Search results for "Reliability"
showing 10 items of 1563 documents
Per-user availability for ultra-reliable communication in 5G: Concept and analysis
2018
Emerging 5G mobile networks envisage ultra-reliable communication (URC) as one of the major requirements for anytime anywhere communication. Although URC has recently attracted a lot of attention in the research community, existing work seems to rely on approaching reliability merely from a time domain perspective. However, both time and space domain parameters affect reliability and need to be investigated. This paper introduces a dependability theory based definition for per-user availability targeted at 5G networks. The advocated definition promotes both space and time domain components for URC provisioning. Furthermore, we perform reliability and availability analysis and simulations co…
On Distinguishing between Reliable and Unreliable Sensors Without a Knowledge of the Ground Truth
2015
In many applications, data from different sensors are aggregated in order to obtain more reliable information about the process that the sensors are monitoring. However, the quality of the aggregated information is intricately dependent on the reliability of the individual sensors. In fact, unreliable sensors will tend to report erroneous values of the ground truth, and thus degrade the quality of the fused information. Finding strategies to identify unreliable sensors can assist in having a counter-effect on their respective detrimental influences on the fusion process, and this has has been a focal concern in the literature. The purpose of this paper is to propose a solution to an extreme…
On Solving the Problem of Identifying Unreliable Sensors Without a Knowledge of the Ground Truth: The Case of Stochastic Environments.
2017
The purpose of this paper is to propose a solution to an extremely pertinent problem, namely, that of identifying unreliable sensors (in a domain of reliable and unreliable ones) without any knowledge of the ground truth. This fascinating paradox can be formulated in simple terms as trying to identify stochastic liars without any additional information about the truth. Though apparently impossible, we will show that it is feasible to solve the problem, a claim that is counterintuitive in and of itself. One aspect of our contribution is to show how redundancy can be introduced, and how it can be effectively utilized in resolving this paradox. Legacy work and the reported literature (for exam…
Unbiased Simultaneous Prediction Limits on Observations in Future Samples
2013
This paper provides procedures for constructing unbiased simultaneous prediction limits on the observations or functions of observations of all of k future samples using the results of a previous sample from the same underlying distribution belonging to invariant family. The results have direct application in reliability theory, where the time until the first failure in a group of several items in service provides a measure of assurance regarding the operation of the items. The simultaneous prediction limits are required as specifications on future life for components, as warranty limits for the future performance of a specified number of systems with standby units, and in various other app…
Time-Space Domain Availability Analysis Under Reliability Impairments
2019
Availability and reliability are two essential metrics for the design, deployment, and operation of future ultra-reliable low latency communication (URLLC) networks. Despite a vast amount of research efforts toward URLLC, very little attention has been made on the ultra-reliable communication (URC) aspect of URLLC from a dependability perspective. As an effort toward achieving anytime and anywhere communication, this letter consolidates a dependability theory-based availability concept for individual users by taking into account reliability impairments that affect URC in both spatial and temporal domains . To this end, we perform per-user availability analysis by considering channel status …
A Joint Time-Space Domain Analysis for Ultra-Reliable Communication in 5G Networks
2018
Reliable communication is a fundamental service level agreement criterion in wireless networks. Moreover, it is a performance indicator for ultra- reliable communication (URC) in emerging 5G networks. In URC, the quality of the delivered services to end-users ultimately depends on the availability of network resources as well as the quality of the received signal. Therefore, in order to analyze URC in cellular networks, both time- dependent spectrum availability and space-dependent service quality need to be considered. In this paper, we present a combined time and space domain analysis on network reliability based on a continuous time Markov chain model. To this end, we introduce a new rel…
Achieving Ultra Reliable Communication in 5G Networks: A Dependability Perspective Availability Analysis in the Space Domain
2017
As part of the 5G communication paradigm, ultra reliable communication (URC) is envisaged as an important technology pillar for providing anywhere and anytime services to end users. While most existing studies on reliable communication do not investigate this problem from a dependability theory perspective, those dependability-based studies tend to define reliability merely in the time domain. In this letter, we advocate extending the concept of URC from the dependability perspective also in the space domain . We initiate definitions on cell availability and system availability. The availability and the probability of providing a guaranteed level of availability in a network are analyzed bo…
Assessment of building energy modelling studies to meet the requirements of the new Energy Performance of Buildings Directive
2020
Abstract The cost optimal method (COM) as applied in the Energy Performance of Buildings Directive (EPBD) uses “non-calibrated deterministic reference buildings (RBs)”. Such RBs are defined with single envelope and equipment parameter values, for which calibration with actual building stock energy performance (EP) is not undertaken. Thus, it is not possible to visualise the effect of uncertainties or diversity in the input parameters on cost-optimal level benchmarks and to verify the choice of RBs. The paper proposes an update to the COM via use of “Probabilistic Bayesian calibrated RBs” to handle uncertainties and produce more realistic cost optimal levels to support policy makers in devis…
Performance assessment of institutional photovoltaic based energy system for operating as a micro-grid
2020
Abstract A building integrated photovoltaic (PV) system with energy storage within an institution may need appropriate coordination among distributed energy sources (DERs). It is required to have an appropriate energy management strategy to improve system performance as well as to operate it as a micro-grid during the grid outage condition. In this paper, TERI’s (India) Retreat Facility’s energy system has been used, and its performance with a distributed generator has been assessed with operational strategies for fulfilling the institutional load demand in coordination with the PV, grid and battery storage; and with possibility of operating it as a micro-grid during the grid outage period …
A comparison of different one-diode models for the representation of I–V characteristic of a PV cell
2014
Predictive performance tools are an important factor in the success of any new technology because they permit demonstration of whether a system will be efficient and economically feasible. A reliable predictive tool should allow the designer to optimise system performance and to maximise the cost effectiveness of a system prior to installation. This article discusses the five main parametric models for photovoltaic (PV) systems available in the literature. The current–voltage characteristics of a photovoltaic module can be reproduced modelling the PV panel as an equivalent electrical circuit made of linear and non-linear components. The parameters describing such components are directly rel…