Search results for "FAILURE"
showing 10 items of 1977 documents
multimodal and multi-criteria analysis for the expertise and locating faults in modern electrical components
2017
The purpose of this manuscript is to exhibit the research work solving the issue of data processing stem from defect localization techniques. This step being decisive in the failure analysis process, scientists have to harness data coming from light emission and laser techniques. Nevertheless, this analysis process is sequential and only depends on the expert’s decision. This factor leads to a not quantified probability of localization. Consequently to solve these issues, a multimodaland multicriteria analysis has been developped, taking advantage of the heterogeneous and complementary nature of light emission and laser probing techniques. This kind of process is based on advanced level too…
Multimodal and multicriteria analysis for VLSI expertises and defects localization
2017
The purpose of this manuscript is to exhibit the research work solving the issue of data processing stem from defect localization techniques. This step being decisive in the failure analysis process, scientists have to harness data coming from light emission and laser techniques. Nevertheless, this analysis process is sequential and only depends on the expert’s decision. This factor leads to a not quantified probability of localization. Consequently to solve these issues, a multimodal and multicriteria analysis has been developped, taking advantage of the heterogeneous andcomplementary nature of light emission and laser probing techniques. This kind of process is based on advanced level too…
Improved FMECA for effective risk management decision making by failure modes classification under uncertainty
2022
Failure Mode, Effects, and Criticality Analysis (FMECA) is a proactive reliability and risk management technique extensively used in practice to ensure high system performance by prioritising failure modes. Owing to the limitations of traditional FMECA, multi-criteria decision-making methods have been employed over the past two decades to enhance its effectiveness. To consider the vagueness and uncertainty of the FMECA evaluation process, an interval-based extension of the Elimination et Choice Translating Reality (ELECTRE) TRI method is proposed in the present paper for the classification of failure modes into risk categories. Therefore, ratings of failure modes against risk parameters are…
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.
Risk Assessment and Analysis
2014
Once threats are identified, they must be assessed or evaluated, which is the objective of this chapter. There is usually a large number of threats, making it impossible or unprofitable to analyze them all, meaning selection of the threats that will be addressed is important. It is a decision-making process; an example is proposed and solved by one of the many techniques available. The chapter proposes a very standard requested study, which is the assessment of the economic and financial risks of a project. This is done through a real-life-example, followed by another appraisal, this time devoted to economic issues, as well as another for transportation, introducing the important concept of…
Diffractive optics for quasi-direct space-to-time pulse shaping.
2008
The strong chromatic behavior associated with a conventional diffractive lens is fully exploited to propose a novel optical device for pulse shaping in the femtosecond regime. This device consists of two optical elements: a spatially patterned circularly symmetric mask and a kinoform diffractive lens, which are facing each other. The system performs a mapping between the spatial position of the masking function expressed in the squared radial coordinate and the temporal position in the output waveform. This space-to-time conversion occurs at the chromatic focus of the diffractive lens, and makes it possible to tailor the output central wavelength along the axial location of the output point…
Femtosecond parabolic pulse shaping in normally dispersive optical fibers
2013
Formation of parabolic pulses at femtosecond time scale by means of passive nonlinear reshaping in normally dispersive optical fibers is analyzed. Two approaches are examined and compared: the parabolic waveform formation in transient propagation regime and parabolic waveform formation in the steady-state propagation regime. It is found that both approaches could produce parabolic pulses as short as few hundred femtoseconds applying commercially available fibers, specially designed all-normal dispersion photonic crystal fiber and modern femtosecond lasers for pumping. The ranges of parameters providing parabolic pulse formation at the femtosecond time scale are found depending on the initia…
Pulse quality analysis on soliton pulse compression and soliton self-frequency shift in a hollow-core photonic bandgap fiber.
2013
A numerical investigation of low-order soliton evolution in a proposed seven-cell hollow-core photonic bandgap fiber is reported. In the numerical simulation, we analyze the pulse quality evolution in soliton pulse compression and soliton self-frequency shift in three fiber structures with different cross-section sizes. In the simulation, we consider unchirped soliton pulses (of 400 fs) at the wavelength of 1060 nm. Our numerical results show that the seven-cell hollow-core photonic crystal fiber, with a cross-section size reduction of 2%, promotes the pulse quality on the soliton pulse compression and soliton self-frequency shift. For an input soliton pulse of order 3 (which corresponds to…
La soluzione italiana alla crisi delle filiere agroalimentari: il decreto legge 19 marzo 2019, n. 27
2019
L’Autore affronta il tema della regolazione della filiera agroalimentare e dei tentativi di porre rimedio ai fallimenti del mercato . Analizzando i recenti interventi normativi in risposta alle gravi crisi del comparto lattiero-caseario, emergono difficoltà e incertezze del legislatore e del governo italiano nell’affrontare queste criticità, che sono legate all’assenza di un’adeguata regolazione di tipo contrattuale . Inadeguatezza che può essere affrontata e risolta puntando su di un mutamento di approccio e considerando che le relazioni contrattuali di filiera necessitano di interventi proporzionati, più efficaci ed efficienti, in grado di esaltare i momenti di autonomia contrattuale disc…
‘Too interconnected to fail’ financial network of US CDS market: Topological fragility and systemic risk
2012
A small segment of credit default swaps (CDS) on residential mortgage backed securities (RMBS) stand implicated in the 2007 financial crisis. The dominance of a few big players in the chains of insurance and reinsurance for CDS credit risk mitigation for banks' assets has led to the idea of too interconnected to fail (TITF) resulting, as in the case of AIG, of a tax payer bailout. We provide an empirical reconstruction of the US CDS network based on the FDIC Call Reports for off balance sheet bank data for the 4th quarter in 2007 and 2008. The propagation of financial contagion in networks with dense clustering which reflects high concentration or localization of exposures between few parti…