50,501 research outputs found

    Methods of Technical Prognostics Applicable to Embedded Systems

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    HlavnĂ­ cĂ­lem dizertace je poskytnutĂ­ ucelenĂ©ho pohledu na problematiku technickĂ© prognostiky, kterĂĄ nachĂĄzĂ­ uplatněnĂ­ v tzv. prediktivnĂ­ ĂșdrĆŸbě zaloĆŸenĂ© na trvalĂ©m monitorovĂĄnĂ­ zaƙízenĂ­ a odhadu Ășrovně degradace systĂ©mu či jeho zbĂœvajĂ­cĂ­ ĆŸivotnosti a to zejmĂ©na v oblasti komplexnĂ­ch zaƙízenĂ­ a strojĆŻ. V současnosti je technickĂĄ diagnostika poměrně dobƙe zmapovanĂĄ a reĂĄlně nasazenĂĄ na rozdĂ­l od technickĂ© prognostiky, kterĂĄ je stĂĄle rozvĂ­jejĂ­cĂ­m se oborem, kterĂœ ovĆĄem postrĂĄdĂĄ větĆĄĂ­ mnoĆŸstvĂ­ reĂĄlnĂœch aplikaci a navĂ­c ne vĆĄechny metody jsou dostatečně pƙesnĂ© a aplikovatelnĂ© pro embedded systĂ©my. DizertačnĂ­ prĂĄce pƙinĂĄĆĄĂ­ pƙehled zĂĄkladnĂ­ch metod pouĆŸitelnĂœch pro Ășčely predikce zbĂœvajĂ­cĂ­ uĆŸitnĂ© ĆŸivotnosti, jsou zde popsĂĄny metriky pomocĂ­, kterĂœch je moĆŸnĂ© jednotlivĂ© pƙístupy porovnĂĄvat aĆ„ uĆŸ z pohledu pƙesnosti, ale takĂ© i z pohledu vĂœpočetnĂ­ nĂĄročnosti. Jedno z dizertačnĂ­ch jader tvoƙí doporučenĂ­ a postup pro vĂœběr vhodnĂ© prognostickĂ© metody s ohledem na prognostickĂĄ kritĂ©ria. DalĆĄĂ­m dizertačnĂ­m jĂĄdrem je pƙedstavenĂ­ tzv. částicovĂ©ho filtrovanĂ­ (particle filtering) vhodnĂ© pro model-based prognostiku s ověƙenĂ­m jejich implementace a porovnĂĄnĂ­m. HlavnĂ­ dizertačnĂ­ jĂĄdro reprezentuje pƙípadovou studii pro velmi aktuĂĄlnĂ­ tĂ©ma prognostiky Li-Ion baterii s ohledem na trvalĂ© monitorovĂĄnĂ­. PƙípadovĂĄ studie demonstruje proces prognostiky zaloĆŸenĂ© na modelu a srovnĂĄvĂĄ moĆŸnĂ© pƙístupy jednak pro odhad doby pƙed vybitĂ­m baterie, ale takĂ© sleduje moĆŸnĂ© vlivy na degradaci baterie. SoučástĂ­ prĂĄce je zĂĄkladnĂ­ ověƙenĂ­ modelu Li-Ion baterie a nĂĄvrh prognostickĂ©ho procesu.The main aim of the thesis is to provide a comprehensive overview of technical prognosis, which is applied in the condition based maintenance, based on continuous device monitoring and remaining useful life estimation, especially in the field of complex equipment and machinery. Nowadays technical prognosis is still evolving discipline with limited number of real applications and is not so well developed as technical diagnostics, which is fairly well mapped and deployed in real systems. Thesis provides an overview of basic methods applicable for prediction of remaining useful life, metrics, which can help to compare the different approaches both in terms of accuracy and in terms of computational/deployment cost. One of the research cores consists of recommendations and guide for selecting the appropriate forecasting method with regard to the prognostic criteria. Second thesis research core provides description and applicability of particle filtering framework suitable for model-based forecasting. Verification of their implementation and comparison is provided. The main research topic of the thesis provides a case study for a very actual Li-Ion battery health monitoring and prognostics with respect to continuous monitoring. The case study demonstrates the prognostic process based on the model and compares the possible approaches for estimating both the runtime and capacity fade. Proposed methodology is verified on real measured data.

    An Overview on Application of Machine Learning Techniques in Optical Networks

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    Today's telecommunication networks have become sources of enormous amounts of widely heterogeneous data. This information can be retrieved from network traffic traces, network alarms, signal quality indicators, users' behavioral data, etc. Advanced mathematical tools are required to extract meaningful information from these data and take decisions pertaining to the proper functioning of the networks from the network-generated data. Among these mathematical tools, Machine Learning (ML) is regarded as one of the most promising methodological approaches to perform network-data analysis and enable automated network self-configuration and fault management. The adoption of ML techniques in the field of optical communication networks is motivated by the unprecedented growth of network complexity faced by optical networks in the last few years. Such complexity increase is due to the introduction of a huge number of adjustable and interdependent system parameters (e.g., routing configurations, modulation format, symbol rate, coding schemes, etc.) that are enabled by the usage of coherent transmission/reception technologies, advanced digital signal processing and compensation of nonlinear effects in optical fiber propagation. In this paper we provide an overview of the application of ML to optical communications and networking. We classify and survey relevant literature dealing with the topic, and we also provide an introductory tutorial on ML for researchers and practitioners interested in this field. Although a good number of research papers have recently appeared, the application of ML to optical networks is still in its infancy: to stimulate further work in this area, we conclude the paper proposing new possible research directions

    Report from GI-Dagstuhl Seminar 16394: Software Performance Engineering in the DevOps World

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    This report documents the program and the outcomes of GI-Dagstuhl Seminar 16394 "Software Performance Engineering in the DevOps World". The seminar addressed the problem of performance-aware DevOps. Both, DevOps and performance engineering have been growing trends over the past one to two years, in no small part due to the rise in importance of identifying performance anomalies in the operations (Ops) of cloud and big data systems and feeding these back to the development (Dev). However, so far, the research community has treated software engineering, performance engineering, and cloud computing mostly as individual research areas. We aimed to identify cross-community collaboration, and to set the path for long-lasting collaborations towards performance-aware DevOps. The main goal of the seminar was to bring together young researchers (PhD students in a later stage of their PhD, as well as PostDocs or Junior Professors) in the areas of (i) software engineering, (ii) performance engineering, and (iii) cloud computing and big data to present their current research projects, to exchange experience and expertise, to discuss research challenges, and to develop ideas for future collaborations

    Smart Grid Technologies in Europe: An Overview

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    The old electricity network infrastructure has proven to be inadequate, with respect to modern challenges such as alternative energy sources, electricity demand and energy saving policies. Moreover, Information and Communication Technologies (ICT) seem to have reached an adequate level of reliability and flexibility in order to support a new concept of electricity network—the smart grid. In this work, we will analyse the state-of-the-art of smart grids, in their technical, management, security, and optimization aspects. We will also provide a brief overview of the regulatory aspects involved in the development of a smart grid, mainly from the viewpoint of the European Unio

    A Simple Flood Forecasting Scheme Using Wireless Sensor Networks

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    This paper presents a forecasting model designed using WSNs (Wireless Sensor Networks) to predict flood in rivers using simple and fast calculations to provide real-time results and save the lives of people who may be affected by the flood. Our prediction model uses multiple variable robust linear regression which is easy to understand and simple and cost effective in implementation, is speed efficient, but has low resource utilization and yet provides real time predictions with reliable accuracy, thus having features which are desirable in any real world algorithm. Our prediction model is independent of the number of parameters, i.e. any number of parameters may be added or removed based on the on-site requirements. When the water level rises, we represent it using a polynomial whose nature is used to determine if the water level may exceed the flood line in the near future. We compare our work with a contemporary algorithm to demonstrate our improvements over it. Then we present our simulation results for the predicted water level compared to the actual water level.Comment: 16 pages, 4 figures, published in International Journal Of Ad-Hoc, Sensor And Ubiquitous Computing, February 2012; V. seal et al, 'A Simple Flood Forecasting Scheme Using Wireless Sensor Networks', IJASUC, Feb.201
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