The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Power factor correction (PFC) converter consumes a large part of volume of power supply. Typical switching frequency of commercial PFC converter is usually not higher than several hundred kHz. Increasing the switching frequency of PFC converter to MHz by using GaN devices can greatly reduce the size and increase power density of power supply. In order to eliminate the high turn-on loss of cascode...
The vane support system (VSS) causes less distortion to the rear fuselage. It is an ideal support mechanism for large aircraft wind tunnel tests. Investigating on its support interference will contribute much to the conduction and development of VSS tests. This paper presents a numerical investigation on the support interference of VSS in high speed wind tunnel using Ty154 model. CFD results are compared...
Supercritical wing is widely used in modern transport aircrafts, whose aerodynamic characteristics are rather sensitive to Reynolds number. The aerodynamic design of large airplane mainly depends on the wind tunnel, which is time consuming and costly especially for high Reynolds number test. This paper aimed to investigate the transonic Reynolds number effects of supercritical wing by numerical simulation...
This paper investigates how to integrate state-trajectory control functions of LLC resonant converter within a commercial low-cost microcontroller, including Simplified Optimal Trajectory Control (SOTC) for load transient, burst mode and soft start up. Simplified calculation process is proposed for SOTC to minimize digital delay. Guideline to select a proper microcontroller is presented to limit calculation...
Presently, cycloid gears are widely applied in horologes, apparatuses and the meters. This paper makes double-circular-arc modified cycloid gears apply to power transmission system which has the high contact strength and the high lifetime. This paper starts from the transmission characteristics of cycloid gears, then double-circular-arc modified cycloid gears are proposed and whose mathematical model...
In this paper, a notion of S*-pair wise compactness in L-bitopological space is introduced and its basical properties are studied. It is proved that the intersection of an S*-pair wise compactness L-set with a biclosed L-set ( resp., the finite sum of some S*-pair wise compactness L-sets, the continuous image of an S*-pair wise compactness L-set and the product of some S*-pair wise compactness L-sets)...
The time-interleaved analog-to-digital converter is an efficient approach to systems requiring very high sampling rate with medium to high resolution. However, the inter-channel mismatch and process variations introduce additional errors as compared to single-channel ADC, which results in degradation of the ADC performance. The mismatches include gain, offset and timing, among which the timing errors...
The governing equations are introduced for the viscous incompressible Newtonian fluids, in which the three-dimensional mathematical models of gas-liquid two-phase flow are established for gas-assisted injection molding (GAIM). The flow process of GAIM is simulated by coupling the level set method and the finite volume method based on non-staggered grid, which can precisely capture the gas-melt interface...
In this paper, we first propose an Integration Wavelet Neural Network (I_WNN) based on spline wavelet functions for solving differential equations. Then the proposed method is verified successfully by solving two steady convection dominated diffusion problems and the numerical perturbation doesn't happen when the ratio of convective coefficient to diffusive coefficient is as high as 100. Moreover,...
A new kind of exponential inertia weight particle swarm algorithm is presented and the astringency analysis is finished in the paper. The results of application example proved that practical optimization parameters can be obtained in limited time by the method, and it is a kind of effective way to solve such kind of problem.
The preimage distributions of perfect nonlinear functions from an Abelian group of order n to an Abelian group of order 3 or 4, respectively, are studied. Based on the properties of the preimage distributions of perfect nonlinear functions from an Abelian group of order 3r to an Abelian group of order 3, the weight distributions of the ternary linear codes CPi from the perfect nonlinear functions...
Based on backstepping control laws, a method of separating the coupling variables is proposed, and the decoupling control strategy is developed for passive force control system. The coupling mathematic model of passive force control system is built first. Then using the developed method, the coupling relation of the system is moved to the initial input of each subsystem step by step, then gets the...
The permanent magnet brushless DC motor speed control system (PMBDCSCS) is simple control, high power density and high performance, and used in many domains. The voltage inverter used widely in the PMBDCSCS operates commonly in the six PWM methods: H_PWM_L_PWM, ON_PWM, H_PWM_L_ON, H_ON_L_PWM, PWM_ON and PWM_ON_PWM. In this paper, the six PWM methods are introduced in theory and are compared in detail...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.