3,828 research outputs found

    Transient fault behavior in a microprocessor: A case study

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    An experimental analysis is described which studies the susceptibility of a microprocessor based jet engine controller to upsets caused by current and voltage transients. A design automation environment which allows the run time injection of transients and the tracing from their impact device to the pin level is described. The resulting error data are categorized by the charge levels of the injected transients by location and by their potential to cause logic upsets, latched errors, and pin errors. The results show a 3 picoCouloumb threshold, below which the transients have little impact. An Arithmetic and Logic Unit transient is most likely to result in logic upsets and pin errors (i.e., impact the external environment). The transients in the countdown unit are potentially serious since they can result in latched errors, thus causing latent faults. Suggestions to protect the processor against these errors, by incorporating internal error detection and transient suppression techniques, are also made

    Temperature Effects on Soft Error Rate Due to Atmospheric Neutrons on 28 nm FPGAs

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    In ambiti come l'avionica e l'automotive e' difficile garantire un'alta affidabilita' dell'elettronica per la presenza di radiazione. In tale lavoro sperimentale su FPGA si vuole tracciare una relazione fra il tasso di Single Event Upset dovuti a neutroni atmosferici nelle memorie SRAM e la frequenza di funzionamento del circuito. I risultati mostrano che e' difficile avere una spiegazione teorica del fenomeno e che il tasso di SEU e' legato più alla temperatura del ciruito che alla frequenza.ope

    Fault-tolerant building-block computer study

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    Ultra-reliable core computers are required for improving the reliability of complex military systems. Such computers can provide reliable fault diagnosis, failure circumvention, and, in some cases serve as an automated repairman for their host systems. A small set of building-block circuits which can be implemented as single very large integration devices, and which can be used with off-the-shelf microprocessors and memories to build self checking computer modules (SCCM) is described. Each SCCM is a microcomputer which is capable of detecting its own faults during normal operation and is described to communicate with other identical modules over one or more Mil Standard 1553A buses. Several SCCMs can be connected into a network with backup spares to provide fault-tolerant operation, i.e. automated recovery from faults. Alternative fault-tolerant SCCM configurations are discussed along with the cost and reliability associated with their implementation

    Design methods for fault-tolerant navigation computers

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    Design methods for fault tolerant navigation computer

    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

    Evaluation of Resiliency in a Wide-area Backup Protection System via Model Checking

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    Modern civilization relies heavily on having access to reliable power sources. Recent history has shown that present day protection systems are not adequate. Numerous backup protection (BP) systems have been proposed to mitigate the impact of primary protection system failures. Many of these novel BP systems rely on autonomous agents communicating via wide-area networks. These systems are highly complex and their control logic is based on distributed computing. Model checking has been shown to be a powerful tool in analyzing the behavior of distributed systems. In this research the model checker SPIN is used to evaluate the resiliency of an agent based wide-area backup protection (WABP) system. All combinations of WABP system component malfunctions that lead to system failure are identified and classified. The results of this research indicate that the WABP system evaluated is more resilient to component malfunctions than previously reported. Possible WABP system improvements are introduced as well

    System data communication structures for active-control transport aircraft, volume 2

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    The application of communication structures to advanced transport aircraft are addressed. First, a set of avionic functional requirements is established, and a baseline set of avionics equipment is defined that will meet the requirements. Three alternative configurations for this equipment are then identified that represent the evolution toward more dispersed systems. Candidate communication structures are proposed for each system configuration, and these are compared using trade off analyses; these analyses emphasize reliability but also address complexity. Multiplex buses are recognized as the likely near term choice with mesh networks being desirable for advanced, highly dispersed systems

    Pre-clinical validation and risk management of autonomous tumor prosthesis using FMEA approach

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    Since prostheses are biomedical devices implanted directly on the patient's body, they carry a higher risk compared to other engineering products. In the development process, it is a critical issue to identify potential errors and malfunctions that may arise during the clinical use of prostheses and to take precautions against them. Autonomous tumor prostheses have a higher risk than any other prosthesis due to its extension capacity of approximately 100 mm, having a large battery in its structure and performing non-clinical extension without physician control. In this study, the risk analysis of the autonomous tumor prosthesis previously developed by the authors was performed using the failure mode and effects analysis (FMEA) method. In order to determine potential failure risks, a literature review was performed on clinical errors of tumor prostheses. In addition, malfunctions caused by each component of the prosthesis have been identified. Risk Priority Number (RPN) values are calculated for each risk determined. The design of the prosthesis was changed by taking the necessary precautions for the risks with high RPN values. After taking the necessary precautions, the RPN values of the risks that the prosthesis still carries have been recalculated and discussed. As a result of the measures taken, the RPN values of all risks were reduced to below the threshold value that was generally accepted

    Measurement and Analysis of Electromagnetic Field, Noise and IC Logic Error due to system-level ESD

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    Department of Electrical EngineeringAs the high performance very-large-scale integration (VLSI) systems operate with high speed and low voltage, the system-level electrostatic discharge (ESD) event is becoming one of the important noise sources causing logic errors and system malfunctions such as system reboot or fault. To understand the ESD noise phenomena and improve the system-level ESD noise immunity for devices, the accurate ESD noise measurement and analysis of IC logic errors are necessary. Section I is written for the tendency of ESD research and previous research. This paper presents the noise type correlation by measuring the signal-ground noise and power-ground noise simultaneously on the fundamental F/F operation circuit and shows the type of error from chip, in section II. Furthermore, the decoupling capacitors (de-cap) effect that can reduce the error occurrence by checking the error rate are analyzed. A generator is designed on the main board which is based on real operating laptop, and the chip on dual in-line memory module (DIMM) is also designed to perform the basic F/F operation. The clock and data input from generator are connected to the chip on the DIMM through the small outline dual in-line memory module (SODIMM) socket. ESD occurs at the corner of the ground plane of main board. The specification of the ESD generator satisfies IEC 61000-4-2 [1]. The ESD current flows along the ground strap, and affects the DIMM. IN-ground, CLK-ground, OUT-ground and power-ground on the DIMM are simultaneously measured to determine the effect of ESD on the main board. To analyze the error ratio according to the ESD voltage level, the voltage setup of the ESD gun is 3kV, 5kV and 8kV. To investigate the effects of chip shielding and DIMM de-caps on the error probability of DIMM, the experiment is conducted under the several conditions. After confirming the normal operation for each condition, the error type on the DIMM due to the ESD occurred in the circuit is analyzed and the statistics are shown. The results are verified by H-spice simulation, Vector Network Analyzer (VNA) and HFSS simulation. In order to obtain the improvement method of the DIMM immunity, experiments are conducted to find out the effective position and number of DIMM de-cap. Accurate measurements of electromagnetic fields are also essential to analyze the radiated noise due to unwanted electrostatic discharge (ESD) events at electronic devices. Usually, to know the radiated noise by ESD events, the voltages induced at field probes are measured, and the fields are obtained from the voltage by de-convolving the probe factor. In section ???, the two probe-factor deconvolution methods are investigated and compared in the measurements of the fields induced by system-level ESD events.ope

    Predictive Maintenance Support System in Industry 4.0 Scenario

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    The fourth industrial revolution that is being witnessed nowadays, also known as Industry 4.0, is heavily related to the digitization of manufacturing systems and the integration of different technologies to optimize manufacturing. By combining data acquisition using specific sensors and machine learning algorithms to analyze this data and predict a failure before it happens, Predictive Maintenance is a critical tool to implement towards reducing downtime due to unpredicted stoppages caused by malfunctions. Based on the reality of Commercial Specialty Tires factory at Continental Mabor - Indústria de Pneus, S.A., the present work describes several problems faced regarding equipment maintenance. Taking advantage of the information gathered from studying the processes incorporated in the factory, it is designed a solution model for applying predictive maintenance in these processes. The model is divided into two primary layers, hardware, and software. Concerning hardware, sensors and respective applications are delineated. In terms of software, techniques of data analysis namely machine learning algorithms are described so that the collected data is studied to detect possible failures
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