Academic literature on the topic 'Multi-failures mode'
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Journal articles on the topic "Multi-failures mode"
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Nappa, Dario, and Gergana I. Drandova. "Estimating activation energies for multi-mode failures." Microelectronics Reliability 54, no. 2 (February 2014): 349–53. http://dx.doi.org/10.1016/j.microrel.2013.09.025.
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Hou, Zhi. "Decision Method of Equipment Reliability Assurance Based on Multi-Level Management." Applied Mechanics and Materials 101-102 (September 2011): 832–37. http://dx.doi.org/10.4028/www.scientific.net/amm.101-102.832.
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This paper classifies reliability assurance management strategies into four modes, i.e., reactive mode, preventive mode, predictive mode and proactive mode, advanced a decision method of equipment reliability assurance based on multilevel management. The risks of equipment failures are also categorized into four levels according to their degrees of severity and occurring rates. In order to improve pertinence and reduce cost of reliability assurance, it is proposed to adopt a multi-level management strategy in handling the risks. For this purpose, a model for relationship between risk levels and reliability assurance modes, a model for equipment reliability assurance cost and a model for equipment risk increments after reliability assurance have been established. The applied risk management mode for each concrete risk is determined by minimizing the total reliability assurance cost with risk increment serving as a constraint condition. The proposed approach has been demonstrated by using an example.
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Haktanır, Elif, and Cengiz Kahraman. "Interval-valued neutrosophic failure mode and effect analysis." Journal of Intelligent & Fuzzy Systems 39, no. 5 (November 19, 2020): 6591–601. http://dx.doi.org/10.3233/jifs-189121.
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Failure mode and effects analysis (FMEA) is a structured approach for discovering possible failures that may occur in the design of a product or process. Since classical FMEA is not sufficient to represent the vagueness and impreciseness in human decisions and evaluations, many extensions of ordinary fuzzy sets such as hesitant fuzzy sets, intuitionistic fuzzy sets, Pythagorean fuzzy sets, spherical fuzzy sets, and picture fuzzy sets. Classical FMEA has been handled to capture the uncertainty through these extensions. Neutrosophic sets is a different extension from the others handling the uncertainty parameters independently. A novel interval-valued neutrosophic FMEA method is developed in this study. The proposed method is presented in several steps with its application to an automotive company in order to prioritize the potential causes of failures during the design process by considering multi-experts’ evaluations.
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Liu, Xiangxiang, Lingling Li, Diganta Das, Ijaz Haider Naqvi, and Michael G. Pecht. "Online Degradation State Assessment Methodology for Multi-Mode Failures of Insulated Gate Bipolar Transistor." IEEE Access 8 (2020): 69471–81. http://dx.doi.org/10.1109/access.2020.2984385.
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Zhang, Xi, Hongju Wang, Xuehui Li, Shoujun Gao, Kui Guo, and Yingle Wei. "Fault Diagnosis of Mine Ventilator Bearing Based on Improved Variational Mode Decomposition and Density Peak Clustering." Machines 11, no. 1 (December 26, 2022): 27. http://dx.doi.org/10.3390/machines11010027.
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The mine ventilator plays a role in protecting the life safety of underground workers, which is very significant to the production and development of coal mines. In total, 70% of ventilator failures are mechanical failures, and bearing failures are the most likely to occur in mechanical failures, which are also difficult to find. In order to identify fan bearing faults accurately, this paper proposes a fault diagnosis method based on improved variational mode decomposition and density peak clustering. First, the variational mode decomposition’s modal number K and secondary penalty factor α are chosen employing the improved sparrow optimization process. The bearing vibration signal is decomposed by the variational mode decomposition algorithm with optimized parameters. To create the characteristic vector, the multi-scale permutation entropy of the fourth order intrinsic mode function is determined. Then, the characteristic matrix is dimensionally reduced by kernel principal component analysis, and the two-dimensional matrix after dimensionality reduction is divided by density peak clustering method to find the clustering center of the training sample features. Lastly, the membership degree is assessed using the normalized clustering distance between the characteristic matrix of the test sample and the cluster center of the training sample. The accuracy of bearing fault identification on the self-constructed experimental platform can reach 100%, which verifies the effectiveness and potential of the proposed method.
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Hu, Yingjun, Anmin Zhang, Wuliu Tian, Jinfen Zhang, and Zebei Hou. "Multi-Ship Collision Avoidance Decision-Making Based on Collision Risk Index." Journal of Marine Science and Engineering 8, no. 9 (August 20, 2020): 640. http://dx.doi.org/10.3390/jmse8090640.
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Most maritime accidents are caused by human errors or failures. Providing early warning and decision support to the officer on watch (OOW) is one of the primary issues to reduce such errors and failures. In this paper, a quantitative real-time multi-ship collision risk analysis and collision avoidance decision-making model is proposed. Firstly, a multi-ship real-time collision risk analysis system was established under the overall requirements of the International Code for Collision Avoidance at Sea (COLREGs) and good seamanship, based on five collision risk influencing factors. Then, the fuzzy logic method is used to calculate the collision risk and analyze these elements in real time. Finally, decisions on changing course or changing speed are made to avoid collision. The results of collision avoidance decisions made at different collision risk thresholds are compared in a series of simulations. The results reflect that the multi-ship collision avoidance decision problem can be well-resolved using the proposed multi-ship collision risk evaluation method. In particular, the model can also make correct decisions when the collision risk thresholds of ships in the same scenario are different. The model can provide a good collision risk warning and decision support for the OOW in real-time mode.
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Dong, Lijing, and Kaige Liu. "Adaptive sliding mode control for uncertain nonlinear multi-agent tracking systems subject to node failures." Journal of the Franklin Institute 359, no. 2 (January 2022): 1385–402. http://dx.doi.org/10.1016/j.jfranklin.2021.11.039.
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Zhang, F., Z. Zhou, Y. Wang, D. Wang, M. Wu, and L. Zhu. "An SEU fault injection platform for radiation-harden design debugging in the FPGA." Journal of Instrumentation 17, no. 08 (August 1, 2022): P08007. http://dx.doi.org/10.1088/1748-0221/17/08/p08007.
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Abstract An SEU fault injection platform was designed to ease the debugging of radiation-harden design in FPGA. The platform includes the FPGA being tested, the functional firmware being debugged, the essential-bit extraction algorithm based on Python, and the random fault injection algorithm. The platform can inject single-bit SEU failures, adjacent two-bit SEU failures, and three-bit SEU failures. It works in two modes: normal injection mode and essential-bit injection mode. Functional failure rate is the performance metric which used to evaluate the development. It is the probability of triggering a DUT function failure. In this experiment, the SEU fault injection platform is verified by measuring whether TCP/IP communication links are disconnected due to SEU faults. Experimental results show that the probability of TCP/IP link disconnection in normal injection mode is 0.13%, 0.23% and 0.25% respectively when random injection of single-bit SEU failure, adjacent two-bit SEU failure and multi-bit SEU failure occurs 10,000 times. In the essential-bit injection mode, the probability of TCP/IP link disconnection caused by single-bit SEUs failure, adjacent two-bit SEUs failure and three-bit SEUs failure is 0.87%, 6.97% and 11.76% respectively, indicating a significant increase in the functional failure rates. This shows that the essential-bit injection mode can be used to expose problems more quickly and accelerate the debugging process of FPGA radiation-harden design.
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Powell, Emilie S., Lanty M. O’Connor, Anna P. Nannicelli, Lisa T. Barker, Rahul K. Khare, Nicholas P. Seivert, Jane L. Holl, and John A. Vozenilek. "Failure mode effects and criticality analysis: innovative risk assessment to identify critical areas for improvement in emergency department sepsis resuscitation." Diagnosis 1, no. 2 (June 1, 2014): 173–81. http://dx.doi.org/10.1515/dx-2014-0007.
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AbstractSepsis is an increasing problem in the practice of emergency medicine as the prevalence is increasing and optimal care to reduce mortality requires significant resources and time. Evidence-based septic shock resuscitation strategies exist, and rely on appropriate recognition and diagnosis, but variation in adherence to the recommendations and therefore outcomes remains. Our objective was to perform a multi-institutional prospective risk-assessment, using failure mode effects and criticality analysis (FMECA), to identify high-risk failures in ED sepsis resuscitation.We conducted a FMECA, which prospectively identifies critical areas for improvement in systems and processes of care, across three diverse hospitals. A multidisciplinary group of participants described the process of emergency department (ED) sepsis resuscitation to then create a comprehensive map and table listing all process steps and identified process failures. High-risk failures in sepsis resuscitation from each of the institutions were compiled to identify common high-risk failures.Common high-risk failures included limited availability of equipment to place the central venous catheter and conduct invasive monitoring, and cognitive overload leading to errors in decision-making. Additionally, we identified great variability in care processes across institutions.Several common high-risk failures in sepsis care exist: a disparity in resources available across hospitals, a lack of adherence to the invasive components of care, and cognitive barriers that affect expert clinicians’ decision-making capabilities. Future work may concentrate on dissemination of non-invasive alternatives and overcoming cognitive barriers in diagnosis and knowledge translation.
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Rachieru, Nicoleta, Nadia Belu, and Daniel Constantin Anghel. "Evaluating the Risk of Failure on Injection Pump Using Fuzzy FMEA Method." Applied Mechanics and Materials 657 (October 2014): 976–80. http://dx.doi.org/10.4028/www.scientific.net/amm.657.976.
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This research is aimed at utilizing failure mode and effect analysis (FMEA) which is a reliability analysis method applicable to rotary injection pump design. In traditional FMEA, Risk Priority Number (RPN) ranking system is used to evaluate, the risk level of failures to rank failures and to prioritize actions. RPN is obtained by multiplying the scores of three risk factors like the Severity (S), Occurrence (O) and Detection (D) of each failure mode. RPN method can not emphasise the nature of the problem, which is multi-attributable and has a group of experts' opinions. Furthermore, attributes are subjective and have different importance levels. In this paper, a framework is proposed to overcome the shortcomings of the traditional method through the fuzzy set theory. Two case studies have been shown to demonstrate the methodology thus developed. It is illustrated a parallel between the results obtained by the traditional method and fuzzy logic for determining the RPNs. We expect that fuzzy FMEA model will assist FMEA team in assess and rank risks more precisely compared with risk assessment model of method.
Dissertations / Theses on the topic "Multi-failures mode"
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Bristow, Elizabeth Catherine. "Interdependent infrastructures and multi-mode attacks and failures: improving the security of urban water systems and fire response." 2006. http://hdl.handle.net/1969.1/ETD-TAMU-1082.
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This dissertation examines the interdependence between urban water distribution
systems and urban fire response. The focus on interdependent critical infrastructures is
driven by concern for security of water systems and the effects on related infrastructures
if water distribution systems are damaged by terrorist attack or natural disaster.
A model of interdependent infrastructures (principally water distribution systems
and fire response) is developed called the Model of Urban Fire Spread (MUFS). The
model includes the capacity to simulate firefighting water demands in a community
water system hydraulic model, building-to-building urban fire spread, and suppression
activities. MUFS is an improvement over previous similar models because it allows
simulation of urban fires at the level of individual buildings and it permits simulation of
interdependent infrastructures working in concert.
MUFS is used to simulate a series of multi-mode attacks and failures (MMAFs) –
events which disable the water distribution system and simultaneously ignite an urban
fire. The consequences of MMAF scenarios are analyzed to determine the most serious modes of infrastructure failure and urban fire ignition. Various methods to determine
worst-case configurations of urban fire ignition points are also examined.
These MMAF scenarios are used to inform the design of potential mitigation
measures to decrease the consequences of the urban fire. The effectiveness of mitigation
methods is determined using the MUFS simulation tool. Novel metrics are developed to
quantify the effectiveness of the mitigation methods from the time-series development of
their consequences. A cost-benefit analysis of the various mitigation measures is
conducted to provide additional insight into the methods’ effectiveness and better inform
the decision-making process of selecting mitigation methods.
Planned future work includes further refinement of the representation of fire
propagation and suppression in MUFS and investigation of historical MMAF events to
validate simulation predictions. Future efforts will continue development of appropriate
optimization methods for determining worst-case MMAF scenarios.
This work should be of interest to water utility managers and emergency
planners, who can adapt the methodology to analyze their communities’ vulnerability to
MMAFs and design mitigation techniques to meet their unique needs, as well as to
researchers interested in infrastructure modeling and disaster simulation.
Book chapters on the topic "Multi-failures mode"
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Müller, Tim M., Andreas Schmitt, Philipp Leise, Tobias Meck, Lena C. Altherr, Peter F. Pelz, and Marc E. Pfetsch. "Validation of an Optimized Resilient Water Supply System." In Lecture Notes in Mechanical Engineering, 70–80. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-77256-7_7.
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AbstractComponent failures within water supply systems can lead to significant performance losses. One way to address these losses is the explicit anticipation of failures within the design process. We consider a water supply system for high-rise buildings, where pump failures are the most likely failure scenarios. We explicitly consider these failures within an early design stage which leads to a more resilient system, i.e., a system which is able to operate under a predefined number of arbitrary pump failures. We use a mathematical optimization approach to compute such a resilient design. This is based on a multi-stage model for topology optimization, which can be described by a system of nonlinear inequalities and integrality constraints. Such a model has to be both computationally tractable and to represent the real-world system accurately. We therefore validate the algorithmic solutions using experiments on a scaled test rig for high-rise buildings. The test rig allows for an arbitrary connection of pumps to reproduce scaled versions of booster station designs for high-rise buildings. We experimentally verify the applicability of the presented optimization model and that the proposed resilience properties are also fulfilled in real systems.
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Littlewood, B., and D. R. Miller. "A Conceptual Model of the Effect of Diverse Methodologies on Coincident Failures in Multi-Version Software." In Fehlertolerierende Rechensysteme / Fault-Tolerant Computing Systems, 263–72. Berlin, Heidelberg: Springer Berlin Heidelberg, 1987. http://dx.doi.org/10.1007/978-3-642-45628-2_23.
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Santucci, Jack. "Party Government and Electoral Reform." In More Parties or No Parties, 75–99. Oxford University PressNew York, 2022. http://dx.doi.org/10.1093/oso/9780197630655.003.0004.
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Abstract Reform coalitions can be insulating or realigning (setting aside for now the “polarizing” mode in Chapter 7). Further, they can be pro- or anti-party. This chapter documents reform coalitions in STV-adopting cities, contrasting them with negative cases (STV failures and non-STV reform “victories”). Based on available information, all were of the anti-party-realigning type. None involved a strictly multi-party reform coalition, which explains why STV and other features of the Model City Charter were not revisited. STV found traction in relatively competitive jurisdictions where reformers were able to split the dominant party, then bring it into coalition with the main out-party. Key exceptions are Cleveland and New York City, whose reform coalitions also contained minor parties. Sources of dominant-party disunity include organized labor, targets of ethnic discrimination, and local women’s movements.
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Rinauro, Barbara, Ermina Begovic, Inno Gatin, and Hrvoje Jasak. "Surf-Riding Operational Measures for Fast Semidisplacement Naval Hull Form." In Progress in Marine Science and Technology. IOS Press, 2020. http://dx.doi.org/10.3233/pmst200046.
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Surf-riding/broaching failure mode is one of the Second Generation Intact Stability Criteria (SGISC) dealt by IMO. The SGISC are structured with a multi-tiered approach: Level 1, Level 2 and Direct Stability Assessment (DSA). When a ship does not verify one level, the next once must be applied, or the ship design must be modified. If ship changes are not feasible, Operational Measures (OM) can be provided to avoid dangerous situations and reduce the likelihood of stability failures. The OM are divided into Operational Limitations (OL) related to areas or routes and related to maximum significant wave heights and Operational Guidance (OG). The surf-riding criterion has been applied on the parent hull of the Systematic Series D, a fast semi-displacement naval hull with forms typically vulnerable to surf-riding phenomenon. The 90 m length ship results vulnerable to Level 1 and 2, therefore Operational Measures have been discussed and provided for a hypothetical route in the Mediterranean Sea (Area 26). Following the OL, in considered Area 26 the ship operations are limited when significant wave heights exceed 3.8 m. The simplified OG define critical ship speeds to be avoided for each considered sea state.
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Oikonomou, Kostas N., Rakesh K. Sinha, and Robert D. Doverspike. "Multi-Layer Network Performance and Reliability Analysis." In Networking and Telecommunications, 167–93. IGI Global, 2010. http://dx.doi.org/10.4018/978-1-60566-986-1.ch014.
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The authors describe a methodology for evaluating the performability (combined performance and reliability) of large communications networks. Networks are represented by a 4-level hierarchical model, consisting of traffic matrix, network graph, “components” representing failure modes, and reliability information. Network states are assignments of modes to the network components, which usually represent network elements and their key modules, although they can be more abstract. The components can be binary or multi-modal, and each of their failure modes may change a set of attributes of the graph (e.g. the capacity or cost of a link). Their methodology also captures the effect of automatic restoration against network failures by including two common rerouting methods. To compute network performability measures, including upper and lower bounds on their cumulative distribution functions, we augment existing probabilistic state-space generation algorithms with our new “hybrid” algorithm. To characterize the network failures of highest impact, we compute the Pareto boundaries of the network’s risk space. The authors have developed a network analysis tool called nperf that embodies this methodology. To illustrate the methodology and the practicality of the tool, they describe a performability analysis of three design alternatives for a large commercial IP backbone network.
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Liu, Sichao, Lihui Wang, Xi Vincent Wang, and Magnus Wiktorsson. "Complex-Network-Based Cyber-Physical Production Systems Subject to Cascading Failures." In Advances in Transdisciplinary Engineering. IOS Press, 2020. http://dx.doi.org/10.3233/atde200177.
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The manufacturing industry is facing multi-dimensional, ever-growing challenges ranging from the lack of real-time manufacturing resource data, the inability of catching production exceptions, to the occurrence of cascading failures. This paper proposes a network-based cyber-physical production system to model, diagnose and control complex production systems subject to cascading failures. The goal is to study and characterise the evolution of cascading failure mechanisms and further mitigate the vulnerability of the manufacturing system. This is achieved through the deployment and synergistic integration of the Internet of technology with the reliability importance theory. The paper contributes to the network reliability theory and applications by proposing new importance measures and strategies to support the operation of cyber-physical production systems.
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Li, Xin, Yu Liu, Hong Wang, Wei Xu, and Shanguo Huang. "Content Connectivity Based Polyhedron Protection Against Multiple Link Failures in Optical Data Center Networks." In Frontiers in Artificial Intelligence and Applications. IOS Press, 2022. http://dx.doi.org/10.3233/faia220564.
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To further improve the resource efficiency of the p-polyhedron protection scheme against multi-link failures in optical data center networks (ODCNs), the content connectivity is considered when constructing the p-polyhedron structure. In this paper, the content connectivity-based polyhedron protection (CCPP) scheme is proposed. An ILP model and a heuristic algorithm are developed to realize the CCPP scheme. Numerical results show that the proposed CCPP scheme has a lower network redundancy. Moreover, the network redundancy of the CCPP scheme is positively correlated with the degree of content connectivity.
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Jovančić, Predrag D., Miloš Tanasijević, Vladimir Milisavljević, Aleksandar Cvjetić, Dejan Ivezić, and Uglješa Srbislav Bugarić. "Applying the Fuzzy Inference Model in Maintenance Centered to Safety." In Advances in Civil and Industrial Engineering, 142–65. IGI Global, 2020. http://dx.doi.org/10.4018/978-1-7998-3904-0.ch009.
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The main idea of this chapter is to promote maintenance centered to safety, in accordance to adaptive fuzzy inference model, which has online adjustment to working conditions. Input data for this model are quality of service indicators of analyzed engineering system: reliability, maintainability, failure consequence, and severity and detectability. Indicators in final form are obtained with permanent monitoring of the engineering system and statistical processing. Level of safety is established by composition and ranking of indicators according to fuzzy inference engine. The problem of monitoring and processing of indicators comprising safety is solved by using the features that Industry4.0 provides. Maintenance centered to safety is important for complex, multi-hierarchy engineering systems. Sudden failures on such systems could have significant financial and environmental effect. Developed model will be tested in the final part of the chapter, in the case study of bucket wheel excavator.
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Dai, Yuan-Shun, and Jack Dongarra. "Reliability and Performance Models for Grid Computing." In Handbook of Research on Scalable Computing Technologies, 219–45. IGI Global, 2010. http://dx.doi.org/10.4018/978-1-60566-661-7.ch010.
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Grid computing is a newly developed technology for complex systems with large-scale resource sharing, wide-area communication, and multi-institutional collaboration. It is hard to analyze and model the Grid reliability because of its largeness, complexity and stiffness. Therefore, this chapter introduces the Grid computing technology, presents different types of failures in grid system, models the grid reliability with star structure and tree structure, and finally studies optimization problems for grid task partitioning and allocation. The chapter then presents models for star-topology considering data dependence and treestructure considering failure correlation. Evaluation tools and algorithms are developed, evolved from Universal generating function and Graph Theory. Then, the failure correlation and data dependence are considered in the model. Numerical examples are illustrated to show the modeling and analysis.
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Dai, Yuan-Shun, and Jack Dongarra. "Reliability and Performance Models for Grid Computing." In Grid and Cloud Computing, 119–40. IGI Global, 2012. http://dx.doi.org/10.4018/978-1-4666-0879-5.ch106.
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Grid computing is a newly developed technology for complex systems with large-scale resource sharing, wide-area communication, and multi-institutional collaboration. It is hard to analyze and model the Grid reliability because of its largeness, complexity and stiffness. Therefore, this chapter introduces the Grid computing technology, presents different types of failures in grid system, models the grid reliability with star structure and tree structure, and finally studies optimization problems for grid task partitioning and allocation. The chapter then presents models for star-topology considering data dependence and tree-structure considering failure correlation. Evaluation tools and algorithms are developed, evolved from Universal generating function and Graph Theory. Then, the failure correlation and data dependence are considered in the model. Numerical examples are illustrated to show the modeling and analysis.
Conference papers on the topic "Multi-failures mode"
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Hu, Tao, Hou-shun Zhou, and Feng Liu. "Reliability simulation for phased mission system with multi-mode failures based on CPN." In 2011 9th International Conference on Reliability, Maintainability and Safety (ICRMS 2011). IEEE, 2011. http://dx.doi.org/10.1109/icrms.2011.5979418.
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Zhang, Lu, and Didem Ozevin. "The influence of multi-mode failures in composites on the characteristics of elastic waves." In SPIE Smart Structures and Materials + Nondestructive Evaluation and Health Monitoring, edited by Tzu Yang Yu, Andrew L. Gyekenyesi, Peter J. Shull, Aaron A. Diaz, H. Felix Wu, and A. Emin Aktan. SPIE, 2013. http://dx.doi.org/10.1117/12.2009244.
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Potluri, Sri Shanti, Ananda Mohan Bommakanti Srinivasa, Isai Thamizh Ramasamy, Srinivasa Rao Potu, and Ananda Rao Patnaik Balivada Venkata. "High Cycle Fatigue Life Assessment of Compressor Blades Under Multi-Axial Fatigue Mode." In ASME 2014 Gas Turbine India Conference. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/gtindia2014-8222.
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Stringent mission requirements of Aero Gas Turbine engines result in severe aerodynamic loads on engine components. Structural integrity and durability of blades is an important aspect with fatigue being a major failure mode and especially High Cycle Fatigue being a critical design concern. HCF failures in blades are mainly attributed to resonant excitations where the dynamic stress amplitude in the blade increases as the exciting frequency approaches the resonant speed. These excitations could be due to integral orders, i.e. as multiples of rotational speeds and also due to nozzle or blade pass frequencies. The frequency of these excitations is very high and under these excitations, the blades are subjected to highly complex modes or deformation patterns resulting in a multi-axial state of stress. Other causes for multi-axial state of stress may be attributed to anisotropy in material, presence of stress raisers and end fixity/ support mechanism of the blade in context. Assessing the severity of this multi-axial stress state in the blade from HCF is very important from the designer’s perspective. This paper describes the methodology employed in a compressor stator blade to assess the HCF damage by distortion energy based multi-axial fatigue failure criteria with a modification to include the mean static stresses. Based on this method, safe operating strain limits are established and are used as guide lines to monitor the stator blades during engine testing. When this methodology is checked for a pure bending mode of a compressor stator blade, i.e. for a state of stress which is predominantly unidirectional, both the Goodman approach and the distortion energy based multi-axial method yield the same assessment under HCF, whereas for a complex mode with a multi-axial state of stress, considerable difference in results is observed.
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Hong, Jeong K., and Thomas P. Forte. "Fatigue Evaluation Procedures for Multi-Axial Stress State in Welded Joints." In ASME 2015 34th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/omae2015-41412.
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The Battelle structural stress method (BSSM) for fatigue life evaluation is examined for multi-axial stress states that develop due to uniaxial loading in welded structures. The resultant multi-axial stress state due to simple uniaxial loading is easily observed in common joint types such as a plate with a welded tube or a plate with an angled attachment. In these joint types, under simple loading, the stress distribution at the location of failure along the weld line shows significant in-plane shear stress (parallel to the weld line) as well as normal stress (normal to weld line). Although the fatigue data, as exemplified by the inverse slope of the S-N curve for the subject joints under uniaxial loading, are observed to be similar to that for normal-loading-mode dominant (Mode I) failures in welded joints, when only the normal structural stress is considered for these joints the predictions of both the fatigue failure location and the fatigue life using the master S-N curve approach are inaccurate because the in-plane shear stress plays a significant role in the development of the crack. The slope of fatigue data exhibited in S-N curves taken from weld fatigue data for resultant multi-axial stress state generated by uniaxial loading is different from multi-axial fatigue loading conditions for tubular joints as discussed in the recent work [OMAE2014-23459]. In this article, the fatigue behavior of welded joints with multi-axial stress states is evaluated using an effective equivalent structural stress range parameter that is formulated as a von Mises form of the combined normal and in-plane shear equivalent structural stress ranges. When the effective equivalent structural stress range parameter is employed, the fatigue failure location can be predicted correctly. It is also found that the cycles-to-failure data from the subject joint types are comparable with the master S-N curve for Mode I loading dominant behavior (inverse slope of 3.125). Therefore, the master S-N curve that was developed for Mode I failures can be equally applicable for fatigue life prediction for these joints by replacing the equivalent structural stress range with effective equivalent structural stress range on the ordinate axis.
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Kristensen, Claus Egebjerg, Jan Muren, Geir Skeie, Håvard Skjerve, and Nils Sødahl. "Carcass Tear Out Load Model for Multi-Layer Pressure Sheath Risers." In ASME 2014 33rd International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/omae2014-24129.
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Recent failures of multi-layer pressure sheath risers have shown that the carcass may fail in the top termination due to excessive axial loads. This is a new failure mode for flexible risers, recently presented by the authors in more general terms. The present paper explains details of the established load model and the validation against mid-scale tests, risers failed during operation, and operating risers close to failure by this new mode. The key driver in the model is the temperature contraction of pressure sheath layers. Also influenced by changes in polymer properties over the operational history, temperature and time is explained. Other contributing factors in the load model are gravity-component and bore pressure. The prediction model for the carcass loads are developed during Statoils investigation in 2011–12. The model is regarded representative for 20% of the most exposed risers. Several of the input parameters are uncertain and a Monte Carlo simulation approach is selected to study the variability and predict the probability of failure, given that radial contact pressure is sufficiently low. The approach adopted in the model may be applicable to other risers where polymers and steel components act together, and in such circumstances act as a guide for alternative model developments.
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Gnanavel, B. K., G. Raja, and D. Chandramohan. "Effect of Interfacial Contact Forces and Lay Ratio in Cardiac Lead Outer Insulation due to Internal Cable Motion." In ASME 2020 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/imece2020-23091.
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Abstract Wearing cardiac lead implanted may result in various failures, including in-appropriate or missing treatments. Contacts are used on the lateral and radial link in the multi-layered (1 + 6 + 12) pacemaker lead cable. The effect of the coupling mode, however, is not the same as it does when the lateral and radial contact combine. On the transverse wire the forces and moments developed along the regular, bi-natural, and axial directions on a helical wire of the multi-faceted pacemaker cable. The equilibrium equations derived from Love’s thin rod theory (1944) shall provide geometric nomenclatures of the cabling generated by axial stress and rotational pressures from the multi-layered pacemaker lead. A steepness matrix is derived for multi-layered pacemakers leading cable elements, leading to strand strength, a twisting moment, axial strand strain and rotational strain.
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Srinivas, Siva, Hardik Roy, and Esakki Muthu Shanmugam. "Study of the Effect of Multi-Stage Cyclic Symmetric Modeling on the Natural Frequencies of Bladed Disks of an Aero Engine Rotor System." In ASME 2015 Gas Turbine India Conference. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/gtindia2015-1297.
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Majority of the failures in Gas turbine Blades are caused by High Cycle Fatigue induced by the vibratory stresses in the rotor blades. The first step in blade design is the prevention of coincidence of natural frequencies of the blades with the frequencies of the fluctuating Gas loads. The forcing frequency is a function of number of upstream and downstream stator blades, and rotational speed. In gas turbines with multiple stages, modal analysis of bladed-disks is individually performed i.e. stage by stage. As the structure is rotationally periodic, cyclic symmetric boundary conditions can be utilized, over 360 degree modeling. The advantage of cyclic symmetry over full model lies in reduced degrees of freedom and hence reduced computational time. In most of the available tools, cyclic symmetry for modal analysis is limited to single stage. As such there is no provision to model and analyze multiple stages at the same time. This leads to inaccurate values of natural frequencies as the flexibility introduced by the adjacent stages is not being taken into consideration. An alternative to this is full 3D modeling and analysis of all the combined stages. Bladh et al. (2003) [1] have shown that interstage coupling can significantly affect the dynamics of the multi-stage assembly and in some cases lead to an underestimation of vibratory levels. Sokolowski et al [2] studied the influence of inclusion of shaft in the model on the natural frequencies and mode shapes of the shrouded bladed discs up to four nodal diameters for first two frequency series (mode shapes). Rzadkowski and Drewczynski (2006) [3] have used full 360 degrees models to study the free and forced dynamics of multi-stage systems. However this method is avoided as the computational cost is prohibitive. Multi stage cyclic symmetry overcomes this obstacle in which each stage is cyclically modeled and an inter-stage coupling is introduced between adjacent stages. The advantage of multi stage cyclic symmetry lies in the significant reduction in the number of elements and therefore computational time. Laxalde et al. (2007) [4] were the first to come up with the method of dynamic analysis of turbo machinery rotors with multi stage cyclic symmetry using interstage coupling. They considered an example of two-stage High Pressure compressor. The results were validated against a complete 360 degrees reference model. Forced response analysis of rotor stages to fluctuating gas loads with and without interstage coupling definition was also presented and compared. In the present work a complete Gas Turbine rotor system with multiple stages of Compressor, Shaft and Turbine were analyzed together.
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Omer, A., and A. Baz. "Vibration Control of Plates Using Electromagnetic Compressional Damping Treatment." In ASME 1999 Design Engineering Technical Conferences. American Society of Mechanical Engineers, 1999. http://dx.doi.org/10.1115/detc99/vib-8018.
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Abstract A new class of structural damping treatments is introduced. This class is the Electromagnetic Compressional Damping Treatment (ECDT) which relies in its operation on a viscoelastic damping layer sandwiched between an electromagnet and a permanent magnet. Interaction between the magnets generates magnetic forces that enhance the compressional damping mechanism of the viscoelastic layer. With proper tuning of the magnetic forces, in response to the structural vibration, undesirable resonances and catastrophic failures can be avoided. The fundamentals and the underlying phenomena associated with the ECDT are investigated theoretically and experimentally. A finite element model is developed to describe the interaction between the dynamics of flexible plates, the visco-elastic damping layer and the electro-magnetic actuators. The validity of the developed finite element model is checked experimentally using aluminum plates treated with single and multi-ECDT patches. The plate/ECDT system is subjected to sinusoidal excitations and its multi-mode response is monitored when the electro-magnetic actuator is activated or not. Several control strategies are considered to activate the electro-magnetic actuator including simple PD controllers. The performance of the uncontrolled and controlled system is determined at various operating conditions. Comparisons with conventional Passive Constrained Layer Damping (PCLD) treatments emphasize the potential of the ECDT treatment as an effective means for controlling structural vibrations.
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Wu, Tsung-Liang, and Yu-Chun Hwang. "Failure Detection for Multiple Micro-Punches Outfitted in Progressive Piercing Processes With Artificial Intelligent Model." In ASME 2019 28th Conference on Information Storage and Processing Systems. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/isps2019-7494.
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Abstract The purpose of this study is to establish a model for the diagnosis of multiple micro-punch failures. The punch is assumed to a rigid body structure with a small change in the stiffness during the piercing process and its diameter is varied between Ø0.8–1.2 mm. Thus, the wearing trend of multiple punches in the piercing process and source of the interfered signals make it extremely difficult to analyze. The two major challenges that affect punch failure estimation are the poor signal-to-noise ratio within the factory environment and the rigid body mode disturbance in the signal. To acquire the vibratory signals of the piercing motion, uniaxial accelerometers were outfitted in the vertical direction on the progressive die. Since the piercing process is a series of highly nonlinear transient processes, the Ensemble Empirical Mode Decomposition (EEMD) is adopted as a decoupling operation tool for this kind of non-stationary signal. Furthermore, the dimension-reduced process can be manipulated by Intrinsic Mode Function (IMF) and a function representative of the feature is selected as the input for neural network model training. The training target is the most direct relationship with the product quality, the selected models are multi-layer perceptron and the back-propagation neural network (BPNN) of the error inversion algorithm. The artificial intelligence failure diagnosis of the piercing process is also realized.
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Oh, J., S. Poh, M. Ruzzene, and A. Baz. "Vibration Control of Beams Using Electro-Magnetic Damping Treatment." In ASME 1999 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 1999. http://dx.doi.org/10.1115/imece1999-0558.
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Abstract A new class of structural damping treatments is introduced. This class is the Electro-Magnetic Damping Treatment (EMDT) which relies in its operation on a viscoelastic damping layer sandwiched between two magnetic layers. Interaction between the magnets generates magnetic forces that enhance the compressional damping mechanism of the viscoelastic layer. With proper tuning of the magnetic forces, in response to the structural vibration, undesirable resonances and catastrophic failures can be avoided. The fundamentals and the underlying phenomena associated with the EMDT are investigated theoretically and experimentally. A finite element model is developed to describe the interaction between the dynamics of flexible beams, the viscoelastic damping layer and the magnetic layers. The validity of the developed finite element model is checked experimentally using aluminum beams treated with EMDT patches. The beam/EMDT system is subjected to sinusoidal excitations and its multi-mode response is monitored when the magnetic layers are activated or not. Several control strategies are considered to activate the magnetic layers including simple PD controllers. The performance of the uncontrolled and controlled system is determined at various operating conditions. Comparisons with conventional Passive Constrained Layer Damping (PCLD) treatments emphasize the potential of the EMDT treatment as an effective means for controlling structural vibrations.
Reports on the topic "Multi-failures mode"
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Seginer, Ido, Louis D. Albright, and Robert W. Langhans. On-line Fault Detection and Diagnosis for Greenhouse Environmental Control. United States Department of Agriculture, February 2001. http://dx.doi.org/10.32747/2001.7575271.bard.
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Background Early detection and identification of faulty greenhouse operation is essential, if losses are to be minimized by taking immediate corrective actions. Automatic detection and identification would also free the greenhouse manager to tend to his other business. Original objectives The general objective was to develop a method, or methods, for the detection, identification and accommodation of faults in the greenhouse. More specific objectives were as follows: 1. Develop accurate systems models, which will enable the detection of small deviations from normal behavior (of sensors, control, structure and crop). 2. Using these models, develop algorithms for an early detection of deviations from the normal. 3. Develop identifying procedures for the most important faults. 4. Develop accommodation procedures while awaiting a repair. The Technion team focused on the shoot environment and the Cornell University team focused on the root environment. Achievements Models: Accurate models were developed for both shoot and root environment in the greenhouse, utilizing neural networks, sometimes combined with robust physical models (hybrid models). Suitable adaptation methods were also successfully developed. The accuracy was sufficient to allow detection of frequently occurring sensor and equipment faults from common measurements. A large data base, covering a wide range of weather conditions, is required for best results. This data base can be created from in-situ routine measurements. Detection and isolation: A robust detection and isolation (formerly referred to as 'identification') method has been developed, which is capable of separating the effect of faults from model inaccuracies and disturbance effects. Sensor and equipment faults: Good detection capabilities have been demonstrated for sensor and equipment failures in both the shoot and root environment. Water stress detection: An excitation method of the shoot environment has been developed, which successfully detected water stress, as soon as the transpiration rate dropped from its normal level. Due to unavailability of suitable monitoring equipment for the root environment, crop faults could not be detected from measurements in the root zone. Dust: The effect of screen clogging by dust has been quantified. Implications Sensor and equipment fault detection and isolation is at a stage where it could be introduced into well equipped and maintained commercial greenhouses on a trial basis. Detection of crop problems requires further work. Dr. Peleg was primarily responsible for developing and implementing the innovative data analysis tools. The cooperation was particularly enhanced by Dr. Peleg's three summer sabbaticals at the ARS, Northem Plains Agricultural Research Laboratory, in Sidney, Montana. Switching from multi-band to hyperspectral remote sensing technology during the last 2 years of the project was advantageous by expanding the scope of detected plant growth attributes e.g. Yield, Leaf Nitrate, Biomass and Sugar Content of sugar beets. However, it disrupted the continuity of the project which was originally planned on a 2 year crop rotation cycle of sugar beets and multiple crops (com and wheat), as commonly planted in eastern Montana. Consequently, at the end of the second year we submitted a continuation BARD proposal which was turned down for funding. This severely hampered our ability to validate our findings as originally planned in a 4-year crop rotation cycle. Thankfully, BARD consented to our request for a one year extension of the project without additional funding. This enabled us to develop most of the methodology for implementing and running the hyperspectral remote sensing system and develop the new analytical tools for solving the non-repeatability problem and analyzing the huge hyperspectral image cube datasets. However, without validation of these tools over a ful14-year crop rotation cycle this project shall remain essentially unfinished. Should the findings of this report prompt the BARD management to encourage us to resubmit our continuation research proposal, we shall be happy to do so.