52,745 research outputs found

    Advanced information processing system: The Army fault tolerant architecture conceptual study. Volume 2: Army fault tolerant architecture design and analysis

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    Described here is the Army Fault Tolerant Architecture (AFTA) hardware architecture and components and the operating system. The architectural and operational theory of the AFTA Fault Tolerant Data Bus is discussed. The test and maintenance strategy developed for use in fielded AFTA installations is presented. An approach to be used in reducing the probability of AFTA failure due to common mode faults is described. Analytical models for AFTA performance, reliability, availability, life cycle cost, weight, power, and volume are developed. An approach is presented for using VHSIC Hardware Description Language (VHDL) to describe and design AFTA's developmental hardware. A plan is described for verifying and validating key AFTA concepts during the Dem/Val phase. Analytical models and partial mission requirements are used to generate AFTA configurations for the TF/TA/NOE and Ground Vehicle missions

    Advanced information processing system: Local system services

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    The Advanced Information Processing System (AIPS) is a multi-computer architecture composed of hardware and software building blocks that can be configured to meet a broad range of application requirements. The hardware building blocks are fault-tolerant, general-purpose computers, fault-and damage-tolerant networks (both computer and input/output), and interfaces between the networks and the computers. The software building blocks are the major software functions: local system services, input/output, system services, inter-computer system services, and the system manager. The foundation of the local system services is an operating system with the functions required for a traditional real-time multi-tasking computer, such as task scheduling, inter-task communication, memory management, interrupt handling, and time maintenance. Resting on this foundation are the redundancy management functions necessary in a redundant computer and the status reporting functions required for an operator interface. The functional requirements, functional design and detailed specifications for all the local system services are documented

    Technology assessment of advanced automation for space missions

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    Six general classes of technology requirements derived during the mission definition phase of the study were identified as having maximum importance and urgency, including autonomous world model based information systems, learning and hypothesis formation, natural language and other man-machine communication, space manufacturing, teleoperators and robot systems, and computer science and technology

    Causality, Information and Biological Computation: An algorithmic software approach to life, disease and the immune system

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    Biology has taken strong steps towards becoming a computer science aiming at reprogramming nature after the realisation that nature herself has reprogrammed organisms by harnessing the power of natural selection and the digital prescriptive nature of replicating DNA. Here we further unpack ideas related to computability, algorithmic information theory and software engineering, in the context of the extent to which biology can be (re)programmed, and with how we may go about doing so in a more systematic way with all the tools and concepts offered by theoretical computer science in a translation exercise from computing to molecular biology and back. These concepts provide a means to a hierarchical organization thereby blurring previously clear-cut lines between concepts like matter and life, or between tumour types that are otherwise taken as different and may not have however a different cause. This does not diminish the properties of life or make its components and functions less interesting. On the contrary, this approach makes for a more encompassing and integrated view of nature, one that subsumes observer and observed within the same system, and can generate new perspectives and tools with which to view complex diseases like cancer, approaching them afresh from a software-engineering viewpoint that casts evolution in the role of programmer, cells as computing machines, DNA and genes as instructions and computer programs, viruses as hacking devices, the immune system as a software debugging tool, and diseases as an information-theoretic battlefield where all these forces deploy. We show how information theory and algorithmic programming may explain fundamental mechanisms of life and death.Comment: 30 pages, 8 figures. Invited chapter contribution to Information and Causality: From Matter to Life. Sara I. Walker, Paul C.W. Davies and George Ellis (eds.), Cambridge University Pres

    Airborne Advanced Reconfigurable Computer System (ARCS)

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    A digital computer subsystem fault-tolerant concept was defined, and the potential benefits and costs of such a subsystem were assessed when used as the central element of a new transport's flight control system. The derived advanced reconfigurable computer system (ARCS) is a triple-redundant computer subsystem that automatically reconfigures, under multiple fault conditions, from triplex to duplex to simplex operation, with redundancy recovery if the fault condition is transient. The study included criteria development covering factors at the aircraft's operation level that would influence the design of a fault-tolerant system for commercial airline use. A new reliability analysis tool was developed for evaluating redundant, fault-tolerant system availability and survivability; and a stringent digital system software design methodology was used to achieve design/implementation visibility

    Preliminary candidate advanced avionics system for general aviation

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    An integrated avionics system design was carried out to the level which indicates subsystem function, and the methods of overall system integration. Sufficient detail was included to allow identification of possible system component technologies, and to perform reliability, modularity, maintainability, cost, and risk analysis upon the system design. Retrofit to older aircraft, availability of this system to the single engine two place aircraft, was considered

    Fsm-Based Enhanced March C- Algorithm For Memory Built-In Self-Test

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    Algorithms plays an important role in the Memory Built-In Self-Test as its structure will define the fault coverage of the system. Thus, the improvement of the algorithms will allow more fault types being identified in single test. For MARCH C- algorithm, it was a quite balance algorithm as it has the ability to cover Address Decoder Fault, Stuck-At Fault, Transition Fault and Coupling Fault but it was not able to identify Read Destructive Fault and Data Retention Fault. To increase the fault coverage of the MARCH C- algorithm on that two fault types, some enhancements were needed to make on the algorithm. Through the analysis of the fault patterns and other algorithm, it was found that multiple read operation within a single MARCH element from MARCH-NU algorithm can aid in the identification of the Read Destructive Fault whereas having HOLD time in the MARCH 9N algorithm would expose the Data Retention Fault. By integrating both new fault identification methodologies into the MARCH C- algorithm and enhance it so that it would able to increase the identification of the Data Retention Fault and Read Destructive Fault by 100% and without causing any performance to interfere with the original fault identification ability. Besides that, the enhanced MARCH C- algorithm can structurally identify the fault types and differentiate among the behavioural faults (Data Retention Faults) and common memory faults as well as among Stuck-At Fault and Transition Fault. Fault injection test were carried out to ensure the coverage of the enhanced MARCH C- algorithm. It was having high passing rate which are 100% v identification of the Stuck-At Fault, Transition Fault, Data Retention Fault, Inversion Read Fault, Incorrect Read Fault and Read Destructive Fault. It also obtained 95.16% for the State Coupling Fault and Idempotent Coupling Fault. As a conclusion, the enhanced MARCH C- algorithm had increased its fault type identification in Data Retention Fault and Read Destructive Fault while having the ability to structurally identify the fault types

    A fault-tolerant multiprocessor architecture for aircraft, volume 1

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    A fault-tolerant multiprocessor architecture is reported. This architecture, together with a comprehensive information system architecture, has important potential for future aircraft applications. A preliminary definition and assessment of a suitable multiprocessor architecture for such applications is developed
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