Phased-Mission Reliability and Importance Measure Analysis for Linear and Circular UAV Swarms

The phased-mission reliability of unmanned aerial vehicle (UAV) swarm refers to its capability to successfully complete the missions of each phase under specified conditions for a specified period. In order to study the reliability of phased-mission in UAV swarm, this paper firstly studies the reliability of a single UAV under fault coverage. Then, considering the mission characteristics of UAV swarm, the consecutive k-out-of-n system is studied to model and predict the reliability of UAV swarm phase mission. Some importance measures are introduced to analyze the influence of UAV in different positions on the reliability of the whole system. Finally, numerical examples of linear and circular UAV swarms are given to demonstrate and verify the correctness of the model. The reliability modeling established in this paper can predict the phased-mission reliability of UAV swarm scientifically

Management of major system programs and projects. Handbook

This Handbook establishes the detailed policies and processes for implementing NMI 7120.4, 'Management of Major System Programs and Projects'. It constitutes a comprehensive source of the specific policies and processes governing management of major development programs/projects and is intended as a resource to the entire program/project management (PPM) community

Aeronautical Engineering: A continuing bibliography with indexes, supplement 107

Reports, articles, and other documents introduced into the NASA scientific and technical information system in February 1979 are listed in this bibliography

Aerospace Safety Advisory Panel

The results of the Panel's activities are presented in a set of findings and recommendations. Highlighted here are both improvements in NASA's safety and reliability activities and specific areas where additional gains might be realized. One area of particular concern involves the curtailment or elimination of Space Shuttle safety and reliability enhancements. Several findings and recommendations address this area of concern, reflecting the opinion that safety and reliability enhancements are essential to the continued successful operation of the Space Shuttle. It is recommended that a comprehensive and continuing program of safety and reliability improvements in all areas of Space Shuttle hardware/software be considered an inherent component of ongoing Space Shuttle operations

1995 BRAC Commission

DoD Depot - Business Plan, Consolidation Study. Box 267.2, XS-002

Space station System Engineering and Integration (SE and I). Volume 2: Study results

A summary of significant study results that are products of the Phase B conceptual design task are contained. Major elements are addressed. Study results applicable to each major element or area of design are summarized and included where appropriate. Areas addressed include: system engineering and integration; customer accommodations; test and program verification; product assurance; conceptual design; operations and planning; technical and management information system (TMIS); and advanced development

Air Force Institute of Technology Research Report 2006

This report summarizes the research activities of the Air Force Institute of Technology’s Graduate School of Engineering and Management. It describes research interests and faculty expertise; lists student theses/dissertations; identifies research sponsors and contributions; and outlines the procedures for contacting the school. Included in the report are: faculty publications, conference presentations, consultations, and funded research projects. Research was conducted in the areas of Aeronautical and Astronautical Engineering, Electrical Engineering and Electro-Optics, Computer Engineering and Computer Science, Systems and Engineering Management, Operational Sciences, Mathematics, Statistics and Engineering Physics

Reliability of multi-channel IEC 61850 mission-critical substation communication networks based on Markov process incorporating linear dynamical systems and calculus inferences.

Doctoral Degree. University of KwaZulu-Natal, Durban.IEC 61850 based Substation Communication Networks (SCN) enable substation processes to be digitalised to fulfil the most sought substation monitoring, protection and control of electrical systems. The standard enables peer-to-peer communication of mission critical messages, aided by onboard diagnostic capabilities to ease the identification of system faults. The implementation of Safety-Related Systems in industrial facilities comprising sensors, logic solvers and final elements in power distribution centres necessitate compliance to IEC 61508 standard, where circuit breakers act as final elements to isolate electrical machines. In recent times, combinatorial methods such as the Reliability Block Diagram have been used to evaluate the architecture of IEC 61850 based SCN reliability and availability due to the simplicity of the approach. These methods, however, assume that all system faults are identified and fully repaired, which is not the case in practice. In this thesis, the reliability of a repairable multi-channel IEC 61850 based SCN architecture is modelled using a structure function and the Markov process while Systems Thinking integrates imperfect repair factors into the model. Thereafter, a novel eigenvalue analysis method based on Markov partitions and symbolic dynamics in the context of linear dynamical systems is used to investigate the impact of imperfect repairs on the system's reliability based on the number of mean state transitions and dynamical behaviour. The eigenvalue method is then advanced by a complimentary analysis technique based on the absorbing Markov Chain process and matrix calculus methods to determine the system's responsiveness to repair factors. The case studies results demonstrate that imperfect repairs cannot be ignored for mission-critical applications because the simplifying assumptions of combinatorial analysis methods greatly over-state the system's reliability performance. The results also indicate that common causes of failure coupled with imperfect repairs significantly negatively impact the system's performance. Moreover, system performance is highly dependent on the diagnostic coverage of the individual subsystems than their repair efficiencies for high diagnostic coverages at 90% and 99% based on ISO 13849-1. Hence, the results demonstrate that emphasis should be more on the system diagnostic coverage for the fact that it is embedded in the system design itself that cannot easily be changed once the system is commissioned and operational

Propuesta de herramientas basadas en fiabilidad para el modelado de sistemas productivos complejos.

La importancia de los costes de mantenimiento en procesos intensivos en el uso de activos, puede alcanzar hasta el 40% de los costes de producción, como, por ejemplo, en los procesos de la gran minería del Cobre (Consejo Minero, 2015). Dada su relevancia, resulta indispensable un estudio acabado de cada uno de los procesos, bajo un enfoque de mantenimiento y de coste de ciclo de vida. El estudio y modelado de fiabilidad, es la piedra angular para un análisis de mantenimiento, ya que se relaciona directamente con el comportamiento de fallos de cada uno de los componentes hasta establecer la relación de dependencia dinámica de cada uno de los equipos en estudio, aspectos que son fundamentales para evaluar criticidad y proyectar costes en fases de inversión y operación (CAPEX y OPEX) (Parra et al., 2012). El modelado de fiabilidad, basa su análisis en la ocurrencia de los fallos de un equipo, a través de distribuciones probabilísticas que permiten ajustar los tiempos de buen funcionamiento, las que dan origen a la función de fiabilidad. Dentro de las distribuciones más utilizadas, están la Exponencial y la Weibull, que permiten modelar el comportamiento de un componente durante todo su ciclo de vida; con fases de rodaje, vida útil y degaste, a través de la curva de la bañera (Dhillon, 2006). El modelado de fiabilidad por componentes se hace extensivo a procesos productivos, lo que permite conocer la fiabilidad por componente y sistemas en su conjunto. Sobre este punto, existen diversas metodologías como Reliability Block Diagram (RBD) (Rausand and Hoyland, 2003; Guo and Yang, 2007), Cadenas de Markov (Welte, 2009), Árboles de Fallo (Rauzy et al., 2007), Gráficos de Fiabilidad (Distefano and Puliafito, 2009), Redes de Petri (PNs) (Volovoi, 2014), entre otros. No obstante a lo anterior, existen relaciones de equipos que, dada su configuración, no es posible modelarlas con las técnicas tradicionales. La realidad de los procesos industriales evidencia que una mayor flexibilidad en dichos procesos mejora la productividad, la eficiencia del propio proceso y, en definitiva, los resultados generales de la empresa. En ese contexto, los sistemas dinámicos alcanzan una gran importancia en el modelado de los procesos productivos. Los sistemas dinámicos son aquellos que cambian con el tiempo, es decir, pueden variar sus relaciones de dependencia con el entorno o bien, su habilidad de funcionar en diversos escenarios. El tema de investigación principal de la presente Tesis Doctoral, presentado en el formato por Compendio de Publicaciones, se desarrolla en la revisión y proposición de las técnicas de modelado de fiabilidad, para la evaluación de impacto de fiabilidad y fallos de elementos individuales que se encuentren inmersos en procesos productivos complejos, permitiendo evaluar la criticidad operacional de cada uno de ellos. La determinación del indicador de criticidad operacional es de vital importancia para la identificación de riesgos operacionales en el interior de los procesos productivos de las empresas, permitiendo facilitar el proceso de toma de decisión de manera efectiva. Actualmente , en la literatura existen diversas investigaciones desarrolladas para identificar los factores que afectan directamente la maximización de beneficios. Estos factores se fundamentan en la consideración empírica de los indicadores de fiabilidad, mantenibilidad y disponibilidad (RAM) (Viveros et al., 2012). Como resultado principal del trabajo de doctorado, se obtienen 3 artículos ISI – JCR y la presentación de 4 artículos en congresos internacionales con proceedings. En cada una de estas publicaciones, el candidato a doctor es el primer autor y su tutor, el segundo. El proyecto de Tesis Doctoral que se presenta, se enmarca dentro de la línea de investigación del grupo Sistemas Inteligentes de Mantenimiento - SIM, perteneciente al Departamento de Organización Industrial y Gestión de Empresas de la Universidad de Sevilla

Air Force Institute of Technology Research Report 2005

This report summarizes the research activities of the Air Force Institute of Technology’s Graduate School of Engineering and Management. It describes research interests and faculty expertise; lists student theses/dissertations; identifies research sponsors and contributions; and outlines the procedures for contacting the school. Included in the report are: faculty publications, conference presentations, consultations, and funded research projects. Research was conducted in the areas of Aeronautical and Astronautical Engineering, Electrical Engineering and Electro-Optics, Computer Engineering and Computer Science, Systems and Engineering Management, Operational Sciences, and Engineering Physics