scholarly journals TREE DIAGRAMS APPLIED IN ANALYSIS OF TIME-DEPENDENT SYSTEM FAILURE RATES

1964 ◽  
Author(s):  
F W Mueller
Keyword(s):  
Time Dependent ◽  
System Failure ◽  
Failure Rates ◽  
Time Dependent System

scholarly journals Resilience Assessment Based on Time-Dependent System Reliability Analysis

2016 ◽  
Vol 138 (11) ◽  
Author(s):  
Zhen Hu ◽  
Sankaran Mahadevan
Keyword(s):  
Reliability Analysis ◽  
System Reliability ◽  
Assessment Method ◽  
Time Dependent ◽  
Design Stage ◽  
System Failure ◽  
System Reliability Analysis ◽  
System Resilience ◽  
Resilience Assessment ◽  
Time Dependent System

Significant efforts have been recently devoted to the qualitative and quantitative evaluation of resilience in engineering systems. Current resilience evaluation methods, however, have mainly focused on business supply chains and civil infrastructure, and need to be extended for application in engineering design. A new resilience metric is proposed in this paper for the design of mechanical systems to bridge this gap, by investigating the effects of recovery activity and system failure paths on system resilience. The defined resilience metric is connected to design through time-dependent system reliability analysis. This connection enables us to design a system for a specific resilience target in the design stage. Since computationally expensive computer simulations are usually used in design, a surrogate modeling method is developed to efficiently perform time-dependent system reliability analysis. Based on the time-dependent system reliability analysis, dominant system failure paths are enumerated and then the system resilience is estimated. The connection between the proposed resilience assessment method and design is explored through sensitivity analysis and component importance measure (CIM). Two numerical examples are used to illustrate the effectiveness of the proposed resilience assessment method.

The Integrative Time-Dependent Modeling of the Reliability and Failure of the Causes of Drivers' Error Leading to Road Accidents

2015 ◽  
pp. 1279-1294
Author(s):  
Khashayar Hojjati-Emami ◽  
Balbir S. Dhillon ◽  
Kouroush Jenab
Keyword(s):  
Human Error ◽  
Time Dependent ◽  
Failure Rates ◽  
Road Accidents ◽  
Road Transportation ◽  
The Road ◽  
Representational Model ◽  
On The Road ◽  
The Moment ◽  
Dependent Failure

Nowadays, the human error is usually identified as the conclusive cause of investigations in road accidents. The human although is the person in control of vehicle until the moment of crash but it has to be understood that the human is under continued impact by various factors including road environment, vehicle and human's state, abilities and conduct. The current advances in design of vehicle and roads have been intended to provide drivers with extra comfort with less physical and mental efforts, whereas the fatigue imposed on driver is just being transformed from over-load fatigue to under-load fatigue and boredom. A representational model to illustrate the relationships between design and condition of vehicle and road as well as driver's condition and state on fatigue and the human error leading to accidents has been developed. Thereafter, the stochastic mathematical models based on time-dependent failure rates were developed to make prediction on the road transportation reliability and failure probabilities due to each cause (vehicle, road environment, human due to fatigue, and human due to non fatigue factors). Furthermore, the supportive assessment methodology and models to assess and predict the failure rates of driver due to each category of causes were developed and proposed.

scholarly journals Compacting the description of a time-dependent multivariable system and its multivariable driver by reducing the state vectors to aggregate scalars: the Earth's solar-wind-driven magnetosphere

2019 ◽  
Vol 26 (4) ◽  
pp. 429-443 ◽  
Author(s):  
Joseph E. Borovsky ◽  
Adnane Osmane
Keyword(s):  
Solar Wind ◽  
State Vector ◽  
Complexity Analysis ◽  
Low Noise ◽  
Time Dependent ◽  
Permutation Entropy ◽  
System Response ◽  
System A ◽  
Driven System ◽  
Time Dependent System

Abstract. Using the solar-wind-driven magnetosphere–ionosphere–thermosphere system, a methodology is developed to reduce a state-vector description of a time-dependent driven system to a composite scalar picture of the activity in the system. The technique uses canonical correlation analysis to reduce the time-dependent system and driver state vectors to time-dependent system and driver scalars, with the scalars describing the response in the system that is most-closely related to the driver. This reduced description has advantages: low noise, high prediction efficiency, linearity in the described system response to the driver, and compactness. The methodology identifies independent modes of reaction of a system to its driver. The analysis of the magnetospheric system is demonstrated. Using autocorrelation analysis, Jensen–Shannon complexity analysis, and permutation-entropy analysis the properties of the derived aggregate scalars are assessed and a new mode of reaction of the magnetosphere to the solar wind is found. This state-vector-reduction technique may be useful for other multivariable systems driven by multiple inputs.

scholarly journals Corrosive Environment Assessment and Corrosion-Induced Rockbolt Failure Analysis in a Costal Underground Mine

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Qifeng Guo ◽  
Jiliang Pan ◽  
Min Wang ◽  
Meifeng Cai ◽  
Xun Xi
Keyword(s):  
Chemical Composition ◽  
Corrosion Rate ◽  
Time Dependent ◽  
Gold Mine ◽  
System Failure ◽  
Corrosive Environment ◽  
Support Design ◽  
Ph Values ◽  
Environment Assessment

As an effective ground-reinforcing system, rockbolts have been widely used in underground excavations. Corrosion of rockbolts has been one of the most reasons for rockbolts system failure. In this paper, the chemical composition and pH values of the groundwater in Sanshandao Gold mine are first tested. Corrosion of the slotted rockbolts used in roadways of the mine is analysed. The corrosion rate of rockbolts is evaluated based on experimental results from similar corrosive conditions. A time-dependent analytical model on anchoring force degradation caused by corrosion of the rockbolt is developed. Furthermore, the effects of corrosion rate and geometric parameters of the slotted rockbolts on anchoring force degradation are discussed. Suggestions on rockbolts support design in corrosive conditions are given. It has been found that, with the corrosion time increasing, the anchoring force between the rock and the rockbolt gradually decreases. The larger the corrosion rate is, the faster the anchoring force decreases. For long-term service roadways under corrosive conditions, a slotted rockbolt with a smaller radius and thicker wall can enhance the anchoring force.

LOGISTIC MAPPING WITH A TIME-DEPENDENT SYSTEM-PARAMETER AND ITS ATTRACTOR BASINS WITH SELF-SIMILAR STRUCTURE

2004 ◽  
Vol 14 (07) ◽  
pp. 2407-2416 ◽  
Author(s):  
JOUSUKE KUROIWA ◽  
TAKAFUMI MIKI
Keyword(s):  
System Parameter ◽  
Time Dependent ◽  
Chaotic Attractors ◽  
Self Similarity ◽  
Initial Values ◽  
Logistic Mapping ◽  
Periodic Attractors ◽  
Self Similar ◽  
Basins Of Attractions ◽  
Time Dependent System

In this paper, logistic mapping with a time-dependent system-parameter (referred as "LMTD") is proposed. In various choices of time dependence, the periodic one has been tried in order to investigate the dynamical properties of LMTD. In certain parameter regions, two different attractors coexist depending on the initial values, for instances, two different chaotic attractors, two different periodic attractors, or two periodic/chaotic attractors. In addition, the whole configuration space of the initial values forms basins of attractions of which structures indicate self-similarity.

Extreme Value Metamodeling for System Reliability With Time-Dependent Functions

2015 ◽  
Author(s):  
Zhifu Zhu ◽  
Xiaoping Du
Keyword(s):  
Computational Efficiency ◽  
System Reliability ◽  
Extreme Values ◽  
Random Variables ◽  
Probability Of Failure ◽  
High Accuracy ◽  
Extreme Value ◽  
Time Dependent ◽  
System Failure ◽  
Kriging Method

The reliability of a system is usually measured by the probability that the system performs its intended function in a given period of time. Estimating such reliability is a challenging task when the probability of failure is rare and the responses are nonlinear and time variant. The evaluation of the system reliability defined in a period of time requires the extreme values of the responses in the predefined period of time during which the system is supposed to function. This work builds surrogate models for the extreme values of responses with the Kriging method. For the sake of computational efficiency, the method creates Kriging models with high accuracy only in the region that has high contributions to the system failure; training points of random variables and time are sampled simultaneously so that their interactions could be considered automatically. The example of a mechanism system shows the effectiveness of the proposed method.

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