65,928 research outputs found
Investigating techniques in the generation of support software
The performance of the Meta assembler processor software package previously provided for the Space Ultrareliable Modular Computer (SUMC) at the Marshall Space Flight Center (MSFC) was verified. A number of adjustments were made to the processor following the rehosting of the SUMC software development facility (S4) on a newly acquired IBM 360/65. The assembler was configured to provide cross assembly capability for various target computers
Mechanism for the failure of the Edwards hypothesis in the SK spin glass
The dynamics of the SK model at T=0 starting from random spin configurations
is considered. The metastable states reached by such dynamics are atypical of
such states as a whole, in that the probability density of site energies,
, is small at . Since virtually all metastable states
have a much larger , this behavior demonstrates a qualitative failure of
the Edwards hypothesis. We look for its origins by modelling the changes in the
site energies during the dynamics as a Markov process. We show how the small
arises from features of the Markov process that have a clear physical
basis in the spin-glass, and hence explain the failure of the Edwards
hypothesis.Comment: 5 pages, new title, modified text, additional reference
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Open Science Happens Somewhere: Exploring the use of Science OER in Schools
This paper concerns a pilot exploring the use of openly licensed content in secondary schools. Specifically it looks at the use of the Open Universityās (OU) OpenScienceLab (OSL) in two remote rural schools in the West Highlands of Scotland. OSL is a series of online experiments openly licensed for anyone to use, they are about learning through experimentation, and are part of a wider OU interest in how to support and develop inquiry based learning at a distance (Scanlon 2012). This area is of particular relevance to Scottish schools, as the underlying pedagogy of Curriculum for Excellence (CfE) promotes interdisciplinary thinking and learning through inquiry (Macintyre 2014).
The idea of the pilot was to work on how āopen contentā might be used in schools to understand what openness might mean in and for educational practice. While our initial intention was simply to run these in schools after the first workshops it became apparent while the technical and licences were open and it was relatively clear how to do the experiments, people were uncertain how to use them in their educational practice. Emphasising the need to attend to Educational Practice as well as Openness in OEP.
The pilot took a participatory design approach (Sanders and Westerlund 2011; Mor et.al 2012), to developing and support practices around the use of Open Educational Resources (OER) in classroom. Through a series of workshops and schools visits we looked to solve these problems from the classroom out, using the teachers experience to develop learning journeys that worked for teachers and pupils. With teachers we created a learning journey using the OUās free platform OpenLearnWorks to wrap the experiments in a mixture of existing and newly developed OER.
Two journeys were created, these will be run in two locations with with two sets of teachers in December 2014. The paper will report on the outcomes for pupils and teachers of this final stage. In doing so it will reflect on the participatory design process, highlighting the practices developed to support the use of open content, drawing out broader conclusions might support the use open materials in the classroom
The supersymmetric Penrose transform in six dimensions
We give a supersymmetric extension to the six-dimensional Penrose transform
and give an integral formula for the on-shell (0, 2) supermultiplet. The
relationship between super fields on space-time and twistor space is clarified
and the space-time superfield constraint equations are derived from the
geometry of supertwistor space. We also explain the extension to more general
(0,n) supermultiplets and give twistor actions for these theories.Comment: 20 page
Expert systems for real-time monitoring and fault diagnosis
Methods for building real-time onboard expert systems were investigated, and the use of expert systems technology was demonstrated in improving the performance of current real-time onboard monitoring and fault diagnosis applications. The potential applications of the proposed research include an expert system environment allowing the integration of expert systems into conventional time-critical application solutions, a grammar for describing the discrete event behavior of monitoring and fault diagnosis systems, and their applications to new real-time hardware fault diagnosis and monitoring systems for aircraft
Development of a remote digital augmentation system and application to a remotely piloted research vehicle
A cost-effective approach to flight testing advanced control concepts with remotely piloted vehicles is described. The approach utilizes a ground based digital computer coupled to the remotely piloted vehicle's motion sensors and control surface actuators through telemetry links to provide high bandwidth feedback control. The system was applied to the control of an unmanned 3/8-scale model of the F-15 airplane. The model was remotely augmented; that is, the F-15 mechanical and control augmentation flight control systems were simulated by the ground-based computer, rather than being in the vehicle itself. The results of flight tests of the model at high angles of attack are discussed
A remotely augmented vehicle approach to flight testing RPV control systems
A remotely augmented vehicle concept for flight testing advanced control systems was developed as an outgrowth of a remotely piloted research vehicle (RPV) program in which control laws are implemented through telemetry uplink and downlink data channels using a general purpose ground based digital computer which provides the control law computations. Some advantages of this approach are that the cost of one control system facility is spread over a number of RPV programs, and control laws can be changed quickly as required, without changing the flight hardware. The remotely augmented vehicle concept is described, and flight test results from a subscale F-15 program are discussed. Suggestions of how the concept could lead to more effective testing of RPV control system concepts, and how it is applicable to a military RPV reconnaissance mission are given
Near-Term Options for a Nuclear Thermal Propulsion Flight Demonstrator
The Appropriations Bill passed by the US Congress in February 2019 instructed NASA to direct not less than 70,000,000 shall be for the design of a flight demonstration by 2024 for which a multi-year plan is required by both the House and the Senate within 180 days of enactment of this agreement." As part of NASAs response to this direction, the Advanced Concepts Office (ACO) at the Marshall Space Flight Center (MSFC) was tasked with leading a study to develop a nuclear thermal propulsion (NTP) flight demonstration (FD) concept and evaluate its feasibility with respect to the near-term schedule goal. During formulation for the NTP FD study, two perspectives emerged with regards to FD concept design. The first seeks to strictly observe the immediate near-term schedule goal, embracing a completely off-the-shelf, high-TRL approach to subsystem design and component selection. The downside to this approach is that the propulsion performance to be expected from such a design is significantly lower than what NTP promises for operational systems, and the value of the flight demo is potentially reduced due to a lack of traceability. The second approach advocates for an FD concept that shows increased traceability to the projected designs of operational systems, providing risk reduction for future NTP-enabled missions. This option comes at the cost of schedule and development risks, as it requires some new investments in nuclear reactor fuels and design. In order to understand the implications and differences between these two approaches, the ACO team elected to perform a concept design of each type, labeling the immediate near-term concept Flight Demo 1 (FD1), and the higher traceability concept Flight Demo 2 (FD2). This paper will present a summary of the mission profiles and system designs for both FD1 and FD2, identifying key drivers and challenges for each design
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