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Power transformers play a very critical role in electrical energy transmission. Abnormal performance of transformers would seriously affect the reliability and stability of power system. Non-electrical gas relays are usually used as a main protection of power transformers. Indeed, due to the inherent defects, the gas relay misjudgments happen every year across the world. Given this background, this...
This paper presents a novel wearable leg size sensor for early detection of acute decompensated heart failure. The size sensor is based on the measurement of the magnetic field of an inductor and its variation with size. It has a simple and inexpensive construction involving two 3-axis magnetic sensors, an inductor and a microprocessor. In order to enable robust size estimation during rough real world...
Nearshore wave model was established based on the enhanced Boussinesq equations, which were dispersed into orthogonal grids on spatial distribution and solved using alternating direction implicit (ADI) algorithm. There are three kind of boundary conditions which are absorbing boundary, reflecting boundary and wave-generating boundary in the model, while the wave on open boundary was driven by the...
To effectively control botnets, a study on modeling and analyzing the propagation characteristics of botnets has been lasted for many years. Due to the real network has scale-free properties, it is unrealistic for mainstream propagation models to describe how the bots spread based on random network. Hence, in this paper, we take two key factors which can reflect the scale-free feature of actual Internet...
The use of air bubbler systems to improve the Marine environment is a technique that has been applied in a variety of situations with varying degrees of success. In 2005, the research done by Liang et al was regarded as the beginning of the closed air bubbler systems (injecting gas underwater in the vertical pipe). The analysis was a steady-state evaluation of the lifting efficiency of ocean water...
The parametric array can generate low-frequency, high-directivity beam with small-aperture, and it is widely used in underwater navigation, underwater communication, seafloor sediments detection, sub-bottom physiognomy surveying and mapping. However, the parametric array's conversion efficiency is very low, severely restricting the parametric array's further application. In order to improve the parametric...
This paper investigates pressure regulation for multi-level gas tank by variable universe fuzzy PID control. Pressure vessel is one of important equipments in process industry. Conventional PID controllers in gas tanks must set initial parameters in advance according to engineers' knowledge, which will be unchanged during regulation. To remove these restrictions, variable universe fuzzy logic is applied...
To get a good power integrity (PI) and low electromagnetic interference (EMI) in high-speed circuits, the ground via and/or decoupling capacitor is always applied by the engineers. An appropriate placement of the ground via can reduce the input impedance which is resulted from the resonance between two ground planes, and eliminate the noise source caused by the discontinuity of the signal via, where...
Increasing attention has been paid on Vertical Axis Wind Turbine (VAWT) to improve the poor aerodynamic performances. In this paper, we obtain the aerodynamic coefficients of blades by the method of simulation and experiments, and present along with a prototype of Variable-pitch VAWT. Then, mathematical model and dynamic model have been built, and individual active control for computing the optimal...
A series of model resistance tests of the 4500m3/h self-propelled cutter suction dredger are simulated based on the computational fluid dynamics software in this paper. By comparison of experimental data and CFD calculation results, the reliability of the CFD tools in the study of resistance performance of the vessel with notch in bow is proved. Then the variation of resistance of the vessel with...
In the paper, the characteristics of mode and harmonic response of the axis of the high-speed motorized spindle are presented with the FEM (Finite Element Method). A dual-dimension model with the FEM is developed and simulated using ANSYS commercial software. The result shows that the rated rotating speed of the high-speed motorized spindle is far smaller than the first-order natural resonance speed,...
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