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A new type of subsynchronous resonance (SSR), namely, subsynchronous control interaction (SSCI), was recently observed in doubly-fed induction generators (DFIGs) interfaced with series-compensated power networks. In this paper, a more accurate method based on aggregated RLC circuit model is proposed to intuitively explain and quantitatively evaluate this type of SSR. For a practical power system containing...
Aiming at the problem that existing virtual assembly interfaces lack scenario analysis capabilities and can't effectively perceive user's intentions, the scene knowledge model and the user knowledge model are proposed in this paper. We establish scene knowledge base and user knowledge database according to the scene knowledge model and the user knowledge model respectively. To solve the ambiguity...
In this study we proposed a novel design of the stationary multi-pinhole dedicated cardiac SPECT based on clinical dual-head scanner with high sensitivity and low cost for nuclear medicine myocardial perfusion imaging.
For the problem of determination of maintainability quantitative requirements of equipment in demonstration phase, a model of tradeoff analysis of maintenance time is developed in this paper. Through the operational requirements analysis, the model of maintenance time of system level of equipment is determined. By constraint analysis, the models of maintenance time of levels based on design and maintenance...
This research takes the safety inventory and the uncertainty of supply and demand in inventory distribution network into consideration, establish the reliability model and supply-demand distribution model, and demonstrates the feasibility and practicability of the model which is used to solve problems of reliability of supply-demand distribution in spare parts inventory distribution network.
The worm is still one of the most serious threat to the Network security. The logical worm propagation model could characterize the propagation of Internet worms more exactly, and could be more helpful to carry out the worm protection, detection and suppression technology research. In the initial phase of this paper, a heterogeneous network oriented worm propagation model namely Enhanced-AAWP was...
Enterprise management is improving its capacities, with its practice being advanced. However, it is facing greater challenge of transformation and upgrading, as the result of fiercer competition and accelerated globalization driven by global economic changes and IT revolution. Based on three years of studies of thousands of enterprises in 12 industries, jointly conducted by the experts and scholars...
Within this paper, the modality of vehicle frame is analyzed by finite element software of ALGOR, and carrying out the first 10 steps natural frequency resonance and vibration model. Using mode of two-degree-of-freedom vehicle vibration builds system's movement differential equation and simulates the frame's vibration by Simulink module of Matlab. Then make a dynamic response simulation for vehicle...
A multi-body dynamic model of Electric Power Steering (EPS) is set up by using ADAMS in this paper, and also a PID control strategy for the assist torque of EPS is described. The dynamic model & control system model are combined by ADAMS/Controls. Based on these, steering lightness and dynamic characteristic of vehicle are investigated by simulation analysis. The results show that the dynamic...
Time domain modal analysis method is one of the most important modal analysis methods nowadays, which doesn't need to transform the systematic input and output signal from the time domain to frequency domain, thus it can avoid fast fourier transformation's leakage error, reducing the required equipments and cost. This paper adopts Output-only Modal Analysis to identify the modal parameters of the...
For wireless mesh networks has no support infrastructure and shows a highly dynamic feature, routing becomes a key problem to be solved. Data packets are transmitted on a path that had least hops in AODV protocol. It couldn't consider the path stability. When the node of wireless mesh networks moved quickly and the path had short lifetime, the path recovery and routing again is caused. It is a lot...
In this paper the analysis of small signal stability of grid-connected doubly fed induction generators (DFIG) is presented. The detailed model of grid-connected DFIG wind turbine is firstly established, and the eigenvalues are classified and characterized based on participation factors. Then the modal analysis including its converter and pitch controllers is studied, and model simplification of the...
Conventional PID or fuzzy controller cannot get good controlling performance in the control of hydroelectric generating unit system, which is non-linear, varying with time, high steps system. In order to overcome the shortcoming of conventional fuzzy or PID controller, the fuzzy-PID composite control method is used to control it. The combining modes between fuzzy and PID were introduced in detail...
In this paper, a Product Integrated & Collaborative Design Methodology Based on Virtual Product Prototypes (PICD) is explored. In PICD, A Product Master Model (PMM) is used as a product shared information database, which is also integrated product information model of a Virtual Product Prototype (VPP). A VPP is used to view the product during design process before creation of any physical prototype,...
Complex adaptive system (CAS) approach is effective for modeling supply chain system with structural and behavioral dynamics. This paper proposes a complex adaptive supply chain framework based on information message transfer in terms of the forming mechanism of supply chain. The dynamical growth of the whole network is simulated: isolated nodes randomly distributed in the environment build connections...
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