Utilizing Tribological System Parameters as a Harbinger of Distress in Dynamically and Aerothermally Coupled Systems

2019 ◽  
Vol 2 (2) ◽  
Author(s):  
Sheridon Haye
Keyword(s):  
Health Management ◽  
Real Data ◽  
Coupled System ◽  
Coupled Systems ◽  
Multiple Systems ◽  
Fuzzy Membership Functions ◽  
Tribological System ◽  
Interacting Systems ◽  
Cross System ◽  
Fusion Approach

This paper summarizes a data fusion approach for utilizing conventional lubrication parameters in an unconventional method for identifying deterioration in a thermally coupled system. Complex machines are composed of multiple systems that are intrinsically dependent. Design of these systems requires expertise in distinct disciplines with a determined focus on meeting system-specific requirements. This expertise focused approach promotes a silo mindset to system design, which is then carried through to the design and implementation of the health management system of these machines. These multidisciplinary interacting systems are traditionally monitored as independent entities, with little advantage taken of the direct and cross-coupled effects. For example, parameters required for lubrication health monitoring include, but are not limited to, oil pressure and temperature. These parameters are critical in determining the health of the lubrication system. However, how these parameters change can be an indicative of the health of interacting systems otherwise considered independent and isolated. By exploring the rationale of the cross-system impacts, physical interactions between these systems (albeit empirical knowledge) can be used for cross-system monitoring. A means of achieving this objective is to utilize parameters that are measured in one system to determine the diagnostic state of another coupled system with limited, or no, system observability. A fuzzy logic fusion approach is employed in this task and was designed and implemented for the above-mentioned purpose. The focus of interest was on the lubrication and hot section interactions with parameters obtained from real machines. Fuzzy membership functions and rules were determined and tuned appropriately from real data and applied to nominal and defective machines.

scholarly journals Research on Electrostatic Monitoring of Tribo-Contacts with Dynamic Adaptive Fusion Method

2022 ◽  
Vol 2022 ◽  
pp. 1-14
Author(s):  
Ruochen Liu ◽  
Han Wang ◽  
Jinwu Zhang ◽  
Shuangshuang Gu ◽  
Jianzhong Sun
Keyword(s):  
Health Management ◽  
High Sensitivity ◽  
Operating Conditions ◽  
Rolling Bearings ◽  
Tribological System ◽  
Monitoring Result ◽  
Electrostatic Charging ◽  
Adaptive Fusion ◽  
Monitoring Platform ◽  
Fusion Approach

Electrostatic monitoring is a unique and rapid developing technique applied in the prognostics and health management of the tribological system based on electrostatic charging and sensing phenomenon. It has considerable advantages in condition monitoring of tribo-contacts with high sensitivity and resolution. Unfortunately, the monitoring result can be affected due to the switch of operating conditions that reduces its accuracy. This paper presents a dynamic adaptive fusion approach, moving window local outlier factor based on electrostatic features to overcome the influence. Life cycle experiments of rolling bearings and railcar gearbox were carried out on an electrostatic monitoring platform. The MWLOF method was used to extract and analyze the experimental data, combined with the Pauta criterion to judge wear faults quantitatively, and compare with other feature extraction results. It is verified that the proposed method can overcome the influence of changes in working conditions on the monitoring results, improve the monitoring sensitivity, and provide an accurate reference for friction and wear faults.

scholarly journals A Finite Element Approach to the Analysis of Rotating Bladed-Disk Assemblies Coupled With Flexible Shaft

1994 ◽  
Author(s):  
Wen Zhang ◽  
Wenliang Wang ◽  
Hao Wang ◽  
Jiong Tang
Keyword(s):  
Finite Element ◽  
Degrees Of Freedom ◽  
Coupled System ◽  
Equation Of Motion ◽  
Coupled Systems ◽  
The Finite Element Method ◽  
Bladed Disk ◽  
Modal Synthesis ◽  
Element Approach ◽  
Final Equation

A method for dynamic analysis of flexible bladed-disk/shaft coupled systems is presented in this paper. Being independant substructures first, the rigid-disk/shaft and each of the bladed-disk assemblies are analyzed separately in a centrifugal force field by means of the finite element method. Then through a modal synthesis approach the equation of motion for the integral system is derived. In the vibration analysis of the rotating bladed-disk substructure, the geometrically nonlinear deformation is taken into account and the rotationally periodic symmetry is utilized to condense the degrees of freedom into one sector. The final equation of motion for the coupled system involves the degrees of freedom of the shaft and those of only one sector of each of the bladed-disks, thereby reducing the computer storage. Some computational and experimental results are given.

Article

1999 ◽  
Vol 77 (11) ◽  
pp. 1810-1812 ◽  
Author(s):  
Alex D Bain
Keyword(s):  
Spin System ◽  
Coupled System ◽  
Coupled Systems ◽  
Physical Reason ◽  
Strongly Coupled ◽  
System Combination ◽  
First Order ◽  
Weakly Coupled ◽  
Quantum Transitions ◽  
Weakly Coupled Systems

Strongly coupled spin systems provide many curious and interesting effects in NMR spectra, one of which is the presence of unexpected (from a first-order viewpoint) lines. A physical reason is given for the presence of these combination lines. The X part of the spectrum of an ABX spin system is analysed as an example. For an ABX system, it is well known that the AB nuclei give a spectrum consisting of two AB-type spectra, corresponding to the two orientations of the X nucleus. It can also be shown that the X part of the spectrum corresponds to the X nucleus undergoing a transition in the presence of an AB-like spin system. For weakly coupled systems, the four observed lines correspond to the four different orientations of the A and B nuclei. For a strongly coupled system, two additional lines may appear, the combination lines. The resulting six lines correspond to the four spin orientations, plus the two zero-quantum transitions. It is shown that these six lines are such that there is no net excitation of the AB-like spin system associated with the X transitions. There is no AB coherence created directly by a pulse applied to X. AB coherence is created as the system evolves, and this is responsible for many of the curious effects. This is shown to be true for all spin sub-systems, which are weakly coupled to a strongly coupled sub-system.Key words: NMR, strong coupling, second-order spectra, ABX spin system, combination lines, spectral analysis.

scholarly journals Identification of Health Expenditures Determinants: A Model to Manage the Economic Burden of Cardiovascular Disease

2021 ◽  
Vol 18 (9) ◽  
pp. 4652
Author(s):  
Fiorella Pia Salvatore ◽  
Alessia Spada ◽  
Francesca Fortunato ◽  
Demetris Vrontis ◽  
Mariantonietta Fiore
Keyword(s):  
Cardiovascular Disease ◽  
Hospital Discharge ◽  
Random Effects ◽  
Economic Burden ◽  
Linear Models ◽  
Health Management ◽  
Model Performance ◽  
Real Data ◽  
Large Set ◽  
Regional Health

The purpose of this paper is to investigate the determinants influencing the costs of cardiovascular disease in the regional health service in Italy’s Apulia region from 2014 to 2016. Data for patients with acute myocardial infarction (AMI), heart failure (HF), and atrial fibrillation (AF) were collected from the hospital discharge registry. Generalized linear models (GLM), and generalized linear mixed models (GLMM) were used to identify the role of random effects in improving the model performance. The study was based on socio-demographic variables and disease-specific variables (diagnosis-related group, hospitalization type, hospital stay, surgery, and economic burden of the hospital discharge form). Firstly, both models indicated an increase in health costs in 2016, and lower spending values for women (p < 0.001) were shown. GLMM indicates a significant increase in health expenditure with increasing age (p < 0.001). Day-hospital has the lowest cost, surgery increases the cost, and AMI is the most expensive pathology, contrary to AF (p < 0.001). Secondly, AIC and BIC assume the lowest values for the GLMM model, indicating the random effects’ relevance in improving the model performance. This study is the first that considers real data to estimate the economic burden of CVD from the regional health service’s perspective. It appears significant for its ability to provide a large set of estimates of the economic burden of CVD, providing information to managers for health management and planning.

New Pathways in Lipopolysaccharide-Induced Toll-Like Receptor 4-to-Nuclear Factor-κB Signaling Through the Coupled Uniform Sequential Reaction Systems Model

2020 ◽  
Vol 12 (10) ◽  
pp. 1246-1256
Author(s):  
Bonawentura Kochel
Keyword(s):  
Signaling Pathways ◽  
Temporal Pattern ◽  
Coupled System ◽  
Direct Consequence ◽  
Nuclear Factor Κb ◽  
Coupled Systems ◽  
Toll Like Receptor 4 ◽  
Sequential Reaction ◽  
Reaction Systems ◽  
Systems Model

The coupled uniform sequential reaction systems (CUSERS) model, which allows for determining the structure of signaling pathways with incomplete information from the temporal patterns of their components, was applied to the experimental records of activities of TLR4 downstream species IKK and NF-κB in LPS-stimulated wild-type (WT), MyD88-deficient and TRIF-deficient macrophages. New signaling pathways targeting IKK were revealed in MyD88-deficient and TRIF-deficient macrophages, and shown to be described by the coupled systems formed by 3- and 5-component or 5- and 10-component pathways, respectively. By comparing the temporal pattern of IKK in WT macrophages with those in MyD88-deficient and TRIF-deficient macrophages, two new signaling pathways, which were absent in the above defective macrophages, were found and described by a system formed by coupling 9- and 10-component pathways. As a direct consequence of the above findings, a coupled system composed of six different 3-, 5-, 5-, 9-, 10- and 10-component pathways targeting IKK and describing its temporal pattern, IKK(f), in WT macrophages was constructed. This system significantly modifies the canonical NF-κB signaling by introducing novel pathways of IKK activation. The expression of nuclear NF-κB in WT macrophages was found to depend on two different signaling pathways and to be modelled by a coupled system composed of 1- and 4-component or 2- and 8-component pathways, in dependence on sampling frequencies used in different experiments. From the three-modal NF-κB(t) temporal pattern in LPS-stimulated WT fibroblasts, three 1-, 12- and 17-component signaling pathways targeting nuclear NF-κB were determined.

scholarly journals A prognostic framework for health management of coupled systems

2011 ◽  
Author(s):  
Chaitanya Sankavaram ◽  
Anuradha Kodali ◽  
Krishna Pattipati ◽  
Bing Wang ◽  
Mohammad S. Azam ◽  
...  
Keyword(s):  
Health Management ◽  
Coupled Systems

ASYMPTOTIC SYNCHRONIZATION IN LATTICES OF COUPLED NONIDENTICAL LORENZ EQUATIONS

2000 ◽  
Vol 10 (12) ◽  
pp. 2717-2728 ◽  
Author(s):  
CHUANG-HSIUNG CHIU ◽  
WEN-WEI LIN ◽  
CHEN-CHANG PENG
Keyword(s):  
Boundary Conditions ◽  
Coupled System ◽  
Lyapunov Stability Theory ◽  
Dirichlet Condition ◽  
Coupled Systems ◽  
Lorenz Equations ◽  
Trivial Equilibrium ◽  
Coupling Strengths ◽  
The Difference ◽  
Asymptotic Synchronization

In this paper we study coupled nonidentical Lorenz equations with three different boundary conditions. Coupling rules and boundary conditions play essential roles in the qualitative analysis of solutions of coupled systems. By using Lyapunov stability theory, a sufficient condition is obtained for the global stability of trivial equilibrium of coupled system with Dirichlet condition. Then we restrict our attention on the dynamics of coupled nonidentical Lorenz equations with Neumann/periodic boundary condition and prove that the asymptotic synchronization occurs provided the coupling strengths are sufficiently large. That is, the difference between any two components of solution is bounded by the quantity O(ε/ max {c1, c2, c3}) as t → ∞, where ε is the maximal deviation of parameters of nonidentical Lorenz equations, and c1, c2 and c3 are the specified coupling strengths.

Study of Improved Multiple Discipline Feasible Strategy for Complicated System Optimization

2010 ◽  
Vol 44-47 ◽  
pp. 3264-3268 ◽  
Author(s):  
Teng Long ◽  
Li Liu ◽  
Huai Jian Li
Keyword(s):  
Computational Efficiency ◽  
Coupled System ◽  
System Optimization ◽  
Coupled Systems ◽  
Sensitivity Equation ◽  
Computation Cost ◽  
Global Sensitivity ◽  
Multiple Discipline ◽  
Complicated System ◽  
Optimization Efficiency

The advantages of global sensitivity equation (GSE) method are firstly pointed out, with which an improved multiple discipline feasible (MDF) strategy based on GSE, denoted as MDF-GSE, is developed. In MDF-GSE strategy, the sensitivity of complicated coupled system is calculated using GSE in a parallel manner, which makes MDF-GSE more efficiency when optimizing complicated coupled system compared with the original MDF strategy. Additionally, the preferable performance in convergence and robustness of MDF is also inherited in MDF-GSE. A conceptual optimization of a training airplane is executed using both MDF and MDF-GSE. The results of quantificational comparison demonstrate that computational efficiency is improved dramatically by using MDF-GSE, which makes required computation cost decreased by about 86%. The optimization time, furthermore, ulteriorly reduced due to the quasi-parallel capability of MDF-GSE. It is indicated that the MDF-GSE strategy can enhance the optimization efficiency for the complicated coupled systems.

An active vibration control model for coupled flexible systems

2008 ◽  
Vol 222 (11) ◽  
pp. 2087-2098
Author(s):  
J C Niu ◽  
A Y T Leung ◽  
C W Lim ◽  
P Q Ge
Keyword(s):  
Optimal Control ◽  
Vibration Control ◽  
State Space ◽  
Power Flow ◽  
Passive Control ◽  
Flexible Structures ◽  
Coupled System ◽  
The State ◽  
Coupled Systems ◽  
Control Force

This paper presents a novel general model for complex flexible coupled systems. In this model, parallel structures of force actuators and passive spring isolators are installed between the machine and the foundation, and some moment actuators such as piezoelectric patches are installed on the flexible foundation whose vibration cancellation feature is the key object of vibration control. This model combines active and passive control, force and moment control into a single unit to achieve the efficient vibration control of flexible structures by multiple approaches. The state-space governing equations of the coupled system are deduced. Based on the description of the state-space equation of the coupled system, the transmission paths for the power flow transmitted into the foundation are discussed in the frequency domain, and then combined into a single function. The function includes two parts: the passive and active terms, which can be conveniently employed in an optimal control strategy to achieve power flow control. The transmission characteristics of the power flow by optimal control are discussed in detail. Numerical simulations are presented to show that both force and moment controls in the analytical model can achieve substantial vibration cancellation.

scholarly journals The Coupling of Carbon, Nitrogen and Sulphur Transformational Processes in River Sediments Based on Correlationship among the Functional Genes

2018 ◽  
Author(s):  
Mingzhu Zhang ◽  
Yang Li ◽  
Qingye Sun ◽  
Piaoxue Chen ◽  
Xuhao Wei
Keyword(s):  
River Sediments ◽  
Coupled System ◽  
Coupled Systems ◽  
Functional Gene ◽  
Coupled Processes ◽  
Functional Genes ◽  
Marker Genes ◽  
Ecological Processes ◽  
Sediment Samples ◽  
Reference Index

Abstract. Microorganisms in sediments play an important role in C-, N- and S-cycles by regulating forms and contents of these elements. The coupled system or synergistic reaction among three elemental cycles can effectively alleviate the pollution of C, N, and S in sediments. However, ecological processes coupling C-, N- and S-cycles in sediments are still poorly understood. In order to understand the ecological processes mediated by microorganisms living in river sediments, a total of 135 sediment samples were collected from Huaihe River and its branches located in the Northern of Anhui Province, the abundance of functional marker genes (mcrA, pmoA, cmo, amoA, hzo, nirK, nirS, nosZ, dsrB, aprA), involving in C-, N- and S-transformation, were determined by qPCR. The correlation among functional genes from 135 river sediment samples was calculated. We supposed that the correlationship among functional genes could be used as a reference index speculating the coupled systems of C-N-S in this reasearch, then the distinct coupling relation of C-N-S was revealed, and probable genetic mechanisms were also expounded based on the hypothesis. The study found that amoA-AOA and dsrB possibly played a secondary role, while S-functional gene (aprA), C-functional gene (mcrA) and N-functional gene (hzo) were the key functional genes that participate in the coupled processes in the elemental biogeochemical cycle. The results also demonstrated that C, N might have combined effects on the coupling of carbon, nitrogen and sulphur transformation.

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