Qingqing Zhai

National University of Singapore

24Publications

12H-index

308Citations

Publications 24

Newest

#1Lanqing Hong (NUS: National University of Singapore)

#2Qingqing Zhai (SHU: Shanghai University)H-Index: 1

Last.Zhi-Sheng Ye (NUS: National University of Singapore)H-Index: 11

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Components in a system work under the same dynamic operating conditions, and their lifetimes are generally positively correlated. Ignorance of the correlation may lead to a significant bias in the evaluation of system reliability. Using the cumulative exposure principle, we model the equivalent operating time of the components, resulting from the cumulative effects of the dynamic environments, as a monotone increasing stochastic time scale. Commonly-used models, such as the compound Poisson, gam...

#1Piao ChenH-Index: 4

#2Zhi-Sheng Ye (NUS: National University of Singapore)H-Index: 11

Last.Qingqing Zhai (SHU: Shanghai University)

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#1Rui PengH-Index: 15

#2Di WuH-Index: 1

Last.Qingqing ZhaiH-Index: 1

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This paper analyzes the optimal strategies for the attacker in an attack-defense game on a network consisting of interdependent subnetworks. The defender moves first and evenly allocates the scarce resource to protect the network nodes. The attacker moves after observing the actions taken by the defender, allocating its limited resources to attack the network nodes. Binary Decision Diagram is employed to obtain all potential states of a given interdependent network after attack. For each of the ...

#1Rui Peng (USTB: University of Science and Technology Beijing)H-Index: 15

#2Di Wu (Xi'an Jiaotong University)H-Index: 1

Last.Qingqing Zhai (SHU: Shanghai University)H-Index: 1

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This paper studies the defense strategy for a parallel system subject to an unintentional impact and an intentional impact. Existing research assumes that system damage is caused by either natural disasters (unintentional impacts) or strategic attackers (intentional impacts). However, in practice, the defender may encounter diverse scenarios, where these two kinds of impacts can happen in a sequential order. Without knowing the precise occurrence sequence, the defender must allocate its limited ...

#1Qingqing Zhai (SHU: Shanghai University)H-Index: 1

#2Piao ChenH-Index: 4

Last.Lijuan Shen (NUS: National University of Singapore)H-Index: 1

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Abstract Due to the variability of raw materials and the fluctuation in the manufacturing process, degradation of products may exhibit unit-to-unit variability in a population. The heterogeneous degradation rates can be viewed as random effects, which are often modeled by a normal distribution. Despite of its mathematical convenience, the normal distribution has certain limitations in modeling the random effects. In this study, we propose a novel random-effects Wiener process model based on idea...

#1Qingqing Zhai (NUS: National University of Singapore)H-Index: 12

#2Zhi-Sheng Ye (NUS: National University of Singapore)H-Index: 11

ABSTRACTDegradation studies are often used to assess reliability of products subject to degradation-induced soft failures. Because of limited test resources, several test subjects may have to share a test rig and have their degradation measured by the same operator. The common environments experienced by subjects in the same group introduce significant interindividual correlations in their degradation, which is known as the block effect. In the present article, the Wiener process is used to mode...

#1Qingqing Zhai (SHU: Shanghai University)H-Index: 1

#2Liudong Xing (UMassD: University of Massachusetts Dartmouth)H-Index: 29

Last.Jun Yang (Beihang University)H-Index: 12

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Phased-mission systems (PMSs) are common in many real-world applications. A PMS has to accomplish a mission with multiple phases with varied requirements on system operation and demand. Reliability evaluation of PMSs is more challenging than single-phased systems due to dynamics in system configuration (or structure function) and component behavior, as well as inherent inter-phase dependence. Though many efforts have been dedicated to the PMS reliability analysis, it is still difficult to evalua...

#1Qingqing Zhai (NUS: National University of Singapore)H-Index: 12

#2Zhi-Sheng Ye (NUS: National University of Singapore)H-Index: 11

Degradation modeling plays an important role in system health diagnosis and remaining useful life (RUL) prediction. Recently, a class of Wiener process models with adaptive drift was proposed for degradation-based RUL prediction, which has been proven flexible and effective. However, the existing studies use an autoregressive model of order 1 for the adaptive drift, which can result in difficulties in both model estimation and RUL prediction. This paper proposes a new adaptive Wiener process mod...

#1Qingqing Zhai (NUS: National University of Singapore)H-Index: 12

#2Zhi-Sheng Ye (NUS: National University of Singapore)H-Index: 11

Degradation analysis is an effective way to infer the health status and lifetime of products. Due to variability in the measurement, degradation observations are often subject to measurement errors. Existing studies generally assume Gaussian measurement errors, which may be deficient when there are outliers in the observations. To make a robust inference, we propose a Wiener degradation model with measurement errors modeled by Student’s t -distribution. The t -distribution is a useful extension ...

#1Piao Chen (NUS: National University of Singapore)H-Index: 4

#2Qingqing Zhai (NUS: National University of Singapore)

Last.Zhi-Sheng Ye (NUS: National University of Singapore)H-Index: 11

view all 3 authors...

For complex systems with many components, it is a heavy burden to accurately record all the failure times of each component. To ease the information storage, practitioners in industry may only record the number of failures during an operation interval instead. Such a type of data compresses the detailed failure information and may be called time-censored aggregate data. Because only limited information is available, the statistical inference for aggregate data is more challenging than traditiona...

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