Optimal joint inspection and mission abort policy for a partially observable system

Cheng, Guoqing; Li, Ling; Shangguan, Chunxia; Yang, Nan; Bo, Jiang; Tao, NingRong

doi:10.1016/j.ress.2022.108870

Cited by 29 publications

(5 citation statements)

References 38 publications

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“…This result is similar to the identification of critical thresholds in the mission abort literature, despite the difference in reward structures (Cheng et al 2023, Qiu et al 2023, Zhao et al 2021. For any time period t, this reduces the number of conditional plans we need to consider from T − t + 1 to 2, drastically reducing the computational cost.…”

Section: Pomdp Modelsupporting

confidence: 75%

“…This degradation process is then converted to a continuous-state MDP. Cheng et al (2023) utilizes a hidden Markov model to model the system's degradation, which is then transformed into a continuous-state MDP. Both of these works solve their models via value iteration (Krishnamurthy 2016), whereas we derive a closed-form equation for our value functions.…”

Section: Literature Reviewmentioning

confidence: 99%

“…Similarly toCheng et al (2023),Qiu et al (2023) andZhao et al (2021), we demonstrate structural properties of our problem when we enforce additional structure on the sequences (P [(dr)] This is a reasonable assumption, as the quality of the facility will degrade over time, which in turn will make the facility more susceptible to a manufacturing failure. As the facility becomes more susceptible to a manufacturing failure, the facility is in turn more likely to halt operations to allow for non-mandatory maintenance to occur.With this additional structure, we can directly compare the values of conditional plans.…”

mentioning

confidence: 98%

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Role of Stress Granules in the Pathogenesis of Pulmonary Hypertension Kosmas Kosmas ^1,2, Fotios Spyropoulos^1,2,Helen Christou ^1,2¹Department of Pediatric Newborn Medicine, Brigham and Women’s Hospital, Boston, MA 02115, USA ²Harvard Medical School, Boston, MA 02215, USA

2022

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Background PAH is a devastating and incurable disease characterized by abnormal pulmonary vascular phenotypes and progressive right ventricular failure, but the underlying mechanisms are incompletely understood. There is an urgent need of new therapeutic approaches, and a better understanding of disease pathogenesis is essential in identifying novel pathways that can be therapeutically targeted. Stress granules (SGs) are small intracellular structures that form in response to stress and contain mRNA molecules and mRNA‐binding proteins. These granules allow cells to temporarily halt translation by “parking” or sequestering certain mRNAs in a protected zone (the stress granule) and this allows the cells to survive in conditions of stress. The role of SGs in abnormal vascular and cardiac homeostasis in PAH is not known. Hypotheses We hypothesized that increased SG formation may contribute to both abnormal vascular cellular phenotypes and cardiac failure in human and experimental PAH. Further, we examined whether treatment with the carbonic anhydrase Acetazolamide (ACTZ) which is known to ameliorate experimental PAH, would alter SG tissue abundance in the lungs and heart. Methods We used the adult rat (Sprague Dawley) sugen/hypoxia (Su/Hx) model of severe pulmonary hypertension and studied tissue sections from lungs, heart and skeletal muscle as well as isolated primary pulmonary artery smooth muscle cells (PASMCs). We also used PASMCs from patients with PAH. We applied a combination of immunofluorescence and protein expression studies as well as drug (ACTZ) treatment and in vitro induction of oxidative stress (arsenite) to assess SG formation and SG related markers in experimental PAH and the effect of ACTZ. Results We have discovered that PASMCs from patients with PAH have a higher number of stress granules in response to oxidative stress than cells from normal individuals. We also found that PASMCs from a preclinical model of PAH (Sugen/Hypoxia) have more stress granules and increased SG components in response to oxidative stress compared to normal animals. Further, we found that treatment of PASMCs with ACTZ resulted in lower number of stress granules after cell stress. In addition, we found increased G3BP1 (key component of SG assembly) puncta in alveoli and bronchi and sarcoplasmic G3BP1 puncta in cardiac and soleus muscles from the rat sugen/hypoxia (Su/Hx) model compared to controls and with ACTZ treatment. Conclusions We conclude that there is increased SG formation in PASMCs and tissues in experimental PAH and acetazolamide inhibits stress granule assembly in response to oxidative stress. Further studies are needed to define the role of SG in disease pathogenesis, and evaluate whether targeting stress granules may be effective in restoring normal cellular function and improving PAH.

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Section: Pomdp Modelsupporting

confidence: 75%

Section: Literature Reviewmentioning

confidence: 99%

mentioning

confidence: 98%

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Role of Stress Granules in the Pathogenesis of Pulmonary Hypertension Kosmas Kosmas ^1,2, Fotios Spyropoulos^1,2,Helen Christou ^1,2¹Department of Pediatric Newborn Medicine, Brigham and Women’s Hospital, Boston, MA 02115, USA ²Harvard Medical School, Boston, MA 02215, USA

2022

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“…Secondly, considering the components with dependent failure processes, 42,43 and competing risks 44 are considered. Moreover, consider the condition‐based mission abort policy 13,45 for a multi‐state system 46 with a multi‐stage mission based on the assumptions of this paper. Finally, study the joint optimization problems related to the mission abort policy 13,33,45 …”

Section: Discussionmentioning

confidence: 99%

Optimal mission abort policy for a balanced system with a restricted mechanism

Dong

2023

Quality & Reliability Eng

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The balanced system often performs key missions in many fields, such as aerospace, new energy storage, and the military. However, the failure of the system can cause major losses. Therefore, the mission needs to be aborted when the risk of system failure is higher. In this paper, the optimal mission abort policy for a k‐out‐of‐n: F balanced system is studied. The system with a restricted mechanism consists of m sectors and there are n components in each sector, in which the components fail due to two situations: internal failure or external shocks. If the number of working components in m sectors is the same, the system is balanced. If one component fails, the system will force down or resume a component with a probability to keep balance. The model of the mentioned system is established, and the Markov process imbedding approach is used for deriving the reliability indices. Two optimization models are established according to two competitive abort criteria. Finally, an unmanned aerial vehicle performing a mission is discussed to illustrate the proposed mission abort policy.

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“…It is worth noting that in most existing condition‐based mission abort models, assume that the system state is fully observable via condition monitoring (Levitin, Xing, et al., 2020; Levitin et al., 2021b; Yang et al., 2022; Peng et al., 2010; Zhao et al., 2022). The mission abort decision‐making problem in case of partial condition monitoring information is studied in only a few recent works (Cheng et al., 2022). The corresponding optimization problems are solved by using a partially observable Markov decision process (POMDP).…”

Section: Introductionmentioning

confidence: 99%

Mission risk control via joint optimization of sampling and abort decisions

2023

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Information‐driven mission abort is an effective way to control the failure risk of safety‐critical systems during mission executions. We investigate the optimal sampling and mission abort decisions of partially observable safety‐critical systems, where the underlying system health state can only be revealed by sampling. In contrast to previous studies, we employ partial health information to jointly determine: (a) whether to execute sampling, and (b) when to abort the mission in a dynamic manner, so as to minimize the expected total cost incurred by sampling, mission failure, and system malfunction. Dynamic sampling and mission abort policies are devised following the belief state, whose optimization model is cast into the framework of a partially observable Markov decision process. Some structural insights with regard to the value function, control limit selection, and optimality existence are presented. The performance of the proposed sampling and abort policy is tested by numerical experiments, which are proved to outperform other heuristic abort policies in mission loss control.

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Optimal joint inspection and mission abort policy for a partially observable system

Cited by 29 publications

References 38 publications

Role of Stress Granules in the Pathogenesis of Pulmonary Hypertension Kosmas Kosmas ^1,2, Fotios Spyropoulos^1,2,Helen Christou ^1,2¹Department of Pediatric Newborn Medicine, Brigham and Women’s Hospital, Boston, MA 02115, USA ²Harvard Medical School, Boston, MA 02215, USA

Role of Stress Granules in the Pathogenesis of Pulmonary Hypertension Kosmas Kosmas ^1,2, Fotios Spyropoulos^1,2,Helen Christou ^1,2¹Department of Pediatric Newborn Medicine, Brigham and Women’s Hospital, Boston, MA 02115, USA ²Harvard Medical School, Boston, MA 02215, USA

Optimal mission abort policy for a balanced system with a restricted mechanism

Mission risk control via joint optimization of sampling and abort decisions

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Optimal joint inspection and mission abort policy for a partially observable system

Cited by 29 publications

References 38 publications

Role of Stress Granules in the Pathogenesis of Pulmonary Hypertension Kosmas Kosmas 1,2, Fotios Spyropoulos1,2,Helen Christou 1,21Department of Pediatric Newborn Medicine, Brigham and Women’s Hospital, Boston, MA 02115, USA 2Harvard Medical School, Boston, MA 02215, USA

Role of Stress Granules in the Pathogenesis of Pulmonary Hypertension Kosmas Kosmas 1,2, Fotios Spyropoulos1,2,Helen Christou 1,21Department of Pediatric Newborn Medicine, Brigham and Women’s Hospital, Boston, MA 02115, USA 2Harvard Medical School, Boston, MA 02215, USA

Optimal mission abort policy for a balanced system with a restricted mechanism

Mission risk control via joint optimization of sampling and abort decisions

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Resources

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Role of Stress Granules in the Pathogenesis of Pulmonary Hypertension Kosmas Kosmas ^1,2, Fotios Spyropoulos^1,2,Helen Christou ^1,2¹Department of Pediatric Newborn Medicine, Brigham and Women’s Hospital, Boston, MA 02115, USA ²Harvard Medical School, Boston, MA 02215, USA

Role of Stress Granules in the Pathogenesis of Pulmonary Hypertension Kosmas Kosmas ^1,2, Fotios Spyropoulos^1,2,Helen Christou ^1,2¹Department of Pediatric Newborn Medicine, Brigham and Women’s Hospital, Boston, MA 02115, USA ²Harvard Medical School, Boston, MA 02215, USA