The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Distinguishing between RFID-tagged objects within different areas poses an important building block for many RFID-based applications. Existing localization techniques, however, often cannot reliably distinguish between tagged objects that are close to the border of adjacent areas. Against this backdrop, we present a hybrid approach based on an ANN and a HMM that leverages not only low-level RFID data...
FTA (Fault Tree Analysis) is one of the most used methods for reliability analysis and to quantify the risks associated with the failures of systems. This method performs analysis of the combination of events that can lead to a critical system failure (called Top Event of the designed Fault Tree) and allows calculating the probability of failure. In this paper, has been built the Fault Tree for a...
Probabilistic safety assessment is one of the standardized ways of assessing safety of nuclear power plants. The objective of the method is to present an extension of the fault tree in order to reduce the size of the shutdown probabilistic safety assessment model. The shutdown probabilistic safety assessment method is developed. The modelling for all plant operating states include consideration of...
Fault tree analysis is an important method in reliability engineering. In order to assess drilling mud pump reliability, system fault tree is established based on collecting its main failure modes, and then the qualitative and quantitative analysis of fault tree is discussed. Finally, failure ratio of the top event is obtained.
Fault tree analysis (FTA) is a traditional tool used to evaluate the reliability of a system without considering the fuzziness and randomness of basic events. A new methodology, called fuzzy FTA (FFTA), is applied in this study to evaluate the reliability of flue gas turbines. The failure of flue gas turbines is determined as a top event and then a fault tree is constructed. The fuzzy probabilities...
Fault tree analysis (FTA) is a top-down approach for failure analysis, starting with a potential undesirable event called a TOP event, and then determining all the ways it can happen. FTA is the most commonly used technique for causal analysis in risk and reliability studies. Mask stage an important part of lithography. In this paper, Fault Tree of the mask stage is built with “Mask stage doesn't...
It is important to evaluate the current reliability of a system during runtime, especially for AUV (Autonomous Unmanned Vehicle). In this paper, a FTA (Fault Tree Analysis) based method is presented to evaluate runtime reliability in system level. we describe how to construct the fault trees for runtime and how to calculate the realtime probability of top-level event. A case study on an autonomous...
To resolve NP problem in FTA, the methodology is developed using a systematic approach of fault tree development, minimal cut sets determination and probability improved by link-list for MCS, transfer event and sub-trees. Based on windows interface a design and implementation method of computer aided active FTA automatic constructing and drawing method are presented. In this paper, a lubrication oil...
As an effective means of solution to traffic congestion, the modern urban transit has attracted worldwide attention. The signal control system, the core parts of the urban transit, is a typical safety critical system which ensures the safe operation and improves the transport efficiency. Therefore, the safety of the system must be analyzed during the development, production, and evaluation processes...
Modularization technique allows efficient simplification of Dynamic and Static Fault Tree (FT). Each independent sub-tree (module) in static FT can be calculated separately and substituted by a basic event with obtained probability of failure. However, there is a significant restriction of this procedure in Dynamic FT, if it is converted to a Markov Chain. An independent sub-tree inside of Dynamic...
This paper presents an algebraic approach allowing to perform the analysis of any Dynamic Fault Tree (DFT). This approach is based on the ability to formally express the structure function of DFTs. We first present the algebraic framework that we introduced to model dynamic gates and hence be able to determine the structure function of DFTs. Then, we show that this structure function can be rewritten...
We present a novel trigonometry-based probability calculation (TPC) method for analyzing circuit behavior and reliability in the presence of errors that occur with extremely low probability. Signal and error probabilities are represented by trigonometric functions controlled by their corresponding angles. By combining trigonometric identities and Taylor expansions, the effect of an error at a particular...
To obtain high performance and high safety degree in induction machine operation, the researchers' attention is directed through monitoring and evaluating their reliability. This paper analyzes the connection between the failure causes and their effects on induction machine, by using Failure Mode and Effects Analysis (FMEA) and Fault Tree Analysis (FTA). The first method identifies possible faults...
Wireless sensors have started being utilized for industrial application which is typical harsh environment due to complicated layout and plentiful stationary/moving obstacles. As two hot standards for wireless industrial, WiHART and ISA100.11a, both adopt the centralized wireless sensor network with mesh topology to enable the reliable monitoring of a variety of environments. This kind of network...
A new method is developed for tracing the unreliability contributions of system components and recognizing the system weak parts using the fault tree analysis (FTA). The method is based on the minimum cut set (MCS) algorithm for evaluating the system reliability using the FTA and the proportional sharing principle (PSP). The fault tree can be expressed as MCSs and the system unreliability can be mathematically...
Due to increasing demand of Electricity, every country in the world wants to construct more and more nuclear power plants and apply different advance techniques for accident prevention, safety and reliability. Probabilistic Safety Assessment (PSA) and Living Probabilistic Safety Assessment (LPSA) are two of them, which are presented in this review paper. The paper consists of four parts, in first...
Traditional approaches to handling functional dependence in systems with imperfect fault coverage are based on Markov models, which are inefficient due to the well-known state space explosion problem. Also, the Markov-based methods typically assume exponential time-to-failure distributions for the system components. In this paper we propose a new combinatorial approach to handling functional dependence...
A distinct characteristic of multistate systems (MSS) is that the systems and/or their components may exhibit multiple performance levels (or states) varying from perfect operation to complete failure. MSS can model behaviors such as shared loads, performance degradation, imperfect fault coverage, standby redundancy, limited repair resources, and limited link capacities. The nonbinary state property...
Traditional fault tree analysis method need obtain exact value of the event occurrence's probability, un-completeness and fuzziness of the data is ignored. Fuzzy fault tree analysis method is proposed in study on the system reliability. The fuzzy fault tree of the AUV is established. Using operational rule calculated the fuzzy probability of the top event which is AUV can't work normally and analysis...
The traditional approach to handling functional dependence loops is based on Markov models, which are inefficient due to the well-known state space explosion problem. This paper proposes a new and efficient approach to handling functional dependence loops in the system reliability analysis. Based on the divide-and-conquer strategy, the approach transforms a system with functional dependence loops...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.