Model-based analysis of the influence of ecological processes on forest point pattern formation—A case study

For rotors supported by active magnetic bearings (AMBs), clearance bearings are commonly used to provide backup support under loss of AMB functionality. Test data from real machines shows that rotor vibration during touchdown on backup bearings may involve steady forward whirling at a sub-synchronous frequency. This excitation is believed to be due to friction forces transmitted between the rotor and a bearing end-face under axial load. This paper proposes a new analytical approach to model and predict such friction-driven forward whirl behaviors. A set of constraint equations are derived that relate a circular whirl motion of arbitrary orbital speed to the frequency response functions of the rotor-housing structure. This model is coupled with an evaluation of Coulomb friction associated with slip between the rotor and the supporting end-face of a thrust bearing. The resulting equations can be used to compute a set of possible whirl motions via a root-finding procedure. A case study is undertaken for a 140 kW energy storage flywheel. Model-based predictions are compared with measured data from spin-down tests and show a good level of agreement. The study confirms the role of friction-related forces in driving forward-whirl response behaviors. It also highlights the key role of housing and machine support characteristics in response behavior. This influence is shown to be complex and not open to simple physical interpretation. Therefore, the proposed analytical method is seen as a useful tool to investigate this influence while avoiding the need for time consuming numerical simulations.

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New Model-Based Analysis Method with Multiple Constraints for Integrated Modular Avionics Dynamic Reconfiguration Process

Processes ◽

10.3390/pr8050574 ◽

2020 ◽

Vol 8 (5) ◽

pp. 574

Author(s):

Zeyong Jiang ◽

Tingdi Zhao ◽

Shihai Wang ◽

Hongyan Ju

Keyword(s):

Petri Net ◽

Simulation Analysis ◽

Dynamic Reconfiguration ◽

Multiple Constraints ◽

Model Based ◽

Integrated Modular Avionics ◽

Configuration Changes ◽

Model Based Analysis ◽

Architecture Analysis

With the development of integrated modular avionics (IMA), the dynamic reconfiguration of IMA not only provides great advantages in resource utilization and aircraft configuration, but also acts as a valid means for resource failure management. It is vital to ensure the correction of the IMA dynamic reconfiguration process. The analysis of the dynamic reconfiguration process is a significant task. The Architecture Analysis & Design Language (AADL) is widely used in complicated real-time embedded systems. The language can describe the system configuration and the execution behaviors, such as configuration changes. Petri net is a widely used tool to conduct simulation analysis in many aspects. In this study, a model-based analyzing method with multiple constraints for the IMA dynamic reconfiguration process was proposed. First, several design constraints on the process were investigated. Second, the dynamic reconfiguration process was modeled based on the AADL. Then, a set of rules for the transition of the model from AADL to Petri net was generated, and the multi-constraints proposed were incorporated into Petri net for analysis. Finally, a simulation multi-constraint analysis with Petri net for the process of IMA dynamic reconfiguration was conducted. Finally, a case study was employed to demonstrate this method. This method is advantageous to the validity of IMA dynamic reconfiguration at the beginning of the system design.

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Model-based analysis and synthesis of tumor growth under angiogenic inhibition: a case study*

IFAC Proceedings Volumes ◽

10.3182/20110828-6-it-1002.02107 ◽

2011 ◽

Vol 44 (1) ◽

pp. 3753-3758 ◽

Cited By ~ 17

Author(s):

Dániel A. Drexler ◽

Levente Kovács ◽

Johanna Sápi ◽

István Harmati ◽

Zoltán Benyó

Keyword(s):

Tumor Growth ◽

Model Based ◽

Analysis And Synthesis ◽

Model Based Analysis

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Case Study: Model-Based Analysis of the Mission Data System Reference Architecture

10.21236/ada528582 ◽

2010 ◽

Cited By ~ 1

Author(s):

Peter H. Feller ◽

David Gluch ◽

Kurt Woodham

Keyword(s):

Data System ◽

Reference Architecture ◽

Model Based ◽

Model Based Analysis

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Combining model-based analysis with phenomenological insight: A case study on hedonic product quality.

Qualitative Psychology ◽

10.1037/qup0000096 ◽

2019 ◽

Vol 6 (1) ◽

pp. 3-26 ◽

Cited By ~ 3

Author(s):

Sarah Diefenbach ◽

Marc Hassenzahl

Keyword(s):

Product Quality ◽

Model Based ◽

Model Based Analysis

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Model-Based Analysis of Friction-Induced Subsynchronous Whirl for a Rotor Contacting With Clearance Bearings Under Axial Load

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.4032343 ◽

2016 ◽

Vol 138 (7) ◽

Author(s):

Matthew O. T. Cole ◽

Lawrence Hawkins

Keyword(s):

Axial Load ◽

Coulomb Friction ◽

Friction Forces ◽

Root Finding ◽

Model Based ◽

Simple Physical Interpretation ◽

Level Of Agreement ◽

Model Based Analysis

For rotors supported by active magnetic bearings (AMBs), clearance bearings are commonly used to provide backup support under loss of AMB functionality. Test data from real machines shows that vibration during touchdown on backup bearings may involve steady forward whirling of the rotor with a subsynchronous frequency. This excitation is believed to be due to friction forces transmitted between the rotor and a bearing end-face under axial load. This paper proposes a new analytical approach to model and predict such friction-driven forward whirl behaviors. A set of constraint equations are derived that relate a circular whirl motion of arbitrary orbital speed to the frequency response functions for the rotor-housing structure. This model is coupled with an evaluation of Coulomb friction associated with slip between the rotor and the supporting end-face of a thrust bearing. The resulting equations can be used to compute a set of possible whirl motions via a root-finding procedure. A case study is undertaken for a 140 kW energy storage flywheel. Model-based predictions are compared with measured data from spin-down tests and show a good level of agreement. The study confirms the role of friction-related forces in driving forward-whirl response behaviors. It also highlights the key role of housing and machine support characteristics in response behavior. This influence is shown to be complex and not open to simple physical interpretation. Therefore, the proposed analytical method is seen as a useful tool to investigate this influence while avoiding the need for time consuming numerical simulations.

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Research on VaR-Model-Based Analysis of Construction Cost Risks

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.584-586.2466 ◽

2014 ◽

Vol 584-586 ◽

pp. 2466-2475

Author(s):

Dong Bing Huang ◽

Qi Jun Li ◽

Li Juan Shen

Keyword(s):

Analytical Model ◽

Construction Cost ◽

Var Model ◽

Key Factors ◽

Accurate Calculation ◽

Model Based ◽

Set Up ◽

The Cost ◽

Model Based Analysis

Construction cost risk management is an essential part of construction cost management,especially in the context of the ‘triple overrun’ that has been rampant across China over the last few years,i.e. the cost overrunning the budget,the budget overrunning the budgetary estimate, and the budgetary estimate overrunning the initial estimate. Since traditional methods of calculating construction reserve funds fail to serve the purpose of curbing the ‘triple overrun’,we deem it necessary to establish a quantitative, rational, and accurate calculation and analytical model to measure basic reserve funds. This paper aims to provide an analytical model based on the VaR technique, where parameters are determined by VaR’s three key factors, and a standard VaR process of analyzing basic reserve funds is set up. The model proves to be effective in our case study when basic reserve funds predicted by the model well match the actual ones,which is shown clearly by the Q-Q plot curves and CDF curves.

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