Shift and rotation invariance properties of linear time-frequency representations are investigated. It is shown that among all linear time-frequency representations, only the short-time Fourier transform (STFT) family with the Hermite–Gaussian kernels satisfies both the shift invariance and rotation invariance properties that are satisfied by the Wigner distribution (WD). By extending the time-...

The effects of wave action and horseshoe crab spawning on the topography and grain-size characteristics on the foreshore of an estuarine sand beach in Delaware Bay, New Jersey, USA were evaluated using data collected over six consecutive high tides. Data were gathered inside and outside a 25 m long exclosure constructed to create a control area free of disturbance by crabs. The density of crabs...

Range exclosures have been used as a tool to restore degraded communal grazing lands in Tigray region of Northern Ethiopia. Although there seems be ecological evidence success rehabilitation rangelands Tigray, is unclear translation these achievements into socio-economic benefits. It was hypothesized that this could partly attributed poor governance the range occasioned by low participation and...

Our research on the herbaceous understory vegetation in the Kluane region, Yukon, has focused on the structure and function of natural forest understory and grassland communities. The research has involved two long-term projects. The first investigated fertilizer addition and mammalian herbivore exclosure in understory vegetation over a 20-year period and showed that nutrient availability, and ...

These notes provide an overview of singleand multi-factor models of the short rate. We will begin with a generic single-factor model where the dynamics of rt under the physical measure, P , are given. Following the approach of Vasicek, we then derive the PDE that must be satisfied by derivative security prices. We then use the martingale approach to give an alternative (and familiar) expression...

In this paper we introduce the concept of the short-time articulation index. This is a procedure for calculating a time-varying articulation index from data on a block-by-block basis. The short-time articulation index can be used to give a running measure of the speech intelligibility for an adaptive noise-cancellation system as it converges. We present an algorithm for calculating the short-ti...

The authors study the short-time dynamics of helix-forming polypeptide chains using an all-atom representation of the molecules and an implicit solvation model to approximate the interaction with the surrounding solvent. The results confirm earlier observations that the helix-coil transition in proteins can be described by a set of critical exponents. The high statistics of the simulations allo...

Successful wavelet estimation is an essential step for seismic methods like impedance inversion, analysis of amplitude variations with offset and full waveform inversion. Homomorphic deconvolution has long intrigued as a potentially elegant solution to the wavelet estimation problem. Yet a successful implementation has proven difficult. Associated disadvantages like phase unwrapping and restric...