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.
Aiming at vortex-induced vibration problem, immersed boundary-lattice Boltzmann method (IB-LBM) is adopted in the paper. In order to establish a baseline for comparison and verify the precision of the algorithm, a uniform flow past a rigid cylinder at Re=200 is simulated first and the numerical results are compared with the results of other documents. The motion of the elastic-supported cylinder is...
This study presents and verifies a new idea for simplifying the frequency matching process of ultrasonic motor by constructing a new sandwich type ultrasonic motor, which utilizes the combination of the symmetrical and anti-symmetrical longitudinal modes of mirror symmetrical structure. Two Langevin transducers in combination with two isosceles triangular beams are used to construct the stator. The...
Highway bridges are subjected to the dynamic tire forces of moving vehicles. This paper attempts to identify local damages in box-girder highway bridges from the dynamic responses induced by passing vehicle. The box-girder bridge is modeled using four-node iso-parametric flat shell element taking into account the transverse shearing deformation in the finite element model. The vehicle is modeled as...
There are many applications that require mid-wavelength infrared (MWIR) and long-wavelength infrared (LWIR) dual-band focal plane arrays (FPAs). For example, a dual-band FPA camera would provide the accurate temperature of a target with unknown emissivity which is extremely important to the process of identifying objects based on their surface temperature. Dual-band infrared FPAs can also play many...
Quantum well infrared photodetectors (QWIPs) are well known for their stability, high pixel-pixel uniformity and high pixel operability which are quintessential parameters for large area imaging arrays. In this paper we report the first demonstration of the megapixel-simultaneously-readable and pixel-co-registered dual-band QWIP focal plane array (FPA). The dual-band QWIP device was developed by stacking...
A novel 2-DOF planar liner ultrasonic motor (USM) based on longitudinal and bending hybrid transducer was proposed and investigated. The USM is a piezoelectric single-oscillator, which consists of a cross orthogonal horn with a driving foot at the intersection. Longitudinal and bending vibration are excited and superimposed in stator and forms elliptical trajectory on the driving foot to cause the...
We have used quantum wells, quantum dots, and strained layer sperlattices for infrared detection and imaging. Quantum well infrared photodetectors (QWIPs) are based on GaAs/AlGaAs material system and the quantum dot infrared detector (QDIPs) are based on InAs/InGaAs/GaAs materials system. Strained layer superlattice (SLS) detectors are based on InAs/GaSb materials system and grown on GaSb substrates.
Mid-wavelength infrared (MWIR) and long-wavelength infrared (LWIR) InGaAs/GaAs/AlGaAs based quantum well infrared photodetector (QWIP) 320times 256 pixel dualband pixel co-registered simultaneous QWIP focal plane array (FPA) have been demonstrated as pathfinders. In this paper, we discuss the development of 1024 times 1024 MWIR/LWIR dualband pixel co-registered simultaneous QWIP focal plane array.
In this paper, a compensation scheme is presented for general actuator nonlinearities. The compensator uses two neural networks, one to estimate the unknown actuator nonlinearities and another to provide adaptive compensation in the feedforward path. Since radial basis function network has the universal approximation property and can avoid the local minima problem, the compensator uses RBF neural...
A novel fuzzy global sliding mode control (FGSMC) scheme is proposed for position tracking of a class of second-order nonlinear uncertain system. In the proposed scheme, we integrate input-output linearization technique to cancel the nonlinearities. By designing global sliding mode surface, the proposed scheme eliminates reaching phase problem so that the closed-loop system always shows invariance...
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.