| 1. |
- Abdulahovic, Tarik, 1976, et al.
(författare)
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Improvement of admittance measurements for modeling of an ungrounded reactor/transformer winding
- 2016
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Ingår i: International Journal of Modeling, Simulation, and Scientific Computing. - 1793-9615 .- 1793-9623. ; 7:3
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, a model of an ungrounded reactor winding is developed for transient voltage studies. The developed model is a black box model where the state-space model is developed using the directly measured admittance matrix of the reactor winding. Furthermore, an improved model is developed, where the accuracy of the admittance matrix measurement set in the low frequency band is obtained indirectly using an additional set of voltage ratio measurements. When the measured admittances are low, the accuracy of the diagonal admittance vectors in the low frequency band is low as well. However, the accuracy at low frequencies obtained using the indirect measurements is improved at nodes with the lowest admittances. In this paper, different approaches for indirect measurements are studied and the most accurate method is identified considering the physical structure of windings.
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| 2. |
- Eek, Magnus, et al.
(författare)
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Study of industrially applied methods for verification, validation and uncertainty quantification of simulator models
- 2015
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Ingår i: International Journal of Modeling, Simulation, and Scientific Computing. - : World Scientific. - 1793-9623 .- 1793-9615. ; 6:2
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Tidskriftsartikel (refereegranskat)abstract
- To better utilize the potential of system simulation models and simulators, industrially applicable methods for Verification, Validation and Uncertainty Quantification (VV&UQ) are crucial. This paper presents an exploratory case study of VV&UQ techniques applied on models integrated in aircraft system simulators at Saab Aeronautics and in driving simulators at the Swedish National Road and Transport Research Institute (VTI). Results show that a large number of Verification and Validation (V&V) techniques are applied, some of which are promising for further development and use in simulator credibility assessment. Regarding the application of UQ, a large gap between academia and this part of industry has been identified, and simplified methods are needed. The applicability of the NASA Credibility Assessment Scale (CAS) at the studied organizations is also evaluated and it can be concluded that the CAS is considered to be a usable tool for achieving a uniform level of V&V for all models included in a simulator, although its implementation at the studied organizations requires tailoring and coordination.
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| 3. |
- Hu, Yanjuan, et al.
(författare)
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Optimization of manufacturers based on agent in cloud manufacturing
- 2022
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Ingår i: International Journal of Modeling, Simulation, and Scientific Computing. - : World Scientific Pub Co Pte Ltd. - 1793-9623 .- 1793-9615.
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Tidskriftsartikel (refereegranskat)abstract
- Manufacturing enterprise management mode from the traditional manufacturing production gradually transformed into service-oriented manufacturing in cloud manufacturing. As a carrier for manufacturing resources and manufacturing capabilities, the manufacturer directly affects the advantages and disadvantages of cloud manufacturing services. Therefore, manufacturer optimization has received increasing attention. This paper studies the problem of manufacturer optimization in cloud manufacturing environment, analyzes the 11 kinds of factors which affect the service quality of the manufacturer, meanwhile, it establishes the evaluation indexes system and objective function, optimization algorithm for solving the objective function, and then, it proposes optimization algorithm for solving the objective function, realizes the optimal selection of manufacturers under different demands. The simulation results show that the established evaluation indexes system can display the manufacturing resources and capabilities more fully. Based on the evaluation indexes system model, all the factors that influence the optimization of the manufacturer can be combined together, and the complex optimization problem can be transformed into the mathematical problem. The algorithm can be used to select the best manufacturer under different requirements, and to provide the best service for users.
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| 4. |
- Ghadimi, P., et al.
(författare)
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Analytical solution of wedge water entry by using Schwartz-Christoffel conformal mapping
- 2011
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Ingår i: International Journal of Modeling, Simulation, and Scientific Computing. - : World Scientific Pub Co Pte Ltd. - 1793-9623. ; 2:3, s. 337-354
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Tidskriftsartikel (refereegranskat)abstract
- Water impact is one of the most critical phenomena from the viewpoint of the structural design of ships and offshore structures. The impact force can impose a large load with high local pressure on the body surface. On the other hand, determination of the maximum impact force during impact and acting point itself is very important in the design of floats. In this paper, the water entry of a two-dimensional wedge section is considered. This study is carried out in the framework of a potential-flow assumption. In particular, water impact on a dropping wedge with a constant velocity is pursued analytically by using the Schwartz-Christoffel conformal mapping. In order to determine a position of the wedge where the instantaneous effective force is largest during the impact, a particular equation is introduced here for the first time. The pressure distribution and maximum impact force are also calculated. The obtained results are compared against other numerical and experimental works and favorable agreement is displayed.
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