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

2019 ◽  
Vol 6 (1) ◽  
pp. 3-26 ◽  
Author(s):  
Sarah Diefenbach ◽  
Marc Hassenzahl
Author(s):  
Pantelis Capros ◽  
Marilena Zampara ◽  
Nikos Tasios ◽  
Dimitris Papadopoulos ◽  
Christoph Kost ◽  
...  

Author(s):  
Matthew O. T. Cole ◽  
Lawrence Hawkins

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.


Processes ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 574
Author(s):  
Zeyong Jiang ◽  
Tingdi Zhao ◽  
Shihai Wang ◽  
Hongyan Ju

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.


2011 ◽  
Vol 44 (1) ◽  
pp. 3753-3758 ◽  
Author(s):  
Dániel A. Drexler ◽  
Levente Kovács ◽  
Johanna Sápi ◽  
István Harmati ◽  
Zoltán Benyó

Author(s):  
Kézia Oliveira ◽  
Kyller Gorgônio ◽  
Angelo Perkusich ◽  
Antônio Lima ◽  
Leandro Dias da Silva

Control Systems are used to produce a certain result with little or no human supervision. The principal aim of such systems is to ensure that resources are used efficiently and that the desired product quality is achieved. Moreover for critical systems such as oil and gas plants, it is important to guarantee the safety and dependability of the operation. Therefore, it is necessary to verify whether what is running in the device is in accordance with what was defined in the specification documents. The goal of this chapter is to present a method that automatically generates the timed automata models from the specification ISA 5.2 Binary Logic Diagrams, and the implementation Ladder programs, for model-based analysis, in order to increase the confidence in the behavior of critical Control Systems. This approach is based on the use of the Uppaal tool and the Uppaal-TRON testing tool.


2016 ◽  
Vol 138 (7) ◽  
Author(s):  
Matthew O. T. Cole ◽  
Lawrence Hawkins

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.


2018 ◽  
Vol 7 (4.15) ◽  
pp. 63 ◽  
Author(s):  
Rabatul Aduni Sulaiman ◽  
Dayang Norhayati A. Jawawi ◽  
Shahliza Abd Halim

Rapid Quality assurance is an important element in software testing in order to produce high quality products in Software Product Line (SPL). One of the testing techniques that can enhance product quality is Model-Based Testing (MBT). Due to MBT effectiveness in terms of reuse and potential to be adapted, this technique has become an efficient approach that is capable to handle SPL requirements. In this paper, the authors present an approach to manage variability and requirements by using Feature Model (FM) and MBT. This paper focuses on modelling the integration towards enhancing product quality and reducing testing effort. Further, the authors considered coverage criteria, including pairwise coverage, all-state coverage, and all-transition coverage, in order to improve the quality of products. For modelling purposes, the authors constructed a mapping model based on variability in FM and behaviour from statecharts. The proposed approach was validated using mobile phone SPL case study. 


2014 ◽  
Vol 584-586 ◽  
pp. 2466-2475
Author(s):  
Dong Bing Huang ◽  
Qi Jun Li ◽  
Li Juan Shen

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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