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.

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.

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 Solving the Coupled System Improves Computational Efficiency of the Bidomain Equations

2009 ◽  
Vol 56 (10) ◽  
pp. 2404-2412 ◽  
Author(s):  
James A. Southern ◽  
Gernot Plank ◽  
Edward J. Vigmond ◽  
Jonathan P. Whiteley
Keyword(s):  
Computational Efficiency ◽  
Coupled System ◽  
Bidomain Equations

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.

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.

Recent Developments in the Seismic Analysis of Multiply Supported Piping Systems

2004 ◽  
Author(s):  
Abhinav Gupta
Keyword(s):  
System Analysis ◽  
Seismic Analysis ◽  
Coupled System ◽  
Coupled Systems ◽  
Coupled Analysis ◽  
Piping System ◽  
Modal Damping ◽  
Peak Broadening ◽  
Piping Systems ◽  
Recent Developments

This paper presents results from some of the recent studies on seismic analysis of multiply supported piping systems. The seismic responses for an actual feedwater piping system as evaluated from the conventional uncoupled analysis are compared with those obtained from an analysis of the coupled building-piping system. A discussion is also presented on the significance of non-classical damping in such analyses. It is illustrated that the composite modal damping is just another form of classical damping. Consideration of composite modal damping in a coupled analysis can give inaccurate piping responses when the modes of uncoupled systems are nearly tuned. In such systems, the effect of nonclassical damping is quite significant. Since the floor spectra are neither generated nor required in a coupled systems analysis, methods like peak broadening or peak shifting cannot be used directly to account for the effect of uncertainties. Formulations are presented to evaluate the design response from a coupled system analysis by considering the effect of uncertainties in modal properties of uncoupled systems.

scholarly journals Analysis of Nonlinear Coupled Systems of Impulsive Fractional Differential Equations with Hadamard Derivatives

2019 ◽  
Vol 2019 ◽  
pp. 1-20 ◽  
Author(s):  
Usman Riaz ◽  
Akbar Zada ◽  
Zeeshan Ali ◽  
Manzoor Ahmad ◽  
Jiafa Xu ◽  
...  
Keyword(s):  
Fixed Point ◽  
Differential Equations ◽  
Fractional Differential Equations ◽  
Coupled System ◽  
Coupled Systems ◽  
Ulam Stability ◽  
Krasnoselskii’S Fixed Point Theorem ◽  
Impulsive Fractional Differential Equations ◽  
Uniqueness Results ◽  
Fractional Differential

This work is committed to establishing the assumptions essential for at least one and unique solution of a switched coupled system of impulsive fractional differential equations having derivative of Hadamard type. Using Krasnoselskii’s fixed point theorem, the existence, as well as uniqueness results, is obtained. Along with this, different kinds of Hyers–Ulam stability are discussed. For supporting the theory, example is provided.

Hermite collocation method for obtaining the chaotic behavior of a nonlinear coupled system of FDEs

2020 ◽  
Vol 31 (07) ◽  
pp. 2050093
Author(s):  
M. M. Khader ◽  
Mohammed M. Babatin
Keyword(s):  
Differential Equations ◽  
Numerical Solutions ◽  
Chaotic Behavior ◽  
Standard Form ◽  
Coupled System ◽  
Coupled Systems ◽  
Electrical Network ◽  
Algebraic Equations ◽  
Home Heating ◽  
Nonlinear Coupled System

This paper is devoted to introduce an efficient solver using the Hermite collocation technique (HCT), of the coupled system of fractional differential equations (FDEs). The given systems are of basic importance in modeling various phenomena like Cascades and Compartment Analysis, Pond Pollution, Home Heating, Chemostats, and Microorganism Culturing, Nutrient Flow in an Aquarium, Biomass Transfer, Forecasting Prices, Electrical Network, Earthquake Effects on Buildings. The proposed method reduces the system of FDEs to a system of algebraic equations in the coefficients of the expansion using the Hermite polynomials. The introduced method is computer oriented and provides highly accurate solution. To demonstrate the efficiency of the method, two examples are solved and the results are displayed graphically. Finally, we convert the presented coupled systems from the case of its standard form to a first-order ordinary differential equations to compare the obtained numerical solutions with those solutions using the fourth-order Runge–Kutta method (RK4).

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