96,514 research outputs found
Reliability and fault tolerance in the European ADS project
After an introduction to the theory of reliability, this paper focuses on a
description of the linear proton accelerator proposed for the European ADS
demonstration project. Design issues are discussed and examples of cases of
fault tolerance are given.Comment: 14 pages, contribution to the CAS - CERN Accelerator School: Course
on High Power Hadron Machines; 24 May - 2 Jun 2011, Bilbao, Spai
Ultrareliable, fault-tolerant control systems: A conceptual description
An Ultrareliable, Fault-Tolerant, Control-System (UFTCS) concept is described using a systems design philosophy which allows development of system structures containing virtually no common elements. Common elements limit achievable system reliability and can cause catastrophic loss of fault-tolerant system function. The UFTCS concept provides the means for removing common system elements by permitting the elements of the system to operate as independent, uncoupled entities. Multiple versions of the application program are run on dissimilar hardware. Fault tolerance is achieved through the use of static redundancy management
Study of high voltage solar array configurations with integrated power control electronics
Solar array electrical configurations for voltage regulatio
A study of the selection of microcomputer architectures to automate planetary spacecraft power systems
Performance and reliability models of alternate microcomputer architectures as a methodology for optimizing system design were examined. A methodology for selecting an optimum microcomputer architecture for autonomous operation of planetary spacecraft power systems was developed. Various microcomputer system architectures are analyzed to determine their application to spacecraft power systems. It is suggested that no standardization formula or common set of guidelines exists which provides an optimum configuration for a given set of specifications
Advanced flight control system study
The architecture, requirements, and system elements of an ultrareliable, advanced flight control system are described. The basic criteria are functional reliability of 10 to the minus 10 power/hour of flight and only 6 month scheduled maintenance. A distributed system architecture is described, including a multiplexed communication system, reliable bus controller, the use of skewed sensor arrays, and actuator interfaces. Test bed and flight evaluation program are proposed
Mars Spacecraft Power System Development Final Report
Development of optimum Mariner spacecraft power system for application to future flyby and orbiter mission
Optimization study of high power static inverters and converters Final report
Optimization study and basic performance characteristics for conceptual designs for high power static inverter
Digital flight control research
The results of studies which were undertaken to contribute to the design of digital flight control systems, particularly for transport aircraft are presented. In addition to the overall design considerations for a digital flight control system, the following topics are discussed in detail: (1) aircraft attitude reference system design, (2) the digital computer configuration, (3) the design of a typical digital autopilot for transport aircraft, and (4) a hybrid flight simulator
A scalable reliable instant messenger using the SD Erlang libraries
Erlang has world leading reliability capabilities, but while it scales
extremely well within a single node, distributed Erlang has some
scalability issues. The Scalable Distributed (SD) Erlang libraries
have been designed to address the scalability limitations while
preserving the reliability model, and shown to deliver significant
performance benefits above 40 hosts using some relatively simple
benchmarks.
This paper compares the reliability and scalability of SD Erlang
and distributed Erlang using an Instant Messaging (IM) server
benchmark that is a far more typical Erlang application; a relatively
large and sophisticated benchmark; has throughput as the key
performance metric; and uses non-trivial reliability mechanisms.
We provide a careful reliability evaluation using chaos monkey.
The key performance results consider scenarios with and without
failures on up to 17 server hosts (272 cores). We show that SD
Erlang adds no performance overhead when all nodes are grouped in
a single s_group. However, either adding redundant router nodes in
distributed Erlang applications, or dividing a set of nodes into small
s_groups in SD Erlang applications, have small negative impact.
Both the distributed Erlang and SD Erlang IM tolerate failures and,
up to the failure rates measured, the failures have no impact on
throughput. The IM implementations show that SD Erlang preserves
the distributed Erlang reliability properties and mechanisms
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