Search results for "reliability"
showing 10 items of 1563 documents
Reliability Analysis of Systems Containing Complex Control Loops
1986
Abstract Many Process Plants employ complex control and trip systems to improve process safety. Reliability prediction requires determination of the failure mechanisms followed by quantification of the failure rates. The fault tree technique is often used for reliability prediction. Fault tree construction is a skilled task and can be complex for systems containing multiple protective devices. The paper compares 3 approaches to the problem of fault tree construction. The problems of quantification and common mode failure is also considered.
Epistemic uncertainty in fault tree analysis approached by the evidence theory
2012
Abstract Process plants may be subjected to dangerous events. Different methodologies are nowadays employed to identify failure events, that can lead to severe accidents, and to assess the relative probability of occurrence. As for rare events reliability data are generally poor, leading to a partial or incomplete knowledge of the process, the classical probabilistic approach can not be successfully used. Such an uncertainty, called epistemic uncertainty, can be treated by means of different methodologies, alternative to the probabilistic one. In this work, the Evidence Theory or Dempster–Shafer theory (DST) is proposed to deal with this kind of uncertainty. In particular, the classical Fau…
A New Approach for the Reliability of Vehicular Ad Hoc Networks
2018
Vehicular ad hoc networks (VANET), a subset of Mobile Ad hoc Networks (MANETs), is a wireless communication technology applied to transportation, referring to a set of smart vehicles used on the road. These vehicles provide communication services among one another (V2V) or with Road Side Infrastructure (V2I). The main benefits of VANET are enhancing road safety, reducing energy use and emissions, and giving information services. Reliability is one of the most critical issues related to VANET since the information transmitted is distributed in an open access environment. We focused in this paper, on the reliability of VANET as a function of reliable hardware and their functionality taking in…
Correction: The genomic and clinical landscape of fetal akinesia
2020
Abstract An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Repeatability and reliability of the footwear assessment tool in Spanish patients: A transcultural adaptation
2023
[Abstract] Background: The footwear assessment tool was designed to advise an appropriate footwear for each situation and patient. Footwear alterations structures can influence in musculoskeletal disorders, developing foot ulcers, increase the peak plantar pressure, bacterial growth, low back pain. Methods: To validate the study 101 subjects were recruited. The study was tested by two expert podiatrists using the tool for the assessment of footwear characteristics that is composed by five domains, fit, general features, general structure, motion control properties and cushioning system. Each domain analyzes different shoe items. Results: An excellent agreement between the test-retest. A sui…
La evaluación del abuso sexual en personas con discapacidad intelectual: proceso de construcción y validación de un instrumento de autoinforme
2018
Las personas con diversidad funcional presentan ciertas limitaciones en el funcionamiento desu día a día, lo que les convierten en dependientes de sus cuidadores principales, quedando su cuerpo expuesto a ellos. Además, presentan menos recursos para detectar y defenderse ante situaciones de abuso. Estos factores, entre otros, hacen que se conviertan en un colectivo vulnerable al abuso sexual. Pero en la detección de las víctimas potenciales, nos encontramos con limitaciones en comprensión y lectoescritura, lo que hace cuestionar la fiabilidad de la información obtenida. El objetivo de este estudio, es la elaboración de un instrumento fiable y válido que se adapte a las características de la…
Property prices index numbers and derived indices
2014
Purpose – A useful instrument to understand and examine the inner workings of the property trade is devising index numbers of property prices based on historical sequences of market prices. The present work aims at the definition of index numbers of property prices, proposing an innovative methodology compared with what usually recurs in literature. The purpose of this paper is to discuss these issues. Design/methodology/approach – The analysis proposed, based on the mechanisms of formation of stock indices, investigates the analogies between stock and property information, according to the peculiarities of the property trade, leading to a methodology approach, derived from Simple Price In…
Architectural Ultrasound Pennation Angle Measurement of Lumbar Multifidus Muscles: A Reliability Study
2022
The pennation angle has been shown to be a relevant parameter of muscle architecture. This parameter has not previously been measured in the lumbar multifidus musculature, and it is for this reason that it has been considered of great interest to establish an assessment protocol to generate new lines of research in the future. Objective: The objective of this study was to establish a protocol for measuring the pennation angle of the multifidus muscles, with a study of intra-rater and interrater reliability values. Design: This was a reliability study following the recommendations of the Guidelines for Reporting Reliability and Agreement Studies (GRRAS). Setting: The study was carried out at…
Strictness vs. flexibility: Simulation-based recognition of strategies and its success in soccer
2021
Abstract Introduction: Recognition and optimization of strategies in sport games is difficult in particular in case of team games, where a number of players are acting “independently” of each other. One way to improve the situation is to cluster the teams into a small number of tactical groups and to analyze the interaction of those groups. The aim of the study is the evaluation of the applicability of SOCCER© simulation in professional soccer by analyzing and simulation of the tactical group interaction. Methods: The players’ positions of tactical groups in soccer can be mapped to formation-patterns and then reflect strategic behaviour and interaction. Based on this information, Monte Carl…
Cognitive Radio Application for Smart Grid
2012
The communication infrastructure between energy generation, transmission, distribution and utilization will require multi-way communications, interoperability between the advanced and existing system, and end-to-end reliable and secure communications with low-latencies. Revolutionary communication architecture is required for effective operation and control of smart grid, and cognitive radio based communication architecture can provide a unique solution. By leveraging cognitive radio technology, the suggested communications infrastructure promises to utilize potentially all available spectrum resources efficiently in the smart grid. The radio agility allows the smart grid devices to sense t…