Vaughn College of Aeronautics and Technology

About: Vaughn College of Aeronautics and Technology is a education organization based out in New York, New York, United States. It is known for research contribution in the topics: Gravitational microlensing & Planetary system. The organization has 727 authors who have published 708 publications receiving 14082 citations. The organization is also known as: College of Aeronautics.

An adaptive single channel EMD-TNMF blind source separation algorithm for both instantaneous and convolutive mixed signal

Abstract: Single channel blind source separation (SCBSS) using time-frequency nonnegative matrix factorization (NMF) has some shortcomings, where the source number and convolution order must be known and it's sensitive to the factors (e.g. window function, window length and overlap ratio of adjacent windows). To compensate these shortcomings that cannot meet the real application, we proposed an adaptive EMD-TNMF algorithm, which can estimate both the source number and the convolution order and is applicable to both single channel linear instantaneous and convolutive mixtures. Firstly, the single channel signal is mapped into multiple channels by utilizing empirical mode decomposition (EMD), and the number of independent sources is estimated by applying eigenvalue descent ratio of the IMFs' covariance matrix. Secondly, the autocorrelation-based method is used to estimate the convolution order. Thirdly, the nonnegative matrix is constructed by adding one positive matrix (all elements are positive). Finally, in time domain, NMF algorithm is used to separate source signals. The algorithm's performance is verified by two experiments where the single channel signal is linear instantaneous mixing of four artificial signals and linear convolutive mixing of two speech signals respectively. Results show that this algorithm can estimate the source number and convolution order correctly and obtain better separated source signals.

The Buckling of Shallow Corrugated Webs in Shear

Abstract: The results of a series of shear buckling tests on shallow, flat-sided, corrugated webs are presented, and a comparison made with a theoretical analysis in which the web is assumed to buckle either as an orthotropic plate or in a local mode. An expression is derived for the efficiency of a corrugated web in shear, and used to compare the four shapes of cross-section tested.

Study of the aerodynamics of in-plane motion

Abstract: A computational analysis is performed of the unsteady aerodynamics associated with the blade sections of helicopter rotors in forward flight. The unsteady flow is studied through solutions of the two- dimensional Reynolds averaged Navier-Stokes equations together with a strongly coupled two-equation model of turbulence. Two motions are studied.The first motion is that of an aerofoil subjected to harmonic in-plane oscillations. The influence of advance ratio and reduced frequency is investigated. It is shown that, in the absence of shock waves, the flow is periodic with a reduced frequency equal to that of the forcing motion. However, the flow development lags behind the forcing motion. Furthermore, for constant reduced frequency the phase lag is independent of advance ratio.In addition to harmonic motion, the aerodynamic response to a step change in Mach number is investigated. Using an assumed form of the response of lift coefficient to a step change in Mach number, a lift transfer operator for s...

Some recent experiments on learning and their training implications.

Abstract: Three experiments are described involving respectively, a repetitive manual task, a sequential task of keying numbers and a task involving the learning of simple guidance. Those experiments are consistent with the concept that although all real tasks have perceptual and. motor aspects skills are essentially either perceptual or motor, and training techniques for these two fundamental kinds of skill may well be different.