Bring forward a new analytical method in order to evaluate the stability of the process of aluminum alloy pulsed MIG welding. The ratio of the first and the second peak in arc voltage signal probability density was selected to evaluate aluminum alloy pulse MIG welding stability. By calculating the arc voltage signal probability density from 80 sets of welding experiments, the ratio of the two p...

The difference between the equilibrium and switching d/p ratio of a bistable twisted nematic ͑BTN͒ liquid crystal display is shown by computer simulation. It is clearly indicated that the optimized d/p ratio has to be determined by the switching rather than equilibrium d/p ratio. It is also shown that the switching d/p ratio is related not only to the pre-tilt angle, but also to liquid crystal vi...

A family of Large Area Synchronised (LAS) codes is studied, which exhibits a so-called Interference Free Window (IFW), where both the Inter Symbol Interference (ISI) and the Multiple User Interference (MAI) are suppressed, provided that the relative time offset of the codes is within the IFW. Hence, LAS codes have the potential of increasing the capacity of CDMA networks. However, a specific dr...

A theoretical and experimental analysis of optical pulse coding techniques applied to distributed optical fiber temperature sensors based on spontaneous Brillouin scattering using the Landau-Placzek ratio (LPR) scheme is presented, quantifying in particular the impact of Simplex coding on stimulated Brillouin and Raman power thresholds. The signal-to-noise ratio (SNR) enhancement and temperatur...

AR = cavity aspect ratio a = speed of sound b = cavity half-width ~ C = dynamic compressibility c = phase speed cp = specific heat at constant pressure f = frequency H = cavity depth k = wave number m = propagation constant P = pressure Pr = Prandtl number R = reflection coefficient p = acoustic pressure pi = initial pulse amplitude Re = acoustic Reynolds number s = cavity spacing T = temperatu...

Orthogonal Frequency Division Multiplexing (OFDM) is an efficient method of data transmission for high speed communication systems. However, the main drawback of OFDM system is the high Peak to Average Power Ratio (PAPR) of the transmitted signal. OFDM consist of large number of independent subcarriers, as a result of which the amplitude of such signal can have high peak values. Pulse shaping u...

This paper outlines a technique which can use multiple transmit antennas to send more than one binary bit using the same number of transmit antennas over a single transmission. It uses Ultra Wideband orthogonal pulse position modulation to achieve this, with the receiver employing a Rake receiver and a Maximum Ratio Combiner optimal detector. This is done over a Space Time Spreading Time Hoppin...

We demonstrated a method to construct high efficiency saturable absorbers based on the evanescent light field interaction of CVD monolayer graphene deposited on side-polished D-shaped optical fiber. A set of samples was fabricated with two different core-graphene distances (0 and 1 μm), covered with graphene ranging between 10 and 25 mm length. The mode-locking was achieved and the best pulse d...

The Orthogonal Frequency Division Multiplexing (OFDM) system have some problems such as carrier frequency offset, timing offset, and Peak to Average Power Ratio (PAPR). The impacts of these problems results into inter carrier interference (ICI) which affects the bit error rate (BER). Therefore, suitable methods are required to mitigate ICI at the receiver. In this paper a new pulse shape, by mo...