3,455 research outputs found
Application of a quasi-open ion source for neutral particle density measurements in the thermosphere
Open ion source mass spectrometer used with omegatron mass spectrometer to measure atmospheric gas density and composition in thermosphere probe experimen
Channels of Firm Adjustment: Theory and Empirical Evidence
We provide a comprehensive analysis of how firms choose between different expansion and contraction forms, unifying existing approaches from the industrial organization and corporate finance literature. Using novel data covering almost the entire universe of UK firms, we document firms? use of internal adjustment, greenfield investment and mergers and acquisitions (M&As). We describe frequency and aggregate importance of the different channels, and show that their use varies systematically with observable firm characteristics, in particular firm size and the magnitude of adjustment. We also demonstrate that there is positive assortative matching on the UK merger market. Based on these facts, we propose a theoretical framework which accommodates all three adjustment channels in a unified setting, and is able to replicate the adjustment and matching patterns found in the data
Pauli blocking effects and Cooper triples in three-component Fermi gases
We investigate the effect of Pauli blocking on universal two- and three-body
states in the medium. Their corresponding energies are extracted from the poles
of two- and three-body in-medium scattering amplitudes. Compared to the vacuum,
the binding of dimer and trimer states is reduced by the medium effects. In
two-body scattering, the well-known physics of Cooper pairs is recovered. In
the three-body sector, we find a new class of positive energy poles which can
be interpreted as Cooper triples.Comment: 19 pages, 9 figures, discussion expanded, final versio
Towards Understanding Spontaneous Speech: Word Accuracy vs. Concept Accuracy
In this paper we describe an approach to automatic evaluation of both the
speech recognition and understanding capabilities of a spoken dialogue system
for train time table information. We use word accuracy for recognition and
concept accuracy for understanding performance judgement. Both measures are
calculated by comparing these modules' output with a correct reference answer.
We report evaluation results for a spontaneous speech corpus with about 10000
utterances. We observed a nearly linear relationship between word accuracy and
concept accuracy.Comment: 4 pages PS, Latex2e source importing 2 eps figures, uses icslp.cls,
caption.sty, psfig.sty; to appear in the Proceedings of the Fourth
International Conference on Spoken Language Processing (ICSLP 96
A Portrait of firm Expansion and Contraction Channels
We present a novel set of stylised facts on forms of firm expansion and contraction, using unique business register data for the United Kingdom between 1997 and 2005. We distinguish between adjustments of employment and turnover at existing establishments, expansions and contractions taking place via greenfield investments and disinvestments, and via acquisitions and sell-offs. We document the relative importance of these three channels and how firms choose between them. We interpret our findings in the light of existing theories of firm dynamics, and propose directions for future theoretical developments
Evaluation of the developmental capacity of cattle embryos after culture and deep-freezing
International audienc
An explicit multi-time-stepping algorithm for aerodynamic flows
An explicit multi-time-stepping algorithm with applications to aerodynamic flows is presented. In the algorithm, in different parts of the computational domain different time steps are taken, and the flow is synchronized at the so-called synchronization levels. The algorithm is validated for aerodynamic turbulent flows. For two-dimensional flows speedups in the order of five with respect to single time stepping are obtained.
- …