scholarly journals The role of bridging nodes in behavioral network models of complex engineered systems

2018 ◽  
Vol 4 ◽  
Author(s):  
Hannah S. Walsh ◽  
Andy Dong ◽  
Irem Y. Tumer
Keyword(s):  
Early Stage ◽  
Network Models ◽  
Vital Role ◽  
System Level ◽  
Complex Engineered Systems ◽  
Failure Tolerance ◽  
Design Variables ◽  
Engineered Systems ◽  
Network Metrics

Recent advances in early stage failure analysis approaches have introduced behavioral network analysis (BNA), which applies a network-based model of a complex engineered system to detect the system-level effect of ‘local’ failures of design variables and parameters. Previous work has shown that changes in microscale network metrics can signify system-level performance degradation. This article introduces a new insight into the influence of the community structure of the behavioral network on the failure tolerance of the system through the role of bridging nodes. Bridging nodes connect a community of nodes in a system to one or more nodes or communities outside of the community. In a study of forty systems, it is found that bridging nodes, under attack, are associated with significantly larger system-level behavioral degradation than non-bridging nodes. This finding indicates that the modularity of the behavioral network could be key to understanding the failure tolerance of the system and that parameters associated with bridging nodes between modules could play a vital role in system degradation.

The Structure of Vulnerable Nodes in Behavioral Network Models of Complex Engineered Systems

2017 ◽  
Author(s):  
Hannah S. Walsh ◽  
Andy Dong ◽  
Irem Y. Tumer
Keyword(s):  
Network Models ◽  
Design Parameters ◽  
Engineering Systems ◽  
Critical Design ◽  
Complex Engineered Systems ◽  
Design Variables ◽  
Engineered Systems ◽  
Process Controls ◽  
Robustness Metrics

All methods associated with failure analysis attempt to identify critical design variables and parameters such that appropriate process controls can be implemented to detect problems before they occur. This paper introduces a new approach to the identification of critical design variables and parameters through the concept of bridging nodes. Using a network-based perspective in which design parameters and variables are modeled as nodes, results show that vulnerable parameters tend to be bridging nodes, which are nodes that connect two or more groups of nodes that are organized together in order to perform an intended function. This paper extends existing modeling capabilities based upon a behavioral network analysis (BNA) approach and presents empirical results identifying the relationship between bridging nodes and parameter vulnerability as determined by existing, network metric-based methods. These topological network robustness metrics were used to analyze a large number of engineering systems. Bridging nodes are associated with significantly larger changes in network degradation, as measured by these metrics, than non-bridging nodes when subject to attack (p < 0.001). The results indicate the structural role of vulnerable design parameters in a behavioral network.

Creating Faultable Network Models of Complex Engineered Systems

2014 ◽  
Author(s):  
Brandon M. Haley ◽  
Andy Dong ◽  
Irem Y. Tumer
Keyword(s):  
Failure Analysis ◽  
Network Models ◽  
System Behavior ◽  
Levels Of Abstraction ◽  
Complex Engineered Systems ◽  
System A ◽  
Topological Configuration ◽  
Engineered Systems ◽  
Types Of Faults ◽  
Insight Into

This paper presents a new methodology for modeling complex engineered systems using complex networks for failure analysis. Many existing network-based modeling approaches for complex engineered systems “abstract away” the functional details to focus on the topological configuration of the system and thus do not provide adequate insight into system behavior. To model failures more adequately, we present two types of network representations of a complex engineered system: a uni-partite architectural network and a weighted bi-partite behavioral network. Whereas the architectural network describes physical inter-connectivity, the behavioral network represents the interaction between functions and variables in mathematical models of the system and its constituent components. The levels of abstraction for nodes in both network types affords the evaluation of failures involving morphology or behavior, respectively. The approach is shown with respect to a drivetrain model. Architectural and behavioral networks are compared with respect to the types of faults that can be described. We conclude with considerations that should be employed when modeling complex engineered systems as networks for the purpose of failure analysis.

Estimate Uncertainty: Miscommunication About Definitions of Engineering Terminology

2019 ◽  
Vol 142 (7) ◽  
Author(s):  
John Meluso ◽  
Jesse Austin-Breneman ◽  
Jose Uribe
Keyword(s):  
System Performance ◽  
Large Scale ◽  
Phase 1 ◽  
Parameter Estimate ◽  
Fortune 500 ◽  
System Level ◽  
Future Design ◽  
Complex Engineered Systems ◽  
Current Design ◽  
Engineered Systems

Abstract Communication has been shown to affect the design of large-scale complex engineered systems. Drawing from engineering design, communication, and management literature, this work defines miscommunication as when communication results in a “deficiency” or “problem” that hinders parties from fulfilling their values. This article details a consequential example of miscommunication at a Fortune 500 engineering firm with the potential to affect system performance. In phase 1, interviews with engineering practitioners (n = 82) identified disagreement about what constitutes a parameter “estimate” in the design process. Phase 2 surveyed engineering practitioners (n = 128) about whether estimates communicated for system-level tracking approximate “current” design statuses or “future” design projections. The survey found that both definitions existed throughout the organization and did not correlate with subsystem, position, or design phase. Engineers inadvertently aggregated both current and future estimates into single system-level parameters that informed decision-making, thereby constituting widespread or systemic miscommunication. Thus, even technical concepts may be susceptible to miscommunication and could affect system performance.

scholarly journals CMTM7 as a novel molecule of ATG14L-Beclin1-VPS34 complex enhances autophagy by Rab5 to regulate tumorigenicity

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Baocai Liu ◽  
Yinliang Lu ◽  
Tingting Zhang ◽  
Xinyue Yu ◽  
Qian Wang ◽  
...  
Keyword(s):  
Early Stage ◽  
Xenograft Model ◽  
Vital Role ◽  
Autophagic Flux ◽  
In Vivo Experiments ◽  
Transmission Electron ◽  
Autophagy Induction

Abstract Background CMTM7 is a tumor suppressor that positively regulates EGFR degradation by promoting Rab5 activation, and plays a vital role in tumor progression. Rab5 forms complexes with Beclin1 and VPS34, and acts in the early stage of autophagy. However, the affects of CMTM7 on autophagy and its mechanism are still unclear. Methods The effect of CMTM7 on autophagy induction was confirmed by western blotting, confocal microscopy and transmission electron microscopy. Co-immunoprecipitation was used to analyse the interaction of CMTM7 with autophagy initiation complex and Rab5. The xenograft model in nude mice was used to elucidate the function of CMTM7 in tumorigenicity and autophagy in vivo. Results In this study, we first demonstrated that CMTM7 facilitated the initiation of autophagosome formation, which consequently promoted the subsequent multistage process of autophagic flux, i.e. from autophagosome assembly till autolysosome formation and degradation. Confocal and co-immunoprecipitation showed that CMTM7 interacted with Rab5, VPS34, Beclin1, and ATG14L, but not with ULK1, UVRAG and LC3B. CMTM7 also increased the activity of ATG14L-linked VPS34 complex and its association with Rab5. Both in vitro and in vivo experiments demonstrated that knockdown of CMTM7 enhanced tumor growth by impairing autophagy. Conclusion These findings highlighted the role of CMTM7 in the regulation of autophagy and tumorigenicity, revealing it as a novel molecule that is associated with the interaction of Rab5 and ATG14L-Beclin1-VPS34 complex.

scholarly journals Complex network models reveal correlations among network metrics, exercise intensity and role of body changes in the fatigue process

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Vanessa Helena Pereira ◽  
Maria Carolina Traina Gama ◽  
Filipe Antônio Barros Sousa ◽  
Theodore Gyle Lewis ◽  
Claudio Alexandre Gobatto ◽  
...  
Keyword(s):  
Complex Network ◽  
Exercise Intensity ◽  
Network Models ◽  
Fatigue Process ◽  
Complex Network Models ◽  
Network Metrics

scholarly journals Assessing the Impacts of Augmented Observations on the Forecast of Typhoon Wutip’s (2013) Formation Using the Ensemble Kalman Filter

2020 ◽  
Vol 35 (4) ◽  
pp. 1483-1503
Author(s):  
Tran Tan Tien ◽  
Dao Nguyen-Quynh Hoa ◽  
Cong Thanh ◽  
Chanh Kieu
Keyword(s):  
Kalman Filter ◽  
Large Scale ◽  
Early Stage ◽  
Wrf Model ◽  
Monsoon Trough ◽  
Vital Role ◽  
Weather Research And Forecasting ◽  
Atmospheric Motion ◽  
Meteorological Satellite

AbstractIn this study, the impacts of different augmented observations on forecasts of Typhoon Wutip’s (2013) formation are examined. Using the local ensemble transformed Kalman filter (LETKF) implemented for the Weather Research and Forecasting (WRF) Model, it is found that the prediction of Wutip’s formation location and timing is strongly governed by the strength of a monsoon trough that extends from the Bay of Bengal to the Philippine Sea. By properly capturing the strength of the monsoon trough after assimilating augmented observations available during Wutip’s early stage, the WRF Model could provide better forecasts of Wutip’s formation location and timing as compared to the forecasts initialized directly from global model analyses. Among different types of augmented observations, the satellite atmospheric motion wind vector (AMV) maintained by the Cooperative Institute for Meteorological Satellite Studies (CIMSS) appears to be the most critical in enhancing the large-scale representation of the monsoon trough. The benefit of augmented observations in Wutip’s formation forecast is most apparent at about 36 h prior to the observed formation time. At the shorter 24-h lead time, there is, however, no clear benefit of augmented observations in predicting the timing and the location of Wutip’s formation due to better global analyses. The results obtained in this study demonstrate the vital role of the CIMSS-AMV data in improving the large-scale environment required for TC formation that one should take into account for real-time TC forecasts.

scholarly journals COVID-19 pandemic and “survival of the fittest”

2021 ◽  
Vol 15 (10) ◽  
pp. 1384-1387
Author(s):  
Richa Mukhra ◽  
Kewal Krishan ◽  
Tanuj Kanchan
Keyword(s):  
Immune System ◽  
Early Stage ◽  
Vital Role ◽  
Complex Relationship ◽  
Human Immune System ◽  
Human Immune ◽  
Micro Organisms ◽  
Relationship Of ◽  
Survival Of The Fittest

Occurrence and recurrence of COVID-19 cases have been observed globally. The complex relationship of host-pathogen and the environment plays a vital role in understanding the widespread recurrence of the SARS-CoV-2 among humans. Though the pathobiology of the disease is not completely understood, it is well established that COVID-19 poses a greater threat to individuals with co-morbidities and a weakened immune system. The article deals with the notion of innate immunity, natural selection, and the survival of the fittest during the COVID-19 outbreak. The article also attempts to introduce the concept of “lifestyle and cultural immunity” that needs to be addressed and incorporated at an early stage of childhood to boost up the human immune system. The communication further discusses the role of vaccination and micro-organisms pre-existing in the environment which are required to enhance the immunity of an individual.

A Comparison of Network-Based Metrics of Behavioral Degradation in Complex Engineered Systems

2016 ◽  
Vol 138 (12) ◽  
Author(s):  
Brandon M. Haley ◽  
Andy Dong ◽  
Irem Y. Tumer
Keyword(s):  
Shortest Path ◽  
Path Length ◽  
System Behavior ◽  
Local Cluster ◽  
Complex Engineered Systems ◽  
Network Diameter ◽  
Edge Removal ◽  
Engineered Systems ◽  
Network Metrics ◽  
Topological Robustness

It has been assumed, but not yet tested, that the topological disintegration of networks is relatable to degradations in complex engineered system behavior and that extant network metrics are capable of capturing these degradations. This paper tests three commonly used network metrics used to quantify the topological robustness of networks for their ability to characterize the degree of failure in engineered systems: average shortest path length, network diameter, and a robustness coefficient. A behavioral network of a complex engineered system is subjected to “attack” to simulate potential failures to the system. Average shortest path length and the robustness coefficient showed topological disintegration patterns which differed between nominal and failed cases, regardless of failure implementation location. The network diameter metric is not sufficiently dependent on local cluster topology to show changes in topology with edge removal failure strategies. The results show that topological metrics from the field of complex networks are applicable to complex engineered systems when they account for both local and global topological changes.

Model Validation in Early Phase of Designing Complex Engineered Systems

2018 ◽  
Author(s):  
Elham Keshavarzi ◽  
Kai Goebel ◽  
Irem Y. Tumer ◽  
Christopher Hoyle
Keyword(s):  
Model Simulation ◽  
Early Stage ◽  
Design Stage ◽  
Early Design ◽  
The Real ◽  
Early Design Stage ◽  
Complex Engineered Systems ◽  
Search Tool ◽  
Engineered Systems

In design process of a complex engineered system, studying the behavior of the system prior to manufacturing plays a key role to reduce cost of design and enhance the efficiency of the system during its lifecycle. To study the behavior of the system in the early design phase, it is required to model the characterization of the system and simulate the system’s behavior. The challenge is the fact that in early design stage, there is no or little information from the real system’s behavior, therefore there is not enough data to use to validate the model simulation and make sure that the model is representing the real system’s behavior appropriately. In this paper, we address this issue and propose methods to validate the model developed in the early design stage. First we propose a method based on FMEA and show how to quantify expert’s knowledge and validate the model simulation in the early design stage. Then, we propose a non-parametric technique to test if the observed behavior of one or more subsystems which currently exist, and the model simulation are the same. In addition, a local sensitivity analysis search tool is developed that helps the designers to focus on sensitive parts of the system in further design stages, particularly when mapping the conceptual model to a component model. We apply the proposed methods to validate the output of failure simulation developed in the early stage of designing a monopropellant propulsion system design.

scholarly journals Favorable function of Ectonucleoside triphosphate diphosphohydrolase 1 high expression in thyroid carcinoma

Hereditas ◽  
2021 ◽  
Vol 158 (1) ◽  
Author(s):  
Jun-hua Luo ◽  
Yun-hua Zhu ◽  
Cheng Xiang
Keyword(s):  
Thyroid Carcinoma ◽  
Early Stage ◽  
Clinical Stage ◽  
Critical Role ◽  
Vital Role ◽  
High Expression ◽  
Male Patients ◽  
Killer T Cells ◽  
Missense Substitution

Abstract Background Ectonucleoside triphosphate diphosphohydrolase 1 (ENTPD1) has been proved to play a vital role in human cancers. Nevertheless, the exact role of ENTPD1 in thyroid carcinoma (THCA) remained unclear. This study aimed to evaluate its prognostic value and reveal the potential regulatory mechanism in THCA. Results (1) Higher expression of ENTPD1 was found in THCA tissue compared with normal tissue (all P < 0.05). ENTPD1 expression was associated with age, sub-type and clinical stage of THCA patients (all P < 0.05). Immunohistochemistry showed its higher expression in patients with early stage. (2) ENTPD1 high expression was associated with favorable overall survival of THCA patients (all P < 0.05), especially for male patients and those with advanced stage, B-cells and Natural killer T-cells decreased (all P < 0.05). (3) Pathway analysis indicated that ENTPD1 mainly participated in metabolic process and negatively regulated metabolism-related pathway such as butanoate metabolism, pyruvate metabolism and fatty acid metabolism ((all P < 0.05). (4) ENTPD1 appeared genetic alteration in THCA, and the main mutation type of ENTPD1 was missense substitution (15.89%). (5) A weak correlation between ENTPD1 expression and methylation was found (P < 0.001). Methylation of ENTPD1 in THCA was lower than in normal group (P < 0.001), but it did not correlate with any clinical phenotypes of THCA patients. Conclusions ENTPD1 was highly expressed in THCA, and ENTPD1 high expression contributed to the prognosis of THCA patients. The present study inferred that ENTPD1 might serve as a metabolism-related gene and play a critical role in THCA through regulating metabolic pathways.

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