The spatial stability of microscopic target droplets used for laser-plasma soft x-ray generation in vacuum is investigated. A long-term drift in drop position is characterized with an ultrafast laser-diode imaging system. The drift is experimentally and theoretically shown to be due to a temperature-induced increase in target-liquid viscosity as a result of evaporation. Finally, the drift is co...

The derivation of block-processing structures for fractional sample rate conversion (FSRC) is revisited. In the past, several timeor frequency-domain approaches [1-6] have been proposed. However, the resulting structures differ concerning their group delay and, as a consequence thereof, in the arrangement of coefficients. In this paper it is shown that a minimum extra delay of z (ML L M+1) is s...

Abstract. Two main performance features of high-bandwidth switches are stability and delay. This paper investigates these performance features for input buffered switch architectures that deploy maximal weight matching algorithms to determine the configurations of the switching core. For this purpose, a novel mathematical model of the dynamics of a maximal weight matching algorithm is developed...

An e cient representation of short-time phase characteristics of speech sounds is proposed, based on recent ndings which suggest perceptual importance of phase characteristics. Subjective tests indicated that the synthesized speech sounds by the proposed method are indistinguishable from the original speech sounds with a moderate data compression. The proposed representation uses lower-order co...

This paper quantifies the fundamental limits of variable-length transmission of a general (possibly analog) source over a memoryless channel with noiseless feedback, under a distortion constraint. We consider excess distortion, average distortion and guaranteed distortion (d-semifaithful codes). In contrast to the asymptotic fundamental limit, a general conclusion is that allowing variable-leng...

A number of previous studies have shown that speech sounds may have an intrinsic low dimensional structure. Such studies have focused on magnitude-based features ignoring phase information, as is the convention in many speech processing applications. In this paper dimensionality reduction methods are applied to MFCC and modified group delay function (MODGDF) features derived from the magnitude ...

The objective of this paper is to minimize the phase delay of the zero-order hold (ZOH) an usual sample-data hold device. In this paper an optimized data holding scheme whose phase delay is significantly less than of the ZOH is presented. The method is based on using optimal extrapolators, which has a better result than extrapolators proposed by Yekutiel (1980) and Belicynski and Kozinski (1984...

In this paper we review two OFDM based architectures, which have recently been proposed for optical long-haul transmission. The BER performance is investigated in presence of chromatic dispersion and differential group delay. In a further step both architectures are extended to polarization diversity receivers. Improvement is achieved by diversity combining at the expense of increased complexity.

We describe a method for generating a wide spectrum and at the same time improving propagation through a model inhomogeneous gaseous medium. The method is based on using a small two-photon detuning from a Raman resonance to adiabatically establish an appropriate molecular superposition state. This state, in turn, generates a broad spectrum of sidebands whose refractive index, Rayleigh scatter, ...

An algorithm is proposed for estimating the band aperiodicity of speech signals, where “aperiodicity” is defined as the power ratio between the speech signal and the aperiodic component of the signal. Since this power ratio depends on the frequency band, the aperiodicity should be given for several frequency bands. The proposed D4C (Definitive Decomposition Derived Dirt-Cheap) estimator is base...