Notions of Diagnosability for Timed Failure Propagation Graphs

2006 ◽  
Author(s):  
Sherif Abdelwahed ◽  
Gabor Karsai
Keyword(s):  
Failure Propagation

A Knowledge based Tool for Failure Propagation Analysis

1989 ◽  
Author(s):  
P.S. Ness ◽  
D. Bereket ◽  
M. Hakimi ◽  
T. Uthus ◽  
A. Chakravarty
Keyword(s):  
Knowledge Based ◽  
Propagation Analysis ◽  
Failure Propagation

scholarly journals Definitions and Concepts for Quantitative Rockfall Hazard and Risk Analysis

Geosciences ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 158
Author(s):  
Didier Hantz ◽  
Jordi Corominas ◽  
Giovanni B. Crosta ◽  
Michel Jaboyedoff
Keyword(s):  
Risk Assessment ◽  
At Risk ◽  
Failure Probability ◽  
Rockfall Hazard ◽  
Process Failure ◽  
Failure Propagation ◽  
Element At Risk ◽  
Hazard And Risk ◽  
Hazard And Risk Assessment ◽  
Definition Of

There is an increasing need for quantitative rockfall hazard and risk assessment that requires a precise definition of the terms and concepts used for this particular type of landslide. This paper suggests using terms that appear to be the most logic and explicit as possible and describes methods to derive some of the main hazards and risk descriptors. The terms and concepts presented concern the rockfall process (failure, propagation, fragmentation, modelling) and the hazard and risk descriptors, distinguishing the cases of localized and diffuse hazards. For a localized hazard, the failure probability of the considered rock compartment in a given period of time has to be assessed, and the probability for a given element at risk to be impacted with a given energy must be derived combining the failure probability, the reach probability, and the exposure of the element. For a diffuse hazard that is characterized by a failure frequency, the number of rockfalls reaching the element at risk per unit of time and with a given energy (passage frequency) can be derived. This frequency is relevant for risk assessment when the element at risk can be damaged several times. If it is not replaced, the probability that it is impacted by at least one rockfall is more relevant.

scholarly journals METAMODEL FOR SAFETY AND SECURITY INTEGRATED SYSTEM ARCHITECTURE MODELING

2021 ◽  
Vol 1 ◽  
pp. 2027-2036
Author(s):  
Aschot Kharatyan ◽  
Julian Tekaat ◽  
Sergej Japs ◽  
Harald Anacker ◽  
Roman Dumitrescu
Keyword(s):  
Information And Communication Technologies ◽  
Systems Engineering ◽  
System Development ◽  
Autonomous Driving ◽  
Integrated System ◽  
Product Complexity ◽  
System Architectures ◽  
Failure Propagation ◽  
Architecture Modeling ◽  
Systemic Development

AbstractAs digitization progresses, the integration of information and communication technologies in technical systems is constantly increasing. Fascinating value potentials are emerging (e.g. autonomous driving), but also challenges in the system development. The constantly increasing product complexity and degree of networking require a systemic development, which is fulfilled by established approaches of Model-Based Systems Engineering (MBSE). To ensure the reliability of tomorrow's systems, an integrative and early consideration of security and safety is additionally required. In order to show the possibility and consequences of failures and attacks, the paper develops a modeling language that links established and partly isolated security and safety approaches within a consistent metamodel. The developer is enabled to synthesize system architectures transparently on an interdisciplinary level and to analyze attack and failure propagation integratively. The approach uncovers synergetic and especially contrasting goals and effects of architectural designs in terms of safety and security in order to make adequate architectural decisions based on trade-off analyses.

Applying Function-Based Failure Propagation in Conceptual Design

2007 ◽  
Author(s):  
Daniel Krus ◽  
Katie Grantham Lough
Keyword(s):  
Risk Analysis ◽  
Product Design ◽  
Conceptual Design ◽  
Functional Model ◽  
Thermal Control ◽  
Design Phase ◽  
Historical Knowledge ◽  
Conceptual Design Phase ◽  
Failure Propagation ◽  
Potential Risks

When designing a product, the earlier the potential risks can be identified, the more costs can be saved, as it is easier to modify a design in its early stages. Several methods exist to analyze the risk in a system, but all require a mature design. However, by applying the concept of “common interfaces” to a functional model and utilizing a historical knowledge base, it is possible to analyze chains of failures during the conceptual phase of product design. This paper presents a method based on these “common interfaces” to be used in conjunction with other methods such as Risk in Early Design in order to allow a more complete risk analysis during the conceptual design phase. Finally, application of this method is demonstrated in a design setting by applying it to a thermal control subsystem.

A multiple failure propagation model in GMPLS-based networks

IEEE Network ◽  
2010 ◽  
Vol 24 (6) ◽  
pp. 17-22 ◽  
Author(s):  
Eusebi Calle ◽  
Jordi Ripoll ◽  
Juan Segovia ◽  
Pere Vilà ◽  
Marc Manzano
Keyword(s):  
Propagation Model ◽  
Failure Propagation

spaceAPPS – A modular approach for on-board software

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Juergen Herpel ◽  
Friedrich Schoen ◽  
Harald Selegrad
Keyword(s):  
Success Factors ◽  
Third Party ◽  
Ground Testing ◽  
Modular Concept ◽  
Failure Propagation ◽  
Software Modularity ◽  
Cost Efficient ◽  
Space Separation ◽  
Target Platform ◽  
Efficient Software

Abstract Software modularity and partial qualification capabilities are key enablers to produce cost efficient software in highly regulated domains. The modular concept (called spaceAPPS) described in this paper has been developed in the frame of the OPS-SAT project aiming at missions where flexibility is one of the success factors. spaceAPPS implements a novel software architecture for satellites inspired by the Apps concept of modern smartphones. In the European space domain the operation of a satellite is based on a set of 18 services. Accordingly, in spaceApps these services are mapped to individual Apps. This is not a one-to-one mapping which means that one App implements one or more services. During OPS-SAT ground testing it was demonstrated that functionality could be easily added through a new App or updated through replacing an existing App. Also during OPS-SAT ground testing it could be shown that a failing UserApp did not impact the basic apps to operate the satellite. Thus, it is possible to run applications of different criticality on the same platform. With operating systems supporting time and space separation the risk of failure propagation can be further reduced. The implementation of a partial validation approach, i. e. testing of third-party Apps in a representative environment and not running the validation on the target platform is feasible but was not demonstrated.

Study of Pullout Performance of Self-Tapping Screws for Human Bone

2011 ◽  
Author(s):  
Zhijun Wu ◽  
Sayed A. Nassar ◽  
Xianjie Yang
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Analytical Model ◽  
Material Properties ◽  
Pedicle Screws ◽  
Pullout Strength ◽  
Bone Material ◽  
Synthetic Bone ◽  
Failure Propagation ◽  
Device Applications

The study investigates the pullout strength of self-tapping pedicle screws using analytical, finite element, and experimental methodologies with focus on medical device applications. The stress distribution and failure propagation around implant threads in the synthetic bone during the pullout process, as well as the pullout strength of pedicle screws, are explored. Based on the FEA results, an analytical model for the pullout strength of the pedicle screw is constructed in terms of the synthetic bone material properties, screw size, and implant depth. The characteristics of pullout behavior of self-tapping pedicle screws are discussed. Both the analytical model and finite element results are validated using experimental techniques.

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