Fuel cells are generally considered as a clean, efficient and silent technology that can produce electricity and heat from fossil fuels, biofuels as well as hydrogen produced from renewable energy sources such as wind energy and solar energy. The expectations with respect to their commercial introduction in transport as early as 2003 and stationary applications by 2001 held since the mid 1990s ...

We give an explicit formula (i.e., a formal stationary phase formula) for the local Fourier-Laplace transform of a formal germ of meromorphic connection of one complex variable with a possibly irregular singularity. Résumé (Une formule de la phase stationnaire explicite pour le transformé de Fourier-Laplace local) On donne une formule explicite (c’est-à-dire une formule de la phase stationnaire...

The detection of continuous gravitational-wave signals requires to account for the motion of the detector with respect to the solar system barycenter in the data analysis. In order to search efficiently for such signals by means of the fast Fourier transform the data needs to be transformed from the topocentric time to the barycentric time by means of resampling. The resampled data form a non-s...

We are pursuing a system that monitors the engine condition under multiple load settings, i.e. under non-stationary operating conditions. We have obtained data from the electronically controlled 2-stroke engine at MAN B&W Research Copenhagen. The running speed when data acquired under simulated marine conditions (different load settings on the propeller curve) was in the range from 60 to 120 ro...

Non-stationary filtering of seismic data can be accomplished in time or in Fourier domain by the theory of non-stationary convolution (Margrave, 1998). Here I show the results of implementing this theory for time-variant filtering of seismic data with an arbitrary number of filters and for forward and inverse NMO correction in the frequency domain. In the first case I show that the filters may ...

A design of a miniaturized stationary Fourier transform IR spectrometer has been developed that produces a two-dimensional interferogram. The latter is disturbed by effects like parasitic interferences or disparities in the cutoff wavelength of the pixels. Thus, a simple Fourier transform cannot be used to estimate the spectrum of the scene. However, as these defects are deterministic, they can...

Abstract The ability to test for statistical causality in linear and nonlinear contexts, stationary or non-stationary settings, identify whether influences trend of volatility forms a particularly important class problems explore multi-modal multivariate processes. In this paper, we develop novel testing frameworks general classes time series models. Our framework accommodates flexible features...

Massively parallel Fourier transforms are widely used in computational sciences, and specifically fluid dynamics which involves unbounded Poisson problems. In practice the latter is usually most time-consuming operation due to its inescapable all-to-all communication pattern. The original flups<...

This study aims to investigate the purchasing power parity (PPP) hypothesis for 38 OECD member countries over period 1994:M1-2021:M9 by performing Hepsag’s (2021) unit root test. It fills gap in literature since it is one of first studies conducted a test that considers structural change and nonlinearity all countries. The study, which conventional tests such as ADF, KPSS, Fourier allow merely ...