7,297 research outputs found

    Satellite on-board processing for earth resources data

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    Results of a survey of earth resources user applications and their data requirements, earth resources multispectral scanner sensor technology, and preprocessing algorithms for correcting the sensor outputs and for data bulk reduction are presented along with a candidate data format. Computational requirements required to implement the data analysis algorithms are included along with a review of computer architectures and organizations. Computer architectures capable of handling the algorithm computational requirements are suggested and the environmental effects of an on-board processor discussed. By relating performance parameters to the system requirements of each of the user requirements the feasibility of on-board processing is determined for each user. A tradeoff analysis is performed to determine the sensitivity of results to each of the system parameters. Significant results and conclusions are discussed, and recommendations are presented

    EDAC software implementation to protect small satellites memory

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    Radiation is a well-known problem for satellites in space. It can produce different negative effects on electronic components which can provoke errors and failures. Therefore, mitigating these effects is especially important for the success of space missions. One of the techniques to increase the reliability of memory chips and reduce transient errors and permanent faults is Error Detection and Correction (EDAC). EDAC codes are characterised by the use of redundancy to detect and correct errors. This final project consists in the implementation of a software EDAC algorithm to protect the main memory of a microcontroller. The implementation requirements and the issues of software EDAC are described and the test results are commented

    Proposal of a health care network based on big data analytics for PDs

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    Health care networks for Parkinson's disease (PD) already exist and have been already proposed in the literature, but most of them are not able to analyse the vast volume of data generated from medical examinations and collected and organised in a pre-defined manner. In this work, the authors propose a novel health care network based on big data analytics for PD. The main goal of the proposed architecture is to support clinicians in the objective assessment of the typical PD motor issues and alterations. The proposed health care network has the ability to retrieve a vast volume of acquired heterogeneous data from a Data warehouse and train an ensemble SVM to classify and rate the motor severity of a PD patient. Once the network is trained, it will be able to analyse the data collected during motor examinations of a PD patient and generate a diagnostic report on the basis of the previously acquired knowledge. Such a diagnostic report represents a tool both to monitor the follow up of the disease for each patient and give robust advice about the severity of the disease to clinicians

    In-Orbit Radiation Effects Monitoring on the UoSat Satellites

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    Since the summer of 1988, radiation effects, in particular single event upset (SEU) phenomena, have been monitored in the three mass semiconductor memory systems onboard the University of Surrey\u27s UoSAT-2 satellite, which is in a 700 km, near-polar low-Earth orbit. Almost 5000 events have now been logged by the spacecraft, and these have been assembled into a database for analysis by ground-based software. This software has allowed the SEU sensitivity of different device types to be analyzed, and the relative performance of the Mostek 4116, Texas 4416 NMOS DRAMs, the Toshiba TC5516, Harris 6564 and 6516, and the Hitachi 6264 and 6116 CMOS SRAMS, has been evaluated. The logs of in-orbit SEUs on UoSAT-2 have provided several interesting statistics, allowing direct comparison of static and dynamic RAMs ranging in capacity from 4 kilobits to 64 kilobits per chip. An unexpected result has been that none of the 288K bytes of 8-bit wide static RAM on UoSAT-2 have shown multiple-bit (per byte) upsets over the monitoring period. Also, the orbital analysis of UoSAT-2 SEUs shows an overwhelming concentration of events in the South Atlantic Anomaly for all device types. Further studies are now underway with the University of Surrey\u27s UoSAT-3 satellite. This spacecraft carries over 4M bytes of semiconductor memory as part of its store-and-forward communications payload, together with the Cosmic Particle / Total Dose Experiments (CPE / TDE), providing direct measurements of the space radiation environment

    Radiation Effects on Emerging Technologies: Implications of Space Weather Risk Management

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    As NASA and its space partners endeavor to develop a network of satellites capable of supporting humankind's needs for advanced space weather prediction and understanding, one of the key challenges is to design a space system to operate in the natural space radiation environment In this paper, we present a description of the natural space radiation environment, the effects of interest to electronic or photonic systems, and a sample of emerging technologies and their specific issues. We conclude with a discussion of operations in the space radiation hazard and considerations for risk management

    Characterization of Hardening by Design Techniques on Commercial, Small Feature Sized Field-Programmable Gate Arrays

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    In this thesis, a methodology is developed to experimentally test and evaluate a programmable logic device unde r gamma irradiation. The purpose of which is to determine the radiation effects and characterize the improvements of various hardening by design techniques. The techniques analyzed in this thesis include Error Correction Coding (ECC) and Triple Modular Redundancy (TMR). The TMR circuit includes three different functional implementations of adders compared to TMR voted circuits of those same adders. The TMR is implemented with the same functional adders and as a Functional TMR (FTMR) with three different function adders that are voted on. The three functional adders are: a behavioral adder that allows the FPGA synthesis software to create the implementation, a ripple carry adder that consists of multiple single bit full adders linked together, and a carry look ahead adder that operates the fastest by using an algorithm that creates generate and propagate signals. These adders are connected to single voter TMR and FTMR circuits to evaluate the improvements that could be obtained. The ECC circuit includes Block RAM (BRAM) and Distributed RAM memory elements that are loaded both with ECC and non-error corrected data. The circuit is designed to check for errors in memory data, stuck bit values in the memory, and the performance improvements that ECC provides the system

    Towards a cyber physical system for personalised and automatic OSA treatment

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    Obstructive sleep apnea (OSA) is a breathing disorder that takes place in the course of the sleep and is produced by a complete or a partial obstruction of the upper airway that manifests itself as frequent breathing stops and starts during the sleep. The real-time evaluation of whether or not a patient is undergoing OSA episode is a very important task in medicine in many scenarios, as for example for making instantaneous pressure adjustments that should take place when Automatic Positive Airway Pressure (APAP) devices are used during the treatment of OSA. In this paper the design of a possible Cyber Physical System (CPS) suited to real-time monitoring of OSA is described, and its software architecture and possible hardware sensing components are detailed. It should be emphasized here that this paper does not deal with a full CPS, rather with a software part of it under a set of assumptions on the environment. The paper also reports some preliminary experiments about the cognitive and learning capabilities of the designed CPS involving its use on a publicly available sleep apnea database

    Application of advanced on-board processing concepts to future satellite communications systems: Bibliography

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    Abstracts are presented of a literature survey of reports concerning the application of signal processing concepts. Approximately 300 references are included
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