Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Reconfigurable”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,675 records · Page 93
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Using Containers to Speed Up Development, to Run Integration Tests and to Teach About Distributed Systems

GlideinWMS is a workload manager provisioning resources for many experiments, including CMS and DUNE. The software is distributed both as native packages and specialized production containers. Following an approach used in other communities like web development, we built our workspaces, system-like containers to ease development and testing. Developers can change the source tree or check out a different branch and quickly reconfigure the services to see the effect of their changes. In this paper, we will talk about what differentiates workspaces from other containers. We will describe our base system, composed of three containers: a one-node cluster including a compute element and a batch system, a GlideinWMS Factory controlling pilot jobs, and a scheduler and Frontend to submit jobs and provision resources. Additional containers can be used for optional components. This system can easily run on a laptop, and we will share our evaluation of different container runtimes, with an eye for ease of use and performance. Finally, we will talk about our experience as developers and with students. The GlideinWMS workspaces are easily integrated with IDEs like VS Code, simplifying debugging and allowing development and testing of the system even when offline. They simplified the training and onboarding of new team members and summer interns. And they were useful in workshops where students could have first-hand experience with the mechanisms and components that, in production, run millions of jobs.

Mambelli, Marco [Fermilab] (ORCID:0000000294892681↗
DOE OSTI2018

Magnetosphere dynamics during the 14 November 2012 storm inferred from TWINS, AMPERE, Van Allen Probes, and BATS-R-US–CRCM

During the 14 November 2012 geomagnetic storm, the Van Allen Probes spacecraft observed a number of sharp decreases ("dropouts") in particle fluxes for ions and electrons of different energies. In this paper, we investigate the global magnetosphere dynamics and magnetosphere–ionosphere (M–I) coupling during the dropout events using multipoint measurements by Van Allen Probes, TWINS, and AMPERE together with the output of the two-way coupled global BATS-R-US–CRCM model. We find different behavior for two pairs of dropouts. For one pair, the same pattern was repeated: (1) weak nightside Region 1 and 2 Birkeland currents before and during the dropout; (2) intensification of Region 2 currents after the dropout; and (3) a particle injection detected by TWINS after the dropout. The model predicted similar behavior of Birkeland currents. TWINS low-altitude emissions demonstrated high variability during these intervals, indicating high geomagnetic activity in the near-Earth tail region. For the second pair of dropouts, the structure of both Birkeland currents and ENA emissions was relatively stable. The model also showed quasi-stationary behavior of Birkeland currents and simulated ENA emissions with gradual ring current buildup. We confirm that the first pair of dropouts was caused by large-scale motions of the OCB (open–closed boundary) during substorm activity. We show the new result that this OCB motion was associated with global changes in Birkeland (M–I coupling) currents and strong modulation of low-altitude ion precipitation. The second pair of dropouts is the result of smaller OCB disturbances not related to magnetospheric substorms. The local observations of the first pair of dropouts result from a global magnetospheric reconfiguration, which is manifested by ion injections and enhanced ion precipitation detected by TWINS and changes in the structure of Birkeland currents detected by AMPERE. This study demonstrates that multipoint measurements along with the global model results enable the reconstruction of a more complete system-level picture of the dropout events and provides insight into M–I coupling aspects that have not previously been investigated.

79 ASTRONOMY AND ASTROPHYSICS↗
NASA NTRS1972

High field CdS detector for infrared radiation

New and highly sensitive method of detecting infrared irradiation makes possible solid state infrared detector which is more sensitive near room temperature than usual photoconductive low band gap semiconductor devices. Reconfiguration of high field domains in cadmium sulphide crystals provides basis for discovery.

Tyagi, R. C.↗
NASA NTRS1971

Voter-comparator-switch optimization study

The design optimization and simulation effort of the voter-comparator switch (VCS) element are described. The VCS is an adaptive voter element that performs failure detection and reconfiguration function in a computer system designed to tolerate any three single failures in a fail operational fail operational fail safe manner. Detailed logic equations were developed and the design was evaluated and refined using a logic level fault simulator.

Jurison, J.↗
NASA NTRS1972

Strapdown platforms using redundant two-degree-of-freedom gyros

A new concept of high reliability strapdown attitude sensing systems for space vehicles is presented. Each system utilizes a set of redundant two-degree-of-freedom gyros. An optimum system configuration is obtained for maximum system reliability and the best measurement accuracy. Improved accuracy of the final data is obtained by using the least-square data reduction technique. Each system possesses a sensor performance management feature which is capable of failure detection, faulty gyro identification, system reconfiguration, and possibly, sensor recalibration. Improvement in reliability as compared to other types of strapdown systems is demonstrated. Details of the development are described in terms of a system containing four gyros.

Hung, J. C.↗
NASA NTRS1971

Logic design for dynamic and interactive recovery.

Recovery in a fault-tolerant computer means the continuation of system operation with data integrity after an error occurs. This paper delineates two parallel concepts embodied in the hardware and software functions required for recovery; detection, diagnosis, and reconfiguration for hardware, data integrity, checkpointing, and restart for the software. The hardware relies on the recovery variable set, checking circuits, and diagnostics, and the software relies on the recovery information set, audit, and reconstruct routines, to characterize the system state and assist in recovery when required. Of particular utility is a handware unit, the recovery control unit, which serves as an interface between error detection and software recovery programs in the supervisor and provides dynamic interactive recovery.

Carter, W. C.↗
NASA NTRS1972

Optimum spaceborne computer system design by simulation

A deterministic digital simulation model is described which models the Automatically Reconfigurable Modular Multiprocessor System (ARMMS), a candidate computer system for future manned and unmanned space missions. Use of the model as a tool in configuring a minimum computer system for a typical mission is demonstrated. The configuration which is developed as a result of studies with the simulator is optimal with respect to the efficient use of computer system resources, i.e., the configuration derived is a minimal one. Other considerations such as increased reliability through the use of standby spares would be taken into account in the definition of a practical system for a given mission.

Williams, T.↗
NASA NTRS1972

Memory interface simulator: A computer design aid

Results are presented of a study conducted with a digital simulation model being used in the design of the Automatically Reconfigurable Modular Multiprocessor System (ARMMS), a candidate computer system for future manned and unmanned space missions. The model simulates the activity involved as instructions are fetched from random access memory for execution in one of the system central processing units. A series of model runs measured instruction execution time under various assumptions pertaining to the CPU's and the interface between the CPU's and RAM. Design tradeoffs are presented in the following areas: Bus widths, CPU microprogram read only memory cycle time, multiple instruction fetch, and instruction mix.

Taylor, D. S.↗
NASA NTRS1973

Optimum spaceborne computer system design by simulation

A deterministic simulator is described which models the Automatically Reconfigurable Modular Multiprocessor System (ARMMS), a candidate computer system for future manned and unmanned space missions. Its use as a tool to study and determine the minimum computer system configuration necessary to satisfy the on-board computational requirements of a typical mission is presented. The paper describes how the computer system configuration is determined in order to satisfy the data processing demand of the various shuttle booster subsytems. The configuration which is developed as a result of studies with the simulator is optimal with respect to the efficient use of computer system resources.

Williams, T.↗
NASA NTRS1971

Study of Alternate Space Shuttle Concepts. Volume 2. Part 1: Concept Analysis and Definition

Three different space shuttle systems have been defined and analyzed. The first is a stage-and-one-half system optimized to meet program requirements. The second is a two-stage, fully reusable system also designed to meet program requirements. The third is a convertible system which operates initially as a stage-and-one-half system and is subsequently converted to a two-stage, fully reusable system by reconfiguration of the orbiter vehicle and development of a booster vehicle. The design and performance of this third system must necessarily be compromised somewhat to facilitate the conversion. For each system, the applicable requirements, ground rules, and assumptions are defined. The characteristics of each system are listed and a detailed description and analysis of the system are presented. Finally, a cost analysis for the system is given.

Source record↗
NASA NTRS1973

Highly reliable processor system for space application.

Description of a redundant processor organization which can be implemented with off-the-shelf processors for fault-tolerant operation. Reconfiguration can be performed automatically in a transientless manner. To support this system configuration and redundancy management concept, an operating system referred to as a synchronous executive has been designed. This system is directed at real-time closed-loop space applications where minimum response time, no degradation of software solution, and system simplicity are of importance. The system is based on a multicomputer organization with each machine solving the same problem based on a common set of inputs. Processor status is fed to a higher-level device which selects a controlling processor for controlling outputs and monitoring computers for fault detection.

Tsou, H. S. E.↗
NASA NTRS1973

High-reliability strapdown platforms using two-degree-of-freedom gyros.

This paper presents a new concept of high-reliability strapdown attitude sensing systems for space vehicles. Each system utilizes a set of redundant two-degree-of-freedom gyros. An optimum system configuration is obtained for maximum system reliability and the best measurement accuracy. Improved accuracy of the final data is obtained by using the least-square data reduction technique. Each system possesses a 'sensor performance management' feature which is capable of failure detection, faulty gyro identification, system reconfiguration, and, possibly, sensor recalibration. Improvement in reliability, as compared to other types of strapdown systems, is demonstrated. Details of the development are described in terms of a system containing four gyros.

Hung, J. C.↗
NASA NTRS1974

Modular digital computer system design

Automatically-Reconfigurable Modular Multiprocessor System (ARMMS) provides redundant processing with dynamic mode switching in real time. Design will provide higher computer capability than that presently available for same amount of hardware and will furnish modular system which is responsive to diverse problems effectively.

Source record↗
NASA NTRS1972

Design of a modular digital computer system, DRL 4

The design is reported of an advanced modular computer system designated the Automatically Reconfigurable Modular Multiprocessor System, which anticipates requirements for higher computing capacity and reliability for future spaceborne computers. Subjects discussed include: an overview of the architecture, mission analysis, synchronous and nonsynchronous scheduling control, reliability, and data transmission.

Source record↗
NASA NTRS1973

Theory of reliable systems

The analysis and design of reliable systems are discussed. The attributes of system reliability studied are fault tolerance, diagnosability, and reconfigurability. Objectives of the study include: to determine properties of system structure that are conducive to a particular attribute; to determine methods for obtaining reliable realizations of a given system; and to determine how properties of system behavior relate to the complexity of fault tolerant realizations. A list of 34 references is included.

Meyer, J. F.↗
NASA NTRS1974

Appendices for the Space Applications program, 1974

To achieve truly low cost system design with direct evolution for inorbit shuttle resupply, a modular building block approach has been adopted. The heart of the modular building block concept lies in the ability to use a common set of nonoptimized subsystems in such a way that a wide variety of missions can be flown with no detrimental impact on performance. By standardizing the mechanical configurations and electrical interfaces of the subsystem modules, and by designing each of them to be structurally and thermally independent entities, it is possible to cluster these building blocks or modules about an instrument system so as to adequately perform the mission without the need for subsystem redevelopments for each mission. This system concept offers the following capabilities: (1) the ability to launch and orbit the observatory by either the Delta, the Titan, or the space shuttle. (2) the ability to completely reconfigure the spacecraft subsystems for different launch vehicles, and (3) the ability to perform in-orbit resupply and/or emergency retrieval of the observatory.

Source record↗
NASA NTRS1973

The design and utilization of a spacelab for sortie missions

Consideration of the feasibility of a 'sortie' type mission in which a manned laboratory is carried into near-earth orbit for a 7- to 30-day mission and is then returned to earth for reconfiguration and subsequent reflight. The fundamental difference in approach between the proposed Spacelab and concepts previously considered for space stations is that the spacelab will remain attached to the Shuttle Orbiter during its entire mission in space. An important trend in the design approach is the introduction of structural modularity of the Spacelab. Another factor which has been a significant design consideration is the need to properly balance the Shuttle and Spacelab configuration over a wide range of aerodynamic regimes and landing conditions. Also considered are the requirements which may be placed on the laboratory by potential users in fields of science and space applications.

Lord, D. R.↗