert upper stage weight and the ascent steering profile. The sensitivity of the optimal upper stage weight and steering profile to launch month was also investigated. A response surface approach was used to verify the optimization results. The analyses successfully defined monthly ascent trajectories that matched the Ares I reference trajectory dynamic pressure versus Mach number relationship to within 10% through Mach 3.5. The upper stage weight required to achieve the match was found to be feasible and varied less than 5% throughout the year. The paper will discuss the flight test requirements, provide Ares I-X vehicle background, discuss the optimization analyses used to meet the requirements, present analysis results, and compare the reference trajectory to the reconstructed flight trajectory.
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Mechanisms to deploy the two-stage IUS from the shuttle cargo bay
NASA Technical Reports Server (NTRS)
Haynie, H. T.
1980-01-01
The Inertial Upper Stage (IUS) is a two-stage or three-stage booster used to transport spacecraft from the space shuttle orbit to synchronous orbit or on an interplanetary trajectory. The mechanisms which were designed specifically to perform the two-stage IUS required functions while contained within the cargo bay of the space shuttle during the boost phase and while in a low Earth orbit are discussed. The requirements, configuration, and operation of the mechanisms are described, with particular emphasis on the tilt actuator and the mechanism for decoupling the actuators during boost to eliminate redundant load paths.
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Teaching Classroom Management-- A Potential Public Health Intervention?
ERIC Educational Resources Information Center
Marlow, Ruth; Hansford, Lorraine; Edwards, Vanessa; Ukoumunne, Obioha C; Norman, Shelley; Ingarfield, Sara; Sharkey, Siobhan; Logan, Stuart; Ford, Tamsin
2015-01-01
Purpose: The purpose of this paper is to explore the feasibility of a classroom management course as a public health intervention. Improved socio-emotional skills may boost children's developmental and academic trajectory, while the costs of behaviour problems are enormous for schools with considerable impact on others' well-being.…
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2009-08-03
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., a crane is attached to the SV1 spacecraft, part of the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, Program. The SV1 will be lifted and moved to mate with the SV2 on another stand nearby. STSS-Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. The spacecraft is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Jim Grossmann
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2009-08-19
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., this closeup shows part of the mated SV1 and SV2 spacecraft, which is being prepared for center of gravity testing, weighing and balancing. The two spacecraft are known as the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, which is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Jim Grossmann
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Experiences in Delta mission planning
NASA Technical Reports Server (NTRS)
Kork, J.
1981-01-01
The Delta launch vehicle has experienced 153 successful launches since 1960 and 40 more are scheduled. Relying on up-to-date technology and proven flight hardware, the Delta vehicle has been used for low to high circular and geosynchronous transfer orbits, high elliptic probes, and lunar and planetary missions. A history of Delta launches and configuration modifications is presented, noting a 92-95% success rate and its cost effective role in reimbursable missions. Elements of mission planning such as feasibility studies (1-3 yrs), spacecraft restraints manuals, reference trajectories, preliminary mission analysis, detailed test objectives, range/safety studies, guided nominal trajectory, and mission specific studies are discussed. Trajectory shaping determines vehicle and spacecraft restraints, optimizes the trajectory, and maximizes the payload capabilities. Improvements in the Delta vehicle have boosted payloads from 100 to 2890 lbs., improving the price per pound ratio, as costs have risen, only by a factor of three. Current launch schedules extend well into 1985.
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Velocity Requirements for Abort From the Boost Trajectory of a Manned Lunar Mission
NASA Technical Reports Server (NTRS)
Slye, Robert E.
1961-01-01
An investigation is made of the abort velocity requirements associated with failure of a propulsion system for a manned lunar mission. Two cases are considered: abort at less than satellite speed, which results in maximum decelerations in the following entry, and abort at greater than satellite speed with immediate return to earth. The velocity requirements associated with the latter problem are found to be substantial (several thousand feet per second) and are found to be even more severe if boost trajectories which lead to burnout at high altitudes or large flight-path angles are used. The velocity requirements associated with abort at less than satellite speed are found to be less severe than those for abort at greater than satellite speed except for nonlifting vehicles. It is found that abort rockets sufficient for abort at greater than satellite speed can be used to reduce maximum decelerations in entries following an abort at lower speeds. This reduction is accomplished by use of the abort rockets to decrease entry angle immediately prior to entry into the atmosphere.
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IMM tracking of a theater ballistic missile during boost phase
NASA Astrophysics Data System (ADS)
Hutchins, Robert G.; San Jose, Anthony
1998-09-01
Since the SCUD launches in the Gulf War, theater ballistic missile (TBM) systems have become a growing concern for the US military. Detection, tracking and engagement during boost phase or shortly after booster cutoff are goals that grow in importance with the proliferation of weapons of mass destruction. This paper addresses the performance of tracking algorithms for TBMs during boost phase and across the transition to ballistic flight. Three families of tracking algorithms are examined: alpha-beta-gamma trackers, Kalman-based trackers, and the interactive multiple model (IMM) tracker. In addition, a variation on the IMM to include prior knowledge of a booster cutoff parameter is examined. Simulated data is used to compare algorithms. Also, the IMM tracker is run on an actual ballistic missile trajectory. Results indicate that IMM trackers show significant advantage in tracking through the model transition represented by booster cutoff.
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Users guide for guidance and control Launch and Abort Simulation for Spacecraft (LASS), volume 1
NASA Technical Reports Server (NTRS)
Havig, T. F.; Backman, H. D.
1972-01-01
The mathematical models and computer program which are used to implement LASS are described. The computer program provides for a simulation of boost to orbit and abort capability from boost trajectories to a prescribed target. The abort target provides a decision point for engine shutdown from which the vehicle coasts to the vicinity of the selected abort recovery site. The simulation is a six degree of freedom simulation describing a rigid body. The vehicle is influenced by forces and moments from nondistributed aerodynamics. An adaptive autopilot is provided to control vehicle attitudes during powered and unpowered flight. A conventional autopilot is provided for study of vehicle during powered flight.
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Trajectory tracking and backfitting techniques against theater ballistic missiles
NASA Astrophysics Data System (ADS)
Hutchins, Robert G.; Britt, Patrick T.
1999-10-01
Since the SCUD launches in the Gulf War, theater ballistic missile (TBM) systems have become a growing concern for the US military. Detection, fast track initiation, backfitting for launch point determination, and tracking and engagement during boost phase or shortly after booster cutoff are goals that grow in importance with the proliferation of weapons of mass destruction. This paper focuses on track initiation and backfitting techniques, as well as extending some earlier results on tracking a TBM during boost phase cutoff. Results indicate that Kalman techniques are superior to third order polynomial extrapolations in estimating the launch point, and that some knowledge of missile parameters, especially thrust, is extremely helpful in track initiation.
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ERIC Educational Resources Information Center
Lei, Serena
2014-01-01
Pre-K has been shown to strongly boost children's learning trajectories. This is as true, or even truer, for children of immigrants and English language learners (ELLs) as for children overall. Children of immigrants, who make up about a quarter of children in the United States, have significantly lower rates of pre-K enrollment, on average, than…
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ERIC Educational Resources Information Center
Lei, Serena
2014-01-01
Pre-K has been shown to strongly boost children's learning trajectories. This is as true, or even truer, for children of immigrants and English language learners (ELLs) as for children overall. Children of immigrants, who make up about a quarter of children in the United States, have significantly lower rates of pre-K enrollment, on average, than…
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Improving Access to Prekindergarten for Children of Immigrants: "Outreach." Fact Sheet No. 1
ERIC Educational Resources Information Center
Lei, Serena
2014-01-01
Pre-K has been shown to strongly boost children's learning trajectories. This is as true, or even truer, for children of immigrants and English language learners (ELLs) as for children overall. Children of immigrants, who make up about a quarter of children in the United States, have significantly lower rates of pre-K enrollment, on average, than…
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NASA Technical Reports Server (NTRS)
Hepler, A. K.; Swegle, A. R.
1981-01-01
The design and fabrication of two large brazed Rene 41 honeycomb panels, the establishment of a test plan, the design and fabrication of a test fixture to subject the panels to cyclic thermal gradients and mechanical loads equivalent to those imposed on an advanced space transportation vehicle during its boost and entry trajectories are discussed. The panels will be supported at four points, creating three spans. The outer spans are 45.7 cm (18 in.) and the center span 76.2 cm (30 in). Specimen width is 30.5 cm (12 in.). The panels were primarily designed by boost conditions simulated by subjecting the panels to liquid nitrogen, 77K (-320 F) on one side and 455K (360 F) on the other side and by mechanically imposing loads representing vehicle fuel pressure loads. Entry conditions were simulated by radiant heating to 1034K (1400 F). The test program subjected the panels to 500 boost thermal conditions. Results are presented.
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2009-09-12
CAPE CANAVERAL, Fla. – Inside the mobile service tower on Launch Pad 17-B at Cape Canaveral Air Force Station in Florida, workers check the progress of the fairing being moved toward the Space Tracking and Surveillance System – Demonstrator spacecraft for encapsulation. The fairing is a two-part molded structure that fits flush with the outside surface of the rocket and forms an aerodynamically smooth nose cone, protecting the spacecraft during launch and ascent. STSS Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detection, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-4934 (09-22-09) Photo credit: NASA/Cory Huston
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2009-09-12
CAPE CANAVERAL, Fla. – Inside the mobile service tower on Launch Pad 17-B at Cape Canaveral Air Force Station in Florida, the Space Tracking and Surveillance System – Demonstrator spacecraft (foreground) is waiting for encapsulation in the fairing, behind it at left. The fairing is a two-part molded structure that fits flush with the outside surface of the rocket and forms an aerodynamically smooth nose cone, protecting the spacecraft during launch and ascent. STSS Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detection, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-4934 (09-22-09) Photo credit: NASA/Cory Huston
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2009-09-12
CAPE CANAVERAL, Fla. – Inside the mobile service tower on Launch Pad 17-B at Cape Canaveral Air Force Station in Florida, workers help guide the fairing (at right) into place around the Space Tracking and Surveillance System – Demonstrator spacecraft for encapsulation. The fairing is a two-part molded structure that fits flush with the outside surface of the rocket and forms an aerodynamically smooth nose cone, protecting the spacecraft during launch and ascent. STSS Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detection, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-4934 (09-22-09) Photo credit: NASA/Cory Huston
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2009-09-12
CAPE CANAVERAL, Fla. – Inside the mobile service tower on Launch Pad 17-B at Cape Canaveral Air Force Station in Florida, the second half of the fairing is being moved toward the Space Tracking and Surveillance System – Demonstrator spacecraft. The fairing is a two-part molded structure that fits flush with the outside surface of the rocket and forms an aerodynamically smooth nose cone, protecting the spacecraft during launch and ascent. STSS Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detection, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-4934 (09-22-09) Photo credit: NASA/Cory Huston
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2009-09-12
CAPE CANAVERAL, Fla. – Inside the mobile service tower on Launch Pad 17-B at Cape Canaveral Air Force Station in Florida, the first half of the two-part fairing is in place around the Space Tracking and Surveillance System – Demonstrator spacecraft. The fairing is a molded structure that fits flush with the outside surface of the rocket and forms an aerodynamically smooth nose cone, protecting the spacecraft during launch and ascent. STSS Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detection, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-4934 (09-22-09) Photo credit: NASA/Cory Huston
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2009-09-12
CAPE CANAVERAL, Fla. – Inside the mobile service tower on Launch Pad 17-B at Cape Canaveral Air Force Station in Florida, the Space Tracking and Surveillance System – Demonstrator spacecraft is waiting for encapsulation in the fairing. The fairing is a two-part molded structure that fits flush with the outside surface of the rocket and forms an aerodynamically smooth nose cone, protecting the spacecraft during launch and ascent. STSS Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detection, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-4934 (09-22-09) Photo credit: NASA/Cory Huston
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NASA Technical Reports Server (NTRS)
Spangelo, Sara; Dalle, Derek; Longmier, Benjamin
2015-01-01
This paper investigates the feasibility of Earth-transfer and interplanetary mission architectures for miniaturized spacecraft using emerging small solar electric propulsion technologies. Emerging small SEP thrusters offer significant advantages relative to existing technologies and will enable U-class systems to perform trajectory maneuvers with significant Delta V requirements. The approach in this paper is unique because it integrates trajectory design with vehicle sizing and accounts for the system and operational constraints of small U-class missions. The modeling framework includes integrated propulsion, orbit, energy, and external environment dynamics and systems-level power, energy, mass, and volume constraints. The trajectory simulation environment models orbit boosts in Earth orbit and flyby and capture trajectories to interplanetary destinations. A family of small spacecraft mission architectures are studied, including altitude and inclination transfers in Earth orbit and trajectories that escape Earth orbit and travel to interplanetary destinations such as Mercury, Venus, and Mars. Results are presented visually to show the trade-offs between competing performance objectives such as maximizing available mass and volume for payloads and minimizing transfer time. The results demonstrate the feasibility of using small spacecraft to perform significant Earth and interplanetary orbit transfers in less than one year with reasonable U-class mass, power, volume, and mission durations.
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ERIC Educational Resources Information Center
Phillips, Deborah A.
2017-01-01
Preschool education is now firmly linked to two aspirational purposes: as the first step on a trajectory of academic and life success for all children and as wise economic policy for the nation. Both purposes are grounded in an assumption that the early developmental boost children receive from preschool will produce lasting impacts. However,…
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Orbiter aborts from boost: Presimulation report
NASA Technical Reports Server (NTRS)
Backman, H. D.; Brechka, K. G.
1972-01-01
A description of a hybrid simulation of the 040C orbiter aborting from boost to specified landing site is provided. The simulation starts when the abort is initiated and continues until a terminal energy state (associated with the selected landing site) is reached. At abort it is assumed that all SRM's are jettisoned with the external tank remaining with the orbiter. The simulation described has six degrees of freedom with the vehicle simulated as a rigid body. A conventional form of autopilot is provided to control engine gimbaling during powered flight. An ideal form of an autopilot is provided to test conventional autopilot function and provide pseudo RCS function during coasting flight. The simulation is proposed to provide means for studies of abort guidance function and to gain information concerning ability to control the abort trajectory.
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NASA Technical Reports Server (NTRS)
Levin, A. D.; Castellano, C. R.; Hague, D. S.
1975-01-01
An aircraft-missile system which performs a high acceleration takeoff followed by a supersonic dash to a 'safe' distance from the launch site is presented. Topics considered are: (1) technological feasibility to the dash on warning concept; (2) aircraft and boost trajectory requirements; and (3) partial cost estimates for a fleet of aircraft which provide 200 missiles on airborne alert. Various aircraft boost propulsion systems were studied such as an unstaged cryogenic rocket, an unstaged storable liquid, and a solid rocket staged system. Various wing planforms were also studied. Vehicle gross weights are given. The results indicate that the dash on warning concept will meet expected performance criteria, and can be implemented using existing technology, such as all-aluminum aircraft and existing high-bypass-ratio turbofan engines.
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50 Sure Fire Ideas for Boosting Morale and Creating a Can-Do Culture.
ERIC Educational Resources Information Center
Baker, John; And Others
This three-part pamphlet presents 52 ideas contributed by 19 administrators at California community colleges for boosting the morale and performance of college administrators and staff. Following a list of contributors, the first part provides 39 suggestions for acknowledging contributions and encouraging staff members, including writing short…
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Trajectory prediction for ballistic missiles based on boost-phase LOS measurements
NASA Astrophysics Data System (ADS)
Yeddanapudi, Murali; Bar-Shalom, Yaakov
1997-10-01
This paper addresses the problem of the estimation of the trajectory of a tactical ballistic missile using line of sight (LOS) measurements from one or more passive sensors (typically satellites). The major difficulties of this problem include: the estimation of the unknown time of launch, incorporation of (inaccurate) target thrust profiles to model the target dynamics during the boost phase and an overall ill-conditioning of the estimation problem due to poor observability of the target motion via the LOS measurements. We present a robust estimation procedure based on the Levenberg-Marquardt algorithm that provides both the target state estimate and error covariance taking into consideration the complications mentioned above. An important consideration in the defense against tactical ballistic missiles is the determination of the target position and error covariance at the acquisition range of a surveillance radar in the vicinity of the impact point. We present a systematic procedure to propagate the target state and covariance to a nominal time, when it is within the detection range of a surveillance radar to obtain a cueing volume. Mont Carlo simulation studies on typical single and two sensor scenarios indicate that the proposed algorithms are accurate in terms of the estimates and the estimator calculated covariances are consistent with the errors.
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NASA Technical Reports Server (NTRS)
Demakes, P. T.; Hirsch, G. N.; Stewart, W. A.; Glatt, C. R.
1976-01-01
Historical weight estimating relationships were developed for the liquid rocket booster (LRB) using Saturn technology, and modified as required to support the EDIN05 study. Mission performance was computed using February 1975 shuttle configuration groundrules to allow reasonable comparison of the existing shuttle with the EDIN05 designs. The launch trajectory was constrained to pass through both the RTLS/AOA and main engine cut-off points. Performance analysis was based on a point design trajectory model which optimized initial tilt rate and exo-atmospheric pitch profile. A gravity turn was employed during the boost phase in place of the shuttle angle-of-attack profile. Engine throttling add/or shutdown was used to constrain dynamic pressure and/or longitudinal acceleration where necessary.
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Lunar Orbiter II - Photographic Mission Summary
NASA Technical Reports Server (NTRS)
1967-01-01
Lunar Orbiter II photography of landing sites, and spacecraft systems performance. The second of five Lunar Orbiter spacecraft was successfully launched from Launch Complex 13 at the Air Force Eastern Test Range by an Atlas-Agena launch vehicle at 23:21 GMT on November 6, 1966. Tracking data from the Cape Kennedy and Grand Bahama tracking stations were used to control and guide the launch vehicle during Atlas powered flight. The Agena spacecraft combination was maneuvered into a 100-nautical-mile-altitude Earth orbit by the preset on-board Agena computer. In addition, the Agena computer determined the maneuver 1 and engine-bum period required to inject the spacecraft on the cislunar trajectory 20 minutes after launch. Tracking data from the downrange stations and the Johannesburg, South Africa station were used to monitor the entire boost trajectory.
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Voltage-Boosting Driver For Switching Regulator
NASA Technical Reports Server (NTRS)
Trump, Ronald C.
1990-01-01
Driver circuit assures availability of 10- to 15-V gate-to-source voltage needed to turn on n-channel metal oxide/semiconductor field-effect transistor (MOSFET) acting as switch in switching voltage regulator. Includes voltage-boosting circuit efficiently providing gate voltage 10 to 15 V above supply voltage. Contains no exotic parts and does not require additional power supply. Consists of NAND gate and dual voltage booster operating in conjunction with pulse-width modulator part of regulator.
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McAuley, Edward; Mailey, Emily L.; Mullen, Sean P.; Szabo, Amanda N.; Wójcicki, Thomas R.; White, Siobhan M.; Gothe, Neha; Olson, Erin A.; Kramer, Arthur F.
2012-01-01
Objective This study examines differential trajectories of exercise-related self-efficacy beliefs across a 12-month randomized controlled exercise trial. Methods Previously inactive older adults (N = 144; M age = 66.5) were randomly assigned to one of two exercise conditions (walking, flexibility-toning-balance) and completed measures of barriers self-efficacy (BARSE), exercise self-efficacy (EXSE), and self-efficacy for walking (SEW) across a 12-month period. Changes in efficacy were examined according to efficacy type and inter-individual differences. Latent growth curve modeling was employed to (a) examine average levels and change in each type of efficacy for the collapsed sample and by intervention condition, and (b) explore subpopulations (i.e., latent classes) within the sample that differ in their baseline efficacy and trajectory. Results Analyses revealed two negative trends in BARSE and EXSE at predicted transition points, in addition to a positive linear trend in SEW. Two subgroups with unique baseline efficacy and trajectory profiles were also identified. Conclusions These results shed new light on the relationship between exercise and self-efficacy in older adults, and highlight the need for strategies for increasing and maintaining efficacy within interventions, namely targeting participants who start with a disadvantage (lower efficacy) and integrating efficacy-boosting strategies for all participants prior to program end. PMID:21038962
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A methodology for boost-glide transport technology planning
NASA Technical Reports Server (NTRS)
Repic, E. M.; Olson, G. A.; Milliken, R. J.
1974-01-01
A systematic procedure is presented by which the relative economic value of technology factors affecting design, configuration, and operation of boost-glide transport can be evaluated. Use of the methodology results in identification of first-order economic gains potentially achievable by projected advances in each of the definable, hypersonic technologies. Starting with a baseline vehicle, the formulas, procedures and forms which are integral parts of this methodology are developed. A demonstration of the methodology is presented for one specific boost-glide system.
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78 FR 14934 - Airworthiness Directives; The Boeing Company Airplanes
Federal Register 2010, 2011, 2012, 2013, 2014
2013-03-08
... discrepancies of the wiring and surrounding Teflon sleeves of the fuel tank boost pumps and override/jettison... the wiring and sleeves with new parts, as necessary. The first SNPRM proposed to reduce the initial... inspections to detect discrepancies of the wiring and surrounding Teflon sleeves of the fuel tank boost pumps...
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Zheng, Qi; Grice, Elizabeth A
2016-10-01
Accurate mapping of next-generation sequencing (NGS) reads to reference genomes is crucial for almost all NGS applications and downstream analyses. Various repetitive elements in human and other higher eukaryotic genomes contribute in large part to ambiguously (non-uniquely) mapped reads. Most available NGS aligners attempt to address this by either removing all non-uniquely mapping reads, or reporting one random or "best" hit based on simple heuristics. Accurate estimation of the mapping quality of NGS reads is therefore critical albeit completely lacking at present. Here we developed a generalized software toolkit "AlignerBoost", which utilizes a Bayesian-based framework to accurately estimate mapping quality of ambiguously mapped NGS reads. We tested AlignerBoost with both simulated and real DNA-seq and RNA-seq datasets at various thresholds. In most cases, but especially for reads falling within repetitive regions, AlignerBoost dramatically increases the mapping precision of modern NGS aligners without significantly compromising the sensitivity even without mapping quality filters. When using higher mapping quality cutoffs, AlignerBoost achieves a much lower false mapping rate while exhibiting comparable or higher sensitivity compared to the aligner default modes, therefore significantly boosting the detection power of NGS aligners even using extreme thresholds. AlignerBoost is also SNP-aware, and higher quality alignments can be achieved if provided with known SNPs. AlignerBoost's algorithm is computationally efficient, and can process one million alignments within 30 seconds on a typical desktop computer. AlignerBoost is implemented as a uniform Java application and is freely available at https://github.com/Grice-Lab/AlignerBoost.
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Imaginary geometric phases of quantum trajectories in high-order terahertz sideband generation
NASA Astrophysics Data System (ADS)
Yang, Fan; Liu, Ren-Bao
2014-03-01
Quantum evolution of particles under strong fields can be described by a small number of quantum trajectories that satisfy the stationary phase condition in the Dirac-Feynmann path integral. The quantum trajectories are the key concept to understand the high-order terahertz siedeband generation (HSG) in semiconductors. Due to the nontrivial ``vacuum'' states of band materials, the quantum trajectories of optically excited electron-hole pairs in semiconductors can accumulate geometric phases under the driving of an elliptically polarized THz field. We find that the geometric phase of the stationary trajectory is generally complex with both real and imaginary parts. In monolayer MoS2, the imaginary parts of the geometric phase leads to a changing of the polarization ellipticity of the sideband. We further show that the imaginary part originates from the quantum interference of many trajectories with different phases. Thus the observation of the polarization ellipticity of the sideband shall be a good indication of the quantum nature of the stationary trajectory. This work is supported by Hong Kong RGC/GRF 401512 and the CUHK Focused Investments Scheme.
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NASA Technical Reports Server (NTRS)
Coker, Bill E.
1988-01-01
Fixture delimits peened area precisely while boosting productivity. New fixture ensures small tolerances essential for turbine blades. Opens and closes quickly so finished part removed and new part inserted.
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NASA Astrophysics Data System (ADS)
Tahernezhad-Javazm, Farajollah; Azimirad, Vahid; Shoaran, Maryam
2018-04-01
Objective. Considering the importance and the near-future development of noninvasive brain-machine interface (BMI) systems, this paper presents a comprehensive theoretical-experimental survey on the classification and evolutionary methods for BMI-based systems in which EEG signals are used. Approach. The paper is divided into two main parts. In the first part, a wide range of different types of the base and combinatorial classifiers including boosting and bagging classifiers and evolutionary algorithms are reviewed and investigated. In the second part, these classifiers and evolutionary algorithms are assessed and compared based on two types of relatively widely used BMI systems, sensory motor rhythm-BMI and event-related potentials-BMI. Moreover, in the second part, some of the improved evolutionary algorithms as well as bi-objective algorithms are experimentally assessed and compared. Main results. In this study two databases are used, and cross-validation accuracy (CVA) and stability to data volume (SDV) are considered as the evaluation criteria for the classifiers. According to the experimental results on both databases, regarding the base classifiers, linear discriminant analysis and support vector machines with respect to CVA evaluation metric, and naive Bayes with respect to SDV demonstrated the best performances. Among the combinatorial classifiers, four classifiers, Bagg-DT (bagging decision tree), LogitBoost, and GentleBoost with respect to CVA, and Bagging-LR (bagging logistic regression) and AdaBoost (adaptive boosting) with respect to SDV had the best performances. Finally, regarding the evolutionary algorithms, single-objective invasive weed optimization (IWO) and bi-objective nondominated sorting IWO algorithms demonstrated the best performances. Significance. We present a general survey on the base and the combinatorial classification methods for EEG signals (sensory motor rhythm and event-related potentials) as well as their optimization methods through the evolutionary algorithms. In addition, experimental and statistical significance tests are carried out to study the applicability and effectiveness of the reviewed methods.
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Integrated Approach to Drilling Project in Unconventional Reservoir Using Reservoir Simulation
NASA Astrophysics Data System (ADS)
Stopa, Jerzy; Wiśniowski, Rafał; Wojnarowski, Paweł; Janiga, Damian; Skrzypaszek, Krzysztof
2018-03-01
Accumulation and flow mechanisms in unconventional reservoir are different compared to conventional. This requires a special approach of field management with drilling and stimulation treatments as major factor for further production. Integrated approach of unconventional reservoir production optimization assumes coupling drilling project with full scale reservoir simulation for determine best well placement, well length, fracturing treatment design and mid-length distance between wells. Full scale reservoir simulation model emulate a part of polish shale - gas field. The aim of this paper is to establish influence of technical factor for gas production from shale gas field. Due to low reservoir permeability, stimulation treatment should be direct towards maximizing the hydraulic contact. On the basis of production scenarios, 15 stages hydraulic fracturing allows boost gas production over 1.5 times compared to 8 stages. Due to the possible interference of the wells, it is necessary to determine the distance between the horizontal parts of the wells trajectories. In order to determine the distance between the wells allowing to maximize recovery factor of resources in the stimulated zone, a numerical algorithm based on a dynamic model was developed and implemented. Numerical testing and comparative study show that the most favourable arrangement assumes a minimum allowable distance between the wells. This is related to the volume ratio of the drainage zone to the total volume of the stimulated zone.
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2009-09-23
CAPE CANAVERAL, Fla. – Approaching rain clouds at dawn hover over Central Florida's east coast, effectively causing the scrub of the Space Tracking and Surveillance System - Demonstrator spacecraft from Launch Pad 17-B at Cape Canaveral Air Force Station. STSS Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detection, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 24. Photo credit: NASA/Jack Pfaller
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Model of ballistic targets' dynamics used for trajectory tracking algorithms
NASA Astrophysics Data System (ADS)
Okoń-FÄ fara, Marta; Kawalec, Adam; Witczak, Andrzej
2017-04-01
There are known only few ballistic object tracking algorithms. To develop such algorithms and to its further testing, it is necessary to implement possibly simple and reliable objects' dynamics model. The article presents the dynamics' model of a tactical ballistic missile (TBM) including the three stages of flight: the boost stage and two passive stages - the ascending one and the descending one. Additionally, the procedure of transformation from the local coordinate system to the polar-radar oriented and the global is presented. The prepared theoretical data may be used to determine the tracking algorithm parameters and to its further verification.
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2009-08-27
CAPE CANAVERAL, Fla. – The enclosed Space Tracking and Surveillance System – Demonstrators, or STSS-Demo, spacecraft arrives on Cape Canaveral Air Force Station's Launch Pad 17-B. The STSS Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Jack Pfaller
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Uncertainty in predictions of oil spill trajectories in a coastal zone
NASA Astrophysics Data System (ADS)
Sebastião, P.; Guedes Soares, C.
2006-12-01
A method is introduced to determine the uncertainties in the predictions of oil spill trajectories using a classic oil spill model. The method considers the output of the oil spill model as a function of random variables, which are the input parameters, and calculates the standard deviation of the output results which provides a measure of the uncertainty of the model as a result of the uncertainties of the input parameters. In addition to a single trajectory that is calculated by the oil spill model using the mean values of the parameters, a band of trajectories can be defined when various simulations are done taking into account the uncertainties of the input parameters. This band of trajectories defines envelopes of the trajectories that are likely to be followed by the spill given the uncertainties of the input. The method was applied to an oil spill that occurred in 1989 near Sines in the southwestern coast of Portugal. This model represented well the distinction between a wind driven part that remained offshore, and a tide driven part that went ashore. For both parts, the method defined two trajectory envelopes, one calculated exclusively with the wind fields, and the other using wind and tidal currents. In both cases reasonable approximation to the observed results was obtained. The envelope of likely trajectories that is obtained with the uncertainty modelling proved to give a better interpretation of the trajectories that were simulated by the oil spill model.
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Artist concept of Galileo with inertial upper stage (IUS) in low Earth orbit
1989-08-25
S89-42940 (April 1989) --- In this artist's rendition, the Galileo spacecraft is being boosted into its inter-planetary trajectory by the Inertial Upper Stage (IUS) rocket. The Space Shuttle Atlantis, which is scheduled to take Galileo and the IUS from Earth's surface into space, is depicted against the curve of Earth. Galileo will be placed on a trajectory to Venus, from which it will return to Earth at higher velocity and then gain still more energy in two gravity-assist passes, until it has enough velocity to reach Jupiter. Passing Venus, it will take scientific data using instruments designed for observing Jupiter; later, it will make measurements at Earth and the moon, crossing above the moon's north pole in the second pass. Between the two Earth passes, it will edge into the asteroid belt, beyond Mars' orbit; there, the first close-up observation of an asteroid is planned. Crossing the belt later, another asteroid flyby is possible.
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NASA Astrophysics Data System (ADS)
Ivashkin, V. V.; Krylov, I. V.
2014-03-01
The problem of optimization of a spacecraft transfer to the Apophis asteroid is investigated. The scheme of transfer under analysis includes a geocentric stage of boosting the spacecraft with high thrust, a heliocentric stage of control by a low thrust engine, and a stage of deceleration with injection to an orbit of the asteroid's satellite. In doing this, the problem of optimal control is solved for cases of ideal and piecewise-constant low thrust, and the optimal magnitude and direction of spacecraft's hyperbolic velocity "at infinity" during departure from the Earth are determined. The spacecraft trajectories are found based on a specially developed comprehensive method of optimization. This method combines the method of dynamic programming at the first stage of analysis and the Pontryagin maximum principle at the concluding stage, together with the parameter continuation method. The estimates are obtained for the spacecraft's final mass and for the payload mass that can be delivered to the asteroid using the Soyuz-Fregat carrier launcher.
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Zheng, Qi; Grice, Elizabeth A.
2016-01-01
Accurate mapping of next-generation sequencing (NGS) reads to reference genomes is crucial for almost all NGS applications and downstream analyses. Various repetitive elements in human and other higher eukaryotic genomes contribute in large part to ambiguously (non-uniquely) mapped reads. Most available NGS aligners attempt to address this by either removing all non-uniquely mapping reads, or reporting one random or "best" hit based on simple heuristics. Accurate estimation of the mapping quality of NGS reads is therefore critical albeit completely lacking at present. Here we developed a generalized software toolkit "AlignerBoost", which utilizes a Bayesian-based framework to accurately estimate mapping quality of ambiguously mapped NGS reads. We tested AlignerBoost with both simulated and real DNA-seq and RNA-seq datasets at various thresholds. In most cases, but especially for reads falling within repetitive regions, AlignerBoost dramatically increases the mapping precision of modern NGS aligners without significantly compromising the sensitivity even without mapping quality filters. When using higher mapping quality cutoffs, AlignerBoost achieves a much lower false mapping rate while exhibiting comparable or higher sensitivity compared to the aligner default modes, therefore significantly boosting the detection power of NGS aligners even using extreme thresholds. AlignerBoost is also SNP-aware, and higher quality alignments can be achieved if provided with known SNPs. AlignerBoost’s algorithm is computationally efficient, and can process one million alignments within 30 seconds on a typical desktop computer. AlignerBoost is implemented as a uniform Java application and is freely available at https://github.com/Grice-Lab/AlignerBoost. PMID:27706155
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Potential sources of precipitation in Lake Baikal basin
NASA Astrophysics Data System (ADS)
Shukurov, K. A.; Mokhov, I. I.
2017-11-01
Based on the data of long-term measurements at 23 meteorological stations in the Russian part of the Lake Baikal basin the probabilities of daily precipitation with different intensity and their contribution to the total precipitation are estimated. Using the trajectory model HYSPLIT_4 for each meteorological station for the period 1948-2016 the 10-day backward trajectories of air parcels, the height of these trajectories and distribution of specific humidity along the trajectories are calculated. The average field of power of potential sources of daily precipitation (less than 10 mm) for all meteorological stations in the Russian part of the Lake Baikal basin was obtained using the CWT (concentration weighted trajectory) method. The areas have been identified from which within 10 days water vapor can be transported to the Lake Baikal basin, as well as regions of the most and least powerful potential sources. The fields of the mean height of air parcels trajectories and the mean specific humidity along the trajectories are compared with the field of mean power of potential sources.
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NASA Technical Reports Server (NTRS)
Prajous, R.; Mazankine, J.; Ippolito, J. C.
1978-01-01
Methods and algorithms used for the simulation of elementary power conditioning units buck, boost, and buck-boost, as well as shunt PWM are described. Definitions are given of similar converters and reduced parameters. The various parts of the simulation to be carried out are dealt with; local stability, corrective network, measurements of input-output impedance and global stability. A simulation example is given.
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Trajectory design for the Deep Space Program Science Experiment (DSPSE) mission
NASA Astrophysics Data System (ADS)
Carrington, D.; Carrico, J.; Jen, J.; Roberts, C.; Seacord, A.; Sharer, P.; Newman, L.; Richon, K.; Kaufman, B.; Middour, J.
In 1994, the Deep Space Program Science Experiment (DSPSE) spacecraft will become the first spacecraft to perform, in succession, both a lunar orbiting mission and a deep-space asteroid encounter mission. The primary mission objective is to perform a long-duration flight-test of various new-technology lightweight components, such as sensors, in a deep-space environment. The mission has two secondary science objectives: to provide high-resolution imaging of the entire lunar surface for mapping purposes and flyby imaging of the asteroid 1620 Geographos. The DSPSE mission is sponsored by the Strategic Defense Initiative Organization (SDIO). As prime contractor, the Naval Research Laboratory (NRL) is building the spacecraft and will conduct mission operations. The Goddard Space Flight Center's (GSFC) Flight Dynamics Division is supporting NRL in the areas of The Deep Space Network (DSN) will provide tracking support. The DSPSE mission will begin with a launch from the Western Test Range in late January 1994. Following a minimum 1.5-day stay in a low-Earth parking orbit, a solid kick motor burn will boost DSPSE into an 18-day, 2.5-revolution phasing orbit transfer trajectory to the Moon. Two burns to insert DSPSE into a lunar polar orbit suitable for the mapping mission will be followed by mapping orbit maintenance and adjustment operations over a period of 2 sidereal months. In May 1994, a lunar orbit departure maneuver, in conjunction with a lunar swingby 26 days later, will propel DSPSE onto a heliocentric transfer that will intercept Geographos on September 1, 1994. This paper presents the characteristics, deterministic delta-Vs, and design details of each trajectory phase of this unique mission, together with the requirements, constraints, and design considerations to which each phase is subject. Numerous trajectory plots and tables of significant trajectory events are included. Following a discussion of the results of a preliminary launch window analysis, a summary of the deterministic impulsive delta-V budget required to establish the baseline mission trajectory design is presented.
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2009-09-25
CAPE CANAVERAL, Fla. – The United Launch Alliance Delta II rocket carrying the Space Tracking and Surveillance System - Demonstrator, or STSS-Demo, spacecraft leaps into the sky from Launch Pad 17-B at Cape Canaveral Air Force Station. STSS-Demo was launched at 8:20:22 a.m. EDT by NASA for the U.S. Missile Defense Agency. The STSS-Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. Photo credit: NASA/Sandra Joseph- Kevin O'Connell
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2009-09-25
CAPE CANAVERAL, Fla. – The United Launch Alliance Delta II rocket with Space Tracking and Surveillance System - Demonstrator, or STSS-Demo, spacecraft leaps from Launch Pad 17-B at Cape Canaveral Air Force Station amid clouds of smoke. STSS-Demo was launched at 8:20:22 a.m. EDT by NASA for the U.S. Missile Defense Agency. The STSS-Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. Photo credit: NASA/Sandra Joseph- Kevin O'Connell
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2009-09-25
CAPE CANAVERAL, Fla. – The United Launch Alliance Delta II rocket with Space Tracking and Surveillance System - Demonstrator, or STSS-Demo, spacecraft aboard races into the sky leaving a trail of fire and smoke after liftoff from Launch Pad 17-B at Cape Canaveral Air Force Station. It was launched by NASA for the U.S. Missile Defense Agency at 8:20:22 a.m. EDT. The STSS-Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. Photo credit: NASA/Alan Ault
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2009-09-23
CAPE CANAVERAL, Fla. – The mobile service tower on Launch Pad 17-B at Cape Canaveral Air Force Station rolls back to reveal the United Launch Alliance Delta II rocket that will launch the Space Tracking and Surveillance System - Demonstrator into orbit. It is being launched by NASA for the Missile Defense System. The hour-long launch window opens at 8 a.m. EDT today. The STSS Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. Photo credit: NASA/Dimitri Gerondidakis
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2009-08-27
CAPE CANAVERAL, Fla. – The enclosed Space Tracking and Surveillance System – Demonstrators, or STSS-Demo, spacecraft leaves the Astrotech payload processing facility on its way to Cape Canaveral Air Force Station's Launch Pad 17-B. The STSS Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Jack Pfaller
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Boost-phase discrimination research activities
NASA Technical Reports Server (NTRS)
Cooper, David M.; Deiwert, George S.
1989-01-01
Theoretical research in two areas was performed. The aerothermodynamics research focused on the hard-body and rocket plume flows. Analytical real gas models to describe finite rate chemistry were developed and incorporated into the three-dimensional flow codes. New numerical algorithms capable of treating multi-species reacting gas equations and treating flows with large gradients were also developed. The computational chemistry research focused on the determination of spectral radiative intensity factors, transport properties and reaction rates. Ab initio solutions to the Schrodinger equation provided potential energy curves transition moments (radiative probabilities and strengths) and potential energy surfaces. These surfaces were then coupled with classical particle reactive trajectories to compute reaction cross-sections and rates.
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2009-09-23
CAPE CANAVERAL, Fla. – The mobile service tower on Launch Pad 17-B at Cape Canaveral Air Force Station has been rolled back to reveal the United Launch Alliance Delta II rocket ready to launch the Space Tracking and Surveillance System - Demonstrator into orbit. It is being launched by NASA for the Missile Defense System. The hour-long launch window opens at 8 a.m. EDT today. The STSS Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. Photo credit: NASA/Dimitri Gerondidakis
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2009-09-25
CAPE CANAVERAL, Fla. –The United Launch Alliance Delta II rocket with Space Tracking and Surveillance System - Demonstrator, or STSS-Demo, spacecraft leaps from Launch Pad 17-B at Cape Canaveral Air Force Station amid clouds of smoke. STSS-Demo was launched at 8:20:22 a.m. EDT by NASA for the U.S. Missile Defense Agency. The STSS-Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. Photo credit: NASA/Tony Gray-Tim Powers
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2009-09-25
CAPE CANAVERAL, Fla. – The United Launch Alliance Delta II rocket carrying the Space Tracking and Surveillance System - Demonstrator, or STSS-Demo, spacecraft rises from a mantle of smoke as it lifts off from Launch Pad 17-B at Cape Canaveral Air Force Station. STSS-Demo was launched at 8:20:22 a.m. EDT by NASA for the U.S. Missile Defense Agency. The STSS-Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. Photo credit: NASA/Sandra Joseph- Kevin O'Connell
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2009-09-23
CAPE CANAVERAL, Fla. – The mobile service tower on Launch Pad 17-B at Cape Canaveral Air Force Station has been rolled back to reveal the United Launch Alliance Delta II rocket that will launch the Space Tracking and Surveillance System - Demonstrator into orbit. It is being launched by NASA for the Missile Defense System. The hour-long launch window opens at 8 a.m. EDT today. The STSS Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. Photo credit: NASA/Dimitri Gerondidakis
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2009-09-25
CAPE CANAVERAL, Fla. – The Space Tracking and Surveillance System - Demonstrator, or STSS-Demo, spacecraft lifts off through a cloud of smoke from Launch Pad 17-B at Cape Canaveral Air Force Station aboard a United Launch Alliance Delta II rocket. It was launched by NASA for the U.S. Missile Defense Agency. Launch was at 8:20:22 a.m. EDT. The STSS-Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. Photo credit: NASA/Alan Ault
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2009-09-25
CAPE CANAVERAL, Fla. – Under a cloud-streaked sky, the Space Tracking and Surveillance System – Demonstrator, or STSS-Demo, waits through the countdown to liftoff Launch Pad 17-B at Cape Canaveral Air Force Station aboard a United Launch Alliance Delta II rocket. STSS-Demo is being launched by NASA for the U.S. Missile Defense Agency. Liftoff is at 8:20 a.m. EDT. The STSS-Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. Photo credit: NASA/Jack Pfaller
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2009-09-25
CAPE CANAVERAL, Fla. – Under a cloud-streaked sky, the Space Tracking and Surveillance System – Demonstrator, or STSS-Demo, waits through the countdown to liftoff Launch Pad 17-B at Cape Canaveral Air Force Station aboard a United Launch Alliance Delta II rocket. STSS-Demo is being launched by NASA for the U.S. Missile Defense Agency. Liftoff was at 8:20:22 a.m. EDT. The STSS-Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. Photo credit: NASA/Jack Pfaller
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2009-09-23
CAPE CANAVERAL, Fla. – On Launch Pad 17-B at Cape Canaveral Air Force Station in Florida, the Space Tracking and Surveillance System - Demonstrator spacecraft is bathed in light under a dark, cloudy sky. Rain over Central Florida's east coast caused the scrub of the launch. STSS Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detection, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 24. Photo credit: NASA/Jack Pfaller
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2009-08-27
CAPE CANAVERAL, Fla. – The enclosed Space Tracking and Surveillance System – Demonstrators, or STSS-Demo, spacecraft is being lifted into the mobile service tower on Cape Canaveral Air Force Station's Launch Pad 17-B. The STSS Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Jack Pfaller
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2009-09-25
CAPE CANAVERAL, Fla. – The Space Tracking and Surveillance System - Demonstrator, or STSS-Demo, spacecraft lifts off through a cloud of smoke from Launch Pad 17-B at Cape Canaveral Air Force Station aboard a United Launch Alliance Delta II rocket. It was launched by NASA for the U.S. Missile Defense Agency. Launch was at 8:20:22 a.m. EDT. The STSS-Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. Photo credit: NASA/Jack Pfaller
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2009-09-23
CAPE CANAVERAL, Fla. – On Launch Pad 17-B at Cape Canaveral Air Force Station in Florida, the Space Tracking and Surveillance System Demonstrator spacecraft waits for launch under dark, cloudy sky. Rain over Central Florida's east coast caused the scrub of the launch. STSS Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detection, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 24. Photo credit: NASA/Jack Pfaller
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ERIC Educational Resources Information Center
Jensen, Arthur R.
This book is organized in nine parts, as follows. Part I, "Preface," includes an account of how the author went from the rather esoteric research on theoretical problems in serial rote learning to research on the inheritance of mental abilities and its implications for education. Part II, "How Much Can We Boost IQ and Scholastic Achievement?," is…
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Puncture initial data for black-hole binaries with high spins and high boosts
NASA Astrophysics Data System (ADS)
Ruchlin, Ian; Healy, James; Lousto, Carlos O.; Zlochower, Yosef
2017-01-01
We solve the Hamiltonian and momentum constraints of general relativity for two black holes with nearly extremal spins and relativistic boosts in the puncture formalism. We use a non-conformally-flat ansatz with an attenuated superposition of two Lorentz-boosted, conformally Kerr or conformally Schwarzschild 3-metrics and their corresponding extrinsic curvatures. We compare evolutions of these data with the standard Bowen-York conformally flat ansatz (technically limited to intrinsic spins χ =S /MADM2=0.928 and boosts P /MADM=0.897 ), finding, typically, an order of magnitude smaller burst of spurious radiation and agreement with inspiral and merger. As a first case study, we evolve two equal-mass black holes from rest with an initial separation of d =12 M and spins χi=Si/mi2=0.99 , compute the waveforms produced by the collision, the energy and angular momentum radiated, and the recoil of the final remnant black hole. We find that the black-hole trajectories curve at close separations, leading to the radiation of angular momentum. We also study orbiting nonspinning and moderate-spin black-hole binaries and compare these with standard Bowen-York data. We find a substantial reduction in the nonphysical initial burst of radiation which leads to cleaner waveforms. Finally, we study the case of orbiting binary black-hole systems with spin magnitude χi=0.95 in an aligned configuration and compare waveform and final remnant results with those of the SXS Collaboration [54 A. H. Mroue et al., Phys. Rev. Lett. 111, 241104 (2013)., 10.1103/PhysRevLett.111.241104], finding excellent agreement. This represents the first moving puncture evolution of orbiting and spinning black holes exceeding the Bowen-York limit. Finally, we study different choices of the initial lapse and lapse evolution equation in the moving puncture approach to improve the accuracy and efficiency of the simulations.
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Hyper-X Research Vehicle (HXRV) Experimental Aerodynamics Test Program Overview
NASA Technical Reports Server (NTRS)
Holland, Scott D.; Woods, William C.; Engelund, Walter C.
2000-01-01
This paper provides an overview of the experimental aerodynamics test program to ensure mission success for the autonomous flight of the Hyper-X Research Vehicle (HXRV). The HXRV is a 12-ft long, 2700 lb lifting body technology demonstrator designed to flight demonstrate for the first time a fully airframe integrated scramjet propulsion system. Three flights are currently planned, two at Mach 7 and one at Mach 10, beginning in the fall of 2000. The research vehicles will be boosted to the prescribed scramjet engine test point where they will separate from the booster, stabilize. and initiate engine test. Following 5+ seconds of powered flight and 15 seconds of cowl-open tares, the cowl will close and the vehicle will fly a controlled deceleration trajectory which includes numerous control doublets for in-flight aerodynamic parameter identification. This paper reviews the preflight testing activities, wind tunnel models, test rationale. risk reduction activities, and sample results from wind tunnel tests supporting the flight trajectory of the HXRV from hypersonic engine test point through subsonic flight termination.
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Hyper-X Research Vehicle (HXRV) Experimental Aerodynamics Test Program Overview
NASA Technical Reports Server (NTRS)
Holland, Scott D.; Woods, William C.; Engelund, Walter C.
2000-01-01
This paper provides an overview of the experimental aerodynamics test program to ensure mission success for the autonomous flight of the Hyper-X Research Vehicle (HXRV). The HXRV is a 12-ft long, 2700 lb lifting body technology demonstrator designed to flight demonstrate for the first time a fully airframe integrated scramjet propulsion system. Three flights are currently planned, two at Mach 7 and one at Mach 10, beginning in the fall of 2000. The research vehicles will be boosted to the prescribed scramjet engine test point where they will separate from the booster, stabilize, and initiate engine test. Following 5+ seconds of powered flight and 15 seconds of cow-open tares, the cowl will close and the vehicle will fly a controlled deceleration trajectory which includes numerous control doublets for in-flight aerodynamic parameter identification. This paper reviews the preflight testing activities, wind tunnel models, test rationale, risk reduction activities, and sample results from wind tunnel tests supporting the flight trajectory of the HXRV from hypersonic engine test point through subsonic flight termination.
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A Natural Interaction Interface for UAVs Using Intuitive Gesture Recognition
NASA Technical Reports Server (NTRS)
Chandarana, Meghan; Trujillo, Anna; Shimada, Kenji; Allen, Danette
2016-01-01
The popularity of unmanned aerial vehicles (UAVs) is increasing as technological advancements boost their favorability for a broad range of applications. One application is science data collection. In fields like Earth and atmospheric science, researchers are seeking to use UAVs to augment their current portfolio of platforms and increase their accessibility to geographic areas of interest. By increasing the number of data collection platforms UAVs will significantly improve system robustness and allow for more sophisticated studies. Scientists would like be able to deploy an available fleet of UAVs to fly a desired flight path and collect sensor data without needing to understand the complex low-level controls required to describe and coordinate such a mission. A natural interaction interface for a Ground Control System (GCS) using gesture recognition is developed to allow non-expert users (e.g., scientists) to define a complex flight path for a UAV using intuitive hand gesture inputs from the constructed gesture library. The GCS calculates the combined trajectory on-line, verifies the trajectory with the user, and sends it to the UAV controller to be flown.
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14 CFR Appendix B to Part 420 - Method for Defining a Flight Corridor
Code of Federal Regulations, 2010 CFR
2010-01-01
... trajectory simulation software. Trajectory time intervals shall be no greater than one second. If an... applicant shall construct a launch area of a flight corridor using the processes and equations of this paragraph for each trajectory position. An applicant shall repeat these processes at time points on the...
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The Inertial Upper Stage - Flight experience and capabilities
NASA Astrophysics Data System (ADS)
Kuhns, Randall H.; Maricich, Peter L.; Bangsund, Edward L.; Friske, Stephen A.; Hallman, Wayne P.; Goldstein, Allen E.
1993-10-01
The Inertial Upper Stage (IUS) is a two-stage rocket designed to place a variety of payloads in high earth orbit or on interplanetary trajectories, which has been boosted to date, together with its payloads, from the earth's surface to low altitude park orbits by the USAF Titan launcher and the NASA Space Shuttle. This paper discusses the IUS redundancy and presents data on the value of the IST's redundant design and the past uses of the vehicle's redundant capability to achieve mission success. The value of IUS's redundancy has been confirmed on several flights. The paper presents block diagrams of the IUS redundancy architecture and of the redundancy hardware switching and commands.
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2009-08-22
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., the upper segment of the transportation canister is moved toward the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, spacecraft, at left. The STSS Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Kim Shiflett
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2009-08-20
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., workers observe as the SV1-SV2 spacecraft is lifted for weighing. The two spacecraft are known as the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, which is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Jim Grossmann
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2009-08-20
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., the SV1-SV2 spacecraft is ready to be weighed. The two spacecraft are known as the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, which is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Jim Grossmann
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2009-08-22
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., the upper segment of the transportation canister is lifted to be placed on the top of the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, spacecraft. The STSS Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Kim Shiflett
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2009-08-20
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., workers observe as the SV1-SV2 spacecraft is lifted for weighing. The two spacecraft are known as the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, which is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Jim Grossmann
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2009-08-27
CAPE CANAVERAL, Fla. – The enclosed Space Tracking and Surveillance System – Demonstrators, or STSS-Demo, spacecraft moves out of the Astrotech payload processing facility. It is being moved to Cape Canaveral Air Force Station's Launch Pad 17-B. The STSS Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Jack Pfaller
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2009-08-22
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., workers maneuver one of the second-row segments of the transportation canister that will be placed around the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, spacecraft. The STSS Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Kim Shiflett
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NASA Technical Reports Server (NTRS)
Macconochie, I. O.; Eldred, C. H.; Martin, J. A.
1983-01-01
A satellite in the form of a large rotating rim which can be used to boost spacecraft from low-Earth orbit to higher orbits is described. The rim rotates in the plane of its orbit such that the lower portion of the rim is traveling at suborbital velocity, while the upper portion is travelling at greater than orbital velocity. Ascending spacecraft or payloads arrive at the lowest portion of the rim at suborbital velocities, where the payloads are released on a trajectory for higher orbits; descending payloads employ the reverse procedure. Electric thrusters placed on the rim maintain rim rotational speed and altitude. From the standpoint of currently known materials, the capture-ejector concept may be useful for relatively small velocity increments.
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2009-08-20
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., the SV1-SV2 spacecraft sits on the rotation stand after weighing. The two spacecraft are known as the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, which is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Jim Grossmann
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2009-08-20
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., workers begin center of gravity testing, weighing and balancing on the SV1-SV2 spacecraft. The two spacecraft are known as the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, which is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Jim Grossmann
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2009-08-22
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., the upper segment of the transportation canister is moved toward the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, spacecraft, at bottom left. The STSS Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Kim Shiflett
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2009-08-22
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., workers place the second row of segments of the transportation canister around the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, spacecraft. The STSS Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Kim Shiflett
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2009-08-22
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., workers attach the upper segment of the transportation canister to the lower segments around the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, spacecraft. The STSS Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Kim Shiflett
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2009-08-22
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., workers place the first segments of the transportation canister around the base of the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, spacecraft. The STSS Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Kim Shiflett
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2009-09-23
CAPE CANAVERAL, Fla. – The mobile service tower on Launch Pad 17-B at Cape Canaveral Air Force Station has been rolled back as the countdown proceeds to launch of the United Launch Alliance Delta II rocket with the Space Tracking and Surveillance System - Demonstrator spacecraft aboard. It is being launched by NASA for the Missile Defense System. The hour-long launch window opens at 8 a.m. EDT today. The STSS Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. Photo credit: NASA/Dimitri Gerondidakis
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2009-08-20
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., the SV1-SV2 spacecraft is lifted for weighing. The two spacecraft are known as the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, which is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Jim Grossmann
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2009-08-22
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, spacecraft is under a protective cover before being encased in the transportation canister. The STSS Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Kim Shiflett
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2009-09-25
CAPE CANAVERAL, Fla. – The United Launch Alliance Delta II rocket with Space Tracking and Surveillance System - Demonstrator, or STSS-Demo, spacecraft aboard races into the sky leaving a trail of fire and smoke after liftoff from Launch Pad 17-B at Cape Canaveral Air Force Station. It was launched by NASA for the U.S. Missile Defense Agency. Launch was at 8:20:22 a.m. EDT. The STSS-Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. Photo credit: NASA/Jack Pfaller
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2009-08-22
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., workers maneuver one of the second-row segments of the transportation canister that will be placed around the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, spacecraft. The STSS Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Kim Shiflett
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2009-08-03
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., workers prepare to lift the SV1 and mate it to the SV2 spacecraft for the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, Program. STSS-Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. The spacecraft is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Jim Grossmann
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NASA Astrophysics Data System (ADS)
Erskine, David J.; Edelstein, Jerry; Wishnow, Edward; Sirk, Martin; Muirhead, Philip S.; Muterspaugh, Matthew W.; Lloyd, James P.
2016-10-01
High-resolution broadband spectroscopy at near-infrared (NIR) wavelengths (950 to 2450 nm) has been performed using externally dispersed interferometry (EDI) at the Hale telescope at Mt. Palomar, with the TEDI interferometer mounted within the central hole of the 200-in. primary mirror in series with the comounted TripleSpec NIR echelle spectrograph. These are the first multidelay EDI demonstrations on starlight. We demonstrated very high (10×) resolution boost and dramatic (20× or more) robustness to point spread function wavelength drifts in the native spectrograph. Data analysis, results, and instrument noise are described in a companion paper (part 1). This part 2 describes theoretical photon limited and readout noise limited behaviors, using simulated spectra and instrument model with noise added at the detector. We show that a single interferometer delay can be used to reduce the high frequency noise at the original resolution (1× boost case), and that except for delays much smaller than the native response peak half width, the fringing and nonfringing noises act uncorrelated and add in quadrature. This is due to the frequency shifting of the noise due to the heterodyning effect. We find a sum rule for the noise variance for multiple delays. The multiple delay EDI using a Gaussian distribution of exposure times has noise-to-signal ratio for photon-limited noise similar to a classical spectrograph with reduced slitwidth and reduced flux, proportional to the square root of resolution boost achieved, but without the focal spot limitation and pixel spacing Nyquist limitations. At low boost (˜1×) EDI has ˜1.4× smaller noise than conventional, and at >10× boost, EDI has ˜1.4× larger noise than conventional. Readout noise is minimized by the use of three or four steps instead of 10 of TEDI. Net noise grows as step phases change from symmetrical arrangement with wavenumber across the band. For three (or four) steps, we calculate a multiplicative bandwidth of 1.8:1 (2.3:1), sufficient to handle the visible band (400 to 700 nm, 1.8:1) and most of TripleSpec (2.6:1).
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Erskine, David J.; Edelstein, Jerry; Wishnow, Edward; ...
2016-10-01
High-resolution broadband spectroscopy at near-infrared (NIR) wavelengths (950 to 2450 nm) has been performed using externally dispersed interferometry (EDI) at the Hale telescope at Mt. Palomar, with the TEDI interferometer mounted within the central hole of the 200-in. primary mirror in series with the comounted TripleSpec NIR echelle spectrograph. These are the first multidelay EDI demonstrations on starlight. We demonstrated very high (10×) resolution boost and dramatic (20× or more) robustness to point spread function wavelength drifts in the native spectrograph. Data analysis, results, and instrument noise are described in a companion paper (part 1). This part 2 describes theoreticalmore » photon limited and readout noise limited behaviors, using simulated spectra and instrument model with noise added at the detector. We show that a single interferometer delay can be used to reduce the high frequency noise at the original resolution (1× boost case), and that except for delays much smaller than the native response peak half width, the fringing and nonfringing noises act uncorrelated and add in quadrature. This is due to the frequency shifting of the noise due to the heterodyning effect. We find a sum rule for the noise variance for multiple delays. The multiple delay EDI using a Gaussian distribution of exposure times has noise-to-signal ratio for photon-limited noise similar to a classical spectrograph with reduced slitwidth and reduced flux, proportional to the square root of resolution boost achieved, but without the focal spot limitation and pixel spacing Nyquist limitations. At low boost (~1×) EDI has ~1.4× smaller noise than conventional, and at >10× boost, EDI has ~1.4× larger noise than conventional. Readout noise is minimized by the use of three or four steps instead of 10 of TEDI. Net noise grows as step phases change from symmetrical arrangement with wavenumber across the band. As a result, for three (or four) steps, we calculate a multiplicative bandwidth of 1.8:1 (2.3:1), sufficient to handle the visible band (400 to 700 nm, 1.8:1) and most of TripleSpec (2.6:1).« less
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Erskine, David J.; Edelstein, Jerry; Wishnow, Edward
High-resolution broadband spectroscopy at near-infrared (NIR) wavelengths (950 to 2450 nm) has been performed using externally dispersed interferometry (EDI) at the Hale telescope at Mt. Palomar, with the TEDI interferometer mounted within the central hole of the 200-in. primary mirror in series with the comounted TripleSpec NIR echelle spectrograph. These are the first multidelay EDI demonstrations on starlight. We demonstrated very high (10×) resolution boost and dramatic (20× or more) robustness to point spread function wavelength drifts in the native spectrograph. Data analysis, results, and instrument noise are described in a companion paper (part 1). This part 2 describes theoreticalmore » photon limited and readout noise limited behaviors, using simulated spectra and instrument model with noise added at the detector. We show that a single interferometer delay can be used to reduce the high frequency noise at the original resolution (1× boost case), and that except for delays much smaller than the native response peak half width, the fringing and nonfringing noises act uncorrelated and add in quadrature. This is due to the frequency shifting of the noise due to the heterodyning effect. We find a sum rule for the noise variance for multiple delays. The multiple delay EDI using a Gaussian distribution of exposure times has noise-to-signal ratio for photon-limited noise similar to a classical spectrograph with reduced slitwidth and reduced flux, proportional to the square root of resolution boost achieved, but without the focal spot limitation and pixel spacing Nyquist limitations. At low boost (~1×) EDI has ~1.4× smaller noise than conventional, and at >10× boost, EDI has ~1.4× larger noise than conventional. Readout noise is minimized by the use of three or four steps instead of 10 of TEDI. Net noise grows as step phases change from symmetrical arrangement with wavenumber across the band. As a result, for three (or four) steps, we calculate a multiplicative bandwidth of 1.8:1 (2.3:1), sufficient to handle the visible band (400 to 700 nm, 1.8:1) and most of TripleSpec (2.6:1).« less
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Wagenaar, Alfred F; Kompier, Michiel A J; Houtman, Irene L D; van den Bossche, Seth N J; Taris, Toon W
2012-01-01
Changes in employment contracts may impact the quality of working life, job insecurity, health and work-related attitudes. We examined the validity of two partly competing theoretical approaches. Based upon a segmentation approach, we expected no change in scores among stable trajectories, whereas upward trajectories were expected to be for the better and downward trajectories to be for the worse (Hypothesis 1). As turnover theories suggest that this hypothesis may only apply to workers who do not change employer, we also examined these contract trajectories stratified for a change of employer (Hypothesis 2). Drawing on the 2007 and 2008 waves of the Netherlands Working Conditions Cohort Study (N=9,688), repeated measures analysis of covariance showed little across-time change in the criterion variables, thus largely disconfirming our first hypothesis. These results could (at least partly) be explained by employer change; this was generally associated with improved scores among all contract trajectories (Hypothesis 2). However, workers receiving a less stable contract from the same employer were found to be at risk for health and well-being problems. Segmentation theory-based assumptions on contract trajectories primarily apply to stable and downward contract trajectories at the same employer, whereas assumptions from turnover theories better apply to contract trajectories combined with a change of employer. Future research should focus more closely on factors predicting "involuntary" downward trajectories into precarious temporary employment or unemployment.
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Program For Simulation Of Trajectories And Events
NASA Technical Reports Server (NTRS)
Gottlieb, Robert G.
1992-01-01
Universal Simulation Executive (USE) program accelerates and eases generation of application programs for numerical simulation of continuous trajectories interrupted by or containing discrete events. Developed for simulation of multiple spacecraft trajectories with events as one spacecraft crossing the equator, two spacecraft meeting or parting, or firing rocket engine. USE also simulates operation of chemical batch processing factory. Written in Ada.
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A GNM mission and system design proposal
NASA Technical Reports Server (NTRS)
Bailey, Stephen
1990-01-01
Here, the author takes an advocacy position for the proposed Mars Global Network Mission (GNM); it is not intended to be an objective review, although both pros and cons are presented in summary. The mission consists of launches from earth in the '96, '98, and '01 opportunities on Delta-class launch vehicles (approx. 1000 kg injected to Mars in 8 to 10 ft diameter shroud). The trans Mars boost stage injects a stack of small independent, aeroshelled spacecraft. The stack separates from the boost stage and each rigid (as opposed to deployable) aeroshell flies to Mars on its own, performing midcourse maneuvers as necessary. Each spacecraft flies a unique trajectory which is targeted to achieve approach atmospheric interface at the desired latitude and lighting conditions; arrival times may vary by a month or more. A direct entry is performed, there is no propulsive orbit capture. The aeroshelled rough-landers are targeted to achieve a desired attitude and entry flight path angle, and then follow a passive ballistic trajectory until terminal descent. Based on sensed acceleration (integrated to deduce altitude), the aft aeroshell skirt is jettisoned; a short later a supersonic parachute is deployed. The ballistic coefficient of the parachute is sized to achieve terminal velocity at about 8 km. However the parachute is not deployed until a few Km above the surface to minimize wind-induced drift. The nose cap descent imaging begins, a laser altimeter also measures true altitude. Based on range and range rate to the surface, the parachute is jettisoned and the lander uses descent engines to achieve touchdown velocity. A contact sensor shuts down the motors to avoid cratering, and the lander rough-lands at less than 5 m/sec. The remaining aeroshell and a deployable bladder attenuate landing loads and minimize the possibility of tip over. Science instruments are deployed and activated, and the network is established.
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NASA Technical Reports Server (NTRS)
1972-01-01
The Performance Analysis and Design Synthesis (PADS) computer program has a two-fold purpose. It can size launch vehicles in conjunction with calculus-of-variations optimal trajectories and can also be used as a general-purpose branched trajectory optimization program. In the former use, it has the Space Shuttle Synthesis Program as well as a simplified stage weight module for optimally sizing manned recoverable launch vehicles. For trajectory optimization alone or with sizing, PADS has two trajectory modules. The first trajectory module uses the method of steepest descent; the second employs the method of quasilinearization, which requires a starting solution from the first trajectory module. For Volume 1 see N73-13199.
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Boosting of HIV-1 Neutralizing Antibody Responses by a Distally Related Retroviral Envelope Protein
Uchtenhagen, Hannes; Schiffner, Torben; Bowles, Emma; Heyndrickx, Leo; LaBranche, Celia; Applequist, Steven E.; Jansson, Marianne; De Silva, Thushan; Back, Jaap Willem; Achour, Adnane; Scarlatti, Gabriella; Fomsgaard, Anders; Montefiori, David; Stewart-Jones, Guillaume; Spetz, Anna-Lena
2014-01-01
Our knowledge of the binding sites for neutralizing antibodies (NAbs) that recognize a broad range of HIV-1 strains (bNAb) has substantially increased in recent years. However, gaps remain in our understanding of how to focus B-cell responses to vulnerable conserved sites within the HIV-1 envelope glycoprotein (Env). Here we report an immunization strategy composed of a trivalent HIV-1 (clade B envs) DNA prime, followed by a SIVmac239 gp140 Env protein boost that aimed to focus the immune response to structurally conserved parts of the HIV-1 and SIV Envs. Heterologous NAb titres, primarily to tier 1 HIV-1 isolates, elicited during the trivalent HIV-1 env prime, were significantly increased by the SIVmac239 gp140 protein boost in rabbits. Epitope mapping of antibody binding reactivity revealed preferential recognition of the C1, C2, V2, V3 and V5 regions. These results provide a proof of concept that a distally related retroviral SIV Env protein boost can increase pre-existing NAb responses against HIV-1. PMID:24829409
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Energy Beam Highways Through the Skies
NASA Technical Reports Server (NTRS)
Myrabo, Leik N.
1996-01-01
The emergence of Energy Beam Flight Transportation Systems could dramatically change the way we travel in the 21st Century. A framework for formulating 'Highways of Light' and the top level architectures that invoke radically new Space Power Grid infrastructure, are introduced. Basically, such flight systems, hereafter called Lightcraft, would employ off-board energy beam sources (either laser or microwave) to energize on-board dependent 'motors' -- instead of the traditional autonomous 'engines' with their on-board energy sources (e.g., chemical fuels). Extreme reductions in vehicle dry mass appear feasible with the use of off-board power and a high degree of on-board artificial intelligence. Such vehicles may no longer need airports for refueling (since they require no propellant), and could possibly pick up travelers at their homes -- before motoring over to one of many local boost stations, for the flight out. With off-board power, hyper-energetic acceleration performance and boost-glide trajectories become feasible. Hypersonic MS airbreathing propulsion can enable boosts up to twice escape velocity, which will cut trip times to the moon down to 5.5 hours. The predominant technological, environmental and social factors that will result from such transportation systems will be stressed. This presentation first introduces the remote source siting options for the space power system infrastructure, and then provides three representative laser/microwave Lightcraft options (derived from historical Case Studies): i.e., 'Acorn', 'Toy Top', and 'Disc.' Next the gamut of combined-cycle engine options developed for these Lightcraft are examined -- to illuminate the 'emerging technologies' that must be harnessed to produce flight hardware. Needed proof-of concept experiments are identified, along with the Macro-Level Issues that can springboard these revolutionary concepts into hardware reality.
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2009-08-19
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., workers remove a cover from around the mated SV1 and SV2 spacecraft before center of gravity testing, weighing and balancing. The two spacecraft are known as the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, which is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Jim Grossmann
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2009-08-19
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., the mated SV1 and SV2 spacecraft are largely uncovered before center of gravity testing, weighing and balancing. The two spacecraft are known as the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, which is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Jim Grossmann
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2009-08-22
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., the upper segment of the transportation canister is lowered toward the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, spacecraft. It will be installed onto the lower segments already in place. The STSS Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Kim Shiflett
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2009-08-19
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., workers remove covers around the mated SV1 and SV2 spacecraft before center of gravity testing, weighing and balancing. The two spacecraft are known as the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, which is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Jim Grossmann
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2009-08-19
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., the mated SV1 and SV2 spacecraft are on a rotation stand for center of gravity testing, weighing and balancing. The two spacecraft are known as the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, which is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Jim Grossmann
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2009-08-20
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., an overhead crane with a scale is being attached to the SV1-SV2 spacecraft, which will be weighed. The two spacecraft are known as the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, which is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Jim Grossmann
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2009-08-19
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., workers check the SV1-SV2 spacecraft that will undergo center of gravity testing, weighing and balancing. The two spacecraft are known as the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, which is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Jim Grossmann
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2009-08-19
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., workers remove covers around the mated SV1 and SV2 spacecraft before center of gravity testing, weighing and balancing. The two spacecraft are known as the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, which is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Jim Grossmann
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2009-08-20
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., an overhead crane with a scale is being attached to the SV1-SV2 spacecraft, which will be weighed. The two spacecraft are known as the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, which is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Jim Grossmann
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2009-08-19
CAPE CANAVERAL, Fla. –At the Astrotech payload processing facility in Titusville, Fla., the mated SV1 and SV2 spacecraft are being prepared for center of gravity testing, weighing and balancing. The two spacecraft are known as the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, which is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Jim Grossmann
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2009-08-22
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., the upper segment of the transportation canister is lowered over the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, spacecraft. It will be installed onto the lower segments already in place. The STSS Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Kim Shiflett
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2009-08-20
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., workers observe as the SV1-SV2 spacecraft is lowered again onto the rotation stand after weighing. The two spacecraft are known as the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, which is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Jim Grossmann
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2009-08-19
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., a canister and protective cover are being prepared for placement around the SV1-SV2 spacecraft. The two spacecraft are known as the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, which is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Jim Grossmann
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2009-08-19
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., the mated SV1 and SV2 spacecraft are being prepared for center of gravity testing, weighing and balancing. The two spacecraft are known as the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, which is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Jim Grossmann
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2009-08-19
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., the mated SV1 and SV2 spacecraft are being prepared for center of gravity testing, weighing and balancing. The two spacecraft are known as the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, which is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Jim Grossmann
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2009-08-20
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., an overhead crane with a scale is being attached to the SV1-SV2 spacecraft, which will be weighed. The two spacecraft are known as the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, which is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Jim Grossmann
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2009-08-20
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., an overhead crane with a scale is being moved to attach to the SV1-SV2 spacecraft, which will be weighed. The two spacecraft are known as the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, which is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Jim Grossmann
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2009-08-19
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., the mated SV1 and SV2 spacecraft are placed on a rotation stand for center of gravity testing, weighing and balancing. The two spacecraft are known as the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, which is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Jim Grossmann
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2009-08-20
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., an overhead crane with a scale is being moved to attach to the SV1-SV2 spacecraft, which will be weighed. The two spacecraft are known as the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, which is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Jim Grossmann
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2009-08-19
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., workers remove covers around the mated SV1 and SV2 spacecraft before center of gravity testing, weighing and balancing. The two spacecraft are known as the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, which is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Jim Grossmann
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2009-08-19
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., workers remove covers around the mated SV1 and SV2 spacecraft before center of gravity testing, weighing and balancing. The two spacecraft are known as the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, which is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Jim Grossmann
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2009-08-22
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., the upper segment of the transportation canister is lowered over the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, spacecraft. It will be installed onto the lower segments already in place. The STSS Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Kim Shiflett
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ERIC Educational Resources Information Center
Sarama, Julie; Clements, Douglas H.; Spitler, Mary Elaine
2017-01-01
Increased attention has been given to learning trajectories (LT) as structural frameworks for educational instruction. The purpose of this study was to explore preschool teachers' descriptions of self-change, seven years after the start of their participation in LT-based professional development and instruction. This study was part of a larger…
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Electric field makes Leidenfrost droplets take a leap.
Wildeman, Sander; Sun, Chao
2016-12-06
Leidenfrost droplets, i.e. droplets whose mobility is ensured by a thin vapor film between the droplet and a hot plate, are exposed to an external electric field. We find that in a strong vertical electric field the droplet can start to bounce progressively higher, defying gravitational attraction. From the droplet's trajectory we infer the temporal evolution of the amount of charge on the droplet. This reveals that the charge starts high and then decreases in steps as the droplet slowly evaporates. After each discharge event the charge is in a fixed proportion to the droplet's surface area. We show that this behavior can be accurately modeled by treating the droplet as a conducting sphere that occasionally makes electrical contact with the hot plate, at intervals dictated by an electro-capillary instability in the vapor film. An analysis of the kinetic and potential energies of the bouncing droplet reveals that, while the overall motion is damped, the droplet occasionally experiences a sudden boost, keeping its energy close to the value for which the free fall trajectory and droplet oscillation are in sync. This helps the droplet to escape from the hot surface when finally the electrical surface forces overtake gravity.
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NASA Technical Reports Server (NTRS)
Demakes, P. T.; Hirsch, G. N.; Stewart, W. A.; Glatt, C. R.
1976-01-01
The use of a recoverable liquid rocket booster (LRB) system to replace the existing solid rocket booster (SRB) system for the shuttle was studied. Historical weight estimating relationships were developed for the LRB using Saturn technology and modified as required. Mission performance was computed using February 1975 shuttle configuration groundrules to allow reasonable comparison of the existing shuttle with the study designs. The launch trajectory was constrained to pass through both the RTLS/AOA and main engine cut off points of the shuttle reference mission 1. Performance analysis is based on a point design trajectory model which optimizes initial tilt rate and exoatmospheric pitch profile. A gravity turn was employed during the boost phase in place of the shuttle angle of attack profile. Engine throttling add/or shutdown was used to constrain dynamic pressure and/or longitudinal acceleration where necessary. Four basic configurations were investigated: a parallel burn vehicle with an F-1 engine powered LRB; a parallel burn vehicle with a high pressure engine powered LRB; a series burn vehicle with a high pressure engine powered LRB. The relative sizes of the LRB and the ET are optimized to minimize GLOW in most cases.
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Germanium: giving microelectronics an efficiency boost
Mercer, Celestine N.
2015-07-30
Germanium is an essentially nontoxic element, with the exception of only a few compounds. However, if dissolved concentrations in drinking water are as high as one or more parts per million chronic diseases may occur.
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Plume trajectory formation under stack tip self-enveloping
NASA Astrophysics Data System (ADS)
Gribkov, A. M.; Zroichikov, N. A.; Prokhorov, V. B.
2017-10-01
The phenomenon of stack tip self-enveloping and its influence upon the conditions of plume formation and on the trajectory of its motion are considered. Processes are described occurring in the initial part of the plume while the interaction between vertically directed flue gases outflowing from the stack and a horizontally directed moving air flow at high wind velocities that lead to the formation of a flag-like plume. Conditions responsible for the origin and evolution of interaction between these flows are demonstrated. For the first time, a plume formed under these conditions without bifurcation is registered. A photo image thereof is presented. A scheme for the calculation of the motion of a plume trajectory is proposed, the quantitative characteristics of which are obtained based on field observations. The wind velocity and direction, air temperature, and atmospheric turbulence at the level of the initial part of the trajectory have been obtained based on data obtained from an automatic meteorological system (mounted on the outer parts of a 250 m high stack no. 1 at the Naberezhnye Chelny TEPP plant) as well as based on the results of photographing and theodolite sighting of smoke puffs' trajectory taking into account their velocity within its initial part. The calculation scheme is supplemented with a new acting force—the force of self-enveloping. Based on the comparison of the new calculation scheme with the previous one, a significant contribution of this force to the development of the trajectory is revealed. A comparison of the natural full-scale data with the results of the calculation according to the proposed new scheme is made. The proposed calculation scheme has allowed us to extend the application of the existing technique to the range of high wind velocities. This approach would make it possible to simulate and investigate the trajectory and full rising height of the calculated the length above the mouth of flue-pipes, depending on various modal and meteorological parameters under the interrelation between the dynamic and thermal components of the rise as well as to obtain a universal calculation expression for determining the height of the plume rise for different classes of atmospheric stability.
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Solar pv fed stand-alone excitation system of a synchronous machine for reactive power generation
NASA Astrophysics Data System (ADS)
Sudhakar, N.; Jain, Siddhartha; Jyotheeswara Reddy, K.
2017-11-01
This paper presents a model of a stand-alone solar energy conversion system based on synchronous machine working as a synchronous condenser in overexcited state. The proposed model consists of a Synchronous Condenser, a DC/DC boost converter whose output is fed to the field of the SC. The boost converter is supplied by the modelled solar panel and a day time variable irradiance is fed to the panel during the simulation time. The model also has one alternate source of rechargeable batteries for the time when irradiance falls below a threshold value. Also the excess power produced when there is ample irradiance is divided in two parts and one is fed to the boost converter while other is utilized to recharge the batteries. A simulation is done in MATLAB-SIMULINK and the obtained results show the utility of such modelling for supplying reactive power is feasible.
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Tamir, Idit; Marmor-Levin, Odeya; Eitan, Renana; Bergman, Hagai; Israel, Zvi
2017-10-01
The clinical outcome of patients with Parkinson disease (PD) who undergo subthalamic nucleus (STN) deep brain stimulation (DBS) is, in part, determined by the length of the electrode trajectory through the motor STN domain, the dorsolateral oscillatory region (DLOR). Trajectory length has been found to correlate with the stimulation-related improvement in patients' motor function (estimated by part III of the United Parkinson's Disease Rating Scale [UPDRS]). Therefore, it seems that ideally trajectories should have maximal DLOR length. We retrospectively studied the influence of various anatomic aspects of the brains of patients with PD and the geometry of trajectories planned on the length of the DLOR and STN recorded during DBS surgery. We examined 212 trajectories and 424 microelectrode recording tracks in 115 patients operated on in our center between 2010 and 2015. We found a strong correlation between the length of the recorded DLOR and STN. Trajectories that were more lateral and/or posterior in orientation had a longer STN and DLOR pass, although the DLOR/STN fraction length remained constant. The STN target was more lateral when the third ventricle was wider, and the latter correlated with older age and male gender. Trajectory angles correlate with the recorded STN and DLOR lengths, and should be altered toward a more posterolateral angle in older patients and atrophied brains to compensate for the changes in STN location and geometry. These fine adjustments should yield a longer motor domain pass, thereby improving the patient's predicted outcome. Copyright © 2017 Elsevier Inc. All rights reserved.
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ASTP (SA-210) Launch vehicle operational flight trajectory. Part 3: Final documentation
NASA Technical Reports Server (NTRS)
Carter, A. B.; Klug, G. W.; Williams, N. W.
1975-01-01
Trajectory data are presented for a nominal and two launch window trajectory simulations. These trajectories are designed to insert a manned Apollo spacecraft into a 150/167 km. (81/90 n. mi.) earth orbit inclined at 51.78 degrees for rendezvous with a Soyuz spacecraft, which will be orbiting at approximately 225 km. (121.5 n. mi.). The launch window allocation defined for this launch is 500 pounds of S-IVB stage propellant. The launch window opening trajectory simulation depicts the earliest launch time deviation from a planar flight launch which conforms to this constraint. The launch window closing trajectory simulation was developed for the more stringent Air Force Eastern Test Range (AFETR) flight azimuth restriction of 37.4 degrees east-of-north. These trajectories enclose a 12.09 minute launch window, pertinent features of which are provided in a tabulation. Planar flight data are included for mid-window reference.
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Boosting of HIV-1 neutralizing antibody responses by a distally related retroviral envelope protein.
Uchtenhagen, Hannes; Schiffner, Torben; Bowles, Emma; Heyndrickx, Leo; LaBranche, Celia; Applequist, Steven E; Jansson, Marianne; De Silva, Thushan; Back, Jaap Willem; Achour, Adnane; Scarlatti, Gabriella; Fomsgaard, Anders; Montefiori, David; Stewart-Jones, Guillaume; Spetz, Anna-Lena
2014-06-15
Our knowledge of the binding sites for neutralizing Abs (NAb) that recognize a broad range of HIV-1 strains (bNAb) has substantially increased in recent years. However, gaps remain in our understanding of how to focus B cell responses to vulnerable conserved sites within the HIV-1 envelope glycoprotein (Env). In this article, we report an immunization strategy composed of a trivalent HIV-1 (clade B envs) DNA prime, followed by a SIVmac239 gp140 Env protein boost that aimed to focus the immune response to structurally conserved parts of the HIV-1 and simian immunodeficiency virus (SIV) Envs. Heterologous NAb titers, primarily to tier 1 HIV-1 isolates, elicited during the trivalent HIV-1 env prime, were significantly increased by the SIVmac239 gp140 protein boost in rabbits. Epitope mapping of Ab-binding reactivity revealed preferential recognition of the C1, C2, V2, V3, and V5 regions. These results provide a proof of concept that a distally related retroviral SIV Env protein boost can increase pre-existing NAb responses against HIV-1. Copyright © 2014 by The American Association of Immunologists, Inc.
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Design and optimization of interplanetary spacecraft trajectories
NASA Astrophysics Data System (ADS)
McConaghy, Thomas Troy
Scientists involved in space exploration are always looking for ways to accomplish more with their limited budgets. Mission designers can decrease operational costs by crafting trajectories with low launch costs, short time-of-flight, or low propellant requirements. Gravity-assist maneuvers and low-thrust, high-efficiency ion propulsion can be of great help. This dissertation describes advances in methods to design and optimize interplanetary spacecraft trajectories. particularly for missions using gravity-assist maneuvers or low-thrust engines (or both). The first part of this dissertation describes a new, efficient, two-step methodology to design and optimize low-thrust gravity-assist trajectories. Models for the launch vehicle, solar arrays, and engines are introduced and several examples of optimized trajectories are presented. For example, a 3.7-year Earth-Venus-Earth-Mars-Jupiter flyby trajectory with maximized final mass is described. The way that the parameterization of the optimization problem affects convergence speed and reliability is also investigated. The choice of coordinate system is shown to make a significant difference. The second part of this dissertation describes a way to construct Earth-Mars cycler trajectories---periodic orbits that repeatedly encounter Earth and Mars, yet require little or no propellant. We find that well-known cyclers, such as the Aldrin cycler, are special cases of a much larger family of cyclers. In fact, so many new cyclers are found that a comprehensive naming system (nomenclature) is proposed. One particularly promising new cycler, the "ballistic S1L1 cycler" is analyzed in greater detail.
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2018-05-05
This video provides an overview of the Management by Trajectory (MBT) concept of operations developed as part on a NASA Research Announcement (NRA) sponsored by NASA’s Aviation Operations and Safety Program (AOSP). Possible changes in roles and responsibilities among various agents in the air traffic system are identified, and the concept’s potential impact on system safety in a way that brings the National Airspace System (NAS) closer to a full Trajectory-Based Operations (TBO) environment is described.
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LINEAR LATTICE AND TRAJECTORY RECONSTRUCTION AND CORRECTION AT FAST LINEAR ACCELERATOR
DOE Office of Scientific and Technical Information (OSTI.GOV)
Romanov, A.; Edstrom, D.; Halavanau, A.
2017-07-16
The low energy part of the FAST linear accelerator based on 1.3 GHz superconducting RF cavities was successfully commissioned [1]. During commissioning, beam based model dependent methods were used to correct linear lattice and trajectory. Lattice correction algorithm is based on analysis of beam shape from profile monitors and trajectory responses to dipole correctors. Trajectory responses to field gradient variations in quadrupoles and phase variations in superconducting RF cavities were used to correct bunch offsets in quadrupoles and accelerating cavities relative to their magnetic axes. Details of used methods and experimental results are presented.
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Lander Trajectory Reconstruction computer program
NASA Technical Reports Server (NTRS)
Adams, G. L.; Bradt, A. J.; Ferguson, J. B.; Schnelker, H. J.
1971-01-01
The Lander Trajectory Reconstruction (LTR) computer program is a tool for analysis of the planetary entry trajectory and atmosphere reconstruction process for a lander or probe. The program can be divided into two parts: (1) the data generator and (2) the reconstructor. The data generator provides the real environment in which the lander or probe is presumed to find itself. The reconstructor reconstructs the entry trajectory and atmosphere using sensor data generated by the data generator and a Kalman-Schmidt consider filter. A wide variety of vehicle and environmental parameters may be either solved-for or considered in the filter process.
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NASA Technical Reports Server (NTRS)
Young, Archie
1999-01-01
The Mars exploration is a candidate pathway to expand human presence and useful activities in the solar system. There are several propulsion system options being considered to place the Mars payload on its inter-planetary transfer trajectory. One propulsion option is the use of Solar Electric Propulsion (SEP) to spiral out with the Mars payload from an initial Low Earth Orbit (LEO) to an elliptical High Earth Orbit (HEO). This report, presented in annotated facing page format, describes the work completed on the design of a crew taxi propulsion stage used in conjunction with the SEP. Transportation system/mission analysis topics covered in this report include sub-system analysis, trajectory profile description, mass performance and crew taxi stage sizing, stage configuration, stage cost, and Trans-Mars Injection (TMI) launch window. The high efficiency of SEP is used to provide the major part of the TMI propulsion maneuver. Orbital energy is continuously added over a period of approximately twelve months. The SEP and Mars payload follow a spiral trajectory from an initial LEO to a final elliptical HEO. A small chemical stage is then used to provide the final part of the TMI. The now unloaded SEP returns to LEO to repeat another spiral trajectory with payload to HEO. The spiral phase of the SEP's trajectory takes several months to reach HEO, thus significantly increasing the exposure time of the crew to zero-gravity. In order to minimize the long zero-gravity effects, a high thrust chemical stage delivers the crew to the SEP's HEO. The crew rendezvous with the Mars payload in HEO. After a checkout period the Mars payload with the crew is injected onto a Trans-Mars Trajectory by a small chemical stage.
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NASA Astrophysics Data System (ADS)
Huang, Peter Jen-Hung
This research first proposes a method to merge photovoltaic (PV) cells or PV panels within the internal components DC-DC converters. The purpose of this merged structure is to reconfigure the PV modules between series and parallel connections using high switching frequencies (hundreds of kHz). This leads to multi-levels of voltages and currents that become applied to the output filter of the converter. Further, this research introduces a concept of a switching cell that utilizes the reconfiguration of series and parallel connections in DC-DC converters. The switching occurs at high switching frequency and the switches can be integrated to be within the solar panels or in between the solar cells. The concept is generalized and applied to basic buck and boost topologies. As examples of the new types of converters: reconfigurable PV-buck and PV-boost converter topologies are presented. It is also possible to create other reconfigurable power converters: non-isolated and isolated topologies. Analysis, simulation and experimental verification for the reconfigurable PV-buck and PV-boost converters are presented extensively to illustrate proof of concept. Benefits and drawbacks of the new approach are discussed. The second part of this research proposes to utilize the internal solar cell capacitance and internal solar module wire parasitic inductances to replace the input capacitor and filter inductor in boost derived DC-DC converters for energy harvesting applications. High switching frequency (MHz) hard switched and resonant boost converters are proposed. Their analysis, simulation and experimental prototypes are presented. A specific proof-of-concept application is especially tested for foldable PV panels, which are known for their high internal wire inductance. The experimental converters successfully boost solar module voltage without adding any external input capacitance or filter inductor. Benefits and drawbacks of new proposed PV submodule integrated boost converters are discussed.
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2009-08-19
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., the top of the mated SV1 and SV2 remains covered. The spacecraft are being prepared for center of gravity testing, weighing and balancing. The two spacecraft are known as the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, which is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Jim Grossmann
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2009-08-19
CAPE CANAVERAL, Fla. – At the Astrotech payload processing facility in Titusville, Fla., the mated SV1 and SV2 spacecraft retain the covers on the top which are being removed before center of gravity testing, weighing and balancing. The two spacecraft are known as the Space Tracking and Surveillance System – Demonstrators, or STSS Demo, which is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detecting, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-04886 (10 SEPT 09) Photo credit: NASA/Jim Grossmann
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Performance of Gas Turbine Engines Using Wave Rotors Modeled
NASA Technical Reports Server (NTRS)
1997-01-01
A wave rotor is a device that can boost the pressure and temperature of an airflow. When used as part of the core of a gas turbine engine, a wave rotor can significantly improve the thrust or shaft horsepower by boosting the flow pressure without raising the turbine inlet temperature. The NASA Lewis Research Center's Aeropropulsion Analysis Office, which is identifying technologies and research opportunities that will enhance the technical and economic competitiveness of the U.S. aeronautics industry, is evaluating the wave rotor to quantify the potential benefits of this device. Preliminary studies such as these are critical to identifying technologies that have high payoffs.
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Optimal starting conditions for the rendezvous maneuver: Analytical and computational approach
NASA Astrophysics Data System (ADS)
Ciarcia, Marco
The three-dimensional rendezvous between two spacecraft is considered: a target spacecraft on a circular orbit around the Earth and a chaser spacecraft initially on some elliptical orbit yet to be determined. The chaser spacecraft has variable mass, limited thrust, and its trajectory is governed by three controls, one determining the thrust magnitude and two determining the thrust direction. We seek the time history of the controls in such a way that the propellant mass required to execute the rendezvous maneuver is minimized. Two cases are considered: (i) time-to-rendezvous free and (ii) time-to-rendezvous given, respectively equivalent to (i) free angular travel and (ii) fixed angular travel for the target spacecraft. The above problem has been studied by several authors under the assumption that the initial separation coordinates and the initial separation velocities are given, hence known initial conditions for the chaser spacecraft. In this paper, it is assumed that both the initial separation coordinates and initial separation velocities are free except for the requirement that the initial chaser-to-target distance is given so as to prevent the occurrence of trivial solutions. Two approaches are employed: optimal control formulation (Part A) and mathematical programming formulation (Part B). In Part A, analyses are performed with the multiple-subarc sequential gradient-restoration algorithm for optimal control problems. They show that the fuel-optimal trajectory is zero-bang, namely it is characterized by two subarcs: a long coasting zero-thrust subarc followed by a short powered max-thrust braking subarc. While the thrust direction of the powered subarc is continuously variable for the optimal trajectory, its replacement with a constant (yet optimized) thrust direction produces a very efficient guidance trajectory. Indeed, for all values of the initial distance, the fuel required by the guidance trajectory is within less than one percent of the fuel required by the optimal trajectory. For the guidance trajectory, because of the replacement of the variable thrust direction of the powered subarc with a constant thrust direction, the optimal control problem degenerates into a mathematical programming problem with a relatively small number of degrees of freedom, more precisely: three for case (i) time-to-rendezvous free and two for case (ii) time-to-rendezvous given. In particular, we consider the rendezvous between the Space Shuttle (chaser) and the International Space Station (target). Once a given initial distance SS-to-ISS is preselected, the present work supplies not only the best initial conditions for the rendezvous trajectory, but simultaneously the corresponding final conditions for the ascent trajectory. In Part B, an analytical solution of the Clohessy-Wiltshire equations is presented (i) neglecting the change of the spacecraft mass due to the fuel consumption and (ii) and assuming that the thrust is finite, that is, the trajectory includes powered subarcs flown with max thrust and coasting subarc flown with zero thrust. Then, employing the found analytical solution, we study the rendezvous problem under the assumption that the initial separation coordinates and initial separation velocities are free except for the requirement that the initial chaser-to-target distance is given. The main contribution of Part B is the development of analytical solutions for the powered subarcs, an important extension of the analytical solutions already available for the coasting subarcs. One consequence is that the entire optimal trajectory can be described analytically. Another consequence is that the optimal control problems degenerate into mathematical programming problems. A further consequence is that, vis-a-vis the optimal control formulation, the mathematical programming formulation reduces the CPU time by a factor of order 1000. Key words. Space trajectories, rendezvous, optimization, guidance, optimal control, calculus of variations, Mayer problems, Bolza problems, transformation techniques, multiple-subarc sequential gradient-restoration algorithm.
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Quinn, Kylie M.; Costa, Andreia Da; Yamamoto, Ayako; Berry, Dana; Lindsay, Ross W.B.; Darrah, Patricia A.; Wang, Lingshu; Cheng, Cheng; Kong, Wing-Pui; Gall, Jason G.D.; Nicosia, Alfredo; Folgori, Antonella; Colloca, Stefano; Cortese, Riccardo; Gostick, Emma; Price, David A.; Gomez, Carmen E.; Esteban, Mariano; Wyatt, Linda S.; Moss, Bernard; Morgan, Cecilia; Roederer, Mario; Bailer, Robert T.; Nabel, Gary J.; Koup, Richard A.; Seder, Robert A.
2013-01-01
Recombinant adenoviral vectors (rAds) are the most potent recombinant vaccines for eliciting CD8+ T cell-mediated immunity in humans; however, prior exposure from natural adenoviral infection can decrease such responses. Here we show low seroreactivity in humans against simian- (sAd11, sAd16), or chimpanzee-derived (chAd3, chAd63) compared to human-derived (rAd5, rAd28, rAd35) vectors across multiple geographic regions. We then compared the magnitude, quality, phenotype and protective capacity of CD8+ T cell responses in mice vaccinated with rAds encoding SIV Gag. Using a dose range (1 × 107 to 109 PU), we defined a hierarchy among rAd vectors based on the magnitude and protective capacity of CD8+ T cell responses, from most to least as: rAd5 and chAd3, rAd28 and sAd11, chAd63, sAd16, and rAd35. Selection of rAd vector or dose could modulate the proportion and/or frequency of IFNγ+TNFα+IL-2+ and KLRG1+CD127- CD8+ T cells, but strikingly ~30–80% of memory CD8+ T cells co-expressed CD127 and KLRG1. To further optimise CD8+ T cell responses, we assessed rAds as part of prime-boost regimens. Mice primed with rAds and boosted with NYVAC generated Gag-specific responses that approached ~60% of total CD8+ T cells at peak. Alternatively, priming with DNA or rAd28 and boosting with rAd5 or chAd3 induced robust and equivalent CD8+ T cell responses compared to prime or boost alone. Collectively, these data provide the immunologic basis for using specific rAd vectors alone or as part of prime-boost regimens to induce CD8+ T cells for rapid effector function or robust long-term memory, respectively. PMID:23390298
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NASA Technical Reports Server (NTRS)
Byrnes, D. V.; Carney, P. C.; Underwood, J. W.; Vogt, E. D.
1974-01-01
The six month effort was responsible for the development, test, conversion, and documentation of computer software for the mission analysis of missions to halo orbits about libration points in the earth-sun system. The software consisting of two programs called NOMNAL and ERRAN is part of the Space Trajectories Error Analysis Programs. The program NOMNAL targets a transfer trajectory from earth on a given launch date to a specified halo orbit on a required arrival date. Either impulsive or finite thrust insertion maneuvers into halo orbit are permitted by the program. The transfer trajectory is consistent with a realistic launch profile input by the user. The second program ERRAN conducts error analyses of the targeted transfer trajectory. Measurements including range, doppler, star-planet angles, and apparent planet diameter are processed in a Kalman-Schmidt filter to determine the trajectory knowledge uncertainty.
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Situated Trajectories of Learning in Vocational Training Interactions
ERIC Educational Resources Information Center
de Saint-Georges, Ingrid; Filliettaz, Laurent
2008-01-01
This paper investigates smaller-scale transitions that are part of the longer-term processes of subjective transformation and adaptation to new professional competencies for learners in the field of vocational education. On the conceptual level, it proposes to view transitions as intermediate states in situated trajectories of learning. The notion…
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NASA Technical Reports Server (NTRS)
Stalos, S.
1990-01-01
The double-lunar swingby trajectory is a method for maintaining alignment of an Earth satellite's line of apsides with the Sun-Earth line. From a Keplerian point of view, successive close encounters with the Moon cause discrete, instantaneous changes in the satellite's eccentricity and semimajor axis. Numerical solutions to the planar, restricted problem of three bodies as double-lunar swingby trajectories are identified. The method of solution is described and the results compared to the Keplerian formulation.
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Achieving Rigorous Accelerated Conformational Sampling in Explicit Solvent.
Doshi, Urmi; Hamelberg, Donald
2014-04-03
Molecular dynamics simulations can provide valuable atomistic insights into biomolecular function. However, the accuracy of molecular simulations on general-purpose computers depends on the time scale of the events of interest. Advanced simulation methods, such as accelerated molecular dynamics, have shown tremendous promise in sampling the conformational dynamics of biomolecules, where standard molecular dynamics simulations are nonergodic. Here we present a sampling method based on accelerated molecular dynamics in which rotatable dihedral angles and nonbonded interactions are boosted separately. This method (RaMD-db) is a different implementation of the dual-boost accelerated molecular dynamics, introduced earlier. The advantage is that this method speeds up sampling of the conformational space of biomolecules in explicit solvent, as the degrees of freedom most relevant for conformational transitions are accelerated. We tested RaMD-db on one of the most difficult sampling problems - protein folding. Starting from fully extended polypeptide chains, two fast folding α-helical proteins (Trpcage and the double mutant of C-terminal fragment of Villin headpiece) and a designed β-hairpin (Chignolin) were completely folded to their native structures in very short simulation time. Multiple folding/unfolding transitions could be observed in a single trajectory. Our results show that RaMD-db is a promisingly fast and efficient sampling method for conformational transitions in explicit solvent. RaMD-db thus opens new avenues for understanding biomolecular self-assembly and functional dynamics occurring on long time and length scales.
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Shopping for Dollars? Try This List!
ERIC Educational Resources Information Center
DiGeronimo, Joseph
1991-01-01
A California school superintendent presents clever savings tips, including boosting average daily attendance, sparing new hires, bird dogging insurance interest, disposing of surplus school property, recruiting students attending nonpublic schools, creating more classroom space, contracting for part-time help, reducing vandalism, marketing staff…
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NASA Astrophysics Data System (ADS)
Aoyagi, Yuzo; Kunishima, Eiji; Asaumi, Yasuo; Aihara, Yoshiaki; Odaka, Matsuo; Goto, Yuichi
Heavy-duty diesel engines have adopted numerous technologies for clean emissions and low fuel consumption. Some are direct fuel injection combined with high injection pressure and adequate in-cylinder air motion, turbo-intercooler systems, and strong steel pistons. Using these technologies, diesel engines have achieved an extremely low CO2 emission as a prime mover. However, heavy-duty diesel engines with even lower NOx and PM emission levels are anticipated. This study achieved high-boost and lean diesel combustion using a single cylinder engine that provides good engine performance and clean exhaust emission. The experiment was done under conditions of intake air quantity up to five times that of a naturally aspirated (NA) engine and 200MPa injection pressure. The adopted pressure booster is an external supercharger that can control intake air temperature. In this engine, the maximum cylinder pressure was increased and new technologies were adopted, including a monotherm piston for endurance of Pmax =30MPa. Moreover, every engine part is newly designed. As the boost pressure increases, the rate of heat release resembles the injection rate and becomes sharper. The combustion and brake thermal efficiency are improved. This high boost and lean diesel combustion creates little smoke; ISCO and ISTHC without the ISNOx increase. It also yields good thermal efficiency.
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NASA Technical Reports Server (NTRS)
Huang, L. C. P.; Cook, R. A.
1973-01-01
Models utilizing various sub-sets of the six degrees of freedom are used in trajectory simulation. A 3-D model with only linear degrees of freedom is especially attractive, since the coefficients for the angular degrees of freedom are the most difficult to determine and the angular equations are the most time consuming for the computer to evaluate. A computer program is developed that uses three separate subsections to predict trajectories. A launch rail subsection is used until the rocket has left its launcher. The program then switches to a special 3-D section which computes motions in two linear and one angular degrees of freedom. When the rocket trims out, the program switches to the standard, three linear degrees of freedom model.
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This is a webinar page for the Sustainable Management of Materials (SMM) Web Academy webinar titled Let’s WRAP (Wrap Recycling Action Program): Best Practices to Boost Plastic Film Recycling in Your Community
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This is a webinar page for the Sustainable Management of Materials (SMM) Web Academy webinar titled Let’s WRAP (Wrap Recycling Action Program): Best Practices to Boost Plastic Film Recycling in Your Community
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Trend-Residual Dual Modeling for Detection of Outliers in Low-Cost GPS Trajectories.
Chen, Xiaojian; Cui, Tingting; Fu, Jianhong; Peng, Jianwei; Shan, Jie
2016-12-01
Low-cost GPS (receiver) has become a ubiquitous and integral part of our daily life. Despite noticeable advantages such as being cheap, small, light, and easy to use, its limited positioning accuracy devalues and hampers its wide applications for reliable mapping and analysis. Two conventional techniques to remove outliers in a GPS trajectory are thresholding and Kalman-based methods, which are difficult in selecting appropriate thresholds and modeling the trajectories. Moreover, they are insensitive to medium and small outliers, especially for low-sample-rate trajectories. This paper proposes a model-based GPS trajectory cleaner. Rather than examining speed and acceleration or assuming a pre-determined trajectory model, we first use cubic smooth spline to adaptively model the trend of the trajectory. The residuals, i.e., the differences between the trend and GPS measurements, are then further modeled by time series method. Outliers are detected by scoring the residuals at every GPS trajectory point. Comparing to the conventional procedures, the trend-residual dual modeling approach has the following features: (a) it is able to model trajectories and detect outliers adaptively; (b) only one critical value for outlier scores needs to be set; (c) it is able to robustly detect unapparent outliers; and (d) it is effective in cleaning outliers for GPS trajectories with low sample rates. Tests are carried out on three real-world GPS trajectories datasets. The evaluation demonstrates an average of 9.27 times better performance in outlier detection for GPS trajectories than thresholding and Kalman-based techniques.
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The role of invariant manifolds in lowthrust trajectory design (part III)
NASA Technical Reports Server (NTRS)
Lo, Martin W.; Anderson, Rodney L.; Lam, Try; Whiffen, Greg
2006-01-01
This paper is the third in a series to explore the role of invariant manifolds in the design of low thrust trajectories. In previous papers, we analyzed an impulsive thrust resonant gravity assist flyby trajectory to capture into Europa orbit using the invariant manifolds of unstable resonant periodic orbits and libration orbits. The energy savings provided by the gravity assist may be interpreted dynamically as the result of a finite number of intersecting invariant manifolds. In this paper we demonstrate that the same dynamics is at work for low thrust trajectories with resonant flybys and low energy capture. However, in this case, the flybys and capture are effected by continuous families of intersecting invariant manifolds.
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Main-belt asteroid exploration - Mission options for the 1990s
NASA Technical Reports Server (NTRS)
Yen, C.-W. L.
1982-01-01
Mission configurations, propulsion systems, and target bodies for possible NASA asteroid exploration projects are examined. Noting that an announced delay in the development of a solar electric propulsion system has led to a consideration of chemical rocket systems, asteroid missions are grouped in terms of five potential areas for investigation, each successively further from the sun. The Shuttle-launched IUS is suggested as the prime candidate for boosting probes into trajectories for asteroid rendezvous with a number of the 3000 known asteroids. Planetary swingbys are mentioned as the only suitable method for satisfying the large energy requirements of the asteroid missions. Performance analyses are presented of the IUS 2-stage/Star-48 and Centaur vehicles, and sample missions to Fortuna, Anahita, and Urania in 1990 and further missions to the middle, outer, and Trojans asteroids are outlined.
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Best bang for your buck: GPU nodes for GROMACS biomolecular simulations
Páll, Szilárd; Fechner, Martin; Esztermann, Ansgar; de Groot, Bert L.; Grubmüller, Helmut
2015-01-01
The molecular dynamics simulation package GROMACS runs efficiently on a wide variety of hardware from commodity workstations to high performance computing clusters. Hardware features are well‐exploited with a combination of single instruction multiple data, multithreading, and message passing interface (MPI)‐based single program multiple data/multiple program multiple data parallelism while graphics processing units (GPUs) can be used as accelerators to compute interactions off‐loaded from the CPU. Here, we evaluate which hardware produces trajectories with GROMACS 4.6 or 5.0 in the most economical way. We have assembled and benchmarked compute nodes with various CPU/GPU combinations to identify optimal compositions in terms of raw trajectory production rate, performance‐to‐price ratio, energy efficiency, and several other criteria. Although hardware prices are naturally subject to trends and fluctuations, general tendencies are clearly visible. Adding any type of GPU significantly boosts a node's simulation performance. For inexpensive consumer‐class GPUs this improvement equally reflects in the performance‐to‐price ratio. Although memory issues in consumer‐class GPUs could pass unnoticed as these cards do not support error checking and correction memory, unreliable GPUs can be sorted out with memory checking tools. Apart from the obvious determinants for cost‐efficiency like hardware expenses and raw performance, the energy consumption of a node is a major cost factor. Over the typical hardware lifetime until replacement of a few years, the costs for electrical power and cooling can become larger than the costs of the hardware itself. Taking that into account, nodes with a well‐balanced ratio of CPU and consumer‐class GPU resources produce the maximum amount of GROMACS trajectory over their lifetime. © 2015 The Authors. Journal of Computational Chemistry Published by Wiley Periodicals, Inc. PMID:26238484
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Best bang for your buck: GPU nodes for GROMACS biomolecular simulations.
Kutzner, Carsten; Páll, Szilárd; Fechner, Martin; Esztermann, Ansgar; de Groot, Bert L; Grubmüller, Helmut
2015-10-05
The molecular dynamics simulation package GROMACS runs efficiently on a wide variety of hardware from commodity workstations to high performance computing clusters. Hardware features are well-exploited with a combination of single instruction multiple data, multithreading, and message passing interface (MPI)-based single program multiple data/multiple program multiple data parallelism while graphics processing units (GPUs) can be used as accelerators to compute interactions off-loaded from the CPU. Here, we evaluate which hardware produces trajectories with GROMACS 4.6 or 5.0 in the most economical way. We have assembled and benchmarked compute nodes with various CPU/GPU combinations to identify optimal compositions in terms of raw trajectory production rate, performance-to-price ratio, energy efficiency, and several other criteria. Although hardware prices are naturally subject to trends and fluctuations, general tendencies are clearly visible. Adding any type of GPU significantly boosts a node's simulation performance. For inexpensive consumer-class GPUs this improvement equally reflects in the performance-to-price ratio. Although memory issues in consumer-class GPUs could pass unnoticed as these cards do not support error checking and correction memory, unreliable GPUs can be sorted out with memory checking tools. Apart from the obvious determinants for cost-efficiency like hardware expenses and raw performance, the energy consumption of a node is a major cost factor. Over the typical hardware lifetime until replacement of a few years, the costs for electrical power and cooling can become larger than the costs of the hardware itself. Taking that into account, nodes with a well-balanced ratio of CPU and consumer-class GPU resources produce the maximum amount of GROMACS trajectory over their lifetime. © 2015 The Authors. Journal of Computational Chemistry Published by Wiley Periodicals, Inc.
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NASA Astrophysics Data System (ADS)
Ileana, Ioan; Risteiu, Mircea; Marc, Gheorghe
2016-12-01
This paper is a part of our research dedicated to high power LED lamps designing. The boost-up selected technology wants to meet driver producers' tendency in the frame of efficiency and disturbances constrains. In our work we used modeling and simulation tools for implementing scenarios of the driver work when some controlling functions are executed (output voltage/ current versus input voltage and fixed switching frequency, input and output electric power transfer versus switching frequency, transient inductor voltage analysis, and transient out capacitor analysis). Some electrical and thermal stress conditions are also analyzed. Based on these aspects, a high reliable power LED driver has been designed.
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Practice reduces task relevant variance modulation and forms nominal trajectory
NASA Astrophysics Data System (ADS)
Osu, Rieko; Morishige, Ken-Ichi; Nakanishi, Jun; Miyamoto, Hiroyuki; Kawato, Mitsuo
2015-12-01
Humans are capable of achieving complex tasks with redundant degrees of freedom. Much attention has been paid to task relevant variance modulation as an indication of online feedback control strategies to cope with motor variability. Meanwhile, it has been discussed that the brain learns internal models of environments to realize feedforward control with nominal trajectories. Here we examined trajectory variance in both spatial and temporal domains to elucidate the relative contribution of these control schemas. We asked subjects to learn reaching movements with multiple via-points, and found that hand trajectories converged to stereotyped trajectories with the reduction of task relevant variance modulation as learning proceeded. Furthermore, variance reduction was not always associated with task constraints but was highly correlated with the velocity profile. A model assuming noise both on the nominal trajectory and motor command was able to reproduce the observed variance modulation, supporting an expression of nominal trajectories in the brain. The learning-related decrease in task-relevant modulation revealed a reduction in the influence of optimal feedback around the task constraints. After practice, the major part of computation seems to be taken over by the feedforward controller around the nominal trajectory with feedback added only when it becomes necessary.
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NASA Technical Reports Server (NTRS)
Byrnes, D. V.; Carney, P. C.; Underwood, J. W.; Vogt, E. D.
1974-01-01
Development, test, conversion, and documentation of computer software for the mission analysis of missions to halo orbits about libration points in the earth-sun system is reported. The software consisting of two programs called NOMNAL and ERRAN is part of the Space Trajectories Error Analysis Programs (STEAP). The program NOMNAL targets a transfer trajectory from Earth on a given launch date to a specified halo orbit on a required arrival date. Either impulsive or finite thrust insertion maneuvers into halo orbit are permitted by the program. The transfer trajectory is consistent with a realistic launch profile input by the user. The second program ERRAN conducts error analyses of the targeted transfer trajectory. Measurements including range, doppler, star-planet angles, and apparent planet diameter are processed in a Kalman-Schmidt filter to determine the trajectory knowledge uncertainty. Execution errors at injection, midcourse correction and orbit insertion maneuvers are analyzed along with the navigation uncertainty to determine trajectory control uncertainties and fuel-sizing requirements. The program is also capable of generalized covariance analyses.
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Relativistic spin-orbit interactions of photons and electrons
NASA Astrophysics Data System (ADS)
Smirnova, D. A.; Travin, V. M.; Bliokh, K. Y.; Nori, F.
2018-04-01
Laboratory optics, typically dealing with monochromatic light beams in a single reference frame, exhibits numerous spin-orbit interaction phenomena due to the coupling between the spin and orbital degrees of freedom of light. Similar phenomena appear for electrons and other spinning particles. Here we examine transformations of paraxial photon and relativistic-electron states carrying the spin and orbital angular momenta (AM) under the Lorentz boosts between different reference frames. We show that transverse boosts inevitably produce a rather nontrivial conversion from spin to orbital AM. The converted part is then separated between the intrinsic (vortex) and extrinsic (transverse shift or Hall effect) contributions. Although the spin, intrinsic-orbital, and extrinsic-orbital parts all point in different directions, such complex behavior is necessary for the proper Lorentz transformation of the total AM of the particle. Relativistic spin-orbit interactions can be important in scattering processes involving photons, electrons, and other relativistic spinning particles, as well as when studying light emitted by fast-moving bodies.
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Trajectory-Based Loads for the Ares I-X Test Flight Vehicle
NASA Technical Reports Server (NTRS)
Vause, Roland F.; Starr, Brett R.
2011-01-01
In trajectory-based loads, the structural engineer treats each point on the trajectory as a load case. Distributed aero, inertial, and propulsion forces are developed for the structural model which are equivalent to the integrated values of the trajectory model. Free-body diagrams are then used to solve for the internal forces, or loads, that keep the applied aero, inertial, and propulsion forces in dynamic equilibrium. There are several advantages to using trajectory-based loads. First, consistency is maintained between the integrated equilibrium equations of the trajectory analysis and the distributed equilibrium equations of the structural analysis. Second, the structural loads equations are tied to the uncertainty model for the trajectory systems analysis model. Atmosphere, aero, propulsion, mass property, and controls uncertainty models all feed into the dispersions that are generated for the trajectory systems analysis model. Changes in any of these input models will affect structural loads response. The trajectory systems model manages these inputs as well as the output from the structural model over thousands of dispersed cases. Large structural models with hundreds of thousands of degrees of freedom would execute too slowly to be an efficient part of several thousand system analyses. Trajectory-based loads provide a means for the structures discipline to be included in the integrated systems analysis. Successful applications of trajectory-based loads methods for the Ares I-X vehicle are covered in this paper. Preliminary design loads were based on 2000 trajectories using Monte Carlo dispersions. Range safety loads were tied to 8423 malfunction turn trajectories. In addition, active control system loads were based on 2000 preflight trajectories using Monte Carlo dispersions.
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NASA Astrophysics Data System (ADS)
Srinivasan, V.
2015-02-01
The developing world is rapidly urbanizing. One of the challenges associated with this growth will be to supply water to growing cities of the developing world. Traditional planning tools fare poorly over 30-50 year time horizons because these systems are changing so rapidly. Models that hold land use, economic patterns, governance systems or technology static over a long planning horizon could result in inaccurate predictions leading to sub-optimal or paradoxical outcomes. Most models fail to account for adaptive responses by humans that in turn influence water resource availability, resulting in coevolution of the human-water system. Is a particular trajectory inevitable given a city's natural resource endowment, is the trajectory purely driven by policy or are there tipping points in the evolution of a city's growth that shift it from one trajectory onto another? Socio-hydrology has been defined as a new science of water and people that will explicitly account for such bi-directional feedbacks. However, a particular challenge in incorporating such feedbacks is imagining technological, social and political futures that could fundamentally alter future water demand, allocation and use. This paper offers an alternative approach - the use of counterfactual trajectories - that allows policy insights to be gleaned without having to predict social futures. The approach allows us to "reimagine the past"; to observe how outcomes would differ if different decisions had been made. The paper presents a "socio-hydrological" model that simulates the feedbacks between the human, engineered and hydrological systems in Chennai, India over a 40-year period. The model offers several interesting insights. First, the study demonstrates that urban household water security goes beyond piped water supply. When piped supply fails, users turn to their own wells. If the wells dry up, consumers purchase expensive tanker water or curtail water use and thus become water insecure. Second, unsurprisingly, different initial conditions result in different trajectories. But initial advantages in piped infrastructure are eroded if the utility is unable to expand the piped system to keep up with growth. Both infrastructure and sound management decisions are necessary to ensure household water security although the impacts of mismanagement may not manifest until much later when the population has grown and a multi-year drought strikes. Third, natural resource endowments can limit the benefits of good policy and infrastructure. Cities can boost recharge through artificial recharge schemes. However, cities underlain by productive aquifers can better rely on groundwater as a buffer against drought, compared to cities with unproductive aquifers.
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ERIC Educational Resources Information Center
Gonsalves, Allison J.
2018-01-01
[This paper is part of the Focused Collection on Astronomy Education Research.] This paper presents the cases of two doctoral students in observational astrophysics whose circumstances and experiences led them on a career trajectory out of academic research. In this article, I employ a sociocultural lens that provides insight into the dynamics of…
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Lagrangian Transport Calculations Using UARS Data. Part I: Passive Tracers
NASA Technical Reports Server (NTRS)
Manney, G. L.; Lahoz, W. A.; Harwood, R. S.; Zurek, R. W.; Kumer, J. B.; Mergenthaler, J. L.; Roche, A. E.; O'Neill, A; Swinbank, R.; Waters, J. W.
1994-01-01
The transport of passive tracers observed by UARS has been simulated using computed trajectories of thousands of air parcels initialized on a three-dimensional stratospheric grid. These trajectories are calculated in isentropic coordinates using horizontal winds provided by the United Kingdom Meteorological Office data assimilation system and vertical (cross-isentropic) velocities computed using a fast radiation code.
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Poonawalla, Insiya B; Kendzor, Darla E; Owen, Margaret Tresch; Caughy, Margaret O
2014-10-01
Although childhood socioeconomic disadvantage has been linked with adolescent tobacco and alcohol use in cross-sectional research, less is known about the influence of changes in socioeconomic status during childhood. Upward socioeconomic mobility may attenuate the negative influence of earlier socioeconomic disadvantage on health, while downward mobility may counter the health benefits of earlier socioeconomic advantage. This study evaluated the influence of common trajectories of family income during childhood on smoking and alcohol use during adolescence. Data utilized were part of the 15-year longitudinal Study of Early Child Care and Youth Development. A 5-class trajectory model (two stable, one downward, and two upward income trajectories) was developed previously with this sample (N=1356). Logistic regression analyses were conducted to determine whether children of the more disadvantaged income trajectories were more likely to engage in tobacco and alcohol use at age 15 relative to those of the most advantaged trajectory. Family income trajectory was significantly associated with ever-smoking (p=.02) and past-year alcohol use at age 15years (p=.008). Children from the less advantaged trajectories were more likely to have ever-smoked than children of the most advantaged trajectory (all p's<.05). Children of the downwardly mobile trajectory were more likely to have used alcohol within the past year than children of the most advantaged trajectories as well as the most disadvantaged trajectory (all p's<.05). Findings indicate that childhood socioeconomic disadvantage influences adolescent smoking, while downward socioeconomic mobility influences adolescent alcohol use. Copyright © 2014 Elsevier Ltd. All rights reserved.
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Poonawalla, Insiya B.; Kendzor, Darla E.; Owen, Margaret Tresch; Caughy, Margaret O.
2014-01-01
Background Although childhood socioeconomic disadvantage has been linked with adolescent tobacco and alcohol use in cross-sectional research, less is known about the influence of changes in socioeconomic status during childhood. Upward socioeconomic mobility may attenuate the negative influence of earlier socioeconomic disadvantage on health, while downward mobility may counter the health benefits of earlier socioeconomic advantage. This study evaluated the influence of common trajectories of family income during childhood on smoking and alcohol use during adolescence. Methods Data utilized were part of the 15-year longitudinal Study of Early Child Care and Youth Development. A 5-class trajectory model (two stable, one downward, and two upward income trajectories) was developed previously with this sample (N = 1356). Logistic regression analyses were conducted to determine whether children of the more disadvantaged income trajectories were more likely to engage in tobacco and alcohol use at age 15 relative to those of the most advantaged trajectory. Results Family income trajectory was significantly associated with ever-smoking (p = .02) and past-year alcohol use at age 15 years (p = .008). Children from the less advantaged trajectories were more likely to have ever-smoked than children of the most advantaged trajectory (all p’s < .05). Children of the downwardly mobile trajectory were more likely to have used alcohol within the past year than children of the most advantaged trajectories as well as the most disadvantaged trajectory (all p’s < .05). Conclusions Findings indicate that childhood socioeconomic disadvantage influences adolescent smoking, while downward socioeconomic mobility influences adolescent alcohol use. PMID:24922527
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Trend-Residual Dual Modeling for Detection of Outliers in Low-Cost GPS Trajectories
Chen, Xiaojian; Cui, Tingting; Fu, Jianhong; Peng, Jianwei; Shan, Jie
2016-01-01
Low-cost GPS (receiver) has become a ubiquitous and integral part of our daily life. Despite noticeable advantages such as being cheap, small, light, and easy to use, its limited positioning accuracy devalues and hampers its wide applications for reliable mapping and analysis. Two conventional techniques to remove outliers in a GPS trajectory are thresholding and Kalman-based methods, which are difficult in selecting appropriate thresholds and modeling the trajectories. Moreover, they are insensitive to medium and small outliers, especially for low-sample-rate trajectories. This paper proposes a model-based GPS trajectory cleaner. Rather than examining speed and acceleration or assuming a pre-determined trajectory model, we first use cubic smooth spline to adaptively model the trend of the trajectory. The residuals, i.e., the differences between the trend and GPS measurements, are then further modeled by time series method. Outliers are detected by scoring the residuals at every GPS trajectory point. Comparing to the conventional procedures, the trend-residual dual modeling approach has the following features: (a) it is able to model trajectories and detect outliers adaptively; (b) only one critical value for outlier scores needs to be set; (c) it is able to robustly detect unapparent outliers; and (d) it is effective in cleaning outliers for GPS trajectories with low sample rates. Tests are carried out on three real-world GPS trajectories datasets. The evaluation demonstrates an average of 9.27 times better performance in outlier detection for GPS trajectories than thresholding and Kalman-based techniques. PMID:27916944
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NASA Astrophysics Data System (ADS)
Starinova, Olga L.
2014-12-01
This paper outlines the optimization methods of the control law of the low thrust spacecraft for the restrict problem of three-body. The conditions for fragmentation trajectory on the specific parts of trajectory are formulated. The mathematical statement and methods to solve the optimal control problem on these parts are stated. Results of the decision of applied problems for various classes of spacecrafts which are carrying out maneuvers with low thrust are presented. In particular, the non-coplanar maneuvers of the low thrust spacecraft in the Earth-Moon system are viewed.
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Perceived employability trajectories: A Swedish cohort study
Törnroos (née Kirves), Kaisa; Bernhard-Oettel, Claudia; Leineweber, Constanze
2017-01-01
Objectives: This study identified perceived employability trajectories and their associations with sleeping difficulties and depressive symptoms over time. Methods: The sample was part of the Swedish Longitudinal Survey on Health from 2008 to 2014 (n=4,583). Results: Two stable trajectories (high and low perceived employability over time) and three trajectories with changes (increasing, decreasing, and V-shaped perceived employability over time) were identified. Workers with stable low perceived employability reported more sleeping difficulties and depressive symptoms than those who perceived high or increasing employability. Conclusion: Perceived employability is a rather stable personal resource, which is associated with well-being over time. However, changes in perceived employability do not seem to be echoed in well-being, at least not as immediately as theoretically expected. PMID:28539535
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NASA Technical Reports Server (NTRS)
Striepe, Scott A.; Blanchard, Robert C.; Kirsch, Michael F.; Fowler, Wallace T.
2007-01-01
On January 14, 2005, ESA's Huygens probe separated from NASA's Cassini spacecraft, entered the Titan atmosphere and landed on its surface. As part of NASA Engineering Safety Center Independent Technical Assessment of the Huygens entry, descent, and landing, and an agreement with ESA, NASA provided results of all EDL analyses and associated findings to the Huygens project team prior to probe entry. In return, NASA was provided the flight data from the probe so that trajectory reconstruction could be done and simulation models assessed. Trajectory reconstruction of the Huygens entry probe at Titan was accomplished using two independent approaches: a traditional method and a POST2-based method. Results from both approaches are discussed in this paper.
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Optimal trajectories for the aeroassisted flight experiment. Part 4: Data, tables, and graphs
NASA Technical Reports Server (NTRS)
Miele, A.; Wang, T.; Lee, W. Y.; Wang, H.; Wu, G. D.
1989-01-01
The determination of optimal trajectories for the aeroassisted flight experiment (AFE) is discussed. Data, tables, and graphs relative to the following transfers are presented: (IA) indirect ascent to a 178 NM perigee via a 197 NM apogee; and (DA) direct ascent to a 178 NM apogee. For both transfers, two cases are investigated: (1) the bank angle is continuously variable; and (2) the trajectory is divided into segments along which the bank angle is constant. For case (2), the following subcases are studied: two segments, three segments, four segments, and five segments; because the time duration of each segment is optimized, the above subcases involve four, six, eight, and ten parameters, respectively. Presented here are systematic data on a total of ten optimal trajectories (OT), five for Transfer IA and five for Transfer DA. For comparison purposes and only for Transfer IA, a five-segment reference trajectory RT is also considered.
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Basics of Compounding: 3D Printing--Pharmacy Applications, Part 1.
Allen, Loyd V
2017-01-01
Three-dimensional printing quickly became a standard tool in the automotive, aerospace, and consumer goods industries and, recently, has begun gaining traction in pharmaceutical manufacturing. 3D printing has steadily grown, introducing a new element into dosage form development, and has received a boost with U.S. Food and Drug Administration (FDA) approval of the 3D-printed orodispersible tablet, Spritam (levetiracetam). This part 1 of a 3-part article introduces 3D printing and its application to pharmacy. Copyright© by International Journal of Pharmaceutical Compounding, Inc.
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Carollo, Maria; Pandolfi, Elisabetta; Tozzi, Alberto Eugenio; Buisman, Anne-Marie; Mascart, Françoise; Ausiello, Clara Maria
2014-04-11
The resurgence of pertussis suggests the need for greater efforts in understanding the long-lasting protective responses induced by vaccination. In this paper we dissect the persistence of humoral and B-cell memory responses induced by primary vaccination with two different acellular pertussis (aP) vaccines, hexavalent Hexavac(®) vaccine (Hexavac) (Sanofi Pasteur MSD) and Infanrix hexa(®) (Infanrix) (GlaxoSmithKline Biologicals). We evaluated the specific immune responses in the two groups of children, 5 years after primary vaccination by measuring the persistence of IgG and antibody secreting cells (ASC) specific for vaccine antigens. Part of the enrolled children received only primary vaccination, while others had the pre-school boost dose. A similar level of antigen-specific IgG and ASC was found in Infanrix and Hexavac vaccinated children. The mean IgG levels were significantly higher in children that received the pre-school boost as compared with children that did not receive the boost dose. A longer persistence after the pre-school boost of IgG-Pertussis Toxin (PT) and IgG-pertactin levels was observed in Infanrix primed children, but it was not statistically significant. More than 80% of children presented a positive ASC B memory response. Around 50% of children still presented protective IgG-PT levels which are reduced to 36% in no-boosted children. The pre-school booster dose restores the percentage of protected children above 50%. In conclusion our data underline the importance of giving a booster dose 5 years after primary vaccination and suggest the need for a new vaccine able to induce a long lasting protective response. Copyright © 2014 Elsevier Ltd. All rights reserved.
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Net Results: Online Protocols Boost Group Learning Potential
ERIC Educational Resources Information Center
Dichter, Alan; Zydney, Janet Mannheimer
2015-01-01
Educators have begun to use protocols to facilitate professional development in online spaces--partly because people need to connect from different places, but also to take advantage of new environments for learning. For example, asynchronous tools, such as discussion forums, blogs, or Google+, where participants post messages to one another at…
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AdaBoost-based on-line signature verifier
NASA Astrophysics Data System (ADS)
Hongo, Yasunori; Muramatsu, Daigo; Matsumoto, Takashi
2005-03-01
Authentication of individuals is rapidly becoming an important issue. The authors previously proposed a Pen-input online signature verification algorithm. The algorithm considers a writer"s signature as a trajectory of pen position, pen pressure, pen azimuth, and pen altitude that evolve over time, so that it is dynamic and biometric. Many algorithms have been proposed and reported to achieve accuracy for on-line signature verification, but setting the threshold value for these algorithms is a problem. In this paper, we introduce a user-generic model generated by AdaBoost, which resolves this problem. When user- specific models (one model for each user) are used for signature verification problems, we need to generate the models using only genuine signatures. Forged signatures are not available because imposters do not give forged signatures for training in advance. However, we can make use of another's forged signature in addition to the genuine signatures for learning by introducing a user generic model. And Adaboost is a well-known classification algorithm, making final decisions depending on the sign of the output value. Therefore, it is not necessary to set the threshold value. A preliminary experiment is performed on a database consisting of data from 50 individuals. This set consists of western-alphabet-based signatures provide by a European research group. In this experiment, our algorithm gives an FRR of 1.88% and an FAR of 1.60%. Since no fine-tuning was done, this preliminary result looks very promising.
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Recombinant modified vaccinia virus Ankara-based malaria vaccines.
Sebastian, Sarah; Gilbert, Sarah C
2016-01-01
A safe and effective malaria vaccine is a crucial part of the roadmap to malaria elimination/eradication by the year 2050. Viral-vectored vaccines based on adenoviruses and modified vaccinia virus Ankara (MVA) expressing malaria immunogens are currently being used in heterologous prime-boost regimes in clinical trials for induction of strong antigen-specific T-cell responses and high-titer antibodies. Recombinant MVA is a safe and well-tolerated attenuated vector that has consistently shown significant boosting potential. Advances have been made in large-scale MVA manufacture as high-yield producer cell lines and high-throughput purification processes have recently been developed. This review describes the use of MVA as malaria vaccine vector in both preclinical and clinical studies in the past 5 years.
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A Proposed Ascent Abort Flight Test for the Max Launch Abort System
NASA Technical Reports Server (NTRS)
Tartabini, Paul V.; Gilbert, Michael G.; Starr, Brett R.
2016-01-01
The NASA Engineering and Safety Center initiated the Max Launch Abort System (MLAS) Project to investigate alternate crew escape system concepts that eliminate the conventional launch escape tower by integrating the escape system into an aerodynamic fairing that fully encapsulates the crew capsule and smoothly integrates with the launch vehicle. This paper proposes an ascent abort flight test for an all-propulsive towerless escape system concept that is actively controlled and sized to accommodate the Orion Crew Module. The goal of the flight test is to demonstrate a high dynamic pressure escape and to characterize jet interaction effects during operation of the attitude control thrusters at transonic and supersonic conditions. The flight-test vehicle is delivered to the required test conditions by a booster configuration selected to meet cost, manufacturability, and operability objectives. Data return is augmented through judicious design of the boost trajectory, which is optimized to obtain data at a range of relevant points, rather than just a single flight condition. Secondary flight objectives are included after the escape to obtain aerodynamic damping data for the crew module and to perform a high-altitude contingency deployment of the drogue parachutes. Both 3- and 6-degree-of-freedom trajectory simulation results are presented that establish concept feasibility, and a Monte Carlo uncertainty assessment is performed to provide confidence that test objectives can be met.
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Single-cell technologies to study the immune system.
Proserpio, Valentina; Mahata, Bidesh
2016-02-01
The immune system is composed of a variety of cells that act in a coordinated fashion to protect the organism against a multitude of different pathogens. The great variability of existing pathogens corresponds to a similar high heterogeneity of the immune cells. The study of individual immune cells, the fundamental unit of immunity, has recently transformed from a qualitative microscopic imaging to a nearly complete quantitative transcriptomic analysis. This shift has been driven by the rapid development of multiple single-cell technologies. These new advances are expected to boost the detection of less frequent cell types and transient or intermediate cell states. They will highlight the individuality of each single cell and greatly expand the resolution of current available classifications and differentiation trajectories. In this review we discuss the recent advancement and application of single-cell technologies, their limitations and future applications to study the immune system. © 2015 The Authors. Immunology Published by John Wiley & Sons Ltd.
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NASA Technical Reports Server (NTRS)
Fehrman, A. L.; Masek, R. V.
1972-01-01
Quantitative estimates of the uncertainty in predicting aerodynamic heating rates for a fully reusable space shuttle system are developed and the impact of these uncertainties on Thermal Protection System (TPS) weight are discussed. The study approach consisted of statistical evaluations of the scatter of heating data on shuttle configurations about state-of-the-art heating prediction methods to define the uncertainty in these heating predictions. The uncertainties were then applied as heating rate increments to the nominal predicted heating rate to define the uncertainty in TPS weight. Separate evaluations were made for the booster and orbiter, for trajectories which included boost through reentry and touchdown. For purposes of analysis, the vehicle configuration is divided into areas in which a given prediction method is expected to apply, and separate uncertainty factors and corresponding uncertainty in TPS weight derived for each area.
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Fuel-optimal trajectories of aeroassisted orbital transfer with plane change
NASA Technical Reports Server (NTRS)
Naidu, Desineni Subbaramaiah; Hibey, Joseph L.
1989-01-01
The problem of minimization of fuel consumption during the atmospheric portion of an aeroassisted, orbital transfer with plane change is addressed. The complete mission has required three characteristic velocities, a deorbit impulse at high earth orbit (HEO), a boost impulse at the atmospheric exit, and a reorbit impulse at low earth orbit (LEO). A performance index has been formulated as the sum of these three impulses. Application of optimal control principles has led to a nonlinear, two-point, boundary value problem which was solved by using a multiple shooting algorithm. The strategy for the atmospheric portion of the minimum-fuel transfer is to start initially with the maximum positive lift in order to recover from the downward plunge, and then to fly with a gradually decreasing lift such that the vehicle skips out of the atmosphere with a flight path angle near zero degrees.
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Economic Analysis of a Laser-Powered, Global Small Aerospacecraft Transportation System (G-SATS)
NASA Astrophysics Data System (ADS)
Walton, David; List, George; Myrabo, Leik N.
2005-04-01
A first-order economic analysis is performed for a revolutionary transport technology intended for hypersonic world travel — powered by laser energy beamed from satellite solar power stations, with relay mirrors in low Earth orbit. A fleet of 1-person to 5-person, `tractor-beam' lightcraft will enable direct port-to-port (no refueling) trips, half-way around the globe in under an hour — riding suborbital boost-glide trajectories through space. Estimates are presented of vehicle size, ridership, revenues, fleet size, capital, operating and maintenance costs, and expected profitability for a lightcraft-based global transportation system called G-SATS. On a net present value basis, over a 20-year time span, G-SATS should have a profit margin of over 20% — implying not only the ability to be profitable, but also a potential market penetrability that goes well beyond the conservative assumptions made in this analysis.
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Social Dimensions of Personal Growth following Widowhood: A Three-Wave Study.
Recksiedler, Claudia; Loter, Katharina; Klaas, Hannah S; Hollstein, Betina; Perrig-Chiello, Pasqualina
2018-01-01
Losing one's spouse is one of the most stressful life events in old age, yet research on positive consequences of overcoming critical life events describes experiences of personal growth for survivors. Because prior studies conceptualized personal growth as a stable accomplishment of an individual, our study challenges this assumption by examining trajectories of personal growth and its links to two aspects of social support. We assume that personal growth is boosted by heightened levels of loss-related social support seeking during early years of widowhood. However, toward the later stages in the bereavement process, we expect personal growth to be fostered by perceived social embeddedness. Data stem from a survey on relationships in later life conducted in 2012, 2014, and 2016 in Switzerland. The final analytical sample consisted of 508 individuals aged 50+ years, who were on average 73 years old and widowed for about 3 years at baseline. Longitudinal explorative factor analyses yielded a 3-factorial solution for personal growth. Random-effects group-specific growth curves were used to examine the trajectories of personal growth and its subdimensions, by different levels of loss-related social support seeking and embeddedness in a supportive network, over the first 8 years of widowhood. Our analyses included time-invariant and time-varying covariates. On average, our findings point to a stable trajectory of personal growth after having become widowed in later life. Group-specific analyses, however, showed different courses in the trajectories for specific subdimensions of personal growth - particularly for spiritual change and appreciation of life. Average marginal effects also yielded group differences by loss-related support seeking in the level of personal growth over time, which highlight the importance of social support seeking, rather than social embeddedness, at all stages of the bereavement process. Findings underline the importance of a longitudinal and linked-lives perspective on personal growth and point to different pathways regarding its various subdimensions. Future research should further examine the validity of personal growth scales for other populations and consider the possibility to experience personal growth already during the anticipation of a traumatic event (e.g., in the case of long-term caretaking). © 2017 S. Karger AG, Basel.
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Crocker, Anne G; Nicholls, Tonia L; Seto, Michael C; Côté, Gilles; Charette, Yanick; Caulet, Malijai
2015-01-01
The National Trajectory Project examined longitudinal data from a large sample of people found not criminally responsible on account of mental disorder (NCRMD) to assess the presence of provincial differences in the application of the law, to examine the characteristics of people with serious mental illness who come into conflict with the law and receive this verdict, and to investigate the trajectories of NCRMD–accused people as they traverse the mental health and criminal justice systems. Our paper describes the rationale for the National Trajectory Project and the methods used to collect data in Quebec, Ontario, and British Columbia, the 3 most populous provinces in Canada and the 3 provinces with the most people found NCRMD. PMID:25886685
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Surface Modeling of Workpiece and Tool Trajectory Planning for Spray Painting Robot
Tang, Yang; Chen, Wei
2015-01-01
Automated tool trajectory planning for spray-painting robots is still a challenging problem, especially for a large free-form surface. A grid approximation of a free-form surface is adopted in CAD modeling in this paper. A free-form surface model is approximated by a set of flat patches. We describe here an efficient and flexible tool trajectory optimization scheme using T-Bézier curves calculated in a new way from trigonometrical bases. The distance between the spray gun and the free-form surface along the normal vector is varied. Automotive body parts, which are large free-form surfaces, are used to test the scheme. The experimental results show that the trajectory planning algorithm achieves satisfactory performance. This algorithm can also be extended to other applications. PMID:25993663
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Surface modeling of workpiece and tool trajectory planning for spray painting robot.
Tang, Yang; Chen, Wei
2015-01-01
Automated tool trajectory planning for spray-painting robots is still a challenging problem, especially for a large free-form surface. A grid approximation of a free-form surface is adopted in CAD modeling in this paper. A free-form surface model is approximated by a set of flat patches. We describe here an efficient and flexible tool trajectory optimization scheme using T-Bézier curves calculated in a new way from trigonometrical bases. The distance between the spray gun and the free-form surface along the normal vector is varied. Automotive body parts, which are large free-form surfaces, are used to test the scheme. The experimental results show that the trajectory planning algorithm achieves satisfactory performance. This algorithm can also be extended to other applications.
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NASA Technical Reports Server (NTRS)
Murad, P. A.
1993-01-01
Tsien's method is extended to treat the orbital motion of a body undergoing accelerations and decelerations. A generalized solution is discussed for the generalized case where a body undergoes azimuthal and radial thrust and the problem is further simplified for azimuthal thrust alone. Judicious selection of thrust could generate either an elliptic or hyperbolic trajectory. This is unexpected especially when the body has only enough energy for a lower state trajectory. The methodology is extended treating the problem of vehicle thrust for orbiting a sphere and vehicle thrust within the classical restricted three-body problem. Results for the latter situation can produce hyperbolic trajectories through eigen value decomposition. Since eigen values for no-thrust can be imaginary, thrust can generate real eigen values to describe hyperbolic trajectories. Keplerian dynamics appears to represent but a small subset of a much larger non-Keplerian domain especially when thrust effects are considered. The need for high thrust long duration space-based propulsion systems for changing a trajectory's canonical form is clearly demonstrated.
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NASA Technical Reports Server (NTRS)
Young, Archie
1999-01-01
The Mars exploration is a candidate pathway to expand human presence and useful activities in the solar system. There are several propulsion system options being considered to place the Mars payload on its interplanetary transfer trajectory. One propulsion option is the use of Solar Electric Propulsion (SEP) to spiral out with the Mars payload from an initial Low Earth Orbit (LEO) to an elliptical High Earth Orbit (HEO). This report, presented in annotated facing page format, describes the work completed on the design of a crew taxi propulsion stage used in conjunction with the SEP. Transportation system/mission analysis topics covered in this report include sub-system analysis, trajectory profile description, mass performance and crew taxi stage sizing, stage configuration, stage cost, and Trans-Mars Injection (TMI) launch window. The high efficiency of SEP is used to provide the major part of the TMI propulsion maneuver. Orbital energy is continuously added over a period of approximately twelve months. The SEP and Mars payload follow a spiral trajectory from an initial LEO to a final elliptical HEO. A small chemical stage is then used to provide the final part of the TMI. The now unloaded SEP returns to LEO to repeat another spiral trajectory with payload to HEO. The spiral phase of the SEP's trajectory takes several months to reach HEO, thus significantly increasing the exposure time of the crew to zero-gravity. In order to minimize the long zero-gravity effects, a high thrust chemical stage delivers the crew to the SEP's HEO. The crew rendezvous with the Mars payload in HEO. After a checkout period the Mars payload with the crew is injected onto a Trans-Mars Trajectory by a small chemical stage.
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Trajectories of Heroin Addiction: Growth Mixture Modeling Results Based on a 33-Year Follow-Up Study
ERIC Educational Resources Information Center
Hser, Yih-Ing; Huang, David; Chou, Chih-Ping; Anglin, M. Douglas
2007-01-01
This study investigates trajectories of heroin use and subsequent consequences in a sample of 471 male heroin addicts who were admitted to the California Civil Addict Program in 1964-1965 and followed over 33 years. Applying a two-part growth mixture modeling strategy to heroin use level during the first 16 years of the addiction careers since…
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Geldhof, Marc F; Van Breedam, Wander; De Jong, Ellen; Lopez Rodriguez, Alfonso; Karniychuk, Uladzimir U; Vanhee, Merijn; Van Doorsselaere, Jan; Maes, Dominiek; Nauwynck, Hans J
2013-12-27
The porcine reproductive and respiratory syndrome virus (PRRSV) causes reproductive failure in sows and respiratory disease in pigs of all ages. Despite the frequent use of vaccines to maintain PRRSV immunity in sows, little is known on how the currently used vaccines affect the immunity against currently circulating and genetically divergent PRRSV variants in PRRSV-immune sows, i.e. sows that have a pre-existing PRRSV-specific immunity due to previous infection with or vaccination against the virus. Therefore, this study aimed to assess the capacity of commercially available attenuated/inactivated PRRSV vaccines and autogenous inactivated PRRSV vaccines - prepared according to a previously optimized in-house protocol - to boost the antibody immunity against currently circulating PRRSV variants in PRRSV-immune sows. PRRSV isolates were obtained from 3 different swine herds experiencing PRRSV-related problems, despite regular vaccination of gilts and sows against the virus. In a first part of the study, the PRRSV-specific antibody response upon booster vaccination with commercial PRRSV vaccines and inactivated farm-specific PRRSV vaccines was evaluated in PRRSV-immune, non-pregnant replacement sows from the 3 herds. A boost in virus-neutralizing antibodies against the farm-specific isolate was observed in all sow groups vaccinated with the corresponding farm-specific inactivated vaccines. Use of the commercial attenuated EU type vaccine boosted neutralizing antibodies against the farm-specific isolate in sows derived from 2 farms, while use of the commercial attenuated NA type vaccine did not boost farm-specific virus-neutralizing antibodies in any of the sow groups. Interestingly, the commercial inactivated EU type vaccine boosted farm-specific virus-neutralizing antibodies in sows from 1 farm. In the second part of the study, a field trial was performed at one of the farms to evaluate the booster effect of an inactivated farm-specific vaccine and a commercial attenuated EU-type vaccine in immune sows at 60 days of gestation. The impact of this vaccination on maternal immunity and on the PRRSV infection pattern in piglets during their first weeks of life was evaluated. Upon vaccination with the farm-specific inactivated vaccine, a significant increase in farm-specific virus-neutralizing antibodies was detected in all sows. Virus-neutralizing antibodies were also transferred to the piglets via colostrum and were detectable in the serum of these animals until 5 weeks after parturition. In contrast, not all sows vaccinated with the commercial attenuated vaccine showed an increase in farm-specific virus-neutralizing antibodies and the piglets of this group generally had lower virus-neutralizing antibody titers. Interestingly, the number of viremic animals (i.e. animals that have infectious virus in their bloodstream) was significantly lower among piglets of both vaccinated groups than among piglets of mock-vaccinated sows and this at least until 9 weeks after parturition. The results of this study indicate that inactivated farm-specific PRRSV vaccines and commercial attenuated vaccines can be useful tools to boost PRRSV-specific (humoral) immunity in sows and reduce viremia in weaned piglets. Copyright © 2013 Elsevier B.V. All rights reserved.
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Kendzor, Darla E; Caughy, Margaret O; Owen, Margaret Tresch
2012-08-05
Childhood socioeconomic disadvantage has been linked with obesity in cross-sectional research, although less is known about how changes in socioeconomic status influence the development of obesity. Researchers have hypothesized that upward socioeconomic mobility may attenuate the health effects of earlier socioeconomic disadvantage; while downward socioeconomic mobility might have a negative influence on health despite relative socioeconomic advantages at earlier stages. The purpose of the current study was to characterize trajectories of family income during childhood, and to evaluate the influence of these trajectories on adiposity at age 15. Data were collected as part of the Study of Early Child Care and Youth Development (SECCYD) between 1991 and 2007 at 10 sites across the United States. A latent class growth analysis (LCGA) was conducted to identify trajectories of family income from birth to 15 years of age. Analyses of covariance (ANCOVAs) were conducted to determine whether measures of adiposity differed by trajectory, while controlling for relevant covariates. The LCGA supported a 5-class trajectory model, which included two stable, one downward, and two upward trajectories. ANCOVAs indicated that BMI percentile, waist circumference, and skinfold thicknesses at age 15 differed significantly by trajectory, such that those who experienced downward mobility or stable low income had greater adiposity relative to the more advantaged trajectories. Conversely, upwardly mobile children and those with consistently adequate incomes had similar and more positive outcomes relative to the most disadvantaged trajectories. Findings suggest that promoting upward socioeconomic mobility among disadvantaged families may have a positive impact on obesity-related outcomes in adolescence.
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Boosting the Supply and Effectiveness of Washington's STEM Teachers. Executive Summary
ERIC Educational Resources Information Center
New Teacher Project, 2010
2010-01-01
In the spring of 2009, the Partnership for Learning (PFL) asked The New Teacher Project (TNTP) to analyze challenges Washington faces in science, technology, engineering and mathematics (STEM) instruction and to make recommendations to overcome these challenges as part of a new STEM initiative. This initiative aims to dramatically raise student…
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Teaching Big Ideas in Diverse Middle School Classrooms
ERIC Educational Resources Information Center
Conderman, Greg; Bresnahan, Val
2008-01-01
With the increase of diversity in classrooms and conflicting or confusing advice from experts, teachers may feel pulled in many directions as they race to cover the curriculum. Successfully meeting the challenge of teaching in diverse classrooms depends, in part, on using research-based instructional methods that boost academic skills and foster…
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California's New School Finance Law.
ERIC Educational Resources Information Center
Lindman, Erick L.
Following a touch-and-go struggle in the California legislature, a school finance reform law, known as the Property Tax Relief Act of 1972, was passed. The contents of this act were affected in part by the California Supreme Court decision--Serrano vs Priest. The new law includes boosts in foundation programs, expressed in dollar amounts per pupil…
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Boosting Underprepared Students: Salish Kootenai College Uses Research to Build Success
ERIC Educational Resources Information Center
Sherwin, Stacey
2011-01-01
As an open-access institution and a tribal college, Salish Kootenai College (SKC, Pablo, Montana) accepts all students who walk through the doors. Part of SKC's mission is to provide educational opportunities and access for students who are historically underrepresented in higher education. In recent years, national attention has focused on the…
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3 Steps, 1 Goal: Teacher Teams Boost Math Instruction Using 3-Part Learning Design
ERIC Educational Resources Information Center
Mistretta, Regina M.
2012-01-01
Teacher education and professional development prepare teachers with up-to-date knowledge, skills, and dispositions necessary for effective teaching. To sustain this, however, hinges on continued professional learning within schools. Research shows that establishing long-term conditions that allow teachers to learn continuously from one another…
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ERIC Educational Resources Information Center
Young, Marisa
2007-01-01
Australian educators now operate in environments that frequently stress marketing activities. This article highlights the ways that colonial school prize ceremonies were deliberately developed to promote teaching activities. These ceremonies were part of carefully considered strategies that helped to boost the status of entrepreneurial teachers…
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NAEP Test-Taking Pool Grows More Inclusive
ERIC Educational Resources Information Center
Maxwell, Lesli A.; Shah, Nirvi
2011-01-01
Following a push to make "the nation's report card" better reflect the academic performance of all children in America's schools, most states boosted the numbers of students with disabilities and English-language learners who participated in the 2011 reading and math tests that are part of the National Assessment of Educational Progress (NAEP).…
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ERIC Educational Resources Information Center
Scott, Michael
2006-01-01
Efforts to expand diversity in the health professions has received a boost from a prominent member of Congress. U.S. Senator Bill Frist, R-Tennessee, recently introduced a bill to amend the Public Health Service Act as part of a comprehensive initiative to improve the health of minority and other underserved populations. This bill, which is being…
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Maintaining Switzerland's Top Innovation Capacity. OECD Economics Department Working Papers, No. 487
ERIC Educational Resources Information Center
Jaumotte, Florence
2006-01-01
Despite some weakening in the 1990s, partly due to sluggish trend growth, the Swiss innovation performance has been very strong. There are, however, areas in which policy reforms could strengthen innovation further and help Switzerland maintain its lead in the face of a changing global environment. Boosting competition, simplifying administrative…
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Narrowing the gap: effects of intervention on developmental trajectories in autism.
Klintwall, Lars; Eldevik, Sigmund; Eikeseth, Svein
2015-01-01
Although still a matter of some debate, there is a growing body of research supporting Early and Intensive Behavioral Intervention as the intervention of choice for children with autism. Learning rate is an alternative to change in standard scores as an outcome measure in studies of early intervention. Learning rates can be displayed graphically as developmental trajectories, which are easy to understand and avoid some of the counter-intuitive properties of changes in standard scores. The data used in this analysis were from 453 children with autism, previously described by Eldevik et al. Children receiving Early and Intensive Behavioral Intervention exhibited significantly steeper developmental trajectories than children in the control group, in both intelligence and adaptive behaviors. However, there was a considerable variability in individual learning rates within the group receiving Early and Intensive Behavioral Intervention. This variability could partly be explained by the intensity of the treatment, partly by children's intake intelligence quotient age-equivalents. Age at intake did not co-vary with learning rate. © The Author(s) 2013.
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Electrochemical, H2O2-Boosted Catalytic Oxidation System
NASA Technical Reports Server (NTRS)
Akse, James R.; Thompson, John O.; Schussel, Leonard J.
2004-01-01
An improved water-sterilizing aqueous-phase catalytic oxidation system (APCOS) is based partly on the electrochemical generation of hydrogen peroxide (H2O2). This H2O2-boosted system offers significant improvements over prior dissolved-oxygen water-sterilizing systems in the way in which it increases oxidation capabilities, supplies H2O2 when needed, reduces the total organic carbon (TOC) content of treated water to a low level, consumes less energy than prior systems do, reduces the risk of contamination, and costs less to operate. This system was developed as a variant of part of an improved waste-management subsystem of the life-support system of a spacecraft. Going beyond its original intended purpose, it offers the advantage of being able to produce H2O2 on demand for surface sterilization and/or decontamination: this is a major advantage inasmuch as the benign byproducts of this H2O2 system, unlike those of systems that utilize other chemical sterilants, place no additional burden of containment control on other spacecraft air- or water-reclamation systems.
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Pair-Wise Trajectory Management-Oceanic (PTM-O) . [Concept of Operations—Version 3.9
NASA Technical Reports Server (NTRS)
Jones, Kenneth M.
2014-01-01
This document describes the Pair-wise Trajectory Management-Oceanic (PTM-O) Concept of Operations (ConOps). Pair-wise Trajectory Management (PTM) is a concept that includes airborne and ground-based capabilities designed to enable and to benefit from, airborne pair-wise distance-monitoring capability. PTM includes the capabilities needed for the controller to issue a PTM clearance that resolves a conflict for a specific pair of aircraft. PTM avionics include the capabilities needed for the flight crew to manage their trajectory relative to specific designated aircraft. Pair-wise Trajectory Management PTM-Oceanic (PTM-O) is a regional specific application of the PTM concept. PTM is sponsored by the National Aeronautics and Space Administration (NASA) Concept and Technology Development Project (part of NASA's Airspace Systems Program). The goal of PTM is to use enhanced and distributed communications and surveillance along with airborne tools to permit reduced separation standards for given aircraft pairs, thereby increasing the capacity and efficiency of aircraft operations at a given altitude or volume of airspace.
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Developmental trajectories of work-family conflict for Finnish workers in midlife.
Rantanen, Johanna; Kinnunen, Ulla; Pulkkinen, Lea; Kokko, Katja
2012-07-01
This study investigated the developmental trajectories of work-family conflict among the same participants (n = 277; 48% female) at ages 36, 42, and 50. Across this 14-year time span, with respect to the sample as a whole, there was no significant change in the mean levels of work-to-family conflict (WFC) or family to-work conflict (FWC). However, latent profile analyses revealed four latent trajectories within the sample, showing both mean-level stability and change in WFC and FWC: (1) "WFC decreasing" (n = 151); (2) "WFC and FWC stable low" (n = 105); (3) "WFC and FWC increasing" (n = 14); and (4) "FWC decreasing" (n = 7). Of these trajectories the strongest contrast existed between the WFC and FWC stable low and the WFC and FWC increasing trajectories: the former had the lowest and the latter the highest number of weekly working hours at ages 36, 42, and 50, and in the former but not in the latter the number of children living at home significantly decreased from age 36 to 50. Also, at ages 42 and 50 the WFC and FWC increasing trajectory showed higher job exhaustion and depressive symptoms than the WFC and FWC stable low trajectory. Altogether these findings suggest that work-family conflict is not limited to the early part of employees' working career and that developmental trajectories of work-family conflict exhibit a substantial amount of heterogeneity.
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Trajectories of change in depression severity during treatment with antidepressants.
Uher, R; Muthén, B; Souery, D; Mors, O; Jaracz, J; Placentino, A; Petrovic, A; Zobel, A; Henigsberg, N; Rietschel, M; Aitchison, K J; Farmer, A; McGuffin, P
2010-08-01
Response and remission defined by cut-off values on the last observed depression severity score are commonly used as outcome criteria in clinical trials, but ignore the time course of symptomatic change and may lead to inefficient analyses. We explore alternative categorization of outcome by naturally occurring trajectories of symptom change. Growth mixture models were applied to repeated measurements of depression severity in 807 participants with major depression treated for 12 weeks with escitalopram or nortriptyline in the part-randomized Genome-based Therapeutic Drugs for Depression study. Latent trajectory classes were validated as outcomes in drug efficacy comparison and pharmacogenetic analyses. The final two-piece growth mixture model categorized participants into a majority (75%) following a gradual improvement trajectory and the remainder following a trajectory with rapid initial improvement. The rapid improvement trajectory was over-represented among nortriptyline-treated participants and showed an antidepressant-specific pattern of pharmacogenetic associations. In contrast, conventional response and remission favoured escitalopram and produced chance results in pharmacogenetic analyses. Controlling for drop-out reduced drug differences on response and remission but did not affect latent trajectory results. Latent trajectory mixture models capture heterogeneity in the development of clinical response after the initiation of antidepressants and provide an outcome that is distinct from traditional endpoint measures. It differentiates between antidepressants with different modes of action and is robust against bias due to differential discontinuation.
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Developmental Trajectories of Part-Based and Configural Object Recognition in Adolescence
ERIC Educational Resources Information Center
Juttner, Martin; Wakui, Elley; Petters, Dean; Kaur, Surinder; Davidoff, Jules
2013-01-01
Three experiments assessed the development of children's part and configural (part-relational) processing in object recognition during adolescence. In total, 312 school children aged 7-16 years and 80 adults were tested in 3-alternative forced choice (3-AFC) tasks. They judged the correct appearance of upright and inverted presented familiar…
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Peng, Zhen; Genewein, Tim; Braun, Daniel A.
2014-01-01
Complexity is a hallmark of intelligent behavior consisting both of regular patterns and random variation. To quantitatively assess the complexity and randomness of human motion, we designed a motor task in which we translated subjects' motion trajectories into strings of symbol sequences. In the first part of the experiment participants were asked to perform self-paced movements to create repetitive patterns, copy pre-specified letter sequences, and generate random movements. To investigate whether the degree of randomness can be manipulated, in the second part of the experiment participants were asked to perform unpredictable movements in the context of a pursuit game, where they received feedback from an online Bayesian predictor guessing their next move. We analyzed symbol sequences representing subjects' motion trajectories with five common complexity measures: predictability, compressibility, approximate entropy, Lempel-Ziv complexity, as well as effective measure complexity. We found that subjects' self-created patterns were the most complex, followed by drawing movements of letters and self-paced random motion. We also found that participants could change the randomness of their behavior depending on context and feedback. Our results suggest that humans can adjust both complexity and regularity in different movement types and contexts and that this can be assessed with information-theoretic measures of the symbolic sequences generated from movement trajectories. PMID:24744716
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Kuo, Li-Min; Huang, Huei-Ling; Liang, Jersey; Kwok, Yam-Ting; Hsu, Wen-Chuin; Liu, Chin-Yi; Shyu, Yea-Ing L
To determine distinct courses of change in health-related quality of life (HRQoL) among family caregivers of individuals with dementia and how participating in a home-based caregiver-training program affects the probability of belonging to each course. Sixty three caregivers were in the intervention group, and 66 caregivers were in the control group of a single-blinded randomized clinical trial. Two distinct trajectories of HRQoL were identified: a well-functioning trajectory and a poor-functioning trajectory. Caregivers who received the training program were more likely than those who did not have a well-functioning trajectory of HRQoL over 18 months. This trajectory included bodily pain (b = 1.02, odds ratio [OR] = 2.76), general health perception (b = 1.28, OR = 3.60), social functioning (b = 1.12, OR = 3.05), vitality (b = 1.51, OR = 4.49), general mental health (b = 1.08, OR = 2.94), and mental component summary (b = 1.27, OR = 3.55). Home-based caregiver training can be considered as part of the protocol for managing patients with dementia and their caregivers. NCT02667951. Copyright © 2016 Elsevier Inc. All rights reserved.
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Nakar, Orit; Brunner, Romuald; Schilling, Oliver; Chanen, Andrew; Fischer, Gloria; Parzer, Peter; Carli, Vladimir; Wasserman, Danuta; Sarchiapone, Marco; Wasserman, Camilla; Hoven, Christina W; Resch, Franz; Kaess, Michael
2016-06-01
Adolescent risk-taking and self-harm behaviors are associated with affect dysregulation and impulsivity, both core features of borderline personality disorder (BPD). We hypothesized that the developmental courses of these behaviors i) tend to cluster rather than appear individually, and ii) might indicate adolescent BPD pathology. Therefore, we explored the developmental trajectories of self-injurious behavior (SIB), suicidal behavior (SB) and substance misuse (SM) in a community sample of adolescents; and we investigated the trajectories' overlap and its associations with BPD traits. 513 adolescents, aged 15-17 years, were followed for two years as part of the Saving and Empowering Young Lives in Europe study and its subsequent follow-up. Distinct developmental trajectories were explored using general growth mixture modeling. Three distinct classes were identified within each of the harmful behaviors SIB, SB and SM. Both the high-risk SIB trajectory and the high-risk SB trajectory demonstrated elevated initial degree of engagement, followed by a gradual decrease. The SM high-risk trajectory had a medium initial degree of engagement, which increased over time. There was a high degree of overlap (80-90%) among the high-risk trajectories for the three behaviors (SIB, SB and SM), and this overlap was significantly associated with elevated levels of BPD pathology. The data collection was based on participants' self-report. The findings indicate a similar pattern of reduction over time between SIB and SB for the high-risk trajectories, whereas the high-risk trajectories for SM show a pattern of increase over time. The observed symptom shift is associated with borderline personality pathology in adolescents. Therefore these behaviors might represent early indicators of risk supporting potential early detection. Copyright © 2016 Elsevier B.V. All rights reserved.
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Computer simulations of optimum boost and buck-boost converters
NASA Technical Reports Server (NTRS)
Rahman, S.
1982-01-01
The development of mathematicl models suitable for minimum weight boost and buck-boost converter designs are presented. The facility of an augumented Lagrangian (ALAG) multiplier-based nonlinear programming technique is demonstrated for minimum weight design optimizations of boost and buck-boost power converters. ALAG-based computer simulation results for those two minimum weight designs are discussed. Certain important features of ALAG are presented in the framework of a comprehensive design example for boost and buck-boost power converter design optimization. The study provides refreshing design insight of power converters and presents such information as weight annd loss profiles of various semiconductor components and magnetics as a function of the switching frequency.
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Zerwas, Stephanie; Von Holle, Ann; Watson, Hunna; Gottfredson, Nisha; Bulik, Cynthia M.
2015-01-01
Objective The goal of the present paper was to examine whether childhood anxiety trajectories predict eating psychopathology. We predicted that girls with trajectories of increasing anxiety across childhood would have significantly greater risk of disordered eating in adolescence in comparison to girls with stable or decreasing trajectories of anxiety over childhood. Method Data were collected as part of the prospective longitudinal NICHD Study of Early Child Care and Youth Development (N=450 girls). Childhood anxiety was assessed yearly (54 months through 6th grade) via maternal report on the Child Behavior Checklist. Disordered eating behaviors were assessed at age 15 via adolescent self-report on the Eating Attitudes Test (EAT-26). We conducted latent growth mixture modeling to define girls’ childhood anxiety trajectories. Maternal sensitivity, maternal postpartum depression, maternal anxiety, and child temperament were included as predictors of trajectory membership. Results The best fitting model included three trajectories of childhood anxiety, the low-decreasing class (22.9% of girls), the high-increasing class (35.4%), and the high-decreasing class (41.6%). Mothers with more symptoms of depression and separation anxiety had girls who were significantly more likely to belong to the high-increasing anxiety trajectory. There were no significant differences in adolescent disordered eating for girls across the three childhood anxiety trajectories. Conclusions Childhood anxiety, as captured by maternal report, may not be the most robust predictor of adolescent disordered eating and may be of limited utility for prevention programs that aim to identify children in the community at greatest risk for disordered eating. PMID:24938214
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The semaphorontic view of homology.
Havstad, Joyce C; Assis, Leandro C S; Rieppel, Olivier
2015-11-01
The relation of homology is generally characterized as an identity relation, or alternatively as a correspondence relation, both of which are transitive. We use the example of the ontogenetic development and evolutionary origin of the gnathostome jaw to discuss identity and transitivity of the homology relation under the transformationist and emergentist paradigms respectively. Token identity and consequent transitivity of homology relations are shown to be requirements that are too strong to allow the origin of genuine evolutionary novelties. We consequently introduce the concept of compositional identity that is grounded in relations prevailing between parts (organs and organ systems) of a whole (organism). We recognize an ontogenetic identity of parts within a whole throughout the sequence of successive developmental stages of those parts: this is an intra-organismal character identity maintained throughout developmental trajectory. Correspondingly, we recognize a phylogenetic identity of homologous parts within two or more organisms of different species: this is an inter-species character identity maintained throughout evolutionary trajectory. These different dimensions of character identity--ontogenetic (through development) and phylogenetic (via shared evolutionary history)--break the transitivity of homology relations. Under the transformationist paradigm, the relation of homology reigns over the entire character (-state) transformation series, and thus encompasses the plesiomorphic as well as the apomorphic condition of form. In contrast, genuine evolutionary novelties originate not through transformation of ancestral characters (-states), but instead through deviating developmental trajectories that result in alternate characters. Under the emergentist paradigm, homology is thus synonymous with synapomorphy. © 2015 The Authors. Journal of Experimental Zoology Part B: Molecular and Developmental Evolution Published by Wiley Periodicals, Inc.
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The rotate-plus-shift C-arm trajectory: complete CT data with limited angular rotation
NASA Astrophysics Data System (ADS)
Ritschl, Ludwig; Kuntz, Jan; Kachelrieß, Marc
2015-03-01
In the last decade C-arm-based cone-beam CT became a widely used modality for intraoperative imaging. Typically a C-arm scan is performed using a circle-like trajectory around a region of interest. Therefor an angular range of at least 180° plus fan-angle must be covered to ensure a completely sampled data set. This fact defines some constraints on the geometry and technical specifications of a C-arm system, for example a larger C radius or a smaller C opening respectively. These technical modifications are usually not beneficial in terms of handling and usability of the C-arm during classical 2D applications like fluoroscopy. The method proposed in this paper relaxes the constraint of 180° plus fan-angle rotation to acquire a complete data set. The proposed C-arm trajectory requires a motorization of the orbital axis of the C and of ideally two orthogonal axis in the C plane. The trajectory consists of three parts: A rotation of the C around a defined iso-center and two translational movements parallel to the detector plane at the begin and at the end of the rotation. Combining these three parts to one trajectory enables for the acquisition of a completely sampled dataset using only 180° minus fan-angle of rotation. To evaluate the method we show animal and cadaver scans acquired with a mobile C-arm prototype. We expect that the transition of this method into clinical routine will lead to a much broader use of intraoperative 3D imaging in a wide field of clinical applications.
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A Randomized Experiment Using Absenteeism Information to "Nudge" Attendance. REL 2017-252
ERIC Educational Resources Information Center
Rogers, Todd; Duncan, Teresa; Wolford, Tonya; Ternovski, John; Subramanyam, Shruthi; Reitano, Adrienne
2017-01-01
Reducing student absenteeism is a key part of the School District of Philadelphia's plan to boost graduation rates. One of the district's goals is to increase guardians' awareness of absenteeism, with the hope that greater awareness will lead to guardians' taking a more active role in improving their student's attendance and academic performance.…
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Rees, Tom
2002-01-01
An award-winning integrated marketing campaign for Rush-Presbyterian-St. Luke's Medical Center, Chicago, showcases the institution's research and developments. Each edition of its 50-part series of print ads features a different case study. These are being promoted through internal communications and also with highly visible collateral materials.
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Boosting Engagement and Growth with Formative Assessment: Leaders Share Their Lessons
ERIC Educational Resources Information Center
Northwest Evaluation Association, 2016
2016-01-01
Our featured leaders saw big gains when their teachers began using formative assessment practice to guide student growth minute-by-minute. Read the fourth article in our five-part series for the scoop on how committing to this high-impact instructional practice paid off for a regional agency, district, and school. Learn: (1) why our featured…
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2016-09-01
severe. Chapter III begins the first part of the comparative case study analysis by focusing on Canada’s current foreign fighter issues, propaganda...violence in their home countries. Through an extensive comparative case study analysis of recent ISIL-related violent incidents and plots in the United...overseas, decided instead to alter their targeting trajectory and commit violence in their home countries. Through an extensive comparative case study
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ERIC Educational Resources Information Center
Jager, Justin; Keyes, Katherine M.; Schulenberg, John E.
2015-01-01
This study examines historical variation in age 18 to 26 binge drinking trajectories, focusing on differences in both levels of use and rates of change (growth) across cohorts of young adults over 3 decades. As part of the national Monitoring the Future Study, over 64,000 youths from the high school classes of 1976 to 2004 were surveyed at…
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Airborne Simulation of Launch Vehicle Dynamics
NASA Technical Reports Server (NTRS)
Gilligan, Eric T.; Miller, Christopher J.; Hanson, Curtis E.; Orr, Jeb S.
2014-01-01
In this paper we present a technique for approximating the short-period dynamics of an exploration-class launch vehicle during flight test with a high-performance surrogate aircraft in relatively benign endoatmospheric flight conditions. The surrogate vehicle relies upon a nonlinear dynamic inversion scheme with proportional-integral feedback to drive a subset of the aircraft states into coincidence with the states of a time-varying reference model that simulates the unstable rigid body dynamics, servodynamics, and parasitic elastic and sloshing dynamics of the launch vehicle. The surrogate aircraft flies a constant pitch rate trajectory to approximate the boost phase gravity-turn ascent, and the aircraft's closed-loop bandwidth is sufficient to simulate the launch vehicle's fundamental lateral bending and sloshing modes by exciting the rigid body dynamics of the aircraft. A novel control allocation scheme is employed to utilize the aircraft's relatively fast control effectors in inducing various failure modes for the purposes of evaluating control system performance. Sufficient dynamic similarity is achieved such that the control system under evaluation is optimized for the full-scale vehicle with no changes to its parameters, and pilot-control system interaction studies can be performed to characterize the effects of guidance takeover during boost. High-fidelity simulation and flight test results are presented that demonstrate the efficacy of the design in simulating the Space Launch System (SLS) launch vehicle dynamics using NASA Dryden Flight Research Center's Full-scale Advanced Systems Testbed (FAST), a modified F/A-18 airplane, over a range of scenarios designed to stress the SLS's adaptive augmenting control (AAC) algorithm.
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Real-time fuzzy inference based robot path planning
NASA Technical Reports Server (NTRS)
Pacini, Peter J.; Teichrow, Jon S.
1990-01-01
This project addresses the problem of adaptive trajectory generation for a robot arm. Conventional trajectory generation involves computing a path in real time to minimize a performance measure such as expended energy. This method can be computationally intensive, and it may yield poor results if the trajectory is weakly constrained. Typically some implicit constraints are known, but cannot be encoded analytically. The alternative approach used here is to formulate domain-specific knowledge, including implicit and ill-defined constraints, in terms of fuzzy rules. These rules utilize linguistic terms to relate input variables to output variables. Since the fuzzy rulebase is determined off-line, only high-level, computationally light processing is required in real time. Potential applications for adaptive trajectory generation include missile guidance and various sophisticated robot control tasks, such as automotive assembly, high speed electrical parts insertion, stepper alignment, and motion control for high speed parcel transfer systems.
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NASA Astrophysics Data System (ADS)
Shinnaka, Shinji
This paper presents a new unified analysis of estimate errors by model-matching extended-back-EMF estimation methods for sensorless drive of permanent-magnet synchronous motors. Analytical solutions about estimate errors, whose validity is confirmed by numerical experiments, are rich in universality and applicability. As an example of universality and applicability, a new trajectory-oriented vector control method is proposed, which can realize directly quasi-optimal strategy minimizing total losses with no additional computational loads by simply orienting one of vector-control coordinates to the associated quasi-optimal trajectory. The coordinate orientation rule, which is analytically derived, is surprisingly simple. Consequently the trajectory-oriented vector control method can be applied to a number of conventional vector control systems using model-matching extended-back-EMF estimation methods.
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NASA Technical Reports Server (NTRS)
Stensrud, Kjell C.; Hamm, Dustin
2007-01-01
NASA's Johnson Space Center (JSC) / Flight Design and Dynamics Division (DM) has prototyped the use of Open Source middleware technology for building its next generation spacecraft mission support system. This is part of a larger initiative to use open standards and open source software as building blocks for future mission and safety critical systems. JSC is hoping to leverage standardized enterprise architectures, such as Java EE, so that its internal software development efforts can be focused on the core aspects of their problem domain. This presentation will outline the design and implementation of the Trajectory system and the lessons learned during the exercise.
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NASA Astrophysics Data System (ADS)
Suh, Donghyuk; Radak, Brian K.; Chipot, Christophe; Roux, Benoît
2018-01-01
Molecular dynamics (MD) trajectories based on classical equations of motion can be used to sample the configurational space of complex molecular systems. However, brute-force MD often converges slowly due to the ruggedness of the underlying potential energy surface. Several schemes have been proposed to address this problem by effectively smoothing the potential energy surface. However, in order to recover the proper Boltzmann equilibrium probability distribution, these approaches must then rely on statistical reweighting techniques or generate the simulations within a Hamiltonian tempering replica-exchange scheme. The present work puts forth a novel hybrid sampling propagator combining Metropolis-Hastings Monte Carlo (MC) with proposed moves generated by non-equilibrium MD (neMD). This hybrid neMD-MC propagator comprises three elementary elements: (i) an atomic system is dynamically propagated for some period of time using standard equilibrium MD on the correct potential energy surface; (ii) the system is then propagated for a brief period of time during what is referred to as a "boosting phase," via a time-dependent Hamiltonian that is evolved toward the perturbed potential energy surface and then back to the correct potential energy surface; (iii) the resulting configuration at the end of the neMD trajectory is then accepted or rejected according to a Metropolis criterion before returning to step 1. A symmetric two-end momentum reversal prescription is used at the end of the neMD trajectories to guarantee that the hybrid neMD-MC sampling propagator obeys microscopic detailed balance and rigorously yields the equilibrium Boltzmann distribution. The hybrid neMD-MC sampling propagator is designed and implemented to enhance the sampling by relying on the accelerated MD and solute tempering schemes. It is also combined with the adaptive biased force sampling algorithm to examine. Illustrative tests with specific biomolecular systems indicate that the method can yield a significant speedup.
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Suh, Donghyuk; Radak, Brian K; Chipot, Christophe; Roux, Benoît
2018-01-07
Molecular dynamics (MD) trajectories based on classical equations of motion can be used to sample the configurational space of complex molecular systems. However, brute-force MD often converges slowly due to the ruggedness of the underlying potential energy surface. Several schemes have been proposed to address this problem by effectively smoothing the potential energy surface. However, in order to recover the proper Boltzmann equilibrium probability distribution, these approaches must then rely on statistical reweighting techniques or generate the simulations within a Hamiltonian tempering replica-exchange scheme. The present work puts forth a novel hybrid sampling propagator combining Metropolis-Hastings Monte Carlo (MC) with proposed moves generated by non-equilibrium MD (neMD). This hybrid neMD-MC propagator comprises three elementary elements: (i) an atomic system is dynamically propagated for some period of time using standard equilibrium MD on the correct potential energy surface; (ii) the system is then propagated for a brief period of time during what is referred to as a "boosting phase," via a time-dependent Hamiltonian that is evolved toward the perturbed potential energy surface and then back to the correct potential energy surface; (iii) the resulting configuration at the end of the neMD trajectory is then accepted or rejected according to a Metropolis criterion before returning to step 1. A symmetric two-end momentum reversal prescription is used at the end of the neMD trajectories to guarantee that the hybrid neMD-MC sampling propagator obeys microscopic detailed balance and rigorously yields the equilibrium Boltzmann distribution. The hybrid neMD-MC sampling propagator is designed and implemented to enhance the sampling by relying on the accelerated MD and solute tempering schemes. It is also combined with the adaptive biased force sampling algorithm to examine. Illustrative tests with specific biomolecular systems indicate that the method can yield a significant speedup.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Wijesooriya, K; Seitter, K; Desai, V
Purpose: To present our single institution experience on catching errors with trajectory log file analysis. The reported causes of failures, probability of occurrences (O), severity of effects (S), and the probability of the failures to be undetected (D) could be added to guidelines of FMEA analysis. Methods: From March 2013 to March 2014, 19569 patient treatment fields/arcs were analyzed. This work includes checking all 131 treatment delivery parameters for all patients, all treatment sites and all treatment delivery fractions. TrueBeam trajectory log files for all treatment field types as well as all imaging types were accessed, read in every 20ms,more » and every control point (total of 37 million parameters) compared to the physician approved plan in the planning system. Results: Couch angle outlier occurrence: N= 327, range = −1.7 −1.2 deg; gantry angle outlier occurrence: N =59, range = 0.09 – 5.61 deg, collimator angle outlier occurrence: N = 13, range = −0.2 – 0.2 deg. VMAT cases have slightly larger variations in mechanical parameters. MLC: 3D single control point fields have a maximum deviation of 0.04 mm, 39 step and shoot IMRT cases have MLC −0.3 – 0.5 mm deviations, all (1286) VMAT cases have −0.9 – 0.7 mm deviations. Two possible serious errors were found: 1) A 4 cm isocenter shift for the PA beam of an AP-PA pair, under-dosing a portion of PTV by 25%. 2) Delivery with MLC leaves abutted behind the jaws as opposed to the midline as planned, leading to a under-dosing of a small volume of the PTV by 25%, by just the boost plan. Due to their error origin, neither of these errors could have been detected by pre-treatment verification. Conclusion: Performing Trajectory Log file analysis could catch typically undetected errors to avoid potentially adverse incidents.« less
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Diffusion of passive particles in active suspensions
NASA Astrophysics Data System (ADS)
Mussler, Matthias; Rafai, Salima; John, Thomas; Peyla, Philippe; Wagner, Christian
2013-11-01
We study how an active suspension consisting of a definite volume fraction of the microswimmer Chlamydomonas Reinhardtii modifies the Brownian movement of small to medium size microspheres. We present measurements and simulations of trajectories of microspheres with a diameter of 20 μm in suspensions of Chlamydomonas Reinhardtii, a so called ``puller,'' and show that the mean squared displacement of such trajectories consist of parabolic and a linear part. The linear part is due to the hydrodynamic noise of the microswimmers while the parabolic part is a consequence of directed motion events that occur randomly, when a microsphere is transported by a microswimmer on a timescale that is in higher order of magnitude than the Brownian like hydrodynamic interaction. In addition, we theoretically describe this effect with a dimensional analysis that takes the force dipole model used to describe ``puller'' like Chlamydomonas Reinhardtii into account.
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Lester-Coll, Nataniel H; Rutter, Charles E; Evans, Suzanne B
2016-04-01
Breast radiotherapy (RT) for elderly women with estrogen receptor positive early stage breast cancer (ER+ESBC) improves local recurrence (LR) rates without benefitting overall survival. Breast boost is a common practice, although the absolute benefit decreases with age. Consequently, an analysis of its cost-effectiveness in the elderly ESBC populations is warranted. A Markov model was used to compare cost-effectiveness of RT with or without a boost in elderly ER+ESBC patients. The ten-year probability of LR with boost was derived from the CALGB 9343 trial and adjusted by the hazard ratio for LR from boost radiotherapy trial data, yielding the LR rate without boost. Remaining parameters were estimated using published data. Boost RT was associated with an increase in mean cost ($7139 vs $6193) and effectiveness (5.66 vs 5.64 quality adjusted life years; QALYs) relative to no boost. The incremental cost-effectiveness ratio (ICER) for boost was $55,903 per QALY. On one-way sensitivity analysis, boost remained cost-effective if the hazard ratio of LR with boost was <0.67. Boost RT for ER+ESBC patients was cost-effective over a wide range of assumptions and inputs over commonly accepted willingness-to pay-thresholds, but particularly in women at higher risk for LR. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
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New tools for jet analysis in high energy collisions
NASA Astrophysics Data System (ADS)
Duffty, Daniel
Our understanding of the fundamental interactions of particles has come far in the last century, and is still pushing forward. As we build ever more powerful machines to probe higher and higher energies, we will need to develop new tools to not only understand the new physics objects we are trying to detect, but even to understand the environment that we are searching in. We examine methods of identifying both boosted objects and low energy jets which will be shrouded in a sea of noise from other parts of the detector. We display the power of boosted-b tagging in a simulated W search. We also examine the effect of pileup on low energy jet reconstructions. For this purpose we develop a new priority-based jet algorithm, "p-jets", to cluster the energy that belongs together, but ignore the rest.
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NASA Technical Reports Server (NTRS)
Park, Brooke Anderson; Wright, Henry
2012-01-01
PatCon code was developed to help mission designers run trade studies on launch and arrival times for any given planet. Initially developed in Fortran, the required inputs included launch date, arrival date, and other orbital parameters of the launch planet and arrival planets at the given dates. These parameters include the position of the planets, the eccentricity, semi-major axes, argument of periapsis, ascending node, and inclination of the planets. With these inputs, a patched conic approximation is used to determine the trajectory. The patched conic approximation divides the planetary mission into three parts: (1) the departure phase, in which the two relevant bodies are Earth and the spacecraft, and where the trajectory is a departure hyperbola with Earth at the focus; (2) the cruise phase, in which the two bodies are the Sun and the spacecraft, and where the trajectory is a transfer ellipse with the Sun at the focus; and (3) the arrival phase, in which the two bodies are the target planet and the spacecraft, where the trajectory is an arrival hyperbola with the planet as the focus.
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Can you boost your metabolism?
Weight-loss boost metabolism; Obesity - boost metabolism; Overweight - boost metabolism ... Cowley MA, Brown WA, Considine RV. Obesity. In: Jameson JL, De Groot ... and Pediatric . 7th ed. Philadelphia, PA: Elsevier Saunders; ...
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Feedback control for fuel-optimal descents using singular perturbation techniques
NASA Technical Reports Server (NTRS)
Price, D. B.
1984-01-01
In response to rising fuel costs and reduced profit margins for the airline companies, the optimization of the paths flown by transport aircraft has been considered. It was found that application of optimal control theory to the considered problem can result in savings in fuel, time, and direct operating costs. The best solution to the aircraft trajectory problem is an onboard real-time feedback control law. The present paper presents a technique which shows promise of becoming a part of a complete solution. The application of singular perturbation techniques to the problem is discussed, taking into account the benefits and some problems associated with them. A different technique for handling the descent part of a trajectory is also discussed.
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A time domain inverse dynamic method for the end point tracking control of a flexible manipulator
NASA Technical Reports Server (NTRS)
Kwon, Dong-Soo; Book, Wayne J.
1991-01-01
The inverse dynamic equation of a flexible manipulator was solved in the time domain. By dividing the inverse system equation into the causal part and the anticausal part, we calculated the torque and the trajectories of all state variables for a given end point trajectory. The interpretation of this method in the frequency domain was explained in detail using the two-sided Laplace transform and the convolution integral. The open loop control of the inverse dynamic method shows an excellent result in simulation. For real applications, a practical control strategy is proposed by adding a feedback tracking control loop to the inverse dynamic feedforward control, and its good experimental performance is presented.
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Quadruped robots' modular trajectories: Stability issues
NASA Astrophysics Data System (ADS)
Pinto, Carla M. A.
2012-09-01
Pinto, Santos, Rocha and Matos [13, 12] study a CPG model for the generation of modular trajectories of quadruped robots. They consider that each movement is composed of two types of primitives: rhythmic and discrete. The rhythmic primitive models the periodic patterns and the discrete primitive is inserted as a perturbation of those patterns. In this paper we begin to tackle numerically the problem of the stability of that mathematical model. We observe that if the discrete part is inserted in all limbs, with equal values, and as an offset of the rhythmic part, the obtained gait is stable and has the same spatial and spatio-temporal symmetry groups as the purely rhythmic gait, differing only on the value of the offset.
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A PIPO Boost Converter with Low Ripple and Medium Current Application
NASA Astrophysics Data System (ADS)
Bandri, S.; Sofian, A.; Ismail, F.
2018-04-01
This paper presents a Parallel Input Parallel Output (PIPO) boost converter is proposed to gain power ability of converter, and reduce current inductors. The proposed technique will distribute current for n-parallel inductor and switching component. Four parallel boost converters implement on input voltage 20.5Vdc to generate output voltage 28.8Vdc. The PIPO boost converter applied phase shift pulse width modulation which will compare with conventional PIPO boost converters by using a similar pulse for every switching component. The current ripple reduction shows an advantage PIPO boost converter then conventional boost converter. Varies loads and duty cycle will be simulated and analyzed to verify the performance of PIPO boost converter. Finally, the unbalance of current inductor is able to be verified on four area of duty cycle in less than 0.6.
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ERIC Educational Resources Information Center
Hurley, Daniel
2008-01-01
Applied research and development activities at regional state colleges and universities bolster their primary mission of undergraduate education as well as contribute to local and statewide economic growth. As states boost efforts to fund and stimulate research as part of an integrated economic development strategy, they should seek to fully…
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ERIC Educational Resources Information Center
Lauglo, Jon
2016-01-01
This study uses comparative data to examine the impact of political socialization in the home on adolescents' expectations of university participation. The first part of the study is an international partial replication of design and findings of an earlier Norwegian study published in 2011. It examines, in socioculturally diverse countries, the…
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Healthy and Smart: Using Wellness to Boost Performance
ERIC Educational Resources Information Center
Jones, David
2007-01-01
When a survey of students at Eisenhower Middle School in Everett, Washington indicated that they spent a good part of the school day feeling tired and hungry, that they felt unsafe in some areas of the school, and that worn-down facilities left many of them feeling depressed, the author and his staff concluded that, in order to improve the…
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@NWTC Newsletter: Summer 2014 | Wind | NREL
, Developmental Role in Major Wind Journal Boosting Wind Plant Power Output by 4%-5% through Coordinated Turbine . Part 2: Wind Farm Wake Models New Framework Transforms FAST Wind Turbine Modeling Tool (Fact Sheet ) Sensitivity Analysis of Wind Plant Performance to Key Turbine Design Parameters: A Systems Engineering
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You Owe It to Yourself: Boosting Retirement Saving with a Responsibility-Based Appeal
ERIC Educational Resources Information Center
Bryan, Christopher J.; Hershfield, Hal E.
2012-01-01
Americans are not saving enough for retirement. Previous research suggests that this is due, in part, to people's tendency to think of the future self as more like another person than like the present self, making saving feel like giving money away rather than like investing in oneself. Using objective employer saving data, a field experiment…
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ERIC Educational Resources Information Center
Gonzales, Sandra M.; Gabel, Susan L.
2017-01-01
In the United States parental involvement is an important part of a child's education, and teachers often rely on parents to boost student achievement. This qualitative analysis employs a two-step process, first examining the data with regards to parental involvement and then using critical theories in education to examine the intersections…
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Top 10 "Secret Writing Tips" to Boost Your Productivity: Part 2
ERIC Educational Resources Information Center
Berk, Ronald A.
2011-01-01
This is the sequel and companion piece to the first five tips published in this journal's winter 2010 issue. To recap, the first five tips are: (1) Write Everyday; (2) Write Everywhere; (3) Conquer Distractions and Interruptions; (4) Write for a Niche; and (5) Write with a Purpose. Now, in this article, the other five tips are discussed: (6) Write…
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Transformerless dc-Isolated Converter
NASA Technical Reports Server (NTRS)
Rippel, Wally E.
1987-01-01
Efficient voltage converter employs capacitive instead of transformer coupling to provide dc isolation. Offers buck/boost operation, minimal filtering, and low parts count, with possible application in photovoltaic power inverters, power supplies and battery charges. In photovoltaic inverter circuit with transformerless converter, Q2, Q3, Q4, and Q5 form line-commutated inverter. Switching losses and stresses nil because switching performed when current is zero.
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ERIC Educational Resources Information Center
Madland, David; Bunker, Nick
2011-01-01
America's economic future depends in large part on the quality of the nation's public education. Education increases productivity, sparks innovation, and boosts the economic competitiveness. Not surprisingly, the American public thinks that there should be greater investments in education, with polls showing strong and growing support for…
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NASA Technical Reports Server (NTRS)
Delgado, Luis G.
2011-01-01
This slide presentation reviews the trajectory that will take the New Horizons Mission to Pluto. Included are photographs of the spacecraft, the launch vehicle, the assembled vehicle as it is being moved to the launch pad and the launch. Also shown are diagrams of the assembled parts with identifying part names.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Herman, Michael F.
2015-10-28
The time independent semiclassical treatment of barrier tunneling has been understood for a very long time. Several semiclassical approaches to time dependent tunneling through barriers have also been presented. These typically involve trajectories for which the position variable is a complex function of time. In this paper, a method is presented that uses only real valued trajectories, thus avoiding the complications that can arise when complex trajectories are employed. This is accomplished by expressing the time dependent wave packet as an integration over momentum. The action function in the exponent in this expression is expanded to second order in themore » momentum. The expansion is around the momentum, p{sub 0{sup *}}, at which the derivative of the real part of the action is zero. The resulting Gaussian integral is then taken. The stationary phase approximation requires that the derivative of the full action is zero at the expansion point, and this leads to a complex initial momentum and complex tunneling trajectories. The “pseudo-stationary phase” approximation employed in this work results in real values for the initial momentum and real valued trajectories. The transmission probabilities obtained are found to be in good agreement with exact quantum results.« less
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NASA Technical Reports Server (NTRS)
Lamouroux, J.; Gamache, R. R.; Laraia, A. L.; Ma, Q.; Tipping, R. H.
2012-01-01
In this work, Complex Robert-Bonamy calculations of half-widths and line shifts were done for N2-broadening of water for 1639 transitions in the rotational band using two models for the trajectories. The first is a model correct to second order in time, the Robert-Bonamy parabolic approximation. The second is the solution of Hamilton's equations. Both models use the isotropic part of the atom-atom potential to determine the trajectories. The present calculations used an intermolecular potential expanded to 20th order to assure the convergence of the half-widths and line shifts. The aim of the study is to assess if the difference in the half-widths and line shifts determined from the two trajectory models is greater than the accuracy requirements of the spectroscopic and remote sensing communities. The results of the calculations are compared with measurements of the half-widths and line shifts. It is shown that the effects of the trajectory model greatly exceed the needs of current remote sensing measurements and that line shape parameters calculated using trajectories determined by solving Hamilton's equations agree better with measurement.
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Gradient waveform pre-emphasis based on the gradient system transfer function.
Stich, Manuel; Wech, Tobias; Slawig, Anne; Ringler, Ralf; Dewdney, Andrew; Greiser, Andreas; Ruyters, Gudrun; Bley, Thorsten A; Köstler, Herbert
2018-02-25
The gradient system transfer function (GSTF) has been used to describe the distorted k-space trajectory for image reconstruction. The purpose of this work was to use the GSTF to determine the pre-emphasis for an undistorted gradient output and intended k-space trajectory. The GSTF of the MR system was determined using only standard MR hardware without special equipment such as field probes or a field camera. The GSTF was used for trajectory prediction in image reconstruction and for a gradient waveform pre-emphasis. As test sequences, a gradient-echo sequence with phase-encoding gradient modulation and a gradient-echo sequence with a spiral read-out trajectory were implemented and subsequently applied on a structural phantom and in vivo head measurements. Image artifacts were successfully suppressed by applying the GSTF-based pre-emphasis. Equivalent results are achieved with images acquired using GSTF-based post-correction of the trajectory as a part of image reconstruction. In contrast, the pre-emphasis approach allows reconstruction using the initially intended trajectory. The artifact suppression shown for two sequences demonstrates that the GSTF can serve for a novel pre-emphasis. A pre-emphasis based on the GSTF information can be applied to any arbitrary sequence type. © 2018 International Society for Magnetic Resonance in Medicine.
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NASA Astrophysics Data System (ADS)
Chalupka, Uwe; Rothe, Hendrik
2012-03-01
The progress on a laser- and stereo-camera-based trajectory measurement system that we already proposed and described in recent publications is given. The system design was extended from one to two more powerful, DSP-controllable LASER systems. Experimental results of the extended system using different projectile-/weapon combinations will be shown and discussed. Automatic processing of acquired images using common 3DIP techniques was realized. Processing steps to extract trajectory segments from images as representative for the current application will be presented. Used algorithms for backward-calculation of the projectile trajectory will be shown. Verification of produced results is done against simulated trajectories, once in terms of detection robustness and once in terms of detection accuracy. Fields of use for the current system are within the ballistic domain. The first purpose is for trajectory measurement of small and middle caliber projectiles on a shooting range. Extension to big caliber projectiles as well as an application for sniper detection is imaginable, but would require further work. Beside classical RADAR, acoustic and optical projectile detection methods, the current system represents a further projectile location method under the new class of electro-optical methods that have been evolved in recent decades and that uses 3D imaging acquisition and processing techniques.
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NASA Astrophysics Data System (ADS)
Losseau, Romain
The ongoing energy transition is about to entail important changes in the way we use and manage energy. In this view, smart grids are expected to play a significant part through the use of intelligent storage techniques. Initiated in 2014, the SmartDesc project follows this trend to create an innovative load management program by exploiting the thermal storage associated with electric water heaters existing in residential households. The device control algorithms rely on the recent theory of mean field games to achieve a decentralized control of the water heaters temperatures producing an aggregate optimal trajectory, designed to smooth the electric demand of a neighborhood. Currently, this theory does not include power and temperature constraints due to the tank heating system or necessary for the user's safety and comfort. Therefore, a trajectory violating these constraints would not be feasible and would not induce the forecast load smoothing. This master's thesis presents a method to detect the non-feasability, of a target trajectory based on the Kolmogorov equations associated with the controlled electric water heaters and suggests a way to correct it so as to make it achievable under constraints. First, a partial differential equations based model of the water heaters under temperature constraints is presented. Subsequently, a numerical scheme is developed to simulate it, and applied to the mean field control. The results of the mean field control with and without constraints are compared, and non-feasabilities of the target trajectory are highlighted upon violations. The last part of the thesis is dedicated to developing an accelerated version of the mean field and a method of correcting the target trajectory so as to enlarge as much as possible the set of achievable profiles.
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The semaphorontic view of homology
Assis, Leandro C.S.; Rieppel, Olivier
2015-01-01
ABSTRACT The relation of homology is generally characterized as an identity relation, or alternatively as a correspondence relation, both of which are transitive. We use the example of the ontogenetic development and evolutionary origin of the gnathostome jaw to discuss identity and transitivity of the homology relation under the transformationist and emergentist paradigms respectively. Token identity and consequent transitivity of homology relations are shown to be requirements that are too strong to allow the origin of genuine evolutionary novelties. We consequently introduce the concept of compositional identity that is grounded in relations prevailing between parts (organs and organ systems) of a whole (organism). We recognize an ontogenetic identity of parts within a whole throughout the sequence of successive developmental stages of those parts: this is an intra‐organismal character identity maintained throughout developmental trajectory. Correspondingly, we recognize a phylogenetic identity of homologous parts within two or more organisms of different species: this is an inter‐species character identity maintained throughout evolutionary trajectory. These different dimensions of character identity—ontogenetic (through development) and phylogenetic (via shared evolutionary history)—break the transitivity of homology relations. Under the transformationist paradigm, the relation of homology reigns over the entire character (‐state) transformation series, and thus encompasses the plesiomorphic as well as the apomorphic condition of form. In contrast, genuine evolutionary novelties originate not through transformation of ancestral characters (‐states), but instead through deviating developmental trajectories that result in alternate characters. Under the emergentist paradigm, homology is thus synonymous with synapomorphy. J. Exp. Zool. (Mol. Dev. Evol.) 324B: 578–587, 2015. © 2015 The Authors. Journal of Experimental Zoology Part B: Molecular and Developmental Evolution published by Wiley Periodicals, Inc. PMID:26175214
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Nandakumar, Subhadra; Kannanganat, Sunil; Dobos, Karen M; Lucas, Megan; Spencer, John S; Amara, Rama Rao; Plikaytis, Bonnie B; Posey, James E; Sable, Suraj B
2016-05-13
Heterologous prime-boosting has emerged as a powerful vaccination approach against tuberculosis. However, optimal timing to boost BCG-immunity using subunit vaccines remains unclear in clinical trials. Here, we followed the adhesin Apa-specific T-cell responses in BCG-primed mice and investigated its BCG-booster potential. The Apa-specific T-cell response peaked 32-52 weeks after parenteral or mucosal BCG-priming but waned significantly by 78 weeks. A subunit-Apa-boost during the contraction-phase of BCG-response had a greater effect on the magnitude and functional quality of specific cellular and humoral responses compared to a boost at the peak of BCG-response. The cellular response increased following mucosal BCG-prime-Apa-subunit-boost strategy compared to Apa-subunit-prime-BCG-boost approach. However, parenteral BCG-prime-Apa-subunit-boost by a homologous route was the most effective strategy in-terms of enhancing specific T-cell responses during waning in the lung and spleen. Two Apa-boosters markedly improved waning BCG-immunity and significantly reduced Mycobacterium tuberculosis burdens post-challenge. Our results highlight the challenges of optimization of prime-boost regimens in mice where BCG drives persistent immune-activation and suggest that boosting with a heterologous vaccine may be ideal once the specific persisting effector responses are contracted. Our results have important implications for design of prime-boost regimens against tuberculosis in humans.
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WE-G-BRF-07: Non-Circular Scanning Trajectories with Varian Developer Mode
DOE Office of Scientific and Technical Information (OSTI.GOV)
Davis, A; Pearson, E; Pan, X
2014-06-15
Purpose: Cone-beam CT (CBCT) in image-guide radiation therapy (IGRT) typicallyacquires scan data via the circular trajectory of the linearaccelerator's (linac) gantry rotation. Though this lends itself toanalytic reconstruction algorithms like FDK, iterative reconstructionalgorithms allow for a broader range of scanning trajectories. Weimplemented a non-circular scanning trajectory with Varian's TrueBeamDeveloper Mode and performed some preliminary reconstructions toverify the geometry. Methods: We used TrueBeam Developer Mode to program a new scanning trajectorythat increases the field of view (FOV) along the gantry rotation axiswithout moving the patient. This trajectory consisted of moving thegantry in a circle, then translating the source and detector alongmore » theaxial direction before acquiring another circular scan 19 cm away fromthe first. The linear portion of the trajectory includes an additional4.5 cm above and below the axial planes of the source's circularrotation. We scanned a calibration phantom consisting of a lucite tubewith a spiral pattern of CT spots and used the maximum-likelihoodalgorithm to iteratively reconstruct the CBCT volume. Results: With the TrueBeam trajectory definition, we acquired projection dataof the calibration phantom using the previously described trajectory.We obtained a scan of the treatment couch for log normalization byscanning with the same trajectory but without the phantom present.Using the nominal geometric parameters reported in the projectionheaders with our iterative reconstruction algorithm, we obtained acorrect reconstruction of the calibration phantom. Conclusion: The ability to implement new scanning trajectories with the TrueBeamDeveloper Mode enables us access to a new parameter space for imagingwith CBCT for IGRT. Previous simulations and simple dual circle scanshave shown iterative reconstruction with non-circular trajectories canincrease the axial FOV with CBCT. Use of Developer Mode allowsexperimentally testing these and other new scanning trajectories. Support was provided in part by the University of Chicago Research Computing Center, Varian Medical Systems, and NIH Grants 1RO1CA120540, T32EB002103, S10 RR021039 and P30 CA14599. The contents of this work are solely the responsibility of the authors and do not necessarily represent the official views of the supporting organizations.« less
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Training trajectories by continuous recurrent multilayer networks.
Leistritz, L; Galicki, M; Witte, H; Kochs, E
2002-01-01
This paper addresses the problem of training trajectories by means of continuous recurrent neural networks whose feedforward parts are multilayer perceptrons. Such networks can approximate a general nonlinear dynamic system with arbitrary accuracy. The learning process is transformed into an optimal control framework where the weights are the controls to be determined. A training algorithm based upon a variational formulation of Pontryagin's maximum principle is proposed for such networks. Computer examples demonstrating the efficiency of the given approach are also presented.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Shusharina, N; Khan, F; Sharp, G
Purpose: To determine the dose level and timing of the boost in locally advanced lung cancer patients with confirmed tumor recurrence by comparing different boosting strategies by an impact of dose escalation in improvement of the therapeutic ratio. Methods: We selected eighteen patients with advanced NSCLC and confirmed recurrence. For each patient, a base IMRT plan to 60 Gy prescribed to PTV was created. Then we compared three dose escalation strategies: a uniform escalation to the original PTV, an escalation to a PET-defined target planned sequentially and concurrently. The PET-defined targets were delineated by biologically-weighed regions on a pre-treatment 18F-FDGmore » PET. The maximal achievable dose, without violating the OAR constraints, was identified for each boosting method. The EUD for the target, spinal cord, combined lung, and esophagus was compared for each plan. Results: The average prescribed dose was 70.4±13.9 Gy for the uniform boost, 88.5±15.9 Gy for the sequential boost and 89.1±16.5 Gy for concurrent boost. The size of the boost planning volume was 12.8% (range: 1.4 – 27.9%) of the PTV. The most prescription-limiting dose constraints was the V70 of the esophagus. The EUD within the target increased by 10.6 Gy for the uniform boost, by 31.4 Gy for the sequential boost and by 38.2 for the concurrent boost. The EUD for OARs increased by the following amounts: spinal cord, 3.1 Gy for uniform boost, 2.8 Gy for sequential boost, 5.8 Gy for concurrent boost; combined lung, 1.6 Gy for uniform, 1.1 Gy for sequential, 2.8 Gy for concurrent; esophagus, 4.2 Gy for uniform, 1.3 Gy for sequential, 5.6 Gy for concurrent. Conclusion: Dose escalation to a biologically-weighed gross tumor volume defined on a pre-treatment 18F-FDG PET may provide improved therapeutic ratio without breaching predefined OAR constraints. Sequential boost provides better sparing of OARs as compared with concurrent boost.« less
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Final safety analysis report for the Galileo Mission: Volume 2: Summary
DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
The General Purpose Heat Source Radioisotope Thermoelectric Generator (GPHS-RTG) will be used as the prime source of electric power for the spacecraft on the Galileo mission. The use of radioactive material in these missions necessitates evaluations of the radiological risks that may be encountered by launch complex personnel and by the Earth's general population resulting from postulated malfunctions or failures occurring in the mission operations. The purpose of the Final Safety Analysis Report (FSAR) is to present the analyses and results of the latest evaluation of the nuclear safety potential of the GPHS-RTG as employed in the Galileo mission. Thismore » evaluation is an extension of earlier work that addressed the planned 1986 launch using the Space Shuttle Vehicle with the Centaur as the upper stage. This extended evaluation represents the launch by the Space Shuttle/IUS vehicle. The IUS stage has been selected as the vehicle to be used to boost the Galileo spacecraft into the Earth escape trajectory after the parking orbit is attained.« less
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A change in the optical polarization associated with a gamma-ray flare in the blazar 3C 279.
2010-02-18
It is widely accepted that strong and variable radiation detected over all accessible energy bands in a number of active galaxies arises from a relativistic, Doppler-boosted jet pointing close to our line of sight. The size of the emitting zone and the location of this region relative to the central supermassive black hole are, however, poorly known, with estimates ranging from light-hours to a light-year or more. Here we report the coincidence of a gamma (gamma)-ray flare with a dramatic change of optical polarization angle. This provides evidence for co-spatiality of optical and gamma-ray emission regions and indicates a highly ordered jet magnetic field. The results also require a non-axisymmetric structure of the emission zone, implying a curved trajectory for the emitting material within the jet, with the dissipation region located at a considerable distance from the black hole, at about 10(5) gravitational radii.
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A change in the optical polarization associated with a γ-ray flare in the blazar 3C279
Abdo, A. A.; Ackermann, M.; Ajello, M.; ...
2010-02-18
It is widely accepted that strong and variable radiation detected over all accessible energy bands in a number of active galaxies arises from a relativistic, Doppler-boosted jet pointing close to our line of sight1. Furthermore, the size of the emitting zone and the location of this region relative to the central supermassive black hole are, however, poorly known, with estimates ranging from light-hours to a light-year or more. We report the coincidence of a gamma (γ)-ray flare with a dramatic change of optical polarization angle. This provides evidence for co-spatiality of optical and γ-ray emission regions and indicates a highlymore » ordered jet magnetic field. Our results also require a non-axisymmetric structure of the emission zone, implying a curved trajectory for the emitting material within the jet, with the dissipation region located at a considerable distance from the black hole, at about 105 gravitational radii.« less
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Can physical exercise in old age improve memory and hippocampal function?
van Praag, Henriette; Sendtner, Michael
2016-01-01
Abstract Physical exercise can convey a protective effect against cognitive decline in ageing and Alzheimer’s disease. While the long-term health-promoting and protective effects of exercise are encouraging, it’s potential to induce neuronal and vascular plasticity in the ageing brain is still poorly understood. It remains unclear whether exercise slows the trajectory of normal ageing by modifying vascular and metabolic risk factors and/or consistently boosts brain function by inducing structural and neurochemical changes in the hippocampus and related medial temporal lobe circuitry—brain areas that are important for learning and memory. Hence, it remains to be established to what extent exercise interventions in old age can improve brain plasticity above and beyond preservation of function. Existing data suggest that exercise trials aiming for improvement and preservation may require different outcome measures and that the balance between the two may depend on exercise intensity and duration, the presence of preclinical Alzheimer’s disease pathology, vascular and metabolic risk factors and genetic variability. PMID:26912638
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Milne boost from Galilean gauge theory
NASA Astrophysics Data System (ADS)
Banerjee, Rabin; Mukherjee, Pradip
2018-03-01
Physical origin of Milne boost invariance of the Newton Cartan spacetime is traced to the effect of local Galilean boosts in its metric structure, using Galilean gauge theory. Specifically, we do not require any gauge field to understand Milne boost invariance.
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NASA Astrophysics Data System (ADS)
Song, Young-Joo; Bae, Jonghee; Kim, Young-Rok; Kim, Bang-Yeop
2017-12-01
To ensure the successful launch of the Korea pathfinder lunar orbiter (KPLO) mission, the Korea Aerospace Research Institute (KARI) is now performing extensive trajectory design and analysis studies. From the trajectory design perspective, it is crucial to prepare contingency trajectory options for the failure of the first lunar brake or the failure of the first lunar orbit insertion (LOI) maneuver. As part of the early phase trajectory design and analysis activities, the required time of flight (TOF) and associated delta-V magnitudes for each recovery maneuver (RM) to recover the KPLO mission trajectory are analyzed. There are two typical trajectory recovery options, direct recovery and low energy recovery. The current work is focused on the direct recovery option. Results indicate that a quicker execution of the first RM after the failure of the first LOI plays a significant role in saving the magnitudes of the RMs. Under the conditions of the extremely tight delta-V budget that is currently allocated for the KPLO mission, it is found that the recovery of the KPLO without altering the originally planned mission orbit (a 100 km circular orbit) cannot be achieved via direct recovery options. However, feasible recovery options are suggested within the boundaries of the currently planned delta-V budget. By changing the shape and orientation of the recovered final mission orbit, it is expected that the KPLO mission may partially pursue its scientific mission after successful recovery, though it will be limited.
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Robust boosting via convex optimization
NASA Astrophysics Data System (ADS)
Rätsch, Gunnar
2001-12-01
In this work we consider statistical learning problems. A learning machine aims to extract information from a set of training examples such that it is able to predict the associated label on unseen examples. We consider the case where the resulting classification or regression rule is a combination of simple rules - also called base hypotheses. The so-called boosting algorithms iteratively find a weighted linear combination of base hypotheses that predict well on unseen data. We address the following issues: o The statistical learning theory framework for analyzing boosting methods. We study learning theoretic guarantees on the prediction performance on unseen examples. Recently, large margin classification techniques emerged as a practical result of the theory of generalization, in particular Boosting and Support Vector Machines. A large margin implies a good generalization performance. Hence, we analyze how large the margins in boosting are and find an improved algorithm that is able to generate the maximum margin solution. o How can boosting methods be related to mathematical optimization techniques? To analyze the properties of the resulting classification or regression rule, it is of high importance to understand whether and under which conditions boosting converges. We show that boosting can be used to solve large scale constrained optimization problems, whose solutions are well characterizable. To show this, we relate boosting methods to methods known from mathematical optimization, and derive convergence guarantees for a quite general family of boosting algorithms. o How to make Boosting noise robust? One of the problems of current boosting techniques is that they are sensitive to noise in the training sample. In order to make boosting robust, we transfer the soft margin idea from support vector learning to boosting. We develop theoretically motivated regularized algorithms that exhibit a high noise robustness. o How to adapt boosting to regression problems? Boosting methods are originally designed for classification problems. To extend the boosting idea to regression problems, we use the previous convergence results and relations to semi-infinite programming to design boosting-like algorithms for regression problems. We show that these leveraging algorithms have desirable theoretical and practical properties. o Can boosting techniques be useful in practice? The presented theoretical results are guided by simulation results either to illustrate properties of the proposed algorithms or to show that they work well in practice. We report on successful applications in a non-intrusive power monitoring system, chaotic time series analysis and a drug discovery process. --- Anmerkung: Der Autor ist Träger des von der Mathematisch-Naturwissenschaftlichen Fakultät der Universität Potsdam vergebenen Michelson-Preises für die beste Promotion des Jahres 2001/2002. In dieser Arbeit werden statistische Lernprobleme betrachtet. Lernmaschinen extrahieren Informationen aus einer gegebenen Menge von Trainingsmustern, so daß sie in der Lage sind, Eigenschaften von bisher ungesehenen Mustern - z.B. eine Klassenzugehörigkeit - vorherzusagen. Wir betrachten den Fall, bei dem die resultierende Klassifikations- oder Regressionsregel aus einfachen Regeln - den Basishypothesen - zusammengesetzt ist. Die sogenannten Boosting Algorithmen erzeugen iterativ eine gewichtete Summe von Basishypothesen, die gut auf ungesehenen Mustern vorhersagen. Die Arbeit behandelt folgende Sachverhalte: o Die zur Analyse von Boosting-Methoden geeignete Statistische Lerntheorie. Wir studieren lerntheoretische Garantien zur Abschätzung der Vorhersagequalität auf ungesehenen Mustern. Kürzlich haben sich sogenannte Klassifikationstechniken mit großem Margin als ein praktisches Ergebnis dieser Theorie herausgestellt - insbesondere Boosting und Support-Vektor-Maschinen. Ein großer Margin impliziert eine hohe Vorhersagequalität der Entscheidungsregel. Deshalb wird analysiert, wie groß der Margin bei Boosting ist und ein verbesserter Algorithmus vorgeschlagen, der effizient Regeln mit maximalem Margin erzeugt. o Was ist der Zusammenhang von Boosting und Techniken der konvexen Optimierung? Um die Eigenschaften der entstehenden Klassifikations- oder Regressionsregeln zu analysieren, ist es sehr wichtig zu verstehen, ob und unter welchen Bedingungen iterative Algorithmen wie Boosting konvergieren. Wir zeigen, daß solche Algorithmen benutzt werden koennen, um sehr große Optimierungsprobleme mit Nebenbedingungen zu lösen, deren Lösung sich gut charakterisieren laesst. Dazu werden Verbindungen zum Wissenschaftsgebiet der konvexen Optimierung aufgezeigt und ausgenutzt, um Konvergenzgarantien für eine große Familie von Boosting-ähnlichen Algorithmen zu geben. o Kann man Boosting robust gegenüber Meßfehlern und Ausreissern in den Daten machen? Ein Problem bisheriger Boosting-Methoden ist die relativ hohe Sensitivität gegenüber Messungenauigkeiten und Meßfehlern in der Trainingsdatenmenge. Um dieses Problem zu beheben, wird die sogenannte 'Soft-Margin' Idee, die beim Support-Vector Lernen schon benutzt wird, auf Boosting übertragen. Das führt zu theoretisch gut motivierten, regularisierten Algorithmen, die ein hohes Maß an Robustheit aufweisen. o Wie kann man die Anwendbarkeit von Boosting auf Regressionsprobleme erweitern? Boosting-Methoden wurden ursprünglich für Klassifikationsprobleme entwickelt. Um die Anwendbarkeit auf Regressionsprobleme zu erweitern, werden die vorherigen Konvergenzresultate benutzt und neue Boosting-ähnliche Algorithmen zur Regression entwickelt. Wir zeigen, daß diese Algorithmen gute theoretische und praktische Eigenschaften haben. o Ist Boosting praktisch anwendbar? Die dargestellten theoretischen Ergebnisse werden begleitet von Simulationsergebnissen, entweder, um bestimmte Eigenschaften von Algorithmen zu illustrieren, oder um zu zeigen, daß sie in der Praxis tatsächlich gut funktionieren und direkt einsetzbar sind. Die praktische Relevanz der entwickelten Methoden wird in der Analyse chaotischer Zeitreihen und durch industrielle Anwendungen wie ein Stromverbrauch-Überwachungssystem und bei der Entwicklung neuer Medikamente illustriert.
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Heterologous Prime-Boost Immunisation Regimens Against Infectious Diseases
2006-08-01
of these cells by boosting. DNA vaccines are good priming agents since they are internalised by antigen presenting cells and can induce antigen...presentation via both MHC class I and class II, thereby inducing both cytotoxic T lymphocytes and type 1-helper T lymphocytes. Successful boosting agents ...assessing prime-boost vaccine combinations for protection against infectious agents . • In a number of prime - boost studies, the inclusion of growth
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NASA Technical Reports Server (NTRS)
Hastings, Earl C., Jr.; Dickens, Waldo L.
1957-01-01
A flight investigation was conducted to determine the effects of inlet modification and rocket-rack extension on the longitudinal trim and low-lift drag of the Douglas F5D-1 airplane. The investigation was conducted with a 0.125-scale rocket-boosted model between Mach Numbers of 0.81 and 1.64. This paper presents the changes in trim angle of attack, trim lift coefficient, and low-lift drag caused by the modified inlets alone over a small part of the test Mach number range and by a combination of the modified inlets and extended rocket racks throughout the remainder of the test.
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Component Pin Recognition Using Algorithms Based on Machine Learning
NASA Astrophysics Data System (ADS)
Xiao, Yang; Hu, Hong; Liu, Ze; Xu, Jiangchang
2018-04-01
The purpose of machine vision for a plug-in machine is to improve the machine’s stability and accuracy, and recognition of the component pin is an important part of the vision. This paper focuses on component pin recognition using three different techniques. The first technique involves traditional image processing using the core algorithm for binary large object (BLOB) analysis. The second technique uses the histogram of oriented gradients (HOG), to experimentally compare the effect of the support vector machine (SVM) and the adaptive boosting machine (AdaBoost) learning meta-algorithm classifiers. The third technique is the use of an in-depth learning method known as convolution neural network (CNN), which involves identifying the pin by comparing a sample to its training. The main purpose of the research presented in this paper is to increase the knowledge of learning methods used in the plug-in machine industry in order to achieve better results.
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Nandakumar, Subhadra; Kannanganat, Sunil; Dobos, Karen M.; Lucas, Megan; Spencer, John S.; Amara, Rama Rao; Plikaytis, Bonnie B.; Posey, James E.; Sable, Suraj B.
2016-01-01
Heterologous prime–boosting has emerged as a powerful vaccination approach against tuberculosis. However, optimal timing to boost BCG-immunity using subunit vaccines remains unclear in clinical trials. Here, we followed the adhesin Apa-specific T-cell responses in BCG-primed mice and investigated its BCG-booster potential. The Apa-specific T-cell response peaked 32–52 weeks after parenteral or mucosal BCG-priming but waned significantly by 78 weeks. A subunit-Apa-boost during the contraction-phase of BCG-response had a greater effect on the magnitude and functional quality of specific cellular and humoral responses compared to a boost at the peak of BCG-response. The cellular response increased following mucosal BCG-prime–Apa-subunit-boost strategy compared to Apa-subunit-prime–BCG-boost approach. However, parenteral BCG-prime–Apa-subunit-boost by a homologous route was the most effective strategy in-terms of enhancing specific T-cell responses during waning in the lung and spleen. Two Apa-boosters markedly improved waning BCG-immunity and significantly reduced Mycobacterium tuberculosis burdens post-challenge. Our results highlight the challenges of optimization of prime–boost regimens in mice where BCG drives persistent immune-activation and suggest that boosting with a heterologous vaccine may be ideal once the specific persisting effector responses are contracted. Our results have important implications for design of prime–boost regimens against tuberculosis in humans. PMID:27173443
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77 FR 57998 - Airworthiness Directives; Bombardier, Inc. Airplanes
Federal Register 2010, 2011, 2012, 2013, 2014
2012-09-19
... accumulators). A detailed analysis of the calculated line of trajectory of a failed screw cap/end cap for each... Alternative Method of Compliance (AMOC) for a Different Part Number (P/N) Tactair Fluid Controls (Tactair... covered under warranty, we have assumed that there will be no charge for these parts. As we do not control...
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ERIC Educational Resources Information Center
Glade, Matthias; Prediger, Susanne
2017-01-01
According to the design principle of progressive schematization, learning trajectories towards procedural rules can be organized as independent discoveries when the learning arrangement invites the students first to develop models for mathematical concepts and model-based informal strategies; then to explore the strategies and to discover pattern…
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ERIC Educational Resources Information Center
Corona, Víctor
2016-01-01
The ethnographic research presented in this paper consists of two parts developed chronologically. The first part is based on a study (Corona, V., Nussbaum, L., & Unamuno, V. [2012]. The emergence of new linguistic repertoires among Barcelona's youth of Latin American origin. "International Journal of Bilingual Education and…
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Sanz, A S; Miret-Artés, S
2005-01-01
The elastic resonant scattering of He atoms off the Cu(117) surface is fully described with the formalism of quantum trajectories provided by Bohmian mechanics. Within this theory of quantum motion, the concept of trapping is widely studied and discussed. Classically, atoms undergo impulsive collisions with the surface, and then the trapped motion takes place covering at least two consecutive unit cells. However, from a Bohmian viewpoint, atom trajectories can smoothly adjust to the equipotential energy surface profile in a sort of sliding motion; thus the trapping process could eventually occur within one single unit cell. In particular, both threshold and selective adsorption resonances are explained by means of this quantum trapping considering different space and time scales. Furthermore, a mapping between each region of the (initial) incoming plane wave and the different parts of the diffraction and resonance patterns can be easily established, an important issue only provided by a quantum trajectory formalism. (c) 2005 American Institute of Physics.
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NASA Technical Reports Server (NTRS)
Mann, F. I.; Horsewood, J. L.
1974-01-01
A performance-analysis computer program, that was developed explicitly to generate optimum electric propulsion trajectory data for missions of interest in the exploration of the solar system is presented. The program was primarily designed to evaluate the performance capabilities of electric propulsion systems, and in the simulation of a wide variety of interplanetary missions. A numerical integration of the two-body, three-dimensional equations of motion and the Euler-Lagrange equations was used in the program. Transversality conditions which permit the rapid generation of converged maximum-payload trajectory data, and the optimization of numerous other performance indices for which no transversality conditions exist are included. The ability to simulate constrained optimum solutions, including trajectories having specified propulsion time and constant thrust cone angle, is also in the program. The program was designed to handle multiple-target missions with various types of encounters, such as rendezvous, stopover, orbital capture, and flyby. Performance requirements for a variety of launch vehicles can be determined.
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Trajectory Design and Control for the Compton Gamma Ray Observatory Re-Entry
NASA Technical Reports Server (NTRS)
Hoge, Susan; Vaughn, Frank; Bauer, Frank H. (Technical Monitor)
2000-01-01
The Compton Gamma Ray Observatory (CGRO) controlled re-entry operation was successfully conducted in June of 2000. The surviving parts of the spacecraft landed in the Pacific Ocean within the predicted footprint. The design of the maneuvers to control the trajectory to accomplish this re-entry presented several challenges. These challenges included timing and duration of the maneuvers, fuel management, post maneuver position knowledge, collision avoidance with other spacecraft, accounting for the break-up of the spacecraft into several pieces with a wide range of ballistic coefficients, and ensuring that the impact footprint would remain within the desired landing area in the event of contingencies. This paper presents the initial re-entry trajectory design and the evolution of the design into the maneuver sequence used for the re-entry. The paper discusses the constraints on the trajectory design, the modifications made to the initial design and the reasons behind these modifications. Data from the re-entry operation are presented.
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Trajectory Design and Control for the Compton Gamma Ray Observatory Re-Entry
NASA Technical Reports Server (NTRS)
Hoge, Susan; Vaughn, Frank J., Jr.
2001-01-01
The Compton Gamma Ray Observatory (CGRO) controlled re-entry operation was successfully conducted in June of 2000. The surviving parts of the spacecraft landed in the Pacific Ocean within the nominal impact target zone. The design of the maneuvers to control the trajectory to accomplish this re-entry presented several challenges. These challenges included the timing and duration of the maneuvers, propellant management, post-maneuver state determination, collision avoidance with other spacecraft, accounting for the break-up of the spacecraft into several pieces with a wide range of ballistic coefficients, and ensuring that the impact footprint would remain within the desired impact target zone in the event of contingencies. This paper presents the initial re-entry trajectory design and traces the evolution of that design into the maneuver sequence used for the re-entry. The paper also discusses the spacecraft systems and operational constraints imposed on the trajectory design and the required modifications to the initial design based on those constraints. Data from the reentry operation are also presented.
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NASA Astrophysics Data System (ADS)
Shinnaka, Shinji; Sano, Kousuke
This paper presents a new unified analysis of estimate errors by model-matching phase-estimation methods such as rotor-flux state-observers, back EMF state-observers, and back EMF disturbance-observers, for sensorless drive of permanent-magnet synchronous motors. Analytical solutions about estimate errors, whose validity is confirmed by numerical experiments, are rich in universality and applicability. As an example of universality and applicability, a new trajectory-oriented vector control method is proposed, which can realize directly quasi-optimal strategy minimizing total losses with no additional computational loads by simply orienting one of vector-control coordinates to the associated quasi-optimal trajectory. The coordinate orientation rule, which is analytically derived, is surprisingly simple. Consequently the trajectory-oriented vector control method can be applied to a number of conventional vector control systems using one of the model-matching phase-estimation methods.
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Utilization of Global Reference Atmosphere Model (GRAM) for shuttle entry
NASA Technical Reports Server (NTRS)
Joosten, Kent
1987-01-01
At high latitudes, dispersions in values of density for the middle atmosphere from the Global Reference Atmosphere Model (GRAM) are observed to be large, particularly in the winter. Trajectories have been run from 28.5 deg to 98 deg. The critical part of the atmosphere for reentry is 250,000 to 270,000 ft. 250,000 ft is the altitude where the shuttle trajectory levels out. For ascending passes the critical region occurs near the equator. For descending entries the critical region is in northern latitudes. The computed trajectory is input to the GRAM, which computes means and deviations of atmospheric parameters at each point along the trajectory. There is little latitude dispersion for the ascending passes; the strongest source of deviations is seasonal; however, very wide seasonal and latitudinal deviations are exhibited for the descending passes at all orbital inclinations. For shuttle operations the problem is control to maintain the correct entry corridor and avoid either aerodynamic skipping or excessive heat loads.
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Histories of poverty and self-rated health trajectories.
McDonough, Peggy; Berglund, Pat
2003-06-01
This paper investigates the dynamic relationship between poverty histories and self-rated health trajectories. We are interested in patterns of change in individuals' health over time and the ways in which such patterns are structured by continuity and change in poverty experiences. Data, collected for adults aged 25 and older in 1984 (N = 7,258), are from the 1968-1996 annual waves of Panel Study of Income Dynamics (PSID). Individual growth curves allow us to investigate health trajectories as continuous processes, as well as individual and group heterogeneity in these trajectories. We find that, on average, health deteriorates slowly over time, but there is significant variation in health in 1984 and the rate at which health declines. Histories of poverty partly accounted for the sources of individual differences in self-rated health in 1984, but they were not related to health change over time. Although increasing incomes were better for self-rated health than falling incomes, current economic circumstances did not erase the health effects of earlier poverty experiences.
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Boosted ARTMAP: modifications to fuzzy ARTMAP motivated by boosting theory.
Verzi, Stephen J; Heileman, Gregory L; Georgiopoulos, Michael
2006-05-01
In this paper, several modifications to the Fuzzy ARTMAP neural network architecture are proposed for conducting classification in complex, possibly noisy, environments. The goal of these modifications is to improve upon the generalization performance of Fuzzy ART-based neural networks, such as Fuzzy ARTMAP, in these situations. One of the major difficulties of employing Fuzzy ARTMAP on such learning problems involves over-fitting of the training data. Structural risk minimization is a machine-learning framework that addresses the issue of over-fitting by providing a backbone for analysis as well as an impetus for the design of better learning algorithms. The theory of structural risk minimization reveals a trade-off between training error and classifier complexity in reducing generalization error, which will be exploited in the learning algorithms proposed in this paper. Boosted ART extends Fuzzy ART by allowing the spatial extent of each cluster formed to be adjusted independently. Boosted ARTMAP generalizes upon Fuzzy ARTMAP by allowing non-zero training error in an effort to reduce the hypothesis complexity and hence improve overall generalization performance. Although Boosted ARTMAP is strictly speaking not a boosting algorithm, the changes it encompasses were motivated by the goals that one strives to achieve when employing boosting. Boosted ARTMAP is an on-line learner, it does not require excessive parameter tuning to operate, and it reduces precisely to Fuzzy ARTMAP for particular parameter values. Another architecture described in this paper is Structural Boosted ARTMAP, which uses both Boosted ART and Boosted ARTMAP to perform structural risk minimization learning. Structural Boosted ARTMAP will allow comparison of the capabilities of off-line versus on-line learning as well as empirical risk minimization versus structural risk minimization using Fuzzy ARTMAP-based neural network architectures. Both empirical and theoretical results are presented to enhance the understanding of these architectures.
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ERIC Educational Resources Information Center
Moore, Colleen; Jez, Su Jin; Chisholm, Eric; Shulock, Nancy
2012-01-01
The Obama Administration has once again demonstrated the important role community colleges play in educating the nation's workforce and boosting the nation's economy with its recently proposed Community College to Career Fund. This $8 billion fund is aimed at forging partnerships between colleges and businesses to train workers for good-paying…
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Elizabeth A. Freeman; Gretchen G. Moisen; John W. Coulston; Barry T. (Ty) Wilson
2015-01-01
As part of the development of the 2011 National Land Cover Database (NLCD) tree canopy cover layer, a pilot project was launched to test the use of high-resolution photography coupled with extensive ancillary data to map the distribution of tree canopy cover over four study regions in the conterminous US. Two stochastic modeling techniques, random forests (RF...
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This School Works for Me: Creating Choices to Boost Achievement. A Guide for Data Analysts
ERIC Educational Resources Information Center
Bill & Melinda Gates Foundation, 2010
2010-01-01
This document is part of a series of guides designed to help school district leaders address one of the toughest challenges in American education: dropout rates of 30 percent nationwide, 50 percent in many big cities, and 60 percent or more in the lowest-performing schools. It includes tools for data analysts to drill down into the data and use…
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NASA Double Asteroid Redirection Test (Dart) Trajectory Validation and Robustness
NASA Technical Reports Server (NTRS)
Sarli, Bruno V.; Ozimek, Martin T.; Atchison, Justin A.; Englander, Jacob A.; Barbee, Brent W.
2017-01-01
The Double Asteroid Redirection Test (DART) mission will be the first to test the concept of a kinetic impactor. Several studies have been made on asteroid redirection and impact mitigation, however, to this date no mission tested the proposed concepts. An impact study on a representative body allows the measurement of the effects on the target's orbit and physical structure. With this goal, DART's objective is to verify the effectiveness of the kinetic impact concept for planetary defense. The spacecraft uses solar electric propulsion to escape Earth, flyby (138971) 2001 CB21 for impart rehearsal, and impact the secondary body of the (65803) Didymos system. This work focuses on the interplanetary trajectory design part of the mission with the validation of the baseline trajectory, performance comparison to other mission objectives, and assessment of the baseline robustness to missed thrust events. Results show a good performance of the selected trajectory for different mission objectives: latest possible escape date, maximum kinetic energy on impact, shortest possible time of flight, and use of an Earth swing-by. The baseline trajectory was shown to be robust to a missed thrust with 1% of fuel margin being enough to recover the mission for failures of more than 14 days.
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Pavolini, Emmanuele; Kuhlmann, Ellen
2016-06-01
This article assesses professional development trajectories in top-, middle- and basic-level health workforce groups (doctors, nurses, care assistants) in different European Union countries using available international databases. Three theoretical strands (labour market, welfare state, and professions studies) were connected to explore ideal types and to develop a matrix for comparison. With a focus on larger EU-15 countries and four different types of healthcare systems, Germany, Italy, Sweden and the United Kingdom serve as empirical test cases. The analysis draws on selected indicators from public statistics/OECD data and micro-data from the EU Labour Force Survey. Five ideal typical trajectories of professional development were identified from the literature, which served as a matrix to compare developments in the three health workforce groups. The results reveal country-specific trajectories with uneven professional development and bring opportunities for policy interventions into view. First, there is a need for integrated health labour market monitoring systems to improve data on the skills mix of the health workforce. Second, a relevant number of health workers with fixed contracts and involuntary part-time reveals an important source for better recruitment and retention strategies. Third, a general trend towards increasing numbers while worsening working conditions was identified across our country cases. This trend hits care assistants, partly also nurses, the most. The research illustrates how public data sources may serve to create new knowledge and promote more sustainable health workforce policy. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
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Airborne Simulation of Launch Vehicle Dynamics
NASA Technical Reports Server (NTRS)
Miller, Christopher J.; Orr, Jeb S.; Hanson, Curtis E.; Gilligan, Eric T.
2015-01-01
In this paper we present a technique for approximating the short-period dynamics of an exploration-class launch vehicle during flight test with a high-performance surrogate aircraft in relatively benign endoatmospheric flight conditions. The surrogate vehicle relies upon a nonlinear dynamic inversion scheme with proportional-integral feedback to drive a subset of the aircraft states into coincidence with the states of a time-varying reference model that simulates the unstable rigid body dynamics, servodynamics, and parasitic elastic and sloshing dynamics of the launch vehicle. The surrogate aircraft flies a constant pitch rate trajectory to approximate the boost phase gravity turn ascent, and the aircraft's closed-loop bandwidth is sufficient to simulate the launch vehicle's fundamental lateral bending and sloshing modes by exciting the rigid body dynamics of the aircraft. A novel control allocation scheme is employed to utilize the aircraft's relatively fast control effectors in inducing various failure modes for the purposes of evaluating control system performance. Sufficient dynamic similarity is achieved such that the control system under evaluation is configured for the full-scale vehicle with no changes to its parameters, and pilot-control system interaction studies can be performed to characterize the effects of guidance takeover during boost. High-fidelity simulation and flight-test results are presented that demonstrate the efficacy of the design in simulating the Space Launch System (SLS) launch vehicle dynamics using the National Aeronautics and Space Administration (NASA) Armstrong Flight Research Center Fullscale Advanced Systems Testbed (FAST), a modified F/A-18 airplane (McDonnell Douglas, now The Boeing Company, Chicago, Illinois), over a range of scenarios designed to stress the SLS's Adaptive Augmenting Control (AAC) algorithm.
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Slingshot dynamics for self-replicating probes and the effect on exploration timescales
NASA Astrophysics Data System (ADS)
Nicholson, Arwen; Forgan, Duncan
2013-10-01
Interstellar probes can carry out slingshot manoeuvres around the stars they visit, gaining a boost in velocity by extracting energy from the star's motion around the Galactic Centre. These manoeuvres carry little to no extra energy cost, and in previous work it has been shown that a single Voyager-like probe exploring the Galaxy does so 100 times faster when carrying out these slingshots than when navigating purely by powered flight (Forgan et al. 2012). We expand on these results by repeating the experiment with self-replicating probes. The probes explore a box of stars representative of the local Solar neighbourhood, to investigate how self-replication affects exploration timescales when compared with a single non-replicating probe. We explore three different scenarios of probe behaviour: (i) standard powered flight to the nearest unvisited star (no slingshot techniques used), (ii) flight to the nearest unvisited star using slingshot techniques and (iii) flight to the next unvisited star that will give the maximum velocity boost under a slingshot trajectory. In all three scenarios, we find that as expected, using self-replicating probes greatly reduces the exploration time, by up to three orders of magnitude for scenarios (i) and (iii) and two orders of magnitude for (ii). The second case (i.e. nearest-star slingshots) remains the most time effective way to explore a population of stars. As the decision-making algorithms for the fleet are simple, unanticipated `race conditions' among probes are set up, causing the exploration time of the final stars to become much longer than necessary. From the scaling of the probes' performance with star number, we conclude that a fleet of self-replicating probes can indeed explore the Galaxy in a sufficiently short time to warrant the existence of the Fermi Paradox.
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Particle trajectory computer program for icing analysis of axisymmetric bodies
NASA Technical Reports Server (NTRS)
Frost, Walter; Chang, Ho-Pen; Kimble, Kenneth R.
1982-01-01
General aviation aircraft and helicopters exposed to an icing environment can accumulate ice resulting in a sharp increase in drag and reduction of maximum lift causing hazardous flight conditions. NASA Lewis Research Center (LeRC) is conducting a program to examine, with the aid of high-speed computer facilities, how the trajectories of particles contribute to the ice accumulation on airfoils and engine inlets. This study, as part of the NASA/LeRC research program, develops a computer program for the calculation of icing particle trajectories and impingement limits relative to axisymmetric bodies in the leeward-windward symmetry plane. The methodology employed in the current particle trajectory calculation is to integrate the governing equations of particle motion in a flow field computed by the Douglas axisymmetric potential flow program. The three-degrees-of-freedom (horizontal, vertical, and pitch) motion of the particle is considered. The particle is assumed to be acted upon by aerodynamic lift and drag forces, gravitational forces, and for nonspherical particles, aerodynamic moments. The particle momentum equation is integrated to determine the particle trajectory. Derivation of the governing equations and the method of their solution are described in Section 2.0. General features, as well as input/output instructions for the particle trajectory computer program, are described in Section 3.0. The details of the computer program are described in Section 4.0. Examples of the calculation of particle trajectories demonstrating application of the trajectory program to given axisymmetric inlet test cases are presented in Section 5.0. For the examples presented, the particles are treated as spherical water droplets. In Section 6.0, limitations of the program relative to excessive computer time and recommendations in this regard are discussed.
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Trajectories of Substance Use Disorder in Youth After Detention: A 12-Year Longitudinal Study
Welty, Leah J.; Hershfield, Jennifer A.; Abram, Karen M.; Han, Hongyun; Byck, Gayle R.; Teplin, Linda A.
2016-01-01
Objective Identify trajectories of substance use disorders (SUDs) in youth during the 12 years after detention, and how gender, race/ethnicity, and age at baseline predict trajectories. Method As part of the Northwestern Juvenile Project, a longitudinal study of 1,829 youth randomly sampled from detention in Chicago, Illinois, 1995–1998, participants were re-interviewed in the community or correctional facilities up to 9 times over 12 years. Independent interviewers assessed SUDs using the Diagnostic Interview Schedule for Children 2.3 (baseline) and the Diagnostic Interview Schedule IV (follow-ups). Primary outcome was a mutually exclusive 5-category typology of disorder: no SUD, alcohol alone, marijuana alone, comorbid alcohol and marijuana, or “other” illicit (“hard”) drug. We estimated trajectories using growth mixture models with a 3-category ordinal variable derived from the typology. Results During the 12-year follow-up, 19.6% of youth did not have an SUD. The remaining 81.4% were in 3 trajectory classes. Class 1 (24.5%), a bell-shaped trajectory, peaked 5 years after baseline when 42.7% had an SUD and 12.5% had comorbid/“other” illicit drug disorders. Class 2 (41.3%) had higher prevalence of SUD at baseline (73.8%). Although prevalence decreased over time, 23.5% had an SUD 12 years later. Class 3 (14.6%), the most serious and persistent trajectory, had the highest prevalence of comorbid/“other” illicit drug disorders—52.1% at baseline and 17.4% 12 years later. Males, Hispanics, non-Hispanic whites, and youth who were older at baseline (detention) had the worst outcomes. Conclusion Gender, race/ethnicity, and age at detention predict trajectories of SUDs in delinquent youth. Findings provide an empirical basis for child psychiatry to address health disparities and improve prevention. PMID:28117060
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Shen, Xiaoying; Basu, Rahul; Sawant, Sheetal; Beaumont, David; Kwa, Sue Fen; LaBranche, Celia; Seaton, Kelly E; Yates, Nicole L; Montefiori, David C; Ferrari, Guido; Wyatt, Linda S; Moss, Bernard; Alam, S Munir; Haynes, Barton F; Tomaras, Georgia D; Robinson, Harriet L
2017-12-15
An important goal of human immunodeficiency virus (HIV) vaccine design is identification of strategies that elicit effective antiviral humoral immunity. One novel approach comprises priming with DNA and boosting with modified vaccinia virus Ankara (MVA) expressing HIV-1 Env on virus-like particles. In this study, we evaluated whether the addition of a gp120 protein in alum or MVA-expressed secreted gp140 (MVAgp140) could improve immunogenicity of a DNA prime-MVA boost vaccine. Five rhesus macaques per group received two DNA primes at weeks 0 and 8 followed by three MVA boosts (with or without additional protein or MVAgp140) at weeks 18, 26, and 40. Both boost immunogens enhanced the breadth of HIV-1 gp120 and V1V2 responses, antibody-dependent cellular cytotoxicity (ADCC), and low-titer tier 1B and tier 2 neutralizing antibody responses. However, there were differences in antibody kinetics, linear epitope specificity, and CD4 T cell responses between the groups. The gp120 protein boost elicited earlier and higher peak responses, whereas the MVAgp140 boost resulted in improved antibody durability and comparable peak responses after the final immunization. Linear V3 specific IgG responses were particularly enhanced by the gp120 boost, whereas the MVAgp140 boost also enhanced responses to linear C5 and C2.2 epitopes. Interestingly, gp120, but not the MVAgp140 boost, increased peak CD4 + T cell responses. Thus, both gp120 and MVAgp140 can augment potential protection of a DNA/MVA vaccine by enhancing gp120 and V1/V2 antibody responses, whereas potential protection by gp120, but not MVAgp140 boosts, may be further impacted by increased CD4 + T cell responses. IMPORTANCE Prior immune correlate analyses with humans and nonhuman primates revealed the importance of antibody responses in preventing HIV-1 infection. A DNA prime-modified vaccinia virus Ankara (MVA) boost vaccine has proven to be potent in eliciting antibody responses. Here we explore the ability of boosts with recombinant gp120 protein or MVA-expressed gp140 to enhance antibody responses elicited by the GOVX-B11 DNA prime-MVA boost vaccine. We found that both types of immunogen boosts enhanced potentially protective antibody responses, whereas the gp120 protein boosts also increased CD4 + T cell responses. Our data provide important information for HIV vaccine designs that aim for effective and balanced humoral and T cell responses. Copyright © 2017 Shen et al.
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Variable Thrust, Multiple Start Hybrid Motor Solutions for Missile and Space Applications
2010-06-01
considered: I. Boost/Sustain/Boost. Simulating a tactical solid rocket motor profile with another boost at the end to demonstrate a "throttle up", this...of tactical solid rocket motors were tested with 75%, 50%, and lower sustain-to- boost chamber pressure ratios with rapid throttle-up achieved... solid rocket motors were tested with 75%, 50%, and lower sustain-to-boost chamber pressure ratios with rapid throttle-up achieved following the sustain
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Detection and Characterisation of Meteors as a Big Data Citizen Science project
NASA Astrophysics Data System (ADS)
Gritsevich, M.
2017-12-01
Out of a total around 50,000 meteorites currently known to science, the atmospheric passage was recorded instrumentally in only 30 cases with the potential to derive their atmospheric trajectories and pre-impact heliocentric orbits. Similarly, while the observations of meteors, add thousands of new entries per month to existing databases, it is extremely rare they lead to meteorite recovery. Meteor studies thus represent an excellent example of the Big Data citizen science project, where progress in the field largely depends on the prompt identification and characterisation of meteor events as well as on extensive and valuable contributions by amateur observers. Over the last couple of decades technological advancements in observational techniques have yielded drastic improvements in the quality, quantity and diversity of meteor data, while even more ambitious instruments are about to become operational. This empowers meteor science to boost its experimental and theoretical horizons and seek more advanced scientific goals. We review some of the developments that push meteor science into the Big Data era that requires more complex methodological approaches through interdisciplinary collaborations with other branches of physics and computer science. We argue that meteor science should become an integral part of large surveys in astronomy, aeronomy and space physics, and tackle the complexity of micro-physics of meteor plasma and its interaction with the atmosphere. The recent increased interest in meteor science triggered by the Chelyabinsk fireball helps in building the case for technologically and logistically more ambitious meteor projects. This requires developing new methodological approaches in meteor research, with Big Data science and close collaboration between citizen science, geoscience and astronomy as critical elements. We discuss possibilities for improvements and promote an opportunity for collaboration in meteor science within the currently established EU COST BigSkyEarth http://bigskyearth.eu/ network.
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Analyzing JAVAD TR-G2 GPS Receiver's Sensitivities to SLS Trajectory
NASA Technical Reports Server (NTRS)
Schuler, Tristan
2017-01-01
Automated guidance and navigation systems are an integral part to successful space missions. Previous researchers created Python tools to receive and parse data from a JAVAD TR-G2 space-capable GPS receiver. I improved the tool by customizing the output for plotting and comparing several simulations. I analyzed position errors, data loss, and signal loss by comparing simulated receiver data from an IFEN GPS simulator to ‘truth data’ from a proposed trajectory. By adjusting the trajectory simulation’s gain, attitude, and start time, NASA can assess the best time to launch the SLS, where to position the antennas on the Block 1-B, and which filter to use. Some additional testing has begun with the Novatel SpaceQuestGPS receiver as well as a GNSS SDR receiver.
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The neonatal methylome as a gatekeeper in the trajectory to childhood asthma.
DeVries, Avery; Vercelli, Donata
2017-04-01
Asthma is a heterogeneous group of conditions that typically begin in early life and result in recurrent, reversible bronchial obstruction. The role played by epigenetic mechanisms in the pathogenesis of childhood asthma is understood only in part. Here we discuss asthma epigenetics within a developmental perspective based on our recent demonstration that the epigenetic trajectory to childhood asthma begins at birth. We next discuss how this trajectory may be affected by prenatal environmental exposures. Finally, we examine in vitro studies that model the impact of asthma-associated exposures on the epigenome. All of these studies specifically surveyed human DNA methylation and involved a genome-wide component. In combination, their results broaden our understanding of asthma pathogenesis and the role the methylome plays in this process.
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Processing of Cells' Trajectories Data for Blood Flow Simulation Model*
NASA Astrophysics Data System (ADS)
Slavík, Martin; Kovalčíková, Kristína; Bachratý, Hynek; Bachratá, Katarína; Smiešková, Monika
2018-06-01
Simulations of the red blood cells (RBCs) flow as a movement of elastic objects in a fluid, are developed to optimize microfluidic devices used for a blood sample analysis for diagnostic purposes in the medicine. Tracking cell behaviour during simulation helps to improve the model and adjust its parameters. For the optimization of the microfluidic devices, it is also necessary to analyse cell trajectories as well as likelihood and frequency of their occurrence in a particular device area, especially in the parts, where they can affect circulating tumour cells capture. In this article, we propose and verify several ways of processing and analysing the typology and trajectory stability in simulations with single or with a large number of red blood cells (RBCs) in devices with different topologies containing cylindrical obstacles.
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NASA Astrophysics Data System (ADS)
Chastaing, J.-Y.; Bertin, E.; Géminard, J.-C.
2015-06-01
We describe an experiment dedicated to the study of the trajectories of a ball bouncing on a vibrating plate. Using an experimental device of our own design, it is possible to impose arbitrary trajectories on the plate and we show that the entire trajectory of the ball can be reconstructed solely from measurement of the times the ball hits the plate. In this paper, we make use of our apparatus to introduce the notion of dissipative collisions and to propose three different ways to measure the associated restitution coefficient. We then report on correlations in the chaotic regime and theoretically discuss the complex patterns that are exhibited in the case of a sinusoidal vibration. Lastly, we show that the use of an aperiodic driving vibration makes it possible to minimize part of these correlations.
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Hoftman, Gil D.; Lewis, David A.
2011-01-01
Schizophrenia is a disorder of cognitive neurodevelopment with characteristic abnormalities in working memory attributed, at least in part, to alterations in the circuitry of the dorsolateral prefrontal cortex. Various environmental exposures from conception through adolescence increase risk for the illness, possibly by altering the developmental trajectories of prefrontal cortical circuits. Macaque monkeys provide an excellent model system for studying the maturation of prefrontal cortical circuits. Here, we review the development of glutamatergic and γ-aminobutyric acid (GABA)-ergic circuits in macaque monkey prefrontal cortex and discuss how these trajectories may help to identify sensitive periods during which environmental exposures, such as those associated with increased risk for schizophrenia, might lead to the types of abnormalities in prefrontal cortical function present in schizophrenia. PMID:21505116
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Heiblum, Reuven H.; Altaratz, Orit; Koren, Ilan
We study the evolution of warm convective cloud fields using large eddy simulations of continental and trade cumulus. Individual clouds are tracked a posteriori from formation to dissipation using a 3D cloud tracking algorithm and results are presented in the phase- space of center of gravity altitude versus cloud liquid water mass (CvM space). The CvM space is shown to contain rich information on cloud field characteristics, cloud morphology, and common cloud development pathways, together facilitating a comprehensive understanding of the cloud field. In this part we show how the meteorological (thermodynamic) conditions that determine the cloud properties are projectedmore » on the CvM phase space and how changes in the initial conditions affect the clouds' trajectories in this space. This part sets the stage for a detailed microphysical analysis that will be shown in part II.« less
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14 CFR 27.695 - Power boost and power-operated control system.
Code of Federal Regulations, 2013 CFR
2013-01-01
... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Control Systems § 27.695 Power boost and power-operated control system. (a) If a power boost or power-operated... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Power boost and power-operated control...
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14 CFR 29.695 - Power boost and power-operated control system.
Code of Federal Regulations, 2013 CFR
2013-01-01
... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Control Systems § 29.695 Power boost and power-operated control system. (a) If a power boost or power-operated... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Power boost and power-operated control...
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Nonlinear program based optimization of boost and buck-boost converter designs
NASA Astrophysics Data System (ADS)
Rahman, S.; Lee, F. C.
The facility of an Augmented Lagrangian (ALAG) multiplier based nonlinear programming technique is demonstrated for minimum-weight design optimizations of boost and buck-boost power converters. Certain important features of ALAG are presented in the framework of a comprehensive design example for buck-boost power converter design optimization. The study provides refreshing design insight of power converters and presents such information as weight and loss profiles of various semiconductor components and magnetics as a function of the switching frequency.
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77 FR 16193 - Airworthiness Directives; Bombardier, Inc. Airplanes
Federal Register 2010, 2011, 2012, 2013, 2014
2012-03-20
... detailed analysis of the calculated line of trajectory of a failed screw cap/end cap for each of the... assumed that there will be no charge for these parts. As we do not control warranty coverage for affected... and require parts costing $8,988, for a cost of $9,583 per product. We have no way of determining the...
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Slipping and Rolling on an Inclined Plane
ERIC Educational Resources Information Center
Aghamohammadi, Cina; Aghamohammadi, Amir
2011-01-01
In the first part of the paper, using a direct calculation two-dimensional motion of a particle sliding on an inclined plane is investigated for general values of friction coefficient ([mu]). A parametric equation for the trajectory of the particle is also obtained. In the second part of the paper, the motion of a sphere on the inclined plane is…
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Methods, systems and apparatus for controlling operation of two alternating current (AC) machines
Gallegos-Lopez, Gabriel [Torrance, CA; Nagashima, James M [Cerritos, CA; Perisic, Milun [Torrance, CA; Hiti, Silva [Redondo Beach, CA
2012-02-14
A system is provided for controlling two AC machines. The system comprises a DC input voltage source that provides a DC input voltage, a voltage boost command control module (VBCCM), a five-phase PWM inverter module coupled to the two AC machines, and a boost converter coupled to the inverter module and the DC input voltage source. The boost converter is designed to supply a new DC input voltage to the inverter module having a value that is greater than or equal to a value of the DC input voltage. The VBCCM generates a boost command signal (BCS) based on modulation indexes from the two AC machines. The BCS controls the boost converter such that the boost converter generates the new DC input voltage in response to the BCS. When the two AC machines require additional voltage that exceeds the DC input voltage required to meet a combined target mechanical power required by the two AC machines, the BCS controls the boost converter to drive the new DC input voltage generated by the boost converter to a value greater than the DC input voltage.
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Lunar Landing Trajectory Design for Onboard Hazard Detection and Avoidance
NASA Technical Reports Server (NTRS)
Paschall, Steve; Brady, Tye; Sostaric, Ron
2009-01-01
The Autonomous Landing and Hazard Avoidance Technology (ALHAT) Project is developing the software and hardware technology needed to support a safe and precise landing for the next generation of lunar missions. ALHAT provides this capability through terrain-relative navigation measurements to enhance global-scale precision, an onboard hazard detection system to select safe landing locations, and an Autonomous Guidance, Navigation, and Control (AGNC) capability to process these measurements and safely direct the vehicle to a landing location. This paper focuses on the key trajectory design issues relevant to providing an onboard Hazard Detection and Avoidance (HDA) capability for the lander. Hazard detection can be accomplished by the crew visually scanning the terrain through a window, a sensor system imaging the terrain, or some combination of both. For ALHAT, this hazard detection activity is provided by a sensor system, which either augments the crew s perception or entirely replaces the crew in the case of a robotic landing. Detecting hazards influences the trajectory design by requiring the proper perspective, range to the landing site, and sufficient time to view the terrain. Following this, the trajectory design must provide additional time to process this information and make a decision about where to safely land. During the final part of the HDA process, the trajectory design must provide sufficient margin to enable a hazard avoidance maneuver. In order to demonstrate the effects of these constraints on the landing trajectory, a tradespace of trajectory designs was created for the initial ALHAT Design Analysis Cycle (ALDAC-1) and each case evaluated with these HDA constraints active. The ALHAT analysis process, described in this paper, narrows down this tradespace and subsequently better defines the trajectory design needed to support onboard HDA. Future ALDACs will enhance this trajectory design by balancing these issues and others in an overall system design process.
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Van Parijs, Hilde; Reynders, Truus; Heuninckx, Karina; Verellen, Dirk; Storme, Guy; De Ridder, Mark
2014-01-01
Breast conserving surgery followed by whole breast irradiation is widely accepted as standard of care for early breast cancer. Addition of a boost dose to the initial tumor area further reduces local recurrences. We investigated the dosimetric benefits of a simultaneously integrated boost (SIB) compared to a sequential boost to hypofractionate the boost volume, while maintaining normofractionation on the breast. For 10 patients 4 treatment plans were deployed, 1 with a sequential photon boost, and 3 with different SIB techniques: on a conventional linear accelerator, helical TomoTherapy, and static TomoDirect. Dosimetric comparison was performed. PTV-coverage was good in all techniques. Conformity was better with all SIB techniques compared to sequential boost (P = 0.0001). There was less dose spilling to the ipsilateral breast outside the PTVboost (P = 0.04). The dose to the organs at risk (OAR) was not influenced by SIB compared to sequential boost. Helical TomoTherapy showed a higher mean dose to the contralateral breast, but less than 5 Gy for each patient. SIB showed less dose spilling within the breast and equal dose to OAR compared to sequential boost. Both helical TomoTherapy and the conventional technique delivered acceptable dosimetry. SIB seems a safe alternative and can be implemented in clinical routine.
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Reynders, Truus; Heuninckx, Karina; Verellen, Dirk; Storme, Guy; De Ridder, Mark
2014-01-01
Background. Breast conserving surgery followed by whole breast irradiation is widely accepted as standard of care for early breast cancer. Addition of a boost dose to the initial tumor area further reduces local recurrences. We investigated the dosimetric benefits of a simultaneously integrated boost (SIB) compared to a sequential boost to hypofractionate the boost volume, while maintaining normofractionation on the breast. Methods. For 10 patients 4 treatment plans were deployed, 1 with a sequential photon boost, and 3 with different SIB techniques: on a conventional linear accelerator, helical TomoTherapy, and static TomoDirect. Dosimetric comparison was performed. Results. PTV-coverage was good in all techniques. Conformity was better with all SIB techniques compared to sequential boost (P = 0.0001). There was less dose spilling to the ipsilateral breast outside the PTVboost (P = 0.04). The dose to the organs at risk (OAR) was not influenced by SIB compared to sequential boost. Helical TomoTherapy showed a higher mean dose to the contralateral breast, but less than 5 Gy for each patient. Conclusions. SIB showed less dose spilling within the breast and equal dose to OAR compared to sequential boost. Both helical TomoTherapy and the conventional technique delivered acceptable dosimetry. SIB seems a safe alternative and can be implemented in clinical routine. PMID:25162031
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Hau, Eric, E-mail: helloerico@yahoo.com; Browne, Lois H.; Khanna, Sam
Purpose: To evaluate comprehensively the effect of a radiotherapy boost on breast cosmetic outcomes after 5 years in patients treated with breast-conserving surgery. Methods: The St. George and Wollongong trial (NCT00138814) randomized 688 patients with histologically proven Tis-2, N 0-1, M0 carcinoma to the control arm of 50 Gy in 25 fractions (342 patients) and the boost arm of 45 Gy in 25 fractions to the whole breast followed by a 16 Gy in 8 fraction electron boost (346 patients). Five-year cosmetic outcomes were assessed by a panel subjectively in 385 patients and objectively using pBRA (relative breast retraction assessment).more » A subset of patients also had absolute BRA measurements. Clinician assessment and patient self-assessment of overall cosmetic and specific items as well as computer BCCT.core analysis were also performed. Results: The boost arm had improved cosmetic overall outcomes as scored by the panel and BCCT.core software with 79% (p = 0.016) and 81% (p = 0.004) excellent/good cosmesis respectively compared with 68% in no-boost arm. The boost arm also had lower pBRA and BRA values with a mean difference of 0.60 and 1.82 mm, respectively, but was not statistically significant. There was a very high proportion of overall excellent/good cosmetic outcome in 95% and 93% in the boost and no-boost arms using patient self-assessment. However, no difference in overall and specific items scored by clinician assessment and patient self-assessment was found. Conclusion: The results show the negative cosmetic effect of a 16-Gy boost is offset by a lower whole-breast dose of 45 Gy.« less
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A Study of 4-level DC-DC Boost Inverter with Passive Component Reduction Consideration
NASA Astrophysics Data System (ADS)
Kasiran, A. N.; Ponniran, A.; Harimon, M. A.; Hamzah, H. H.
2018-04-01
This study is to analyze design principles of boost inductor and capacitor used in the 4-level DC-DC boost converter to realize size reduction of passive component referring to their attributes. The important feature of this circuit is that most of the boost-up energy is transferred from the capacitor-clamped to the output side which the small inductance can be used at the input side. The inductance of the boost inductor is designed by referring the inductor current ripple. On the other hand, the capacitance of the capacitor-clamped is designed by considering voltage stress on semiconductor devices and also the used switching frequency. Besides that, according to the design specifications, the required inductance in 4-level DC-DC boost converter is decreased compared to a conventional conventional DC-DC boost converter. Meanwhile, voltage stress on semiconductor device is depending on the maximum voltage ripple of the capacitor-clamped. A 50 W 4-level DC-DC boost converter prototype has been constructed. The results show that the inductor current ripple was 1.15 A when the inductors, 1 mH and 0.11 mH were used in the conventional and 4-level DC-DC boost converters, respectively. Thus, based on the experimental results, it shows that the reduction of passive components by referring to their attributes in 4-level DC-DC boost converter is achieved. Moreover, the decreasing of voltage stress on the semiconductor devices is an advantage for the selection of low ON-resistance of the devices which will contribute to the reduction of the semiconductor conduction loss. The integration result of boost converter and H-bridge inverter is also shown.
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Adjunctation and Scalar Product in the Dirac Equation - II
NASA Astrophysics Data System (ADS)
Dima, M.
2017-02-01
Part-I Dima (Int. J. Theor. Phys. 55, 949, 2016) of this paper showed in a representation independent way that γ 0 is the Bergmann-Pauli adjunctator of the Dirac { γ μ } set. The distiction was made between similarity (MATH) transformations and PHYS transformations - related to the (covariant) transformations of physical quantities. Covariance is due solely to the gauging of scalar products between systems of reference and not to the particular action of γ 0 on Lorentz boosts - a matter that in the past led inadvertently to the definition of a second scalar product (the Dirac-bar product). Part-II shows how two scalar products lead to contradictions and eliminates this un-natural duality in favour of the canonical scalar product and its gauge between systems of reference. What constitutes a proper observable is analysed and for instance spin is revealed not to embody one (except as projection on the boost direction - helicity). A thorough investigation into finding a proper-observable current for the theory shows that the Dirac equation does not possess one in operator form. A number of problems with the Dirac current operator are revealed - its Klein-Gordon counterpart being significantly more physical. The alternative suggested is finding a current for the Dirac theory in scalar form j^{μ } = < ρ rangle _{_{ψ }}v^{μ }_{ψ }.
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14 CFR 27.695 - Power boost and power-operated control system.
Code of Federal Regulations, 2014 CFR
2014-01-01
... Systems § 27.695 Power boost and power-operated control system. (a) If a power boost or power-operated... failure of all engines. (b) Each alternate system may be a duplicate power portion or a manually operated... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Power boost and power-operated control...
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14 CFR 29.695 - Power boost and power-operated control system.
Code of Federal Regulations, 2012 CFR
2012-01-01
... Systems § 29.695 Power boost and power-operated control system. (a) If a power boost or power-operated... failure of all engines. (b) Each alternate system may be a duplicate power portion or a manually operated... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Power boost and power-operated control...
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14 CFR 29.695 - Power boost and power-operated control system.
Code of Federal Regulations, 2014 CFR
2014-01-01
... Systems § 29.695 Power boost and power-operated control system. (a) If a power boost or power-operated... failure of all engines. (b) Each alternate system may be a duplicate power portion or a manually operated... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Power boost and power-operated control...
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14 CFR 27.695 - Power boost and power-operated control system.
Code of Federal Regulations, 2011 CFR
2011-01-01
... Systems § 27.695 Power boost and power-operated control system. (a) If a power boost or power-operated... failure of all engines. (b) Each alternate system may be a duplicate power portion or a manually operated... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Power boost and power-operated control...
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14 CFR 29.695 - Power boost and power-operated control system.
Code of Federal Regulations, 2011 CFR
2011-01-01
... Systems § 29.695 Power boost and power-operated control system. (a) If a power boost or power-operated... failure of all engines. (b) Each alternate system may be a duplicate power portion or a manually operated... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Power boost and power-operated control...
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14 CFR 29.695 - Power boost and power-operated control system.
Code of Federal Regulations, 2010 CFR
2010-01-01
... Systems § 29.695 Power boost and power-operated control system. (a) If a power boost or power-operated... failure of all engines. (b) Each alternate system may be a duplicate power portion or a manually operated... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Power boost and power-operated control...
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14 CFR 27.695 - Power boost and power-operated control system.
Code of Federal Regulations, 2012 CFR
2012-01-01
... Systems § 27.695 Power boost and power-operated control system. (a) If a power boost or power-operated... failure of all engines. (b) Each alternate system may be a duplicate power portion or a manually operated... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Power boost and power-operated control...
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14 CFR 27.695 - Power boost and power-operated control system.
Code of Federal Regulations, 2010 CFR
2010-01-01
... Systems § 27.695 Power boost and power-operated control system. (a) If a power boost or power-operated... failure of all engines. (b) Each alternate system may be a duplicate power portion or a manually operated... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Power boost and power-operated control...
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Boosted one dimensional fermionic superfluids on a lattice
NASA Astrophysics Data System (ADS)
Ray, Sayonee; Mukerjee, Subroto; Shenoy, Vijay B.
2017-09-01
We study the effect of a boost (Fermi sea displaced by a finite momentum) on one dimensional systems of lattice fermions with short-ranged interactions. In the absence of a boost such systems with attractive interactions possess algebraic superconducting order. Motivated by physics in higher dimensions, one might naively expect a boost to weaken and ultimately destroy superconductivity. However, we show that for one dimensional systems the effect of the boost can be to strengthen the algebraic superconducting order by making correlation functions fall off more slowly with distance. This phenomenon can manifest in interesting ways, for example, a boost can produce a Luther-Emery phase in a system with both charge and spin gaps by engendering the destruction of the former.
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Takahashi, Hiro; Aoyagi, Kazuhiko; Nakanishi, Yukihiro; Sasaki, Hiroki; Yoshida, Teruhiko; Honda, Hiroyuki
2006-07-01
Esophageal cancer is a well-known cancer with poorer prognosis than other cancers. An optimal and individualized treatment protocol based on accurate diagnosis is urgently needed to improve the treatment of cancer patients. For this purpose, it is important to develop a sophisticated algorithm that can manage a large amount of data, such as gene expression data from DNA microarrays, for optimal and individualized diagnosis. Marker gene selection is essential in the analysis of gene expression data. We have already developed a combination method of the use of the projective adaptive resonance theory and that of a boosted fuzzy classifier with the SWEEP operator denoted PART-BFCS. This method is superior to other methods, and has four features, namely fast calculation, accurate prediction, reliable prediction, and rule extraction. In this study, we applied this method to analyze microarray data obtained from esophageal cancer patients. A combination method of PART-BFCS and the U-test was also investigated. It was necessary to use a specific type of BFCS, namely, BFCS-1,2, because the esophageal cancer data were very complexity. PART-BFCS and PART-BFCS with the U-test models showed higher performances than two conventional methods, namely, k-nearest neighbor (kNN) and weighted voting (WV). The genes including CDK6 could be found by our methods and excellent IF-THEN rules could be extracted. The genes selected in this study have a high potential as new diagnosis markers for esophageal cancer. These results indicate that the new methods can be used in marker gene selection for the diagnosis of cancer patients.
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Characterization of the Optical and X-ray Properties of the Northwestern Wisps in the Crab Nebula
NASA Technical Reports Server (NTRS)
Weisskopf, M. C.; Bucciantini, N.; Idec, W.; Nillson, K.; Schweizer, T.; Tennant, A. F.; Zanin, R.
2013-01-01
We have studied the wisps to the northwest of the Crab pulsar as part of a multi-wavelength campaign in the visible and in X-rays. Optical observations were obtained using the Nordic Optical Telescope in La Palma and X-ray observations were made with the Chandra X-ray Observatory. The observing campaign took place from October 2010 until September 2012. About once per year we observe wisps forming and peeling off from (or near) the region commonly associated with the termination shock of the pulsar wind. We find that the exact locations of the northwestern wisps in the optical and in X-rays are similar but not coincident, with X-ray wisps preferentially located closer to the pulsar. This suggests that the optical and X-ray wisps are not produced by the same particle distribution. It is also interesting to note that the optical and radio wisps are also separated from each other (Bietenholz et al. 2004). Our measurements and their implications are interpreted in terms of a Doppler-boosted ring model that has its origin in MHD modeling. While the Doppler boosting factors inferred from the X-ray wisps are consistent with current MHD simulations of PWNe, the optical boosting factors are not, and typically exceed values from MHD simulations by about a factor of 4.
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Wise, Megan C.; Hutnick, Natalie A.; Pollara, Justin; Myles, Devin J. F.; Williams, Constance; Yan, Jian; LaBranche, Celia C.; Khan, Amir S.; Sardesai, Niranjan Y.; Montefiori, David; Barnett, Susan W.; Zolla-Pazner, Susan; Ferrari, Guido
2015-01-01
ABSTRACT The search for an efficacious human immunodeficiency virus type 1 (HIV-1) vaccine remains a pressing need. The moderate success of the RV144 Thai clinical vaccine trial suggested that vaccine-induced HIV-1-specific antibodies can reduce the risk of HIV-1 infection. We have made several improvements to the DNA platform and have previously shown that improved DNA vaccines alone are capable of inducing both binding and neutralizing antibodies in small-animal models. In this study, we explored how an improved DNA prime and recombinant protein boost would impact HIV-specific vaccine immunogenicity in rhesus macaques (RhM). After DNA immunization with either a single HIV Env consensus sequence or multiple constructs expressing HIV subtype-specific Env consensus sequences, we detected both CD4+ and CD8+ T-cell responses to all vaccine immunogens. These T-cell responses were further increased after protein boosting to levels exceeding those of DNA-only or protein-only immunization. In addition, we observed antibodies that exhibited robust cross-clade binding and neutralizing and antibody-dependent cellular cytotoxicity (ADCC) activity after immunization with the DNA prime-protein boost regimen, with the multiple-Env formulation inducing a more robust and broader response than the single-Env formulation. The magnitude and functionality of these responses emphasize the strong priming effect improved DNA immunogens can induce, which are further expanded upon protein boost. These results support further study of an improved synthetic DNA prime together with a protein boost for enhancing anti-HIV immune responses. IMPORTANCE Even with effective antiretroviral drugs, HIV remains an enormous global health burden. Vaccine development has been problematic in part due to the high degree of diversity and poor immunogenicity of the HIV Env protein. Studies suggest that a relevant HIV vaccine will likely need to induce broad cellular and humoral responses from a simple vaccine regimen due to the resource-limited setting in which the HIV pandemic is most rampant. DNA vaccination lends itself well to increasing the amount of diversity included in a vaccine due to the ease of manufacturing multiple plasmids and formulating them as a single immunization. By increasing the number of Envs within a formulation, we were able to show an increased breadth of responses as well as improved functionality induced in a nonhuman primate model. This increased breadth could be built upon, leading to better coverage against circulating strains with broader vaccine-induced protection. PMID:26085155
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Optimization of Spiral-Based Pulse Sequences for First Pass Myocardial Perfusion Imaging
Salerno, Michael; Sica, Christopher T.; Kramer, Christopher M.; Meyer, Craig H.
2010-01-01
While spiral trajectories have multiple attractive features such as their isotropic resolution, acquisition efficiency, and robustness to motion, there has been limited application of these techniques to first pass perfusion imaging because of potential off-resonance and inconsistent data artifacts. Spiral trajectories may also be less sensitive to dark-rim artifacts (DRA) that are caused, at least in part, by cardiac motion. By careful consideration of the spiral trajectory readout duration, flip angle strategy, and image reconstruction strategy, spiral artifacts can be abated to create high quality first pass myocardial perfusion images with high SNR. The goal of this paper was to design interleaved spiral pulse sequences for first-pass myocardial perfusion imaging, and to evaluate them clinically for image quality and the presence of dark-rim, blurring, and dropout artifacts. PMID:21590802
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Stochastic Representation of Chaos Using Terminal Attractors
NASA Technical Reports Server (NTRS)
Zak, Michail
2006-01-01
A nonlinear version of the Liouville equation based on terminal attractors is part of a mathematical formalism for describing postinstability motions of dynamical systems characterized by exponential divergences of trajectories leading to chaos (including turbulence as a form of chaos). The formalism can be applied to both conservative systems (e.g., multibody systems in celestial mechanics) and dissipative systems (e.g., viscous fluids). The development of the present formalism was undertaken in an effort to remove positive Lyapunov exponents. The means chosen to accomplish this is coupling of the governing dynamical equations with the corresponding Liouville equation that describes the evolution of the flow of error probability. The underlying idea is to suppress the divergences of different trajectories that correspond to different initial conditions, without affecting a target trajectory, which is one that starts with prescribed initial conditions.
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NASA Technical Reports Server (NTRS)
Perkins, Sharon; Martin, Andrea; Bavinger, Bill
1990-01-01
The Trajectory Operations Applications Software Task (TOAST) is a software development project whose purpose is to provide trajectory operation pre-mission and real-time support for the Space Shuttle. The purpose of the evaluation was to evaluate TOAST as an Application Manager - to assess current and planned capabilities, compare capabilities to commercially-available off the shelf (COTS) software, and analyze requirements of MCC and Flight Analysis Design System (FADS) for TOAST implementation. As a major part of the data gathering for the evaluation, interviews were conducted with NASA and contractor personnel. Real-time and flight design users, orbit navigation users, the TOAST developers, and management were interviewed. Code reviews and demonstrations were also held. Each of these interviews was videotaped and transcribed as appropriate. Transcripts were edited and are presented chronologically.
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Flouri, Eirini; Midouhas, Emily; Charman, Tony; Sarmadi, Zahra
2015-09-01
We investigated the longitudinal relationship between socio-economic disadvantage (SED) and trajectories of emotional and conduct problems among children with autism spectrum disorder (ASD) who had comorbid attention deficit/hyperactivity disorder (ADHD; ASD + ADHD) or not (ASD - ADHD). The sample was 209 children with ASD who took part in the UK's Millennium Cohort Study. Trajectories of problems across ages 3, 5 and 7 years were analyzed using growth curve models. The ASD - ADHD group decreased in conduct problems over time but the ASD + ADHD group continued on a high trajectory. Although SED was not a risk factor for ASD + ADHD, it was associated with elevated emotional problems among children with ASD + ADHD. This effect of SED on emotional problems was not attenuated by parenting or peer problems.
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RBOOST: RIEMANNIAN DISTANCE BASED REGULARIZED BOOSTING
Liu, Meizhu; Vemuri, Baba C.
2011-01-01
Boosting is a versatile machine learning technique that has numerous applications including but not limited to image processing, computer vision, data mining etc. It is based on the premise that the classification performance of a set of weak learners can be boosted by some weighted combination of them. There have been a number of boosting methods proposed in the literature, such as the AdaBoost, LPBoost, SoftBoost and their variations. However, the learning update strategies used in these methods usually lead to overfitting and instabilities in the classification accuracy. Improved boosting methods via regularization can overcome such difficulties. In this paper, we propose a Riemannian distance regularized LPBoost, dubbed RBoost. RBoost uses Riemannian distance between two square-root densities (in closed form) – used to represent the distribution over the training data and the classification error respectively – to regularize the error distribution in an iterative update formula. Since this distance is in closed form, RBoost requires much less computational cost compared to other regularized Boosting algorithms. We present several experimental results depicting the performance of our algorithm in comparison to recently published methods, LP-Boost and CAVIAR, on a variety of datasets including the publicly available OASIS database, a home grown Epilepsy database and the well known UCI repository. Results depict that the RBoost algorithm performs better than the competing methods in terms of accuracy and efficiency. PMID:21927643
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NASA Astrophysics Data System (ADS)
Ouyang, Qin; Chen, Quansheng; Zhao, Jiewen
2016-02-01
The approach presented herein reports the application of near infrared (NIR) spectroscopy, in contrast with human sensory panel, as a tool for estimating Chinese rice wine quality; concretely, to achieve the prediction of the overall sensory scores assigned by the trained sensory panel. Back propagation artificial neural network (BPANN) combined with adaptive boosting (AdaBoost) algorithm, namely BP-AdaBoost, as a novel nonlinear algorithm, was proposed in modeling. First, the optimal spectra intervals were selected by synergy interval partial least square (Si-PLS). Then, BP-AdaBoost model based on the optimal spectra intervals was established, called Si-BP-AdaBoost model. These models were optimized by cross validation, and the performance of each final model was evaluated according to correlation coefficient (Rp) and root mean square error of prediction (RMSEP) in prediction set. Si-BP-AdaBoost showed excellent performance in comparison with other models. The best Si-BP-AdaBoost model was achieved with Rp = 0.9180 and RMSEP = 2.23 in the prediction set. It was concluded that NIR spectroscopy combined with Si-BP-AdaBoost was an appropriate method for the prediction of the sensory quality in Chinese rice wine.
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Repeat immigration: A previously unobserved source of heterogeneity?
Aradhya, Siddartha; Scott, Kirk; Smith, Christopher D
2017-07-01
Register data allow for nuanced analyses of heterogeneities between sub-groups which are not observable in other data sources. One heterogeneity for which register data is particularly useful is in identifying unique migration histories of immigrant populations, a group of interest across disciplines. Years since migration is a commonly used measure of integration in studies seeking to understand the outcomes of immigrants. This study constructs detailed migration histories to test whether misclassified migrations may mask important heterogeneities. In doing so, we identify a previously understudied group of migrants called repeat immigrants, and show that they differ systematically from permanent immigrants. In addition, we quantify the degree to which migration information is misreported in the registers. The analysis is carried out in two steps. First, we estimate income trajectories for repeat immigrants and permanent immigrants to understand the degree to which they differ. Second, we test data validity by cross-referencing migration information with changes in income to determine whether there are inconsistencies indicating misreporting. From the first part of the analysis, the results indicate that repeat immigrants systematically differ from permanent immigrants in terms of income trajectories. Furthermore, income trajectories differ based on the way in which years since migration is calculated. The second part of the analysis suggests that misreported migration events, while present, are negligible. Repeat immigrants differ in terms of income trajectories, and may differ in terms of other outcomes as well. Furthermore, this study underlines that Swedish registers provide a reliable data source to analyze groups which are unidentifiable in other data sources.
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Ramsey, Rachelle R.; Loiselle, Kristin; Rausch, Joseph R.; Harrison, Jordan; Modi, Avani C.
2016-01-01
Objective To identify two year trajectories of epilepsy-specific health-related quality of life (HRQOL) among children newly diagnosed with epilepsy and to evaluate the predictive value of a comprehensive set of medical, psychosocial, and family factors. Methods Ninety-four children with epilepsy (8.14 ± 2.37 years of age and 63% male) and their caregivers participated in this study. Caregivers completed the Quality of Life in Childhood Epilepsy Questionnaire (QOLCE) and measures of psychological and family functioning at one month post-diagnosis. The QOLCE was also given at eight additional time points during the subsequent two years as a part of a large observational study in children with epilepsy. Adherence data was collected via MEMS TrackCaps and medical information was collected through chart review. Results Unique trajectories were identified for the overall QOLCE scale, as well as the subscales. Most trajectory models for the QOLCE subscales contained at least one at-risk trajectory for children, indicating that there is a subgroup of children experiencing poor long-term HRQOL. Health-related quality of life trajectories remained predominantly stable during the two year period following treatment initiation. Number of AEDs, Internalizing Problems, and Externalizing Problems emerged as the most consistent predictors across the HRQOL domains. Significance Medical and psychosocial interventions, such as cognitive-behavioral strategies, should target modifiable factors (e.g., internalizing symptoms, externalizing symptoms, number of AEDs trialed) shortly after diagnosis to improve HRQOL for children with epilepsy over the course of their disease. PMID:26974247
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NASA Astrophysics Data System (ADS)
Wu, H.; Chen, X. W.; Fang, Q.; Kong, X. Z.; He, L. L.
2015-08-01
During the high-speed penetration of projectiles into concrete targets (the impact velocity ranges from 1.0 to 1.5 km/s), important factors such as the incident oblique and attacking angles, as well as the asymmetric abrasions of the projectile nose induced by the target-projectile interactions, may lead to obvious deviation of the terminal ballistic trajectory and reduction of the penetration efficiency. Based on the engineering model for the mass loss and nose-blunting of ogive-nosed projectiles established, by using the Differential Area Force Law (DAFL) method and semi-empirical resistance function, a finite differential approach was programmed (PENTRA2D) for predicting the terminal ballistic trajectory of mass abrasive high-speed projectiles penetrating into concrete targets. It accounts for the free-surface effects on the drag force acting on the projectile, which are attributed to the oblique and attacking angles, as well as the asymmetric nose abrasion of the projectile. Its validation on the prediction of curvilinear trajectories of non-normal high-speed penetrators into concrete targets is verified by comparison with available test data. Relevant parametric influential analyses show that the most influential factor for the stability of terminal ballistic trajectories is the attacking angle, followed by the oblique angle, the discrepancy of asymmetric nose abrasion, and the location of mass center of projectile. The terminal ballistic trajectory deviations are aggravated as the above four parameters increase.
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Precise Trajectory Reconstruction of CE-3 Hovering Stage By Landing Camera Images
NASA Astrophysics Data System (ADS)
Yan, W.; Liu, J.; Li, C.; Ren, X.; Mu, L.; Gao, X.; Zeng, X.
2014-12-01
Chang'E-3 (CE-3) is part of the second phase of the Chinese Lunar Exploration Program, incorporating a lander and China's first lunar rover. It was landed on 14 December, 2013 successfully. Hovering and obstacle avoidance stages are essential for CE-3 safety soft landing so that precise spacecraft trajectory in these stages are of great significance to verify orbital control strategy, to optimize orbital design, to accurately determine the landing site of CE-3, and to analyze the geological background of the landing site. Because the time consumption of these stages is just 25s, it is difficult to present spacecraft's subtle movement by Measurement and Control System or by radio observations. Under this background, the trajectory reconstruction based on landing camera images can be used to obtain the trajectory of CE-3 because of its technical advantages such as unaffecting by lunar gravity field spacecraft kinetic model, high resolution, high frame rate, and so on. In this paper, the trajectory of CE-3 before and after entering hovering stage was reconstructed by landing camera images from frame 3092 to frame 3180, which lasted about 9s, under Single Image Space Resection (SISR). The results show that CE-3's subtle changes during hovering stage can be emerged by the reconstructed trajectory. The horizontal accuracy of spacecraft position was up to 1.4m while vertical accuracy was up to 0.76m. The results can be used for orbital control strategy analysis and some other application fields.
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Learning about Gravity II. Trajectories and Orbits: A Guide for Teachers and Curriculum Developers
ERIC Educational Resources Information Center
Kavanagh, Claudine; Sneider, Cary
2007-01-01
This is the second and final part of a review of educational research on children's ideas about gravity. The first part concerned students' understanding of how and why things fall. This article picks up the trail of research studies that address students' understanding of the more complex ideas of projectile motion and orbits and examines how the…
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AC to DC Bridgeless Boost Converter for Ultra Low Input Energy Harvesting
NASA Astrophysics Data System (ADS)
Dawam, A. H. A.; Muhamad, M.
2018-03-01
This paper presents design of circuit which converts low input AC voltage to a higher output DC voltage. A buck-boost topology and boost topology are combined to condition cycle of an AC input voltage. the unique integration of a combining circuit of buck-boost and boost circuit have been proposed in order to introduce a new direct ac-dc power converter topology without conventional diode bridge rectifier. The converter achieved to convert a milli-volt scale of input AC voltage into a volt scale of output DC voltages which is from 400mV to 3.3V.
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Pharmaceutical Advertising and Medicare Part D
Lakdawalla, Darius; Sood, Neeraj; Gu, Qian
2013-01-01
We explore how and to what extent prescription drug insurance expansions affects incentives for pharmaceutical advertising. When insurance expansions make markets more profitable, firms respond by boosting advertising. Theory suggests this effect will be magnified in the least competitive drug classes, where firms internalize a larger share of the benefits from advertising. Empirically, we find that the implementation of Part D coincides with a 14% to 19% increase in total advertising expenditures. This effect is indeed concentrated in the least competitive drug classes. The additional advertising raised utilization among non-elderly patients outside the Part D program by about 3.6%. This is roughly half of the direct utilization effect of Part D on elderly beneficiaries. The results suggest the presence of considerable spillover effects from publicly subsidized prescription drug insurance on the utilization and welfare of consumers outside the program. PMID:24308884
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Narayanasamy, Ganesh; Avila, Gabrielle; Mavroidis, Panayiotis; Papanikolaou, Niko; Gutierrez, Alonso; Baacke, Diana; Shi, Zheng; Stathakis, Sotirios
2016-09-01
Prostate cases commonly consist of dual phase planning with a primary plan followed by a boost. Traditionally, the boost phase is planned independently from the primary plan with the risk of generating hot or cold spots in the composite plan. Alternatively, boost phase can be planned taking into account the primary dose. The aim of this study was to compare the composite plans from independently and dependently planned boosts using dosimetric and radiobiological metrics. Ten consecutive prostate patients previously treated at our institution were used to conduct this study on the Raystation™ 4.0 treatment planning system. For each patient, two composite plans were developed: a primary plan with an independently planned boost and a primary plan with a dependently planned boost phase. The primary plan was prescribed to 54 Gy in 30 fractions to the primary planning target volume (PTV1) which includes prostate and seminal vesicles, while the boost phases were prescribed to 24 Gy in 12 fractions to the boost planning target volume (PTV2) that targets only the prostate. PTV coverage, max dose, median dose, target conformity, dose homogeneity, dose to OARs, and probabilities of benefit, injury, and complication-free tumor control (P+) were compared. Statistical significance was tested using either a 2-tailed Student's t-test or Wilcoxon signed-rank test. Dosimetrically, the composite plan with dependent boost phase exhibited smaller hotspots, lower maximum dose to the target without any significant change to normal tissue dose. Radiobiologically, for all but one patient, the percent difference in the P+ values between the two methods was not significant. A large percent difference in P+ value could be attributed to an inferior primary plan. The benefits of considering the dose in primary plan while planning the boost is not significant unless a poor primary plan was achieved.
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Glynne-Jones, Rob; Sebag-Montefiore, David; Adams, Richard; McDonald, Alec; Gollins, Simon; James, Roger; Northover, John M A; Meadows, Helen M; Jitlal, Mark
2011-12-01
The United Kingdom Coordinating Committee on Cancer Research anal cancer trial demonstrated the benefit of combined modality treatment (CMT) using radiotherapy (RT), infusional 5-fluorouracil, and mitomycin C over RT alone. The present study retrospectively examines the impact of the recommended 6-week treatment gap and local RT boost on long-term outcome. A total of 577 patients were randomly assigned RT alone or CMT. After a 6-week gap responders received a boost using either additional external beam radiotherapy (EBRT) (15 Gy) or iridium-192 implant (25 Gy). The effect of boost, the gap between initial treatment (RT alone or CMT) and boost (Tgap), and overall treatment time (OTT) were examined for their impact on outcome. Among the 490 good responders, 436 (89%) patients received a boost after initial treatment. For boosted patients, the risk of anal cancer death decreased by 38% (hazard ratio [HR]: 0.62, 99% CI 0.35-1.12; p=0.04), but there was no evidence this was mediated via a reduction in locoregional failure (LRF) (HR: 0.90, 99% CI 0.48-1.68; p=0.66). The difference in Tgap was only 1.4 days longer for EBRT boost, compared with implant (p=0.51). OTT was longer by 6.1 days for EBRT (p=0.006). Tgap and OTT were not associated with LRF. Radionecrosis was reported in 8% of boosted, compared with 0% in unboosted patients (p=0.03). These results question the benefit of a radiotherapy boost after a 6-week gap. The higher doses of a boost may contribute more to an increased risk of late morbidity, rather than local control. Copyright © 2011 Elsevier Inc. All rights reserved.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Glynne-Jones, Rob, E-mail: rob.glynnejones@nhs.net; Sebag-Montefiore, David; Adams, Richard
Purpose: The United Kingdom Coordinating Committee on Cancer Research anal cancer trial demonstrated the benefit of combined modality treatment (CMT) using radiotherapy (RT), infusional 5-fluorouracil, and mitomycin C over RT alone. The present study retrospectively examines the impact of the recommended 6-week treatment gap and local RT boost on long-term outcome. Methods and Materials: A total of 577 patients were randomly assigned RT alone or CMT. After a 6-week gap responders received a boost using either additional external beam radiotherapy (EBRT) (15 Gy) or iridium-192 implant (25 Gy). The effect of boost, the gap between initial treatment (RT alone ormore » CMT) and boost (Tgap), and overall treatment time (OTT) were examined for their impact on outcome. Results: Among the 490 good responders, 436 (89%) patients received a boost after initial treatment. For boosted patients, the risk of anal cancer death decreased by 38% (hazard ratio [HR]: 0.62, 99% CI 0.35-1.12; p = 0.04), but there was no evidence this was mediated via a reduction in locoregional failure (LRF) (HR: 0.90, 99% CI 0.48-1.68; p = 0.66). The difference in Tgap was only 1.4 days longer for EBRT boost, compared with implant (p = 0.51). OTT was longer by 6.1 days for EBRT (p = 0.006). Tgap and OTT were not associated with LRF. Radionecrosis was reported in 8% of boosted, compared with 0% in unboosted patients (p = 0.03). Conclusions: These results question the benefit of a radiotherapy boost after a 6-week gap. The higher doses of a boost may contribute more to an increased risk of late morbidity, rather than local control.« less
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Wong, Philip; Lambert, Christine, E-mail: christine.lambert@muhc.mcgill.ca; Agnihotram, Ramanakumar V.
Purpose: Local recurrence (LR) of ductal carcinoma in situ (DCIS) is reduced by whole-breast irradiation after breast-conserving surgery (BCS). However, the benefit of adding a radiotherapy boost to the surgical cavity for DCIS is unclear. We sought to determine the impact of the boost on LR in patients with DCIS treated at the McGill University Health Centre. Methods and Materials: A total of 220 consecutive cases of DCIS treated with BCS and radiotherapy between January 2000 and December 2006 were reviewed. Of the patients, 36% received a radiotherapy boost to the surgical cavity. Median follow-up was 46 months for themore » boost and no-boost groups. Kaplan-Meier survival analyses and Cox regression analyses were performed. Results: Compared with the no-boost group, patients in the boost group more frequently had positive and <0.1-cm margins (48% vs. 8%) (p < 0.0001) and more frequently were in higher-risk categories as defined by the Van Nuys Prognostic (VNP) index (p = 0.006). Despite being at higher risk for LR, none (0/79) of the patients who received a boost experienced LR, whereas 8 of 141 patients who did not receive a boost experienced an in-breast LR (log-rank p = 0.03). Univariate analysis of prognostic factors (age, tumor size, margin status, histological grade, necrosis, and VNP risk category) revealed only the presence of necrosis to significantly correlate with LR (log-rank p = 0.003). The whole-breast irradiation dose and fractionation schedule did not affect LR rate. Conclusions: Our results suggest that the use of a radiotherapy boost improves local control in DCIS and may outweigh the poor prognostic effect of necrosis.« less
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Yang, Enzhuo; Gu, Jin; Wang, Feifei; Wang, Honghai; Shen, Hongbo; Chen, Zheng W
2016-04-01
Since BCG, the only vaccine widely used against tuberculosis (TB) in the world, provides varied protective efficacy and may not be effective for inducing long-term cellular immunity, it is in an urgent need to develop more effective vaccines and more potent immune strategies against TB. Prime-boost is proven to be a good strategy by inducing long-term protection. In this study, we tested the protective effect against Mycobacterium tuberculosis (Mtb) challenge of prime-boost strategy by recombinant BCG (rBCG) expressing PPE protein Rv3425 fused with Ag85B and Rv3425. Results showed that the prime-boost strategy could significantly increase the protective efficiency against Mtb infection, characterized by reduction of bacterial load in lung and spleen, attenuation of tuberculosis lesions in lung tissues. Importantly, we found that Rv3425 boost, superior to Ag85B boost, provided better protection against Mtb infection. Further research proved that rBCG prime-Rv3425 boost could obviously increase the expansion of lymphocytes, significantly induce IL-2 production by lymphocytes upon PPD stimulation, and inhibit IL-6 production at an early stage. It implied that rBCG prime-Rv3425 boost opted to induce Th1 immune response and provided a long-term protection against TB. These results implicated that rBCG prime-Rv3425 boost is a potent and promising strategy to prevent acute Mtb infection. Copyright © 2016 Elsevier Ltd. All rights reserved.
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Jet pump-drive system for heat removal
NASA Technical Reports Server (NTRS)
French, J. R. (Inventor)
1985-01-01
A jet pump, in combination with a TEMP, is employed to assure safe cooling of a nuclear reactor after shutdown. A TEMP, responsive to the heat from the coolant in the secondary flow path, automatically pumps the withdrawn coolant to a higher pressure and thus higher velocity compared to the main flow. The high velocity coolant is applied as a driver flow for the jet pump which has a main flow chamber located in the main flow circulation pump. Upon nuclear shutdown and loss of power for the main reactor pumping system, the TEMP/jet pump combination continues to boost the coolant flow in the direction it is already circulating. During the decay time for the nuclear reactor, the jet pump keeps running until the coolant temperature drops to a lower and safe temperature. At this lower temperature, the TEMP/jet jump combination ceases its circulation boosting operation. The TEMP/jet pump combination is automatic, self-regulating and provides an emergency pumping system free of moving parts.
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Artist concept of STS-49 Endeavour, OV-105, INTELSAT VI astronaut capture
NASA Technical Reports Server (NTRS)
1992-01-01
STS-49 Endeavour, Orbiter Vehicle (OV) 105, International Telecommunications Satellite Organization (INTELSAT) VI artist concept drawing of on-orbit repair and boost sequence shows extravehicular mobility unit (EMU) suited astronaut, positioned on remote manipulator system (RMS) manipulator foot restraint (MFR), attaching capture bar to INTELSAT VI aft side. When in place, the capture bar grapple fixture will be used to pull the satellite into OV-105's payload bay (PLB). This view illustrates part of the sequence of events NASA plans to unfold on the first voyage of OV-105 during the rescue of the errant INTELSAT VI satellite. Once inside the PLB, a perigee stage will be attached to INTELSAT. With its new motor, INTELSAT VI will be released from OV-105's PLB and when a safe distance away be boosted into a 45,000-transfer orbit. It will then be maneuvered into its proper position 22,300 miles above Earth. Photo credit: Hughes Aircraft Co. and NASA.
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NASA Astrophysics Data System (ADS)
Chugh, Saryu; Arivu Selvan, K.; Nadesh, RK
2017-11-01
Numerous destructive things influence the working arrangement of human body as hypertension, smoking, obesity, inappropriate medication taking which causes many contrasting diseases as diabetes, thyroid, strokes and coronary diseases. The impermanence and horribleness of the environment situation is also the reason for the coronary disease. The structure of Apache start relies on the evolution which requires gathering of the data. To break down the significance of use programming focused on data structure the Apache stop ought to be utilized and it gives various central focuses as it is fast in light as it uses memory worked in preparing. Apache Spark continues running on dispersed environment and chops down the data in bunches giving a high profitability rate. Utilizing mining procedure as a part of the determination of coronary disease has been exhaustively examined indicating worthy levels of precision. Decision trees, Neural Network, Gradient Boosting Algorithm are the various apache spark proficiencies which help in collecting the information.
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Large-Nc masses of light mesons from QCD sum rules for nonlinear radial Regge trajectories
NASA Astrophysics Data System (ADS)
Afonin, S. S.; Solomko, T. D.
2018-04-01
The large-Nc masses of light vector, axial, scalar and pseudoscalar mesons are calculated from QCD spectral sum rules for a particular ansatz interpolating the radial Regge trajectories. The ansatz includes a linear part plus exponentially degreasing corrections to the meson masses and residues. The form of corrections was proposed some time ago for consistency with analytical structure of Operator Product Expansion of the two-point correlation functions. We revised that original analysis and found the second solution for the proposed sum rules. The given solution describes better the spectrum of vector and axial mesons.
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Ouyang, Qin; Chen, Quansheng; Zhao, Jiewen
2016-02-05
The approach presented herein reports the application of near infrared (NIR) spectroscopy, in contrast with human sensory panel, as a tool for estimating Chinese rice wine quality; concretely, to achieve the prediction of the overall sensory scores assigned by the trained sensory panel. Back propagation artificial neural network (BPANN) combined with adaptive boosting (AdaBoost) algorithm, namely BP-AdaBoost, as a novel nonlinear algorithm, was proposed in modeling. First, the optimal spectra intervals were selected by synergy interval partial least square (Si-PLS). Then, BP-AdaBoost model based on the optimal spectra intervals was established, called Si-BP-AdaBoost model. These models were optimized by cross validation, and the performance of each final model was evaluated according to correlation coefficient (Rp) and root mean square error of prediction (RMSEP) in prediction set. Si-BP-AdaBoost showed excellent performance in comparison with other models. The best Si-BP-AdaBoost model was achieved with Rp=0.9180 and RMSEP=2.23 in the prediction set. It was concluded that NIR spectroscopy combined with Si-BP-AdaBoost was an appropriate method for the prediction of the sensory quality in Chinese rice wine. Copyright © 2015 Elsevier B.V. All rights reserved.
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Mission Design, Guidance, and Navigation of a Callisto-Io-Ganymede Triple Flyby Jovian Capture
NASA Astrophysics Data System (ADS)
Didion, Alan M.
Use of a triple-satellite-aided capture maneuver to enter Jovian orbit reduces insertion DeltaV and provides close flyby science opportunities at three of Jupiter's four large Galilean moons. This capture can be performed while maintaining appropriate Jupiter standoff distance and setting up a suitable apojove for plotting an extended tour. This paper has three main chapters, the first of which discusses the design and optimization of a triple-flyby capture trajectory. A novel triple-satellite-aided capture uses sequential flybys of Callisto, Io, and Ganymede to reduce the DeltaV required to capture into orbit about Jupiter. An optimal broken-plane maneuver is added between Earth and Jupiter to form a complete chemical/impulsive interplanetary trajectory from Earth to Jupiter. Such a trajectory can yield significant fuel savings over single and double-flyby capture schemes while maintaining a brief and simple interplanetary transfer phase. The second chapter focuses on the guidance and navigation of such trajectories in the presence of spacecraft navigation errors, ephemeris errors, and maneuver execution errors. A powered-flyby trajectory correction maneuver (TCM) is added to the nominal trajectory at Callisto and the nominal Jupiter orbit insertion (JOI) maneuver is modified to both complete the capture and target the Ganymede flyby. A third TCM is employed after all the flybys to act as a JOI cleanup maneuver. A Monte Carlo simulation shows that the statistical DeltaV required to correct the trajectory is quite manageable and the flyby characteristics are very consistent. The developed methods maintain flexibility for adaptation to similar launch, cruise, and capture conditions. The third chapter details the methodology and results behind a completely separate project to design and optimize an Earth-orbiting three satellite constellation to perform very long baseline interferometry (VLBI) as part of the 8th annual Global Trajectory Optimisation Competition (GTOC8). A script is designed to simulate the prescribed constellation and record its observations; the observations made are scored according to a provided performance index.
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Trajectories of Substance Use Disorder in Youth After Detention: A 12-Year Longitudinal Study.
Welty, Leah J; Hershfield, Jennifer A; Abram, Karen M; Han, Hongyun; Byck, Gayle R; Teplin, Linda A
2017-02-01
To identify trajectories of substance use disorders (SUDs) in youth during the 12 years after detention and how gender, race/ethnicity, and age at baseline predict trajectories. As part of the Northwestern Juvenile Project, a longitudinal study of 1,829 youth randomly sampled from detention in Chicago, Illinois from 1995 through 1998, participants were reinterviewed in the community or correctional facilities up to 9 times over 12 years. Independent interviewers assessed SUDs using the Diagnostic Interview Schedule for Children 2.3 (baseline) and the Diagnostic Interview Schedule IV (follow-ups). Primary outcome was a mutually exclusive 5-category typology of disorder: no SUD, alcohol alone, marijuana alone, comorbid alcohol and marijuana, or "other" illicit ("hard") drug. Trajectories were estimated using growth mixture models with a 3-category ordinal variable derived from the typology. During the 12-year follow-up, 19.6% of youth did not have an SUD. The remaining 81.4% were in 3 trajectory classes. Class 1 (24.5%), a bell-shaped trajectory, peaked 5 years after baseline when 42.7% had an SUD and 12.5% had comorbid or "other" illicit drug disorders. Class 2 (41.3%) had a higher prevalence of SUD at baseline, 73.8%. Although prevalence decreased over time, 23.5% had an SUD 12 years later. Class 3 (14.6%), the most serious and persistent trajectory, had the highest prevalence of comorbid or "other" illicit drug disorders-52.1% at baseline and 17.4% 12 years later. Males, Hispanics, non-Hispanic whites, and youth who were older at baseline (detention) had the worst outcomes. Gender, race/ethnicity, and age at detention predict trajectories of SUDs in delinquent youth. Findings provide an empirical basis for child psychiatry to address health disparities and improve prevention. Copyright © 2016 American Academy of Child and Adolescent Psychiatry. Published by Elsevier Inc. All rights reserved.
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Gasser, Constantine E; Mensah, Fiona K; Kerr, Jessica A; Wake, Melissa
2017-12-01
Social patterning of dietary-related diseases may partly be explained by population disparities in children's diets. This study aimed to determine which early life socioeconomic factors best predict dietary trajectories across childhood. For waves 2-6 of the Baby (B) Cohort (ages 2-3 to 10-11 years) and waves 1-6 of the Kindergarten (K) Cohort (ages 4-5 to 14-15 years) of the Longitudinal Study of Australian Children, we constructed trajectories of dietary scores and of empirically derived dietary patterns. Dietary scores, based on the Australian Dietary Guidelines, summed children's consumption frequencies of seven groups of foods or drinks over the last 24 hours. Dietary patterns at each wave were derived using factor analyses of 12-16 food or drink items. Using multinomial logistic regression analyses, we examined associations of baseline single (parental education, remoteness area, parental employment, income, food security and home ownership) and composite (socioeconomic position and neighbourhood disadvantage) factors with adherence to dietary trajectories. All dietary trajectory outcomes across both cohorts showed profound gradients by composite socioeconomic position but not by neighbourhood disadvantage. For example, odds for children in the lowest relative to highest socioeconomic position quintile being in the 'never healthy' relative to the 'always healthy' score trajectory were OR=16.40, 95% CI 9.40 to 28.61 (B Cohort). Among the single variables, only parental education consistently predicted dietary trajectories. Child dietary trajectories vary profoundly by family socioeconomic position. If causal, reducing dietary inequities may require researching underlying pathways, tackling socioeconomic inequities and targeting health promoting interventions to less educated families. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
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Unemployment in the teens and trajectories of alcohol consumption in adulthood
Virtanen, Pekka; Lintonen, Tomi; Westerlund, Hugo; Nummi, Tapio; Janlert, Urban; Hammarström, Anne
2016-01-01
Objectives The unemployed are assumed to adopt unhealthy behaviours, including harmful use of alcohol. This study sought to elucidate the relations between unemployment before age 21 years and consumption of alcohol from 21 to 42 years. The design was based on the conception of youth as a sensitive period for obtaining ‘drinking scars’ that are visible up to middle age. Setting The Northern Swedish Cohort Study has followed up a population sample from 1981 to 2007 with five surveys. Participants All pupils (n=1083) attending the last year of compulsory school in Luleå participated in the baseline survey in classrooms, and 1010 of them (522 men and 488 women) participated in the last follow-up survey that was conducted at classmate reunions or by post or by phone. Outcome measure The trajectory of alcohol consumption from 21 to 43 years, obtained with latent class growth analyses, was scaled. Results Men were assigned to five and women to three consumption trajectories. The trajectory membership was regressed on accumulation of unemployment from 16 to 21 years, with multinomial logistic regression analyses. The trajectory of moderate consumption was preceded by lowest exposure to unemployment in men and in women. With reference to this, the relative risk ratios for high-level trajectory groups were 3.49 (1.25 to 9.79) in men and 1.41 (0.74 to 2.72) in women, but also the trajectories of low-level consumption were more probable (relative risk ratio 3.18 (1.12 to 9.02) in men and 2.41 (1.24 to 4.67) in women). Conclusions High-level alcohol consumption throughout adulthood is, particularly among men, partly due to ‘scars’ from youth unemployment, particularly in men, but there are also groups of men and women where unemployment in the teens predicts a trajectory of low consumption. PMID:27016242
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Unemployment in the teens and trajectories of alcohol consumption in adulthood.
Virtanen, Pekka; Lintonen, Tomi; Westerlund, Hugo; Nummi, Tapio; Janlert, Urban; Hammarström, Anne
2016-03-25
The unemployed are assumed to adopt unhealthy behaviours, including harmful use of alcohol. This study sought to elucidate the relations between unemployment before age 21 years and consumption of alcohol from 21 to 42 years. The design was based on the conception of youth as a sensitive period for obtaining 'drinking scars' that are visible up to middle age. The Northern Swedish Cohort Study has followed up a population sample from 1981 to 2007 with five surveys. All pupils (n=1083) attending the last year of compulsory school in Luleå participated in the baseline survey in classrooms, and 1010 of them (522 men and 488 women) participated in the last follow-up survey that was conducted at classmate reunions or by post or by phone. The trajectory of alcohol consumption from 21 to 43 years, obtained with latent class growth analyses, was scaled. Men were assigned to five and women to three consumption trajectories. The trajectory membership was regressed on accumulation of unemployment from 16 to 21 years, with multinomial logistic regression analyses. The trajectory of moderate consumption was preceded by lowest exposure to unemployment in men and in women. With reference to this, the relative risk ratios for high-level trajectory groups were 3.49 (1.25 to 9.79) in men and 1.41 (0.74 to 2.72) in women, but also the trajectories of low-level consumption were more probable (relative risk ratio 3.18 (1.12 to 9.02) in men and 2.41 (1.24 to 4.67) in women). High-level alcohol consumption throughout adulthood is, particularly among men, partly due to 'scars' from youth unemployment, particularly in men, but there are also groups of men and women where unemployment in the teens predicts a trajectory of low consumption. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/
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Maximum power point tracking techniques for wind energy systems using three levels boost converter
NASA Astrophysics Data System (ADS)
Tran, Cuong Hung; Nollet, Frédéric; Essounbouli, Najib; Hamzaoui, Abdelaziz
2018-05-01
This paper presents modeling and simulation of three level Boost DC-DC converter in Wind Energy Conversion System (WECS). Three-level Boost converter has significant advantage compared to conventional Boost. A maximum power point tracking (MPPT) method for a variable speed wind turbine using permanent magnet synchronous generator (PMSG) is also presented. Simulation of three-level Boost converter topology with Perturb and Observe algorithm and Fuzzy Logic Control is implemented in MATLAB/SIMULINK. Results of this simulation show that the system with MPPT using fuzzy logic controller has better performance to the Perturb and Observe algorithm: fast response under changing conditions and small oscillation.
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Peatross, J; Johansen, J
2014-01-13
Strong-field laser-atom interactions provide extreme conditions that may be useful for investigating the de Broglie-Bohm quantum interpretation. Bohmian trajectories representing bound electrons in individual atoms exhibit both even and odd harmonic motion when subjected to a strong external laser field. The phases of the even harmonics depend on the random initial positions of the trajectories within the wave function, making the even harmonics incoherent. In contrast, the phases of odd harmonics remain for the most part coherent regardless of initial position. Under the conjecture that a Bohmian point particle plays the role of emitter, this suggests an experiment to determine whether both even and odd harmonics are produced at the atomic level. Estimates suggest that incoherent emission of even harmonics may be detectable out the side of an intense laser focus interacting with a large number of atoms.
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Drifting derelict trajectories in the North Atlantic
NASA Astrophysics Data System (ADS)
Richardson, Philip L.
1984-04-01
In December 1883 the U.S. Navy Hydrographic Office, a branch of the Bureau of Navigation of the Navy Department, began to publish monthly Pilot Charts. Earlier, oceanographer M.F. Maury had produced some summary survey charts showing ocean currents, winds, sailing routes, and the locations of whales. The new charts were unique in that they showed updated positions of derelict vessels and other drifting debris. From this series of positions of identified derelicts the first ocean trajectories were obtained. Much of this information has been forgotten during the last 100 years, and good collections of the Pilot Charts are rare. (The only complete collection that I could find is held by the Defense Mapping Agency.) This article is a recompilation and description of these early trajectories and a reminder of the usefulness of the Pilot Charts. It also provides a glimpse of a little known part of maritime history, the last days of wooden sailing vessels.
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Biomechanical analysis of the circular friction hand massage.
Ryu, Jeseong; Son, Jongsang; Ahn, Soonjae; Shin, Isu; Kim, Youngho
2015-01-01
A massage can be beneficial to relieve muscle tension on the neck and shoulder area. Various massage systems have been developed, but their motions are not uniform throughout different body parts nor specifically targeted to the neck and shoulder areas. Pressure pattern and finger movement trajectories of the circular friction hand massage on trapezius, levator scapulae, and deltoid muscles were determined to develop a massage system that can mimic the motion and the pressure of the circular friction massage. During the massage, finger movement trajectories were measured using a 3D motion capture system, and finger pressures were simultaneously obtained using a grip pressure sensor. Results showed that each muscle had different finger movement trajectory and pressure pattern. The trapezius muscle experienced a higher pressure, longer massage time (duration of pressurization), and larger pressure-time integral than the other muscles. These results could be useful to design a better massage system simulating human finger movements.
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Semi-Automatic Determination of Rockfall Trajectories
Volkwein, Axel; Klette, Johannes
2014-01-01
In determining rockfall trajectories in the field, it is essential to calibrate and validate rockfall simulation software. This contribution presents an in situ device and a complementary Local Positioning System (LPS) that allow the determination of parts of the trajectory. An assembly of sensors (herein called rockfall sensor) is installed in the falling block recording the 3D accelerations and rotational velocities. The LPS automatically calculates the position of the block along the slope over time based on Wi-Fi signals emitted from the rockfall sensor. The velocity of the block over time is determined through post-processing. The setup of the rockfall sensor is presented followed by proposed calibration and validation procedures. The performance of the LPS is evaluated by means of different experiments. The results allow for a quality analysis of both the obtained field data and the usability of the rockfall sensor for future/further applications in the field. PMID:25268916
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Sperka, Daniel J; Ditterich, Jochen
2011-01-01
While computer-aided planning of human neurosurgeries is becoming more and more common, animal researchers still largely rely on paper atlases for planning their approach before implanting recording chambers to perform invasive recordings of neural activity, which makes this planning process tedious and error-prone. Here we present SPLASh (Stereotactic PLAnning Software), an interactive software tool for the stereotactic planning of recording chamber placement and electrode trajectories. SPLASh has been developed for monkey cortical recordings and relies on a combination of structural MRIs and electronic brain atlases. Since SPLASh is based on the neuroanatomy software Caret, it should also be possible to use it for other parts of the brain or other species for which Caret atlases are available. The tool allows the user to interactively evaluate different possible placements of recording chambers and to simulate electrode trajectories.
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Sperka, Daniel J.; Ditterich, Jochen
2011-01-01
While computer-aided planning of human neurosurgeries is becoming more and more common, animal researchers still largely rely on paper atlases for planning their approach before implanting recording chambers to perform invasive recordings of neural activity, which makes this planning process tedious and error-prone. Here we present SPLASh (Stereotactic PLAnning Software), an interactive software tool for the stereotactic planning of recording chamber placement and electrode trajectories. SPLASh has been developed for monkey cortical recordings and relies on a combination of structural MRIs and electronic brain atlases. Since SPLASh is based on the neuroanatomy software Caret, it should also be possible to use it for other parts of the brain or other species for which Caret atlases are available. The tool allows the user to interactively evaluate different possible placements of recording chambers and to simulate electrode trajectories. PMID:21472085
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Choukas-Bradley, Sophia; Giletta, Matteo; Neblett, Enrique W; Prinstein, Mitchell J
2015-01-01
Two-part latent growth models examined associations between two forms of peer status (popularity, likability) and adolescents' alcohol use trajectories throughout high school; ethnicity was examined as a moderator. Ninth-grade low-income adolescents (N = 364; Mage = 15.08; 52.5% Caucasian; 25.8% African American; 21.7% Latino) completed sociometric nominations of peer status and aggression at baseline, and reported their alcohol use every 6 months. After controlling for gender, aggression, ethnicity, and socioeconomic status, popularity-but not likability-prospectively predicted alcohol use trajectories. However, these effects were moderated by ethnicity, suggesting popularity as a risk factor for alcohol use probability and frequency among Caucasian and Latino, but not African American adolescents. Results suggest that developmental correlates of peer status should be considered within cultural context. © 2015 The Authors. Child Development © 2015 Society for Research in Child Development, Inc.
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Using simplified Chaos Theory to manage nursing services.
Haigh, Carol A
2008-04-01
The purpose of this study was to evaluate the part simplified chaos theory could play in the management of nursing services. As nursing care becomes more complex, practitioners need to become familiar with business planning and objective time management. There are many time-limited methods that facilitate this type of planning but few that can help practitioners to forecast the end-point outcome of the service they deliver. A growth model was applied to a specialist service to plot service trajectory. Components of chaos theory can play a role in forecasting service outcomes and consequently the impact upon the management of such services. The ability to (1) track the trajectory of a service and (2) manipulate that trajectory by introducing new variables can allow managers to forward plan for service development and to evaluate the effectiveness of a service by plotting its end-point state.
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NASA Technical Reports Server (NTRS)
Miele, A.; Wang, T.; Lee, W. Y.; Zhao, Z. G.
1989-01-01
The determination of optimal trajectories for the aero-assisted flight experiment (AFE) is investigated. The intent of this experiment is to simulate a GEO-to-LEO transfer, where GEO denotes a geosynchronous Earth orbit and LEO denotes a low Earth orbit. The trajectories of an AFE spacecraft are analyzed in a 3D-space, employing the full system of 6 ODEs describing the atmospheric pass. The atmospheric entry conditions are given, and the atmospheric exit conditions are adjusted in such a way that the following conditions are satisfied: (1) the atmospheric velocity depletion is such that, after exiting, the AFE spacecraft first ascends to a specified apogee and then descends to a specified perigee; and (2) the exit orbital plane is identical with the entry orbital plane. The final maneuver, not analyzed here, includes the rendezvous with and the capture by the space shuttle.
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Angel, Caroline M
2016-12-01
As part of the "Joining Forces" Initiative ("JFI"), the White House and nursing leaders announced nurses' commitment to recognize symptoms, provide care, and refer veterans and active duty military members for post-traumatic stress disorder ("PTSD"). The JFI is positioned to save lives through nursing education and raising PTSD awareness. Nurses should also be educated to recognize resilience (stable trajectory of healthy functioning across time following a traumatic event) and assess for post-traumatic growth ("PTG") (positive meaning making) alongside PTSD. In veterans who do develop PTSD, nearly three fourths of them with moderate PTSD will also experience PTG. Nurses' frontline contact with veterans in the VA, private sector healthcare settings, and community enable them to educate veterans and active duty military members about these coping trajectories. Copyright © 2016 Elsevier Ltd. All rights reserved.
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Geometric diffusion of quantum trajectories
Yang, Fan; Liu, Ren-Bao
2015-01-01
A quantum object can acquire a geometric phase (such as Berry phases and Aharonov–Bohm phases) when evolving along a path in a parameter space with non-trivial gauge structures. Inherent to quantum evolutions of wavepackets, quantum diffusion occurs along quantum trajectories. Here we show that quantum diffusion can also be geometric as characterized by the imaginary part of a geometric phase. The geometric quantum diffusion results from interference between different instantaneous eigenstate pathways which have different geometric phases during the adiabatic evolution. As a specific example, we study the quantum trajectories of optically excited electron-hole pairs in time-reversal symmetric insulators, driven by an elliptically polarized terahertz field. The imaginary geometric phase manifests itself as elliptical polarization in the terahertz sideband generation. The geometric quantum diffusion adds a new dimension to geometric phases and may have applications in many fields of physics, e.g., transport in topological insulators and novel electro-optical effects. PMID:26178745
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ERIC Educational Resources Information Center
Tomlinson, Jennifer
2006-01-01
This paper examines the apparently paradoxical notion that women "choose" part-time work when it is consistently documented as being less preferential in employment terms, conditions and prospects when compared to full-time work. Forming a dialogue with Hakim's (2000) preference theory, it is proposed here that four dimensions--care…
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NASA Technical Reports Server (NTRS)
Young, J. W.; Goode, M. W.
1962-01-01
A simulation study has been made to determine a pilot's ability to control a low L/D vehicle to a desired point on the earth with initial conditions ranging from parabolic orbits to abort conditions along the boost phase of a deep-space mission. The program was conducted to develop procedures which would allow the pilot to perform the energy management functions required while avoiding the high deceleration or skipout region and to determine the information display required to aid the pilot in flying these procedures. The abort conditions studied extend from a region of relatively high flight-path angles at suborbital velocities while leaving the atmosphere to a region between orbital and near-escape velocity outside the atmosphere. The conditions studied included guidance from suborbital and superorbital aborts as well as guidance following return from a deepspace mission. In this paper, the role of the human pilot?s ability to combine safe return abort procedures with guidance procedures has been investigated. The range capability from various abort and entry conditions is also presented.
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NASA Technical Reports Server (NTRS)
Grey, J. (Editor); Krop, C.
1979-01-01
Papers are presented on the various technological, political, economic, environmental and social aspects of large manufacturing facilities in space. Specific topics include the potential global market for satellite solar power stations in 2025, the electrostatic separation of lunar soil, methods for extraterrestrial materials processing, the socio-political status of efforts toward the development of space manufacturing facilities, the financing of space industrialization, the optimization of space manufacturing systems, the design and project status of Mass Driver Two, and the use of laser-boosted lighter-than-air-vehicles as heavy-lift launch vehicles. Attention is also given to systems integration in the development of controlled ecological life support systems, the design of a space manufacturing facility to use lunar materials, high performance solar sails, the environmental effects of the satellite power system reference design, the guidance, trajectory and capture of lunar materials ejected from the moon by mass driver, the relative design merits of zero-gravity and one-gravity space environments, consciousness alteration in space and the prospecting and retrieval of asteroids.
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A digital prediction algorithm for a single-phase boost PFC
NASA Astrophysics Data System (ADS)
Qing, Wang; Ning, Chen; Weifeng, Sun; Shengli, Lu; Longxing, Shi
2012-12-01
A novel digital control algorithm for digital control power factor correction is presented, which is called the prediction algorithm and has a feature of a higher PF (power factor) with lower total harmonic distortion, and a faster dynamic response with the change of the input voltage or load current. For a certain system, based on the current system state parameters, the prediction algorithm can estimate the track of the output voltage and the inductor current at the next switching cycle and get a set of optimized control sequences to perfectly track the trajectory of input voltage. The proposed prediction algorithm is verified at different conditions, and computer simulation and experimental results under multi-situations confirm the effectiveness of the prediction algorithm. Under the circumstances that the input voltage is in the range of 90-265 V and the load current in the range of 20%-100%, the PF value is larger than 0.998. The startup and the recovery times respectively are about 0.1 s and 0.02 s without overshoot. The experimental results also verify the validity of the proposed method.
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Rocket-Induced Magnetohydrodynamic Ejector: A Single-Stage-to-Orbit Advanced Propulsion Concept
NASA Technical Reports Server (NTRS)
Cole, John; Campbell, Jonathan; Robertson, Anthony
1995-01-01
During the atmospheric boost phase of a rocket trajectory, magnetohydrodynamic (MHD) principles can be utilized to augment the thrust by several hundred percent without the input of additional energy. The concept is an MHD implementation of a thermodynamic ejector. Some ejector history is described and some test data showing the impressive thrust augmentation capabilities of thermodynamic ejectors are provided. A momentum and energy balance is used to derive the equations to predict the MHD ejector performance. Results of these equations are compared with the test data and then applied to a specific performance example. The rocket-induced MHD ejector (RIME) engine is described and a status of the technology and availability of the engine components is provided. A top level vehicle sizing analysis is performed by scaling existing MHD designs to the required flight vehicle levels. The vehicle can achieve orbit using conservative technology. Modest improvements are suggested using recently developed technologies, such as superconducting magnets, which can improve predicted performance well beyond those expected for current single-stage-to-orbit (SSTO) designs.
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Interplay between topological phase and self-acceleration in a vortex symmetric Airy beam.
Fang, Zhao-Xiang; Chen, Yue; Ren, Yu-Xuan; Gong, Lei; Lu, Rong-De; Zhang, An-Qi; Zhao, Hong-Ze; Wang, Pei
2018-03-19
Photons in an optical vortex usually carry orbital angular momentum, which boosts the application of the micro-rotation of absorbing particles and quantum information encoding. Such photons propagate along a straight line in free space or follow a curved trace once guided by an optical fiber. Teleportation of an optical vortex using a beam with non-diffraction and self-healing is quite challenging. We demonstrate the manipulation of the propagation trace of an optical vortex with a symmetric Airy beam (SAB) and found that the SAB experiences self-rotation with the implementation of a topological phase structure of coaxial vortex. Slight misalignment of the vortex and the SAB enables the guiding of the vortex into one of the self-accelerating channels. Multiple off-axis vortices embedded in SAB are also demonstrated to follow the trajectory of the major lobe for the SAB beam. The Poynting vector for the beams proves the direction of the energy flow corresponding to the intensity distribution. Hence, we anticipate that the proposed vortex symmetric Airy beam (VSAB) will provide new possibilities for optical manipulation and optical communication.
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Marine reserves can mitigate and promote adaptation to climate change
Roberts, Callum M.; O’Leary, Bethan C.; McCauley, Douglas J.; Cury, Philippe Maurice; Duarte, Carlos M.; Lubchenco, Jane; Pauly, Daniel; Sáenz-Arroyo, Andrea; Sumaila, Ussif Rashid; Wilson, Rod W.; Worm, Boris; Castilla, Juan Carlos
2017-01-01
Strong decreases in greenhouse gas emissions are required to meet the reduction trajectory resolved within the 2015 Paris Agreement. However, even these decreases will not avert serious stress and damage to life on Earth, and additional steps are needed to boost the resilience of ecosystems, safeguard their wildlife, and protect their capacity to supply vital goods and services. We discuss how well-managed marine reserves may help marine ecosystems and people adapt to five prominent impacts of climate change: acidification, sea-level rise, intensification of storms, shifts in species distribution, and decreased productivity and oxygen availability, as well as their cumulative effects. We explore the role of managed ecosystems in mitigating climate change by promoting carbon sequestration and storage and by buffering against uncertainty in management, environmental fluctuations, directional change, and extreme events. We highlight both strengths and limitations and conclude that marine reserves are a viable low-tech, cost-effective adaptation strategy that would yield multiple cobenefits from local to global scales, improving the outlook for the environment and people into the future. PMID:28584096
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Marine reserves can mitigate and promote adaptation to climate change.
Roberts, Callum M; O'Leary, Bethan C; McCauley, Douglas J; Cury, Philippe Maurice; Duarte, Carlos M; Lubchenco, Jane; Pauly, Daniel; Sáenz-Arroyo, Andrea; Sumaila, Ussif Rashid; Wilson, Rod W; Worm, Boris; Castilla, Juan Carlos
2017-06-13
Strong decreases in greenhouse gas emissions are required to meet the reduction trajectory resolved within the 2015 Paris Agreement. However, even these decreases will not avert serious stress and damage to life on Earth, and additional steps are needed to boost the resilience of ecosystems, safeguard their wildlife, and protect their capacity to supply vital goods and services. We discuss how well-managed marine reserves may help marine ecosystems and people adapt to five prominent impacts of climate change: acidification, sea-level rise, intensification of storms, shifts in species distribution, and decreased productivity and oxygen availability, as well as their cumulative effects. We explore the role of managed ecosystems in mitigating climate change by promoting carbon sequestration and storage and by buffering against uncertainty in management, environmental fluctuations, directional change, and extreme events. We highlight both strengths and limitations and conclude that marine reserves are a viable low-tech, cost-effective adaptation strategy that would yield multiple cobenefits from local to global scales, improving the outlook for the environment and people into the future.
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Conceptual design of an ascent-phase interceptor missile
DOE Office of Scientific and Technical Information (OSTI.GOV)
Salguero, D E
1994-11-01
A conceptual design for an air-launched interceptor missile to defend against theater ballistic missiles is presented. The missile is designed to intercept the target while ascending, during Or just after the boost phase, before it reaches exo-atmospheric flight. The interceptor consists of a two-stage booster and a shrouded kinetic-kill vehicle. This report concentrates on the booster design required to achieve reasonable standoff ranges. The kinetic-kill vehicle and shroud (the payload) is assumed to weigh 80 lb{sub m} (36 kg) and assumed to contain guidance computers for both the kill vehicle and the booster. The interceptor missile is about 6 mmore » long, .48 m in diameter and weighs about 900 kg. Allowing 25 sec for target detection, trajectory estimation, and interceptor launch, it can intercept 90 sec after target launch from a 220 km stand-off range at an altitude of 60 km. Trade-off studies show that the interceptor performance is most sensitive to the stage mass fractions (with the first-stage mass fraction the most important), the first-stage burn time and the payload weight.« less
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Optimizing the feedback control of Galvo scanners for laser manufacturing systems
NASA Astrophysics Data System (ADS)
Mirtchev, Theodore; Weeks, Robert; Minko, Sergey
2010-06-01
This paper summarizes the factors that limit the performance of moving-magnet galvo scanners driven by closed-loop digital servo amplifiers: torsional resonances, drifts, nonlinearities, feedback noise and friction. Then it describes a detailed Simulink® simulator that takes into account these factors and can be used to automatically tune the controller for best results with given galvo type and trajectory patterns. It allows for rapid testing of different control schemes, for instance combined position/velocity PID loops and displays the corresponding output in terms of torque, angular position and feedback sensor signal. The tool is configurable and can either use a dynamical state-space model of galvo's open-loop response, or can import the experimentally measured frequency domain transfer function. Next a drive signal digital pre-filtering technique is discussed. By performing a real-time Fourier analysis of the raw command signal it can be pre-warped to minimize all harmonics around the torsional resonances while boosting other non-resonant high frequencies. The optimized waveform results in much smaller overshoot and better settling time. Similar performance gain cannot be extracted from the servo controller alone.
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Modeling and Analysis of Power Processing Systems (MAPPS). Volume 2: Appendices
NASA Technical Reports Server (NTRS)
Lee, F. C.; Radman, S.; Carter, R. A.; Wu, C. H.; Yu, Y.; Chang, R.
1980-01-01
The computer programs and derivations generated in support of the modeling and design optimization program are presented. Programs for the buck regulator, boost regulator, and buck-boost regulator are described. The computer program for the design optimization calculations is presented. Constraints for the boost and buck-boost converter were derived. Derivations of state-space equations and transfer functions are presented. Computer lists for the converters are presented, and the input parameters justified.
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Effect of pole zero location on system dynamics of boost converter for micro grid
NASA Astrophysics Data System (ADS)
Lavanya, A.; Vijayakumar, K.; Navamani, J. D.; Jayaseelan, N.
2018-04-01
Green clean energy like photo voltaic, wind energy, fuel cell can be brought together by microgrid.For low voltage sources like photovoltaic cell boost converter is very much essential. This paper explores the dynamic analysis of boost converter in a continuous conduction mode (CCM). The transient performance and stability analysis is carried out in this paper using time domain analysis and frequency domain analysis techniques. Boost converter is simulated using both PSIM and MATLAB software. Furthermore, state space model obtained and the transfer function is derived. The converter behaviour when a step input is applied is analyzed and stability of the converter is analyzed from bode plot frequency for open loop. Effect of the locations of poles and zeros in the transfer function of boost converter and how the performance parameters are affected is discussed in this paper. Closed loop performance with PI controller is also analyzed for boost converter.
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Modeling the effect of boost timing in murine irradiated sporozoite prime-boost vaccines
Zhang, Min; Herrero, Miguel A.; Acosta, Francisco J.; Tsuji, Moriya
2018-01-01
Vaccination with radiation-attenuated sporozoites has been shown to induce CD8+ T cell-mediated protection against pre-erythrocytic stages of malaria. Empirical evidence suggests that successive inoculations often improve the efficacy of this type of vaccines. An initial dose (prime) triggers a specific cellular response, and subsequent inoculations (boost) amplify this response to create a robust CD8+ T cell memory. In this work we propose a model to analyze the effect of T cell dynamics on the performance of prime-boost vaccines. This model suggests that boost doses and timings should be selected according to the T cell response elicited by priming. Specifically, boosting during late stages of clonal contraction would maximize T cell memory production for vaccines using lower doses of irradiated sporozoites. In contrast, single-dose inoculations would be indicated for higher vaccine doses. Experimental data have been obtained that support theoretical predictions of the model. PMID:29329308
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UAV Trajectory Modeling Using Neural Networks
NASA Technical Reports Server (NTRS)
Xue, Min
2017-01-01
Large amount of small Unmanned Aerial Vehicles (sUAVs) are projected to operate in the near future. Potential sUAV applications include, but not limited to, search and rescue, inspection and surveillance, aerial photography and video, precision agriculture, and parcel delivery. sUAVs are expected to operate in the uncontrolled Class G airspace, which is at or below 500 feet above ground level (AGL), where many static and dynamic constraints exist, such as ground properties and terrains, restricted areas, various winds, manned helicopters, and conflict avoidance among sUAVs. How to enable safe, efficient, and massive sUAV operations at the low altitude airspace remains a great challenge. NASA's Unmanned aircraft system Traffic Management (UTM) research initiative works on establishing infrastructure and developing policies, requirement, and rules to enable safe and efficient sUAVs' operations. To achieve this goal, it is important to gain insights of future UTM traffic operations through simulations, where the accurate trajectory model plays an extremely important role. On the other hand, like what happens in current aviation development, trajectory modeling should also serve as the foundation for any advanced concepts and tools in UTM. Accurate models of sUAV dynamics and control systems are very important considering the requirement of the meter level precision in UTM operations. The vehicle dynamics are relatively easy to derive and model, however, vehicle control systems remain unknown as they are usually kept by manufactures as a part of intellectual properties. That brings challenges to trajectory modeling for sUAVs. How to model the vehicle's trajectories with unknown control system? This work proposes to use a neural network to model a vehicle's trajectory. The neural network is first trained to learn the vehicle's responses at numerous conditions. Once being fully trained, given current vehicle states, winds, and desired future trajectory, the neural network should be able to predict the vehicle's future states at next time step. A complete 4-D trajectory are then generated step by step using the trained neural network. Experiments in this work show that the neural network can approximate the sUAV's model and predict the trajectory accurately.
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Appelt, Ane L; Vogelius, Ivan R; Pløen, John; Rafaelsen, Søren R; Lindebjerg, Jan; Havelund, Birgitte M; Bentzen, Søren M; Jakobsen, Anders
2014-01-01
Purpose/Objective(s) Mature data on tumor control and survival are presented from a randomized trial of the addition of a brachytherapy boost to long-course neoadjuvant chemoradiation (CRT) for locally advanced rectal cancer. Methods and Materials Between March 2005 and November 2008, 248 patients withT3-4N0-2M0 rectal cancer were prospectively randomized to either long-course preoperative CRT (50.4Gy in 28 fractions, peroral UFT and L-leucovorin) alone or the same CRT schedule plus a brachytherapy boost (10Gy in 2 fractions). Primary trial endpoint was pathological complete response (pCR) at time of surgery; secondary endpoints included overall survival (OS), progression-free survival (PFS) and freedom from locoregional failure. Results Results for the primary endpoint have previously been reported. This analysis presents survival data for the 224 patients in the Danish part of the trial. 221 patients (111 control arm, 110 brachytherapy boost arm) had data available for analysis, with a median follow-up of 5.4 years. Despite a significant increase in tumor response at the time of surgery, no differences in 5-year OS (70.6% vs 63.6%, HR=1.24, p=0.34) and PFS (63.9% vs 52.0%, HR=1.22, p=0.32) were observed. Freedom from locoregional failure at 5 years were 93.9% and 85.7% (HR=2.60, 1.00–6.73, p=0.06) in the standard and in the brachytherapy arm, respectively. There was no difference in the prevalence of stoma. Explorative analysis based on stratification for tumor regression grade and resection margin status indicated the presence of response migration. Conclusions Despite increased pathological tumor regression at the time of surgery, we observed no benefit on late outcome. Improved tumor regression does not necessarily lead to a relevant clinical benefit when the neoadjuvant treatment is followed by high-quality surgery. PMID:25015203
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NASA Astrophysics Data System (ADS)
Bagheri, Zahra M.; Cazzolato, Benjamin S.; Grainger, Steven; O'Carroll, David C.; Wiederman, Steven D.
2017-08-01
Objective. Many computer vision and robotic applications require the implementation of robust and efficient target-tracking algorithms on a moving platform. However, deployment of a real-time system is challenging, even with the computational power of modern hardware. Lightweight and low-powered flying insects, such as dragonflies, track prey or conspecifics within cluttered natural environments, illustrating an efficient biological solution to the target-tracking problem. Approach. We used our recent recordings from ‘small target motion detector’ neurons in the dragonfly brain to inspire the development of a closed-loop target detection and tracking algorithm. This model exploits facilitation, a slow build-up of response to targets which move along long, continuous trajectories, as seen in our electrophysiological data. To test performance in real-world conditions, we implemented this model on a robotic platform that uses active pursuit strategies based on insect behaviour. Main results. Our robot performs robustly in closed-loop pursuit of targets, despite a range of challenging conditions used in our experiments; low contrast targets, heavily cluttered environments and the presence of distracters. We show that the facilitation stage boosts responses to targets moving along continuous trajectories, improving contrast sensitivity and detection of small moving targets against textured backgrounds. Moreover, the temporal properties of facilitation play a useful role in handling vibration of the robotic platform. We also show that the adoption of feed-forward models which predict the sensory consequences of self-movement can significantly improve target detection during saccadic movements. Significance. Our results provide insight into the neuronal mechanisms that underlie biological target detection and selection (from a moving platform), as well as highlight the effectiveness of our bio-inspired algorithm in an artificial visual system.
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Gutíerrez, Alonso N; Deveau, Michael; Forrest, Lisa J; Tomé, Wolfgang A; Mackie, Thomas R
2007-01-01
Feasibility of delivering a simultaneously integrated boost to canine nasal tumors using helical tomotherapy to improve tumor control probability (TCP) via an increase in total biological equivalent uniform dose (EUD) was evaluated. Eight dogs with varying size nasal tumors (5.8-110.9 cc) were replanned to 42 Gy to the nasal cavity and integrated dose boosts to gross disease of 45.2, 48.3, and 51.3 Gy in 10 fractions. EUD values were calculated for tumors and mean normalized total doses (NTD(mean)) for organs at risk (OAR). Normal Tissue Complication Probability (NTCP) values were obtained for OARs, and estimated TCP values were computed using a logistic dose-response model and based on deliverable EUD boost doses. Significant increases in estimated TCP to 54%, 74%, and 86% can be achieved with 10%, 23%, and 37% mean relative EUD boosts to the gross disease, respectively. NTCP values for blindness of either eye and for brain necrosis were < 0.01% for all boosts. Values for cataract development were 31%, 42%, and 46% for studied boost schemas, respectively. Average NTD(mean) to eyes and brain for mean EUD boosts were 10.2, 11.3, and 12.1 Gy3, and 7.5, 7.2, and 7.9 Gy2, respectively. Using helical tomotherapy, simultaneously integrated dose boosts can be delivered to increase the estimated TCP at 1-year without significantly increasing the NTD(mean) to eyes and brain. Delivery of these treatments in a prospective trial may allow quantification of a dose-response relationship in canine nasal tumors.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Murphy, Colin; Anderson, Penny R.; Li Tianyu
Purpose: We examined the impact of radiation tumor bed boost parameters in early-stage breast cancer on local control and cosmetic outcomes. Methods and Materials: A total of 3,186 women underwent postlumpectomy whole-breast radiation with a tumor bed boost for Tis to T2 breast cancer from 1970 to 2008. Boost parameters analyzed included size, energy, dose, and technique. Endpoints were local control, cosmesis, and fibrosis. The Kaplan-Meier method was used to estimate actuarial incidence, and a Cox proportional hazard model was used to determine independent predictors of outcomes on multivariate analysis (MVA). The median follow-up was 78 months (range, 1-305 months).more » Results: The crude cosmetic results were excellent in 54%, good in 41%, and fair/poor in 5% of patients. The 10-year estimate of an excellent cosmesis was 66%. On MVA, independent predictors for excellent cosmesis were use of electron boost, lower electron energy, adjuvant systemic therapy, and whole-breast IMRT. Fibrosis was reported in 8.4% of patients. The actuarial incidence of fibrosis was 11% at 5 years and 17% at 10 years. On MVA, independent predictors of fibrosis were larger cup size and higher boost energy. The 10-year actuarial local failure was 6.3%. There was no significant difference in local control by boost method, cut-out size, dose, or energy. Conclusions: Likelihood of excellent cosmesis or fibrosis are associated with boost technique, electron energy, and cup size. However, because of high local control and rare incidence of fair/poor cosmesis with a boost, the anatomy of the patient and tumor cavity should ultimately determine the necessary boost parameters.« less
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van der Laan, Hans Paul; Dolsma, Wil V; Maduro, John H; Korevaar, Erik W; Hollander, Miranda; Langendijk, Johannes A
2007-07-15
To compare the target coverage and normal tissue dose with the simultaneously integrated boost (SIB) and the sequential boost technique in breast cancer, and to evaluate the incidence of acute skin toxicity in patients treated with the SIB technique. Thirty patients with early-stage left-sided breast cancer underwent breast-conserving radiotherapy using the SIB technique. The breast and boost planning target volumes (PTVs) were treated simultaneously (i.e., for each fraction, the breast and boost PTVs received 1.81 Gy and 2.3 Gy, respectively). Three-dimensional conformal beams with wedges were shaped and weighted using forward planning. Dose-volume histograms of the PTVs and organs at risk with the SIB technique, 28 x (1.81 + 0.49 Gy), were compared with those for the sequential boost technique, 25 x 2 Gy + 8 x 2 Gy. Acute skin toxicity was evaluated for 90 patients treated with the SIB technique according to Common Terminology Criteria for Adverse Events, version 3.0. PTV coverage was adequate with both techniques. With SIB, more efficiently shaped boost beams resulted in smaller irradiated volumes. The mean volume receiving > or =107% of the breast dose was reduced by 20%, the mean volume outside the boost PTV receiving > or =95% of the boost dose was reduced by 54%, and the mean heart and lung dose were reduced by 10%. Of the evaluated patients, 32.2% had Grade 2 or worse toxicity. The SIB technique is proposed for standard use in breast-conserving radiotherapy because of its dose-limiting capabilities, easy implementation, reduced number of treatment fractions, and relatively low incidence of acute skin toxicity.
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WE-AB-202-10: Modelling Individual Tumor-Specific Control Probability for Hypoxia in Rectal Cancer
DOE Office of Scientific and Technical Information (OSTI.GOV)
Warren, S; Warren, DR; Wilson, JM
Purpose: To investigate hypoxia-guided dose-boosting for increased tumour control and improved normal tissue sparing using FMISO-PET images Methods: Individual tumor-specific control probability (iTSCP) was calculated using a modified linear-quadratic model with rectal-specific radiosensitivity parameters for three limiting-case assumptions of the hypoxia / FMISO uptake relationship. {sup 18}FMISO-PET images from 2 patients (T3N0M0) from the RHYTHM trial (Investigating Hypoxia in Rectal Tumours NCT02157246) were chosen to delineate a hypoxic region (GTV-MISO defined as tumor-to-muscle ratio > 1.3) within the anatomical GTV. Three VMAT treatment plans were created in Eclipse (Varian): STANDARD (45Gy / 25 fractions to PTV4500); BOOST-GTV (simultaneous integrated boostmore » of 60Gy / 25fr to GTV +0.5cm) and BOOST-MISO (60Gy / 25fr to GTV-MISO+0.5cm). GTV mean dose (in EQD2), iTSCP and normal tissue dose-volume metrics (small bowel, bladder, anus, and femoral heads) were recorded. Results: Patient A showed small hypoxic volume (15.8% of GTV) and Patient B moderate hypoxic volume (40.2% of GTV). Dose escalation to 60Gy was achievable, and doses to femoral heads and small bowel in BOOST plans were comparable to STANDARD plans. For patient A, a reduced maximum bladder dose was observed in BOOST-MISO compared to BOOST-GTV (D0.1cc 49.2Gy vs 54.0Gy). For patient B, a smaller high dose volume was observed for the anus region in BOOST-MISO compared to BOOST-GTV (V55Gy 19.9% vs 100%), which could potentially reduce symptoms of fecal incontinence. For BOOST-MISO, the largest iTSCPs (A: 95.5% / B: 90.0%) assumed local correlation between FMISO uptake and hypoxia, and approached iTSCP values seen for BOOST-GTV (A: 96.1% / B: 90.5%). Conclusion: Hypoxia-guided dose-boosting is predicted to improve local control in rectal tumors when FMISO is spatially correlated to hypoxia, and to reduce dose to organs-at-risk compared to boosting the whole GTV. This could lead to organ-preserving treatment strategies for locally-advanced rectal cancer, thereby improving quality of life. Oxford Cancer Imaging Centre (OCIC); Cancer Research UK (CRUK); Medical Research Council (MRC)« less
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Boosting Learning Algorithm for Stock Price Forecasting
NASA Astrophysics Data System (ADS)
Wang, Chengzhang; Bai, Xiaoming
2018-03-01
To tackle complexity and uncertainty of stock market behavior, more studies have introduced machine learning algorithms to forecast stock price. ANN (artificial neural network) is one of the most successful and promising applications. We propose a boosting-ANN model in this paper to predict the stock close price. On the basis of boosting theory, multiple weak predicting machines, i.e. ANNs, are assembled to build a stronger predictor, i.e. boosting-ANN model. New error criteria of the weak studying machine and rules of weights updating are adopted in this study. We select technical factors from financial markets as forecasting input variables. Final results demonstrate the boosting-ANN model works better than other ones for stock price forecasting.
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Inelastic Boosted Dark Matter at direct detection experiments
NASA Astrophysics Data System (ADS)
Giudice, Gian F.; Kim, Doojin; Park, Jong-Chul; Shin, Seodong
2018-05-01
We explore a novel class of multi-particle dark sectors, called Inelastic Boosted Dark Matter (iBDM). These models are constructed by combining properties of particles that scatter off matter by making transitions to heavier states (Inelastic Dark Matter) with properties of particles that are produced with a large Lorentz boost in annihilation processes in the galactic halo (Boosted Dark Matter). This combination leads to new signals that can be observed at ordinary direct detection experiments, but require unconventional searches for energetic recoil electrons in coincidence with displaced multi-track events. Related experimental strategies can also be used to probe MeV-range boosted dark matter via their interactions with electrons inside the target material.
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NASA Astrophysics Data System (ADS)
Favaro, Alberto; Lad, Akash; Formenti, Davide; Zani, Davide Danilo; De Momi, Elena
2017-03-01
In a translational neuroscience/neurosurgery perspective, sheep are considered good candidates to study because of the similarity between their brain and the human one. Automatic planning systems for safe keyhole neurosurgery maximize the probe/catheter distance from vessels and risky structures. This work consists in the development of a trajectories planner for straight catheters placement intended to be used for investigating the drug diffusivity mechanisms in sheep brain. Automatic brain segmentation of gray matter, white matter and cerebrospinal fluid is achieved using an online available sheep atlas. Ventricles, midbrain and cerebellum segmentation have been also carried out. The veterinary surgeon is asked to select a target point within the white matter to be reached by the probe and to define an entry area on the brain cortex. To mitigate the risk of hemorrhage during the insertion process, which can prevent the success of the insertion procedure, the trajectory planner performs a curvature analysis of the brain cortex and wipes out from the poll of possible entry points the sulci, as part of brain cortex where superficial blood vessels are naturally located. A limited set of trajectories is then computed and presented to the surgeon, satisfying an optimality criteria based on a cost function which considers the distance from critical brain areas and the whole trajectory length. The planner proved to be effective in defining rectilinear trajectories accounting for the safety constraints determined by the brain morphology. It also demonstrated a short computational time and good capability in segmenting gyri and sulci surfaces.
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Ramsey, Rachelle R; Loiselle, Kristin; Rausch, Joseph R; Harrison, Jordan; Modi, Avani C
2016-04-01
The objective of this study was to identify two-year trajectories of epilepsy-specific health-related quality of life (HRQOL) among children newly diagnosed with epilepsy and to evaluate the predictive value of a comprehensive set of medical, psychosocial, and family factors. Ninety-four children with epilepsy (8.14 ± 2.37 years of age and 63% male) and their caregivers participated in this study. Caregivers completed the Quality of Life in Childhood Epilepsy Questionnaire (QOLCE) and measures of psychological and family functioning at one month postdiagnosis. The QOLCE was also given at eight additional time points during the subsequent two years as a part of a large observational study in children with epilepsy. Adherence data were collected via MEMS TrackCaps, and medical information was collected through chart review. Unique trajectories were identified for the overall QOLCE scale, as well as the subscales. Most trajectory models for the QOLCE subscales contained at least one at-risk trajectory for children, indicating that there is a subgroup of children experiencing poor long-term HRQOL. Health-related quality-of-life trajectories remained predominantly stable during the two-year period following treatment initiation. The number of AEDs, internalizing problems, and externalizing problems emerged as the most consistent predictors across the HRQOL domains. Medical and psychosocial interventions, such as cognitive-behavioral strategies, should target modifiable factors (e.g., internalizing symptoms, externalizing symptoms, number of AEDs trialed) shortly after diagnosis to improve HRQOL for children with epilepsy over the course of their disease. Copyright © 2016 Elsevier Inc. All rights reserved.
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Self-esteem development across the life span: a longitudinal study with a large sample from Germany.
Orth, Ulrich; Maes, Jürgen; Schmitt, Manfred
2015-02-01
The authors examined the development of self-esteem across the life span. Data came from a German longitudinal study with 3 assessments across 4 years of a sample of 2,509 individuals ages 14 to 89 years. The self-esteem measure used showed strong measurement invariance across assessments and birth cohorts. Latent growth curve analyses indicated that self-esteem follows a quadratic trajectory across the life span, increasing during adolescence, young adulthood, and middle adulthood, reaching a peak at age 60 years, and then declining in old age. No cohort effects on average levels of self-esteem or on the shape of the trajectory were found. Moreover, the trajectory did not differ across gender, level of education, or for individuals who had lived continuously in West versus East Germany (i.e., the 2 parts of Germany that had been separate states from 1949 to 1990). However, the results suggested that employment status, household income, and satisfaction in the domains of work, relationships, and health contribute to a more positive life span trajectory of self-esteem. The findings have significant implications, because they call attention to developmental stages in which individuals may be vulnerable because of low self-esteem (such as adolescence and old age) and to factors that predict successful versus problematic developmental trajectories. PsycINFO Database Record (c) 2015 APA, all rights reserved.
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Crocker, Anne G; Charette, Yanick; Seto, Michael C; Nicholls, Tonia L; Côté, Gilles; Caulet, Malijai
2015-01-01
Objective: To examine the processing and Review Board (RB) disposition outcomes of people found not criminally responsible on account of mental disorder (NCRMD) across the 3 most populous provinces in Canada. Although the Criminal Code is federally legislated, criminal justice is administered by provinces and territories. It follows that a person with mental illness who comes into conflict with the law and subsequently comes under the management of a legally mandated RB may experience different trajectories across jurisdictions. Method: The National Trajectory Project examined 1800 men and women found NCRMD in British Columbia (n = 222), Quebec (n = 1094), and Ontario (n = 484) between May 2000 and April 2005, followed until December 2008. Results: We found significant interprovincial differences in the trajectories of people found NCRMD, including time detained in hospital and time under the supervision of an RB. The odds of being conditionally or absolutely discharged by the RB varied across provinces, even after number of past offences, diagnosis at verdict, and most severe index offence (all covariates decreased likelihood of discharge) were considered. Conclusions: Considerable discrepancies in the application of NCRMD legislation and the processing of NCRMD cases through the forensic system across the provinces suggests that fair and equitable treatment under the law could be enhanced by increased national integration and collaboration. PMID:25886687
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Ares-I-X Vehicle Preliminary Range Safety Malfunction Turn Analysis
NASA Technical Reports Server (NTRS)
Beaty, James R.; Starr, Brett R.; Gowan, John W., Jr.
2008-01-01
Ares-I-X is the designation given to the flight test version of the Ares-I rocket (also known as the Crew Launch Vehicle - CLV) being developed by NASA. As part of the preliminary flight plan approval process for the test vehicle, a range safety malfunction turn analysis was performed to support the launch area risk assessment and vehicle destruct criteria development processes. Several vehicle failure scenarios were identified which could cause the vehicle trajectory to deviate from its normal flight path, and the effects of these failures were evaluated with an Ares-I-X 6 degrees-of-freedom (6-DOF) digital simulation, using the Program to Optimize Simulated Trajectories Version 2 (POST2) simulation framework. The Ares-I-X simulation analysis provides output files containing vehicle state information, which are used by other risk assessment and vehicle debris trajectory simulation tools to determine the risk to personnel and facilities in the vicinity of the launch area at Kennedy Space Center (KSC), and to develop the vehicle destruct criteria used by the flight test range safety officer. The simulation analysis approach used for this study is described, including descriptions of the failure modes which were considered and the underlying assumptions and ground rules of the study, and preliminary results are presented, determined by analysis of the trajectory deviation of the failure cases, compared with the expected vehicle trajectory.
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Metcalfe, Hannah J; Biffar, Lucia; Steinbach, Sabine; Guzman, Efrain; Connelley, Tim; Morrison, Ivan; Vordermeier, H Martin; Villarreal-Ramos, Bernardo
2018-05-11
There is a need to improve the efficacy of the BCG vaccine against human and bovine tuberculosis. Previous data showed that boosting bacilli Calmette-Guerin (BCG)-vaccinated cattle with a recombinant attenuated human type 5 adenovirally vectored subunit vaccine (Ad5-85A) increased BCG protection and was associated with increased frequency of Ag85A-specific CD4 + T cells post-boosting. Here, the capacity of Ag85A-specific CD4 + T cell lines - derived before and after viral boosting - to interact with BCG-infected macrophages was evaluated. No difference before and after boosting was found in the capacity of these Ag85A-specific CD4 + T cell lines to restrict mycobacterial growth, but the secretion of IL-10 in vitro post-boost increased significantly. Furthermore, cell lines derived post-boost had no statistically significant difference in the secretion of pro-inflammatory cytokines (IL-1β, IL-12, IFNγ or TNFα) compared to pre-boost lines. In conclusion, the protection associated with the increased number of Ag85A-specific CD4 + T cells restricting mycobacterial growth may be associated with anti-inflammatory properties to limit immune-pathology. Copyright © 2018 Department for Environment Food and Rural Affairs. Published by Elsevier Ltd.. All rights reserved.
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Climate and Lightning: An updated TRMM-LIS Analysis
NASA Technical Reports Server (NTRS)
Petersen, Walter A.; Buechler, D. E.
2009-01-01
The TRMM Lightning Imaging Sensor (LIS) has sampled global tropical and sub-tropical lightning flash densities for approximately 11 years. These data were originally processed and results presented by the authors in the 3rd AMS MALD Conference held in 2007 using both pre and post TRMM-boost lightning data. These data were normalized for the orbit boost by scaling the pre-boost data by a fixed constant based on the different swath areas for the pre and post-boost years (post-boost after 2001). Inevitably, one must question this simple approach to accounting for the orbit boost when sampling such a noisy quantity. Hence we are in the process of reprocessing the entire 11-year TRMM LIS dataset to reduce the orbit swath of the post-boost era to that of the pre-boost in order to eliminate sampling bias in the dataset. Study of the diurnal/seasonal/annual sampling suggests that those biases are already minimal and should not contribute to error in examination of annual trends. We will present new analysis of the 11-year annual trends in total lightning flash density for all latitudinal belts and select regions/regimes of the tropics as related to conventional climate signals and precipitation contents in the same period. The results should enable us to address, in some fashion, the sensitivity of the lightning flash density to subtle changes in climate.
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NASA Technical Reports Server (NTRS)
Walsh, Ptrick; Coulon, Adam; Edwards, Stephen; Mavris, Dimitri N.
2012-01-01
The problem of trajectory optimization is important in all space missions. The solution of this problem enables one to specify the optimum thrust steering program which should be followed to achieve a specified mission objective, simultaneously satisfying the constraints.1 It is well known that whether or not the ascent trajectory is optimal can have a significant impact on propellant usage for a given payload, or on payload weight for the same gross vehicle weight.2 Consequently, ascent guidance commands are usually optimized in some fashion. Multi-stage vehicles add complexity to this analysis process as changes in vehicle properties in one stage propagate to the other stages through gear ratios and changes in the optimal trajectory. These effects can cause an increase in analysis time as more variables are added and convergence of the optimizer to system closure requires more analysis iterations. In this paper, an approach to simplifying this multi-stage problem through the creation of an upper stage capability boundary is presented. This work was completed as part of a larger study focused on trade space exploration for the advanced booster system that will eventually form a part of NASA s new Space Launch System.3 The approach developed leverages Design of Experiments and Surrogate Modeling4 techniques to create a predictive model of the SLS upper stage performance. The design of the SLS core stages is considered fixed for the purposes of this study, which results in trajectory parameters such as staging conditions being the only variables relevant to the upper stage. Through the creation of a surrogate model, which takes staging conditions as inputs and predicts the payload mass delivered by the SLS upper stage to a reference orbit as the response, it is possible to identify a "surface" of staging conditions which all satisfy the SLS requirement of placing 130 metric tons into low-Earth orbit (LEO).3 This identified surface represents the 130 metric ton capability boundary for the upper stage, such that if the combined first stage and boosters can achieve any one staging point on that surface, then the design is identified as feasible. With the surrogate model created, design and analysis of advanced booster concepts is streamlined, as optimization of the upper stage trajectory is no longer required in every design loop.
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Memari, Nogol; Ramli, Abd Rahman; Bin Saripan, M Iqbal; Mashohor, Syamsiah; Moghbel, Mehrdad
2017-01-01
The structure and appearance of the blood vessel network in retinal fundus images is an essential part of diagnosing various problems associated with the eyes, such as diabetes and hypertension. In this paper, an automatic retinal vessel segmentation method utilizing matched filter techniques coupled with an AdaBoost classifier is proposed. The fundus image is enhanced using morphological operations, the contrast is increased using contrast limited adaptive histogram equalization (CLAHE) method and the inhomogeneity is corrected using Retinex approach. Then, the blood vessels are enhanced using a combination of B-COSFIRE and Frangi matched filters. From this preprocessed image, different statistical features are computed on a pixel-wise basis and used in an AdaBoost classifier to extract the blood vessel network inside the image. Finally, the segmented images are postprocessed to remove the misclassified pixels and regions. The proposed method was validated using publicly accessible Digital Retinal Images for Vessel Extraction (DRIVE), Structured Analysis of the Retina (STARE) and Child Heart and Health Study in England (CHASE_DB1) datasets commonly used for determining the accuracy of retinal vessel segmentation methods. The accuracy of the proposed segmentation method was comparable to other state of the art methods while being very close to the manual segmentation provided by the second human observer with an average accuracy of 0.972, 0.951 and 0.948 in DRIVE, STARE and CHASE_DB1 datasets, respectively.
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Jet pump-drive system for heat removal
NASA Technical Reports Server (NTRS)
French, James R. (Inventor)
1987-01-01
The invention does away with the necessity of moving parts such as a check valve in a nuclear reactor cooling system. Instead, a jet pump, in combination with a TEMP, is employed to assure safe cooling of a nuclear reactor after shutdown. A main flow exists for a reactor coolant. A point of withdrawal is provided for a secondary flow. A TEMP, responsive to the heat from said coolant in the secondary flow path, automatically pumps said withdrawn coolant to a higher pressure and thus higher velocity compared to the main flow. The high velocity coolant is applied as a driver flow for the jet pump which has a main flow chamber located in the main flow circulation pump. Upon nuclear shutdown and loss of power for the main reactor pumping system, the TEMP/jet pump combination continues to boost the coolant flow in the direction it is already circulating. During the decay time for the nuclear reactor, the jet pump keeps running until the coolant temperature drops to a lower and safe temperature where the heat is no longer a problem. At this lower temperature, the TEMP/jet pump combination ceases its circulation boosting operation. When the nuclear reactor is restarted and the coolant again exceeds the lower temperature setting, the TEMP/jet pump automatically resumes operation. The TEMP/jet pump combination is thus automatic, self-regulating and provides an emergency pumping system free of moving parts.
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Genetic and management approaches to boost UK wheat yields by ameliorating water deficits.
Dodd, Ian C; Whalley, W R; Ober, Eric S; Parry, M A J
2011-11-01
Faced with the challenge of increasing global food production, there is the need to exploit all approaches to increasing crop yields. A major obstacle to boosting yields of wheat (an important staple in many parts of the world) is the availability and efficient use of water, since there is increasing stress on water resources used for agriculture globally, and also in parts of the UK. Improved soil and crop management and the development of new genotypes may increase wheat yields when water is limiting. Technical and scientific issues concerning management options such as irrigation and the use of growth-promoting rhizobacteria are explored, since these may allow the more efficient use of irrigation. Fundamental understanding of how crops sense and respond to multiple abiotic stresses can help improve the effective use of irrigation water. Experiments are needed to test the hypothesis that modifying wheat root system architecture (by increasing root proliferation deep in the soil profile) will allow greater soil water extraction thereby benefiting productivity and yield stability. Furthermore, better knowledge of plant and soil interactions and how below-ground and above-ground processes communicate within the plant can help identify traits and ultimately genes (or alleles) that will define genotypes that yield better under dry conditions. Developing new genotypes will take time and, therefore, these challenges need to be addressed now.
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NASA Astrophysics Data System (ADS)
Umansky, Moti; Weihs, Daphne
2012-08-01
In many physical and biophysical studies, single-particle tracking is utilized to reveal interactions, diffusion coefficients, active modes of driving motion, dynamic local structure, micromechanics, and microrheology. The basic analysis applied to those data is to determine the time-dependent mean-square displacement (MSD) of particle trajectories and perform time- and ensemble-averaging of similar motions. The motion of particles typically exhibits time-dependent power-law scaling, and only trajectories with qualitatively and quantitatively comparable MSD should be ensembled. Ensemble averaging trajectories that arise from different mechanisms, e.g., actively driven and diffusive, is incorrect and can result inaccurate correlations between structure, mechanics, and activity. We have developed an algorithm to automatically and accurately determine power-law scaling of experimentally measured single-particle MSD. Trajectories can then categorized and grouped according to user defined cutoffs of time, amplitudes, scaling exponent values, or combinations. Power-law fits are then provided for each trajectory alongside categorized groups of trajectories, histograms of power laws, and the ensemble-averaged MSD of each group. The codes are designed to be easily incorporated into existing user codes. We expect that this algorithm and program will be invaluable to anyone performing single-particle tracking, be it in physical or biophysical systems. Catalogue identifier: AEMD_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEMD_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 25 892 No. of bytes in distributed program, including test data, etc.: 5 572 780 Distribution format: tar.gz Programming language: MATLAB (MathWorks Inc.) version 7.11 (2010b) or higher, program should also be backwards compatible. Symbolic Math Toolboxes (5.5) is required. The Curve Fitting Toolbox (3.0) is recommended. Computer: Tested on Windows only, yet should work on any computer running MATLAB. In Windows 7, should be used as administrator, if the user is not the administrator the program may not be able to save outputs and temporary outputs to all locations. Operating system: Any supporting MATLAB (MathWorks Inc.) v7.11 / 2010b or higher. Supplementary material: Sample output files (approx. 30 MBytes) are available. Classification: 12 External routines: Several MATLAB subfunctions (m-files), freely available on the web, were used as part of and included in, this code: count, NaN suite, parseArgs, roundsd, subaxis, wcov, wmean, and the executable pdfTK.exe. Nature of problem: In many physical and biophysical areas employing single-particle tracking, having the time-dependent power-laws governing the time-averaged meansquare displacement (MSD) of a single particle is crucial. Those power laws determine the mode-of-motion and hint at the underlying mechanisms driving motion. Accurate determination of the power laws that describe each trajectory will allow categorization into groups for further analysis of single trajectories or ensemble analysis, e.g. ensemble and time-averaged MSD. Solution method: The algorithm in the provided program automatically analyzes and fits time-dependent power laws to single particle trajectories, then group particles according to user defined cutoffs. It accepts time-dependent trajectories of several particles, each trajectory is run through the program, its time-averaged MSD is calculated, and power laws are determined in regions where the MSD is linear on a log-log scale. Our algorithm searches for high-curvature points in experimental data, here time-dependent MSD. Those serve as anchor points for determining the ranges of the power-law fits. Power-law scaling is then accurately determined and error estimations of the parameters and quality of fit are provided. After all single trajectory time-averaged MSDs are fit, we obtain cutoffs from the user to categorize and segment the power laws into groups; cutoff are either in exponents of the power laws, time of appearance of the fits, or both together. The trajectories are sorted according to the cutoffs and the time- and ensemble-averaged MSD of each group is provided, with histograms of the distributions of the exponents in each group. The program then allows the user to generate new trajectory files with trajectories segmented according to the determined groups, for any further required analysis. Additional comments: README file giving the names and a brief description of all the files that make-up the package and clear instructions on the installation and execution of the program is included in the distribution package. Running time: On an i5 Windows 7 machine with 4 GB RAM the automated parts of the run (excluding data loading and user input) take less than 45 minutes to analyze and save all stages for an 844 trajectory file, including optional PDF save. Trajectory length did not affect run time (tested up to 3600 frames/trajectory), which was on average 3.2±0.4 seconds per trajectory.
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Pharmaceutical advertising and Medicare Part D.
Lakdawalla, Darius; Sood, Neeraj; Gu, Qian
2013-12-01
We explore how and to what extent prescription drug insurance expansions affect incentives for pharmaceutical advertising. When insurance expansions make markets more profitable, firms respond by boosting advertising. Theory suggests this effect will be magnified in the least competitive drug classes, where firms internalize a larger share of the benefits from advertising. Empirically, we find that the implementation of Part D coincides with a 14-19% increase in total advertising expenditures. This effect is indeed concentrated in the least competitive drug classes. The additional advertising raised utilization among non-elderly patients outside the Part D program by about 3.6%. This is roughly half of the direct utilization effect of Part D on elderly beneficiaries. The results suggest the presence of considerable spillover effects from publicly subsidized prescription drug insurance on the utilization and welfare of consumers outside the program. Copyright © 2013 Elsevier B.V. All rights reserved.
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Change in Seroma Volume During Whole-Breast Radiation Therapy
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sharma, Rajiv; Spierer, Marnee; Mutyala, Subhakar
2009-09-01
Purpose: After breast-conserving surgery, a seroma often forms in the surgical cavity. If not drained, it may affect the volume of tumor bed requiring a boost after whole-breast radiation therapy (WBRT). Our objective was to evaluate the change in seroma volume that occurs during WBRT, before boost planning. Methods and Materials: A retrospective review was performed of women receiving breast-conserving therapy with evidence of seroma at the time of WBRT planning. Computed tomography (CT) simulation was performed before WBRT and before the tumor bed boost. All patients received either a hypofractionated (42.4 Gy/16 fraction + 9.6 Gy/4 fraction boost) ormore » standard fractionated (50.4 Gy/28 fraction + 10 Gy/5 fraction boost) regimen. Seroma volumes were contoured and compared on CT at the time of WBRT simulation and tumor bed boost planning. Results: Twenty-four patients with evidence of seroma were identified and all patients received WBRT without drainage of the seroma. Mean seroma volume before WBRT and at boost planning were significantly different at 65.7 cm{sup 3} (SD, 50.5 cm{sup 3}) and 35.6 cm{sup 3} (SD, 24.8 cm{sup 3}), respectively (p < 0.001). Mean and median reduction in seroma volume during radiation were 39.6% (SD, 23.8%) and 46.2% (range, 10.7-76.7%), respectively. Fractionation schedule was not correlated with change in seroma volume. Length of time from surgery to start of radiation therapy showed an inverse correlation with change in seroma volume (Pearson correlation r = -0.53, p < 0.01). Conclusions: The volume of seroma changes significantly during WBRT. Consequently, the accuracy of breast boost planning is likely affected, as is the volume of normal breast tissue irradiated. CT-based boost planning before boost irradiation is suggested to ensure appropriate coverage.« less
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Santosuosso, Michael; McCormick, Sarah; Zhang, Xizhong; Zganiacz, Anna; Xing, Zhou
2006-08-01
Parenterally administered Mycobacterium bovis BCG vaccine confers only limited immune protection from pulmonary tuberculosis in humans. There is a need for developing effective boosting vaccination strategies. We examined a heterologous prime-boost regimen utilizing BCG as a prime vaccine and our recently described adenoviral vector expressing Ag85A (AdAg85A) as a boost vaccine. Since we recently demonstrated that a single intranasal but not intramuscular immunization with AdAg85A was able to induce potent protection from pulmonary Mycobacterium tuberculosis challenge in a mouse model, we compared the protective effects of parenteral and mucosal booster immunizations following subcutaneous BCG priming. Protection by BCG prime immunization was not effectively boosted by subcutaneous BCG or intramuscular AdAg85A. In contrast, protection by BCG priming was remarkably boosted by intranasal AdAg85A. Such enhanced protection by intranasal AdAg85A was correlated to the numbers of gamma interferon-positive CD4 and CD8 T cells residing in the airway lumen of the lung. Our study demonstrates that intranasal administration of AdAg85A represents an effective way to boost immune protection by parenteral BCG vaccination.
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Depression Symptom Trajectories and Associated Risk Factors among Adolescents in Chile
Stapinski, Lexine A.; Montgomery, Alan A.; Heron, Jon; Jerrim, John; Vignoles, Anna; Araya, Ricardo
2013-01-01
Adolescence is a key period for studying the development of depression, with studies in Europe and North America showing a pattern of elevated risk that begins in early adolescence and continues to increase as adolescents age. Few studies have examined the course of adolescent depression and associated risk factors in low and middle-income countries. This longitudinal cohort study examined depression symptom trajectories and risk factors in a sample of socio-economically disadvantaged adolescents in Chile (n = 2,508). Data were collected over an 18-month period as part of a clinical trial for secondary students aged 12 to 18 (median age 14). Clinical levels of depression were prevalent in this sample at baseline (35% for girls and 28% for boys); yet latent growth models of symptom trajectories revealed a pattern of decreasing symptoms over time. There was evidence of an anxiety-depression developmental pathway for girls, with elevated anxiety levels initially predicting poorer depression outcomes later on. Poor problem-solving skills were associated with initial depression levels but did not predict the course of depressive symptoms. Critically, the declining symptom trajectories raise important methodological issues regarding the effects of repeated assessment in longitudinal studies. PMID:24147131
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Real-time path planning and autonomous control for helicopter autorotation
NASA Astrophysics Data System (ADS)
Yomchinda, Thanan
Autorotation is a descending maneuver that can be used to recover helicopters in the event of total loss of engine power; however it is an extremely difficult and complex maneuver. The objective of this work is to develop a real-time system which provides full autonomous control for autorotation landing of helicopters. The work includes the development of an autorotation path planning method and integration of the path planner with a primary flight control system. The trajectory is divided into three parts: entry, descent and flare. Three different optimization algorithms are used to generate trajectories for each of these segments. The primary flight control is designed using a linear dynamic inversion control scheme, and a path following control law is developed to track the autorotation trajectories. Details of the path planning algorithm, trajectory following control law, and autonomous autorotation system implementation are presented. The integrated system is demonstrated in real-time high fidelity simulations. Results indicate feasibility of the capability of the algorithms to operate in real-time and of the integrated systems ability to provide safe autorotation landings. Preliminary simulations of autonomous autorotation on a small UAV are presented which will lead to a final hardware demonstration of the algorithms.
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Depression symptom trajectories and associated risk factors among adolescents in Chile.
Stapinski, Lexine A; Montgomery, Alan A; Heron, Jon; Jerrim, John; Vignoles, Anna; Araya, Ricardo
2013-01-01
Adolescence is a key period for studying the development of depression, with studies in Europe and North America showing a pattern of elevated risk that begins in early adolescence and continues to increase as adolescents age. Few studies have examined the course of adolescent depression and associated risk factors in low and middle-income countries. This longitudinal cohort study examined depression symptom trajectories and risk factors in a sample of socio-economically disadvantaged adolescents in Chile (n = 2,508). Data were collected over an 18-month period as part of a clinical trial for secondary students aged 12 to 18 (median age 14). Clinical levels of depression were prevalent in this sample at baseline (35% for girls and 28% for boys); yet latent growth models of symptom trajectories revealed a pattern of decreasing symptoms over time. There was evidence of an anxiety-depression developmental pathway for girls, with elevated anxiety levels initially predicting poorer depression outcomes later on. Poor problem-solving skills were associated with initial depression levels but did not predict the course of depressive symptoms. Critically, the declining symptom trajectories raise important methodological issues regarding the effects of repeated assessment in longitudinal studies.
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Zhang, Shuhua; Ma, Jinsong
2018-01-01
With the growing interest in studying the characteristics of people’s access to the food environment and its influence upon individual health, there has been a focus on assessing individual food exposure based on GPS trajectories. However, existing studies have largely focused on the overall activity space using short-period trajectories, which ignores the complexity of human movements and the heterogeneity of the spaces that are experienced by the individual over daily life schedules. In this study, we propose a novel framework to extract the exposure areas consisting of the localized activity spaces around daily life centers and non-motorized commuting routes from long-term GPS trajectories. The newly proposed framework is individual-specific and can incorporate the internal heterogeneity of individual activities (spatial extent, stay duration, and timing) in different places as well as the dynamics of the context. A pilot study of the GeoLife dataset suggests that there are significant variations in the magnitude as well as the composition of the food environment in different parts of the individual exposure area, and residential environment is not representative of the overall foodscape exposure. PMID:29495449
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Gps-Denied Geo-Localisation Using Visual Odometry
NASA Astrophysics Data System (ADS)
Gupta, Ashish; Chang, Huan; Yilmaz, Alper
2016-06-01
The primary method for geo-localization is based on GPS which has issues of localization accuracy, power consumption, and unavailability. This paper proposes a novel approach to geo-localization in a GPS-denied environment for a mobile platform. Our approach has two principal components: public domain transport network data available in GIS databases or OpenStreetMap; and a trajectory of a mobile platform. This trajectory is estimated using visual odometry and 3D view geometry. The transport map information is abstracted as a graph data structure, where various types of roads are modelled as graph edges and typically intersections are modelled as graph nodes. A search for the trajectory in real time in the graph yields the geo-location of the mobile platform. Our approach uses a simple visual sensor and it has a low memory and computational footprint. In this paper, we demonstrate our method for trajectory estimation and provide examples of geolocalization using public-domain map data. With the rapid proliferation of visual sensors as part of automated driving technology and continuous growth in public domain map data, our approach has the potential to completely augment, or even supplant, GPS based navigation since it functions in all environments.
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Nicholas, B L; Brennan, F R; Hamilton, W D O; Wakelin, D
2003-06-02
Expression of a 17-mer peptide sequence from canine parvovirus expressed on cowpea mosaic virus (CPMV) to form chimaeric virus particles (CVPs) creates vaccine antigens that elicit strong anti-peptide immune responses in mice. Systemic (subcutaneous, s.c.) immunisation and boosting with such CVP constructs produces IgG(2a) serum antibody responses, while mucosal (intranasal, i.n.) immunisation and boosting elicits intestinal IgA responses. Combinations of systemic and mucosal routes for priming and boosting immunisations were used to examine their influence on the level, type and location of immune response generated to one of these constructs (CVP-1). In all cases, s.c. administration, whether for immunisation or boosting, generated a Th1-biased response, reflected in a predominantly IgG(2a) serum antibody isotype and secretion of IFN-gamma from in vitro-stimulated lymphocytes. Serum antibody responses were greatest in animals primed and boosted subcutaneously, and least in mucosally vaccinated mice. The i.n. exposure also led to IFN-gamma release from in vitro-stimulated cells, but serum IgG(2a) was significantly elevated only in mice primed intranasally and boosted subcutaneously. Peptide- and wild-type CPMV-specific IgA responses in gut lavage fluid were greatest in animals exposed mucosally and least in those primed and boosted subcutaneously or primed subcutaneously and boosted orally. Lymphocytes from immunised mice proliferated in response to in vitro stimulation with CPMV but not with peptide. The predominant secretion of IFN-gamma from all immunising/boosting combinations indicates that the route of vaccination and challenge does not alter the Th1 bias of the response to CVP constructs. However, optimal serum and intestinal antibody responses were achieved by combining s.c. and i.n. administration.
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Emmer, Kristel L; Wieczorek, Lindsay; Tuyishime, Steven; Molnar, Sebastian; Polonis, Victoria R; Ertl, Hildegund C J
2016-10-23
Over 2 million individuals are infected with HIV type 1 (HIV-1) each year, yet an effective vaccine remains elusive. The most successful HIV-1 vaccine to date demonstrated 31% efficacy. Immune correlate analyses associated HIV-1 envelope (Env)-specific antibodies with protection, thus providing a path toward a more effective vaccine. We sought to test the antibody response from novel prime-boost vaccination with a chimpanzee-derived adenovirus (AdC) vector expressing a subtype C Env glycoprotein (gp)140 combined with either a serologically distinct AdC vector expressing gp140 of a different subtype C isolate or an alum-adjuvanted, partially trimeric gp145 from yet another subtype C isolate. Three different prime-boost regimens were tested in mice: AdC prime-protein boost, protein prime-AdC boost, and AdC prime-AdC boost. Each regimen was tested at two different doses of AdC vector in a total of six experimental groups. Sera were collected at various time points and evaluated by ELISA for Env-specific antibody binding, isotype, and avidity. Antibody functionality was assessed by pseudovirus neutralization assay. Priming with AdC followed by a protein boost or sequential immunizations with two AdC vectors induced HIV-1 Env-specific binding antibodies, including those to the variable region 2, whereas priming with protein followed by an AdC boost was relatively ineffective. Antibodies that cross-neutralized tier 1 HIV-1 from different subtypes were elicited with vaccine regimens that included immunizations with protein. Our study warrants further investigation of AdC vector and gp145 protein prime-boost vaccines and their ability to protect against acquisition in animal challenge studies.
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Black String and Velocity Frame Dragging
NASA Astrophysics Data System (ADS)
Lee, Jungjai; Kim, Hyeong-Chan
We investigate velocity frame dragging with the boosted Schwarzschild black string solution and the boosted Kaluza-Klein bubble solution, in which a translational symmetry along the boosted z-coordinate is implemented. The velocity frame dragging effect can be nullified by the motion of an observer using the boost symmetry along the z-coordinate if it is not compact. However, in spacetime with the compact z-coordinate, we show that the effect cannot be removed since the compactification breaks the global Lorentz boost symmetry. As a result, the comoving velocity depends on r and the momentum parameter along the z-coordinate becomes an observer independent characteristic quantity of the black string and bubble solutions. The dragging induces a spherical ergo-region around the black string.
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Search for Boosted Dark Matter Interacting with Electrons in Super-Kamiokande.
Kachulis, C; Abe, K; Bronner, C; Hayato, Y; Ikeda, M; Iyogi, K; Kameda, J; Kato, Y; Kishimoto, Y; Marti, Ll; Miura, M; Moriyama, S; Nakahata, M; Nakano, Y; Nakayama, S; Okajima, Y; Orii, A; Pronost, G; Sekiya, H; Shiozawa, M; Sonoda, Y; Takeda, A; Takenaka, A; Tanaka, H; Tasaka, S; Tomura, T; Akutsu, R; Kajita, T; Kaneyuki, K; Nishimura, Y; Okumura, K; Tsui, K M; Labarga, L; Fernandez, P; Blaszczyk, F D M; Gustafson, J; Kearns, E; Raaf, J L; Stone, J L; Sulak, L R; Berkman, S; Tobayama, S; Goldhaber, M; Elnimr, M; Kropp, W R; Mine, S; Locke, S; Weatherly, P; Smy, M B; Sobel, H W; Takhistov, V; Ganezer, K S; Hill, J; Kim, J Y; Lim, I T; Park, R G; Himmel, A; Li, Z; O'Sullivan, E; Scholberg, K; Walter, C W; Ishizuka, T; Nakamura, T; Jang, J S; Choi, K; Learned, J G; Matsuno, S; Smith, S N; Amey, J; Litchfield, R P; Ma, W Y; Uchida, Y; Wascko, M O; Cao, S; Friend, M; Hasegawa, T; Ishida, T; Ishii, T; Kobayashi, T; Nakadaira, T; Nakamura, K; Oyama, Y; Sakashita, K; Sekiguchi, T; Tsukamoto, T; Abe, K E; Hasegawa, M; Suzuki, A T; Takeuchi, Y; Yano, T; Hayashino, T; Hiraki, T; Hirota, S; Huang, K; Jiang, M; Nakamura, K E; Nakaya, T; Quilain, B; Patel, N D; Wendell, R A; Anthony, L H V; McCauley, N; Pritchard, A; Fukuda, Y; Itow, Y; Murase, M; Muto, F; Mijakowski, P; Frankiewicz, K; Jung, C K; Li, X; Palomino, J L; Santucci, G; Vilela, C; Wilking, M J; Yanagisawa, C; Ito, S; Fukuda, D; Ishino, H; Kibayashi, A; Koshio, Y; Nagata, H; Sakuda, M; Xu, C; Kuno, Y; Wark, D; Di Lodovico, F; Richards, B; Tacik, R; Kim, S B; Cole, A; Thompson, L; Okazawa, H; Choi, Y; Ito, K; Nishijima, K; Koshiba, M; Totsuka, Y; Suda, Y; Yokoyama, M; Calland, R G; Hartz, M; Martens, K; Simpson, C; Suzuki, Y; Vagins, M R; Hamabe, D; Kuze, M; Yoshida, T; Ishitsuka, M; Martin, J F; Nantais, C M; Tanaka, H A; Konaka, A; Chen, S; Wan, L; Zhang, Y; Wilkes, R J; Minamino, A
2018-06-01
A search for boosted dark matter using 161.9 kt yr of Super-Kamiokande IV data is presented. We search for an excess of elastically scattered electrons above the atmospheric neutrino background, with a visible energy between 100 MeV and 1 TeV, pointing back to the Galactic center or the Sun. No such excess is observed. Limits on boosted dark matter event rates in multiple angular cones around the Galactic center and Sun are calculated. Limits are also calculated for a baseline model of boosted dark matter produced from cold dark matter annihilation or decay. This is the first experimental search for boosted dark matter from the Galactic center or the Sun interacting in a terrestrial detector.
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Search for Boosted Dark Matter Interacting with Electrons in Super-Kamiokande
NASA Astrophysics Data System (ADS)
Kachulis, C.; Abe, K.; Bronner, C.; Hayato, Y.; Ikeda, M.; Iyogi, K.; Kameda, J.; Kato, Y.; Kishimoto, Y.; Marti, Ll.; Miura, M.; Moriyama, S.; Nakahata, M.; Nakano, Y.; Nakayama, S.; Okajima, Y.; Orii, A.; Pronost, G.; Sekiya, H.; Shiozawa, M.; Sonoda, Y.; Takeda, A.; Takenaka, A.; Tanaka, H.; Tasaka, S.; Tomura, T.; Akutsu, R.; Kajita, T.; Kaneyuki, K.; Nishimura, Y.; Okumura, K.; Tsui, K. M.; Labarga, L.; Fernandez, P.; Blaszczyk, F. d. M.; Gustafson, J.; Kearns, E.; Raaf, J. L.; Stone, J. L.; Sulak, L. R.; Berkman, S.; Tobayama, S.; Goldhaber, M.; Elnimr, M.; Kropp, W. R.; Mine, S.; Locke, S.; Weatherly, P.; Smy, M. B.; Sobel, H. W.; Takhistov, V.; Ganezer, K. S.; Hill, J.; Kim, J. Y.; Lim, I. T.; Park, R. G.; Himmel, A.; Li, Z.; O'Sullivan, E.; Scholberg, K.; Walter, C. W.; Ishizuka, T.; Nakamura, T.; Jang, J. S.; Choi, K.; Learned, J. G.; Matsuno, S.; Smith, S. N.; Amey, J.; Litchfield, R. P.; Ma, W. Y.; Uchida, Y.; Wascko, M. O.; Cao, S.; Friend, M.; Hasegawa, T.; Ishida, T.; Ishii, T.; Kobayashi, T.; Nakadaira, T.; Nakamura, K.; Oyama, Y.; Sakashita, K.; Sekiguchi, T.; Tsukamoto, T.; Abe, KE.; Hasegawa, M.; Suzuki, A. T.; Takeuchi, Y.; Yano, T.; Hayashino, T.; Hiraki, T.; Hirota, S.; Huang, K.; Jiang, M.; Nakamura, KE.; Nakaya, T.; Quilain, B.; Patel, N. D.; Wendell, R. A.; Anthony, L. H. V.; McCauley, N.; Pritchard, A.; Fukuda, Y.; Itow, Y.; Murase, M.; Muto, F.; Mijakowski, P.; Frankiewicz, K.; Jung, C. K.; Li, X.; Palomino, J. L.; Santucci, G.; Vilela, C.; Wilking, M. J.; Yanagisawa, C.; Ito, S.; Fukuda, D.; Ishino, H.; Kibayashi, A.; Koshio, Y.; Nagata, H.; Sakuda, M.; Xu, C.; Kuno, Y.; Wark, D.; Di Lodovico, F.; Richards, B.; Tacik, R.; Kim, S. B.; Cole, A.; Thompson, L.; Okazawa, H.; Choi, Y.; Ito, K.; Nishijima, K.; Koshiba, M.; Totsuka, Y.; Suda, Y.; Yokoyama, M.; Calland, R. G.; Hartz, M.; Martens, K.; Simpson, C.; Suzuki, Y.; Vagins, M. R.; Hamabe, D.; Kuze, M.; Yoshida, T.; Ishitsuka, M.; Martin, J. F.; Nantais, C. M.; Tanaka, H. A.; Konaka, A.; Chen, S.; Wan, L.; Zhang, Y.; Wilkes, R. J.; Minamino, A.; Super-Kamiokande Collaboration
2018-06-01
A search for boosted dark matter using 161.9 kt yr of Super-Kamiokande IV data is presented. We search for an excess of elastically scattered electrons above the atmospheric neutrino background, with a visible energy between 100 MeV and 1 TeV, pointing back to the Galactic center or the Sun. No such excess is observed. Limits on boosted dark matter event rates in multiple angular cones around the Galactic center and Sun are calculated. Limits are also calculated for a baseline model of boosted dark matter produced from cold dark matter annihilation or decay. This is the first experimental search for boosted dark matter from the Galactic center or the Sun interacting in a terrestrial detector.
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SEP thrust subsystem performance sensitivity analysis
NASA Technical Reports Server (NTRS)
Atkins, K. L.; Sauer, C. G., Jr.; Kerrisk, D. J.
1973-01-01
This is a two-part report on solar electric propulsion (SEP) performance sensitivity analysis. The first part describes the preliminary analysis of the SEP thrust system performance for an Encke rendezvous mission. A detailed description of thrust subsystem hardware tolerances on mission performance is included together with nominal spacecraft parameters based on these tolerances. The second part describes the method of analysis and graphical techniques used in generating the data for Part 1. Included is a description of both the trajectory program used and the additional software developed for this analysis. Part 2 also includes a comprehensive description of the use of the graphical techniques employed in this performance analysis.
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Reconcile Planck-scale discreteness and the Lorentz-Fitzgerald contraction
NASA Astrophysics Data System (ADS)
Rovelli, Carlo; Speziale, Simone
2003-03-01
A Planck-scale minimal observable length appears in many approaches to quantum gravity. It is sometimes argued that this minimal length might conflict with Lorentz invariance, because a boosted observer can see the minimal length further Lorentz contracted. We show that this is not the case within loop quantum gravity. In loop quantum gravity the minimal length (more precisely, minimal area) does not appear as a fixed property of geometry, but rather as the minimal (nonzero) eigenvalue of a quantum observable. The boosted observer can see the same observable spectrum, with the same minimal area. What changes continuously in the boost transformation is not the value of the minimal length: it is the probability distribution of seeing one or the other of the discrete eigenvalues of the area. We discuss several difficulties associated with boosts and area measurement in quantum gravity. We compute the transformation of the area operator under a local boost, propose an explicit expression for the generator of local boosts, and give the conditions under which its action is unitary.
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Comment on ‘Wind-influenced projectile motion’
NASA Astrophysics Data System (ADS)
Winther Andersen, Poul
2015-11-01
We comment on the article ‘Wind-influenced projectile motion’ by Bernardo et al (2015 Eur. J. Phys. 36 025016) where they examine the trajectory of a particle that is subjected to gravity and a linear air resistance plus the influence from the wind. They find by using the Lambert W function that the particle's trajectory for a special angle, the critical angle {θ }{{C}}, between the initial velocity and the horizontal is part of a straight line. In this comment we will show that this result can be proved without using the Lambert W function which is not that well known to beginning students of physics.
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Quantum dynamics by the constrained adiabatic trajectory method
DOE Office of Scientific and Technical Information (OSTI.GOV)
Leclerc, A.; Jolicard, G.; Guerin, S.
2011-03-15
We develop the constrained adiabatic trajectory method (CATM), which allows one to solve the time-dependent Schroedinger equation constraining the dynamics to a single Floquet eigenstate, as if it were adiabatic. This constrained Floquet state (CFS) is determined from the Hamiltonian modified by an artificial time-dependent absorbing potential whose forms are derived according to the initial conditions. The main advantage of this technique for practical implementation is that the CFS is easy to determine even for large systems since its corresponding eigenvalue is well isolated from the others through its imaginary part. The properties and limitations of the CATM are exploredmore » through simple examples.« less
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Geometrically derived difference formulae for the numerical integration of trajectory problems
NASA Technical Reports Server (NTRS)
Mcleod, R. J. Y.; Sanz-Serna, J. M.
1981-01-01
The term 'trajectory problem' is taken to include problems that can arise, for instance, in connection with contour plotting, or in the application of continuation methods, or during phase-plane analysis. Geometrical techniques are used to construct difference methods for these problems to produce in turn explicit and implicit circularly exact formulae. Based on these formulae, a predictor-corrector method is derived which, when compared with a closely related standard method, shows improved performance. It is found that this latter method produces spurious limit cycles, and this behavior is partly analyzed. Finally, a simple variable-step algorithm is constructed and tested.
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Trajectory Design for the Phobos and Deimos & Mars Environment Spacecraft
NASA Technical Reports Server (NTRS)
Genova, Anthony L.; Korsmeyer, David J.; Loucks, Michel E.; Yang, Fan Yang; Lee, Pascal
2016-01-01
The presented trajectory design and analysis was performed for the Phobos and Deimos & Mars Environment (PADME) mission concept as part of a NASA proposal submission managed by NASA Ames Research Center in the 2014-2015 timeframe. The PADME spacecraft would be a derivative of the successfully flown Lunar Atmosphere & Dust Environment Explorer (LADEE) spacecraft. While LADEE was designed to enter low-lunar orbit, the PADME spacecraft would instead enter an elliptical Mars orbit of 2-week period. This Mars orbit would pass by Phobos near periapsis on successive orbits and then raise periapsis to yield close approaches of Deimos every orbit thereafter.
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Miao, Qiguang; Cao, Ying; Xia, Ge; Gong, Maoguo; Liu, Jiachen; Song, Jianfeng
2016-11-01
AdaBoost has attracted much attention in the machine learning community because of its excellent performance in combining weak classifiers into strong classifiers. However, AdaBoost tends to overfit to the noisy data in many applications. Accordingly, improving the antinoise ability of AdaBoost plays an important role in many applications. The sensitiveness to the noisy data of AdaBoost stems from the exponential loss function, which puts unrestricted penalties to the misclassified samples with very large margins. In this paper, we propose two boosting algorithms, referred to as RBoost1 and RBoost2, which are more robust to the noisy data compared with AdaBoost. RBoost1 and RBoost2 optimize a nonconvex loss function of the classification margin. Because the penalties to the misclassified samples are restricted to an amount less than one, RBoost1 and RBoost2 do not overfocus on the samples that are always misclassified by the previous base learners. Besides the loss function, at each boosting iteration, RBoost1 and RBoost2 use numerically stable ways to compute the base learners. These two improvements contribute to the robustness of the proposed algorithms to the noisy training and testing samples. Experimental results on the synthetic Gaussian data set, the UCI data sets, and a real malware behavior data set illustrate that the proposed RBoost1 and RBoost2 algorithms perform better when the training data sets contain noisy data.
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Riemann curvature of a boosted spacetime geometry
NASA Astrophysics Data System (ADS)
Battista, Emmanuele; Esposito, Giampiero; Scudellaro, Paolo; Tramontano, Francesco
2016-10-01
The ultrarelativistic boosting procedure had been applied in the literature to map the metric of Schwarzschild-de Sitter spacetime into a metric describing de Sitter spacetime plus a shock-wave singularity located on a null hypersurface. This paper evaluates the Riemann curvature tensor of the boosted Schwarzschild-de Sitter metric by means of numerical calculations, which make it possible to reach the ultrarelativistic regime gradually by letting the boost velocity approach the speed of light. Thus, for the first time in the literature, the singular limit of curvature, through Dirac’s δ distribution and its derivatives, is numerically evaluated for this class of spacetimes. Moreover, the analysis of the Kretschmann invariant and the geodesic equation shows that the spacetime possesses a “scalar curvature singularity” within a 3-sphere and it is possible to define what we here call “boosted horizon”, a sort of elastic wall where all particles are surprisingly pushed away, as numerical analysis demonstrates. This seems to suggest that such “boosted geometries” are ruled by a sort of “antigravity effect” since all geodesics seem to refuse to enter the “boosted horizon” and are “reflected” by it, even though their initial conditions are aimed at driving the particles toward the “boosted horizon” itself. Eventually, the equivalence with the coordinate shift method is invoked in order to demonstrate that all δ2 terms appearing in the Riemann curvature tensor give vanishing contribution in distributional sense.
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AveBoost2: Boosting for Noisy Data
NASA Technical Reports Server (NTRS)
Oza, Nikunj C.
2004-01-01
AdaBoost is a well-known ensemble learning algorithm that constructs its constituent or base models in sequence. A key step in AdaBoost is constructing a distribution over the training examples to create each base model. This distribution, represented as a vector, is constructed to be orthogonal to the vector of mistakes made by the pre- vious base model in the sequence. The idea is to make the next base model's errors uncorrelated with those of the previous model. In previous work, we developed an algorithm, AveBoost, that constructed distributions orthogonal to the mistake vectors of all the previous models, and then averaged them to create the next base model s distribution. Our experiments demonstrated the superior accuracy of our approach. In this paper, we slightly revise our algorithm to allow us to obtain non-trivial theoretical results: bounds on the training error and generalization error (difference between training and test error). Our averaging process has a regularizing effect which, as expected, leads us to a worse training error bound for our algorithm than for AdaBoost but a superior generalization error bound. For this paper, we experimented with the data that we used in both as originally supplied and with added label noise-a small fraction of the data has its original label changed. Noisy data are notoriously difficult for AdaBoost to learn. Our algorithm's performance improvement over AdaBoost is even greater on the noisy data than the original data.
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Reducing late effects of radiotherapy in average risk medulloblastoma.
Ibrahim, Noha Yehia; Abdel Aal, Hisham H; Abdel Kader, Mohamed S; Makaar, Wael S; Shaaban, Ahmed H
2014-03-01
To assess the efficacy and safety in average-risk pediatric medulloblastoma (MB) receiving tumor bed boost irradiation compared to a posterior fossa (PF) boost. Thirty patients were enrolled in the study and divided evenly into two treatment arms of 15. Both arms received 23.4 Gy craniospinal irradiation (CS) and a 32.4 Gy boost. Patients in arm 1 were given PF boosts, and those in arm 2 were given boosts to the gross target volume (GTV). Weekly oncovin was given throughout all radiotherapy (RT). Eight cycles of adjuvant chemotherapy of CCNU, oncovin and platinol were given to all patients after RT. MRI, pure tone audiogram (PTA) and intelligence quotient (IQ) tests were performed before and after RT and every three months thereafter. There were significant differences in the sparing dose to the cochlea and brain stem as well as the volume of the normal brain receiving a 100% dose. There was a significant initial improvement of hearing function in patients given the target volume boost after RT, which was lost after chemotherapy. With a median follow up of 23 months, there was no difference in progression free survival or overall survival between the two arms. Irradiation of the tumor bed after 23.4 Gy craniospinal irradiation for average-risk MB results in similar disease control as a PF boost. Dosimetric sparing for the cochleae and normal tissue is evident in patients receiving tumor bed boosts. The hearing improvement and cognitive function preservation effects of the treatment need more follow up.
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[Trajectories of aging in a sample of elderly people: a longitudinal study].
Navarro-González, Elena; Calero, María Dolores; Becerra-Reina, Dolores
2015-01-01
The present study analyzes variables associated with different trajectories of aging, and the level of cognitive functioning in a sample of older adults. Although this work is part of a broader investigation where initially 141 people were assessed, this paper only discusses the cognitive functioning and cognitive development of 64 older people who have been followed up four years after the initial assessment, with a mean age of 83.84 years (age range 65 to 99 years). In the initial assessment all the participants were assessed with a psychological battery that included the MEC, the verbal fluency task FVS, a sustained attention task, a working memory test, a Quality of Life Questionnaire, a scale of dependency, and the AVLT-Learning Potential test. In the follow up assessment, participants have been assessed with the MEC, the verbal fluency task FVS, and the verbal memory test AVLT-PA. the results show relatively stable trajectories of aging and that the variables that better predict cognitive evolution of the elderly are working memory and post-test score in the AVLT-LP. Despite the time lapse between the two assessments and the age of the participants, older adults have remained relatively stable in their cognitive functioning, which in part contradicts the idea that--especially after 80 years--a general decline of cognitive functioning occurs in old age. Copyright © 2014 SEGG. Published by Elsevier Espana. All rights reserved.
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Parametric Thermal Soak Model for Earth Entry Vehicles
NASA Technical Reports Server (NTRS)
Agrawal, Parul; Samareh, Jamshid; Doan, Quy D.
2013-01-01
The analysis and design of an Earth Entry Vehicle (EEV) is multidisciplinary in nature, requiring the application many disciplines. An integrated tool called Multi Mission System Analysis for Planetary Entry Descent and Landing or M-SAPE is being developed as part of Entry Vehicle Technology project under In-Space Technology program. Integration of a multidisciplinary problem is a challenging task. Automation of the execution process and data transfer among disciplines can be accomplished to provide significant benefits. Thermal soak analysis and temperature predictions of various interior components of entry vehicle, including the impact foam and payload container are part of the solution that M-SAPE will offer to spacecraft designers. The present paper focuses on the thermal soak analysis of an entry vehicle design based on the Mars Sample Return entry vehicle geometry and discusses a technical approach to develop parametric models for thermal soak analysis that will be integrated into M-SAPE. One of the main objectives is to be able to identify the important parameters and to develop correlation coefficients so that, for a given trajectory, can estimate the peak payload temperature based on relevant trajectory parameters and vehicle geometry. The models are being developed for two primary thermal protection (TPS) materials: 1) carbon phenolic that was used for Galileo and Pioneer Venus probes and, 2) Phenolic Impregnated Carbon Ablator (PICA), TPS material for Mars Science Lab mission. Several representative trajectories were selected from a very large trade space to include in the thermal analysis in order to develop an effective parametric thermal soak model. The selected trajectories covered a wide range of heatload and heatflux combinations. Non-linear, fully transient, thermal finite element simulations were performed for the selected trajectories to generate the temperature histories at the interior of the vehicle. Figure 1 shows the finite element model that was used for the simulations. The results indicate that it takes several hours for the thermal energy to soak into the interior of the vehicle and achieve maximum payload temperatures. In addition, a strong correlation between the heatload and peak payload container temperature is observed that will help establishing the parametric thermal soak model.
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The common ground of genomics and systems biology
2014-01-01
The rise of systems biology is intertwined with that of genomics, yet their primordial relationship to one another is ill-defined. We discuss how the growth of genomics provided a critical boost to the popularity of systems biology. We describe the parts of genomics that share common areas of interest with systems biology today in the areas of gene expression, network inference, chromatin state analysis, pathway analysis, personalized medicine, and upcoming areas of synergy as genomics continues to expand its scope across all biomedical fields. PMID:25033072