5,327 research outputs found

    Advanced periodic maintenance scheduling methods for aircraft lifecycle management

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    This paper reviews existing methods and techniques addressing the problem of maintenance support throughout the life cycle for high value manufacturing products such as aircrafts. As part of this doctorate research the analysis of current methods of maintenance scheduling was conducted. In order to contribute to a more comprehensive solution, an advanced approach (algorithm) of periodic maintenance is presented. The authors believe that this approach will reduce the cost of maintenance of high value manufacturing products. The algorithm based on constraint programming methods is briefly presented and the future research directions are discussed

    functional modeling in safety by means of foundational ontologies

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    Abstract Modern theory of safety deals with systemic approach to safety, formalized in form of several systemic prediction models or methods such as FRAM (Functional Resonance Analysis Method) or STAMP (System-Theoretic Accident Model and Processes). The theory of each approach emphasizes different viewpoints to be considered in approaching various industrial safety issues. This paper focuses on FRAM and its functional viewpoint for modern complex sociotechnical systems. The methodology in this paper is based on the utilization of foundational ontologies to conceptualize the core ideas of FRAM, with the focus on the concept of functions as used in theory. The outcomes of the case study in the aviation domain provide for what needs to be determined to properly model functions in FRAM and they allow for better utilization of the method in real-case applications. The results also confirm some previous research, suggesting that modern systemic approach to safety is theoretically grounded on common - or at least complementary - tenets, to be prospectively integrated by means of ontology engineering

    Building a Knowledge Graph for the Air Traffic Management Community

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    Historically, most of the focus in the knowledge graph community has been on the support for web, social network, or product search applications. This paper describes some of our experience in developing a large-scale applied knowledge graph for a more technical audience with more specialized information access and analysis needs - the air traffic management community. We describe ATMGRAPH (NASA's Air Traffic Management (ATM) Knowledge Graph), a knowledge graph created by integrating various sources of structured aviation data, provided in large part by US federal agencies. We review some of the practical challenges we faced in creating this knowledge graph

    Ontologies for Industry 4.0

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    The current fourth industrial revolution, or ‘Industry 4.0’ (I4.0), is driven by digital data, connectivity, and cyber systems, and it has the potential to create impressive/new business opportunities. With the arrival of I4.0, the scenario of various intelligent systems interacting reliably and securely with each other becomes a reality which technical systems need to address. One major aspect of I4.0 is to adopt a coherent approach for the semantic communication in between multiple intelligent systems, which include human and artificial (software or hardware) agents. For this purpose, ontologies can provide the solution by formalizing the smart manufacturing knowledge in an interoperable way. Hence, this paper presents the few existing ontologies for I4.0, along with the current state of the standardization effort in the factory 4.0 domain and examples of real-world scenarios for I4.0.Peer ReviewedPostprint (published version

    Semantic-Web Technology: Applications at NASA

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    We provide a description of work at the National Aeronautics and Space Administration (NASA) on building systems based on Semantic-Web concepts and technologies. NASA has been one of the early adopters of Semantic-Web technologies for practical applications. Indeed there are several ongoing (IT) endeavors on building semantics based systems for use in diverse NASA domains ranging from collaborative scientific activity to accident and mishap investigation to enterprise search to scientific information gathering and integration to aviation safety decision support. We provide a brief overview of many applications and ongoing work with the goal of informing the external community of these NASA endeavors

    Doctor of Philosophy

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    dissertationAir medical transport (AMT) is a complex process that requires coordination of aircraft and highly skilled professionals to transport critically ill patients to definitive care. To achieve optimal performance, medical transport services employ quality and safety management systems (QSMS) to report errors and evaluate performance. Unfortunately, there are no standards for classifying miscommunication in these systems. A thoughtfully developed ontology, based upon theoretical models, provides the foundation within a QSMS for reporting communication errors and standardizing analysis. This research used a mixed-methods, pre-post design, with four distinct studies to analyze communication at the Life Flight AMT service. Study 1 was a qualitative study of communication and miscommunication. Study 2 (pre) was a quantitative study measuring communication errors in reports to the QSMS. Study 3 developed a new communication ontology for the QSMS to improve reporting and analysis of communication errors. Study 4 (post) implemented the new ontology and evaluated its performance for analyzing communication errors in the QSMS. Study 1 showed that communication in this AMT service is a complex process that may require more than 28 communication interactions between 10 or more people and utilize as many as 6 different communication technologies. Omissions of information were the most frequent communication errors described. Study 2 revealed that Life Flight's ontology in their QSMS was inadequate for measuring communication errors. iii Two hundred seventy-eight event reports were reviewed from the QSMS with 58 (21%) having evidence of a communication error during transport. Of those 58 reports, only 18 (31%) could be retrieved by a simple query. A new, theory-based, communication ontology was developed in Study 3. Study 4 showed the new communication ontology more than doubled the ability to retrieve reports with communication errors by simple query of the QSMS (71%). Furthermore, analysis showed that 50% of communication errors occurred at the initial phase of transport. The most frequent errors were information not being forwarded to key persons (37%). This research provided the foundation for describing and measuring communication errors in an AMT Service. Further research is needed to identify strategies that will improve information distribution between persons involved with patient transport

    Web application for reliability analysis within civil aviation domain

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    Analýzy spolehlivosti jsou klíčovými složkami při hodnocení posouzení rizik během fáze návrhu v leteckém průmyslu. Analýza stromu poruch (FTA) a analýza poruchových režimů a efektů (FMEA) se běžně kombinují při analýze systému a vyhodnocování možných poruch. Kombinování metodik vyžaduje sjednocení struktury dat tak, aby byla použitelná pro všechny analytické metody zároveň. Existující aplikace poskytují nástroje samostatně, což vede k nekonzistenci dat, duplikátům a překlepům při migraci napříč aplikacemi. Tato práce si klade za cíl vytvořit rozšiřitelné řešení, které by poskytlo nástroje k provedení jedné z technik FTA a FMEA a přitom se spoléhalo na ontologický model použitelný pro obě techniky zároveň. Diplomová práce analyzuje existující řešení a ontologie a na základě těchto vstupů navrhuje nezbytné požadavky, které jsou ve spolupráci se zúčastněnými doménovými odborníky prioritizovány. Výsledné řešení implementuje aplikaci zaměřenou primárně na FTA, která nabízí definování partonomie systému, konstrukci FTA a automatický převod stromů do FMEA vzhledem k jednotnému ontologickému modelu. Aplikace je na závěr otestována doménovými odborníky na základě skutečných leteckých dat.Reliability analyses are key components in a risk assessment evaluation during the design phase in an aviation industry. Fault Tree Analysis (FTA) and Failure Modes and Effects Analysis (FMEA) are commonly combined together to review the system and to evaluate possible failures. The combination of methodologies requires a unified data usable for all the analyses. Existing applications provide the tools separately which introduces inconsistencies, duplicates and typos when the data are migrated across the applications. This thesis thus aims to create an extensible solution that would provide tools to perform one of FTA and FMEA techniques and yet rely on an ontological model usable for both. The thesis analyses existing solutions and ontologies and given these inputs proposes necessary requirements that are prioritized in cooperation with involved domain experts. The resulting solution implements an application focusing primarily on FTA which offers possibilities for system partonomy definition, FTA construction and an automatic conversion of the trees to FMEA tables given the unified ontological model. The application is finally reviewed by the domain experts on real aviation data

    The Microphysics of Deportation A Critical Reading of Return Flight Monitoring Reports

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    In the paper, I argue there is a whole political logistics to deportation. This is made visible by bringing the concept of microphysics to bear on the topic. Taking the case of enforced and escorted removals from the UK, I show that this logistics is vividly and graphically documented in the inspection reports. Hitherto largely ignored, inspection reports offer researchers a trove of information regarding the mechanisms and procedures of deportation. As I finally draw out, this focus can speak to questions about the relationship of ethics to deportation: the inspection reports show how a certain form of ethical calculation, based on a risk-based approach to the use of force has been inscribed into the practices of deportation. DOI 10.17879/95189425134
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