994 research outputs found
High-speed chromatic dispersion monitoring of a two-channel WDM system using a single TPA microcavity
No full textChromatic dispersion monitoring of two 160 Gb/s wavelength channels using a TPA Microcavity is presented. As the microcavity exhibits a wavelength resonance characteristic, a single device could monitor a number of different WDM-channels sequentially
Partially coherent nano-focused x-ray radiation characterized by Talbot Interferometry
No full textWe have studied the spatial coherence properties of a nano-focused x-ray beam by grating (Talbot) interferometry in projection geometry. The beam is focused by a fixed curvature mirror system optimized for high flux density under conditions of partial coherence. The spatial coherence of the divergent exit wave emitted from the mirror focus is measured by Talbot interferometry The results are compared to numerical calculations of coherence propagation. In view of imaging applications, the magnified in-line image of a test pattern formed under conditions of partial coherence is analyzed quantitatively. Finally, additional coherence filtering by use of x-ray waveguides is demonstrated. By insertion of x-ray waveguides, the beam diameter can be reduced from typical values of 200 nm to values below 15 nm. In proportion to the reduction in the focal spot size, the numerical aperture (NA) of the projection imaging system is increased, as well as the coherence length, as quantified by grating interferometry. (C) 2011 Optical Society of Americ
Forecasting banknotes
No full textA central bank’s liquidity forecast is important in ensuring that it supplies the banking system’s need for central bank money. Banknote (or currency in circulation) demand is the largest and for some central banks the most variable component of the liquidity forecast. Accurate forecasting of banknotes is essential in ensuring an accurate liquidity forecast and in turn effective monetary policy implementation. This Handbook discusses these issues and outlines a structural time series state space (STSSS) model which is now used by central banks including the Bank of England and ECB to forecast banknotes (currency in circulation).Forecasting banknotes
Dragocene daritve iz Pomeranije: trije koncerti in sinfonia Christiana Michaela Wolffa (1707–1789)
No full textChristian Michael Wolff, an organist from Szczecin, is a composer already known for his songs, accompanied sonatas, chorale preludes for organ and a motet, but his orchestral music, comprising three concertos and a sinfonia preserved in manuscripts in Stockholm, have hitherto been overlooked. Close examination reveals these early works, probably composed in the 1740s, to be ambitious, attractive pieces fully deserving modern revival.Christian Michael Wolff, organist iz Szczecina, je skladatelj, katerega pesmi, sonate s spremljavo, koralni preludiji za orgle in motet so že znani. Na drugi strani pa je bila njegova orkestrska glasba, ki obsega tri koncerte in sinfonio, ohranjeno v rokopisu v Stockholmu, doslej prezrta. Podrobna raziskava je pokazala, da so ta zgodnja dela, verjetno skomponirana v štiridesetih letih 18. stoletja, ambiciozna, očarljiva in vredna sodobne oživitve
Periodic metallic nanostructures fabricated by coherent Talbot lithography in a table top system
No full text2013 Summer.Includes bibliographical references.This thesis describes a novel technique of extreme ultraviolet (EUV) lithography. A compact nanofabrication system that combines Talbot lithography and a table top extreme ultraviolet laser illumination is presented. The lithographic method based on the Talbot effect provides a robust and simple experimental setup that is capable to print arbitrary periodic structures over millimeter square areas free of defects. Test structures were printed and metalized by ion beam etching system which was rebuilt and calibrated as part of this work. The results demonstrate that a complete coherent extreme ultraviolet lithographic process based on a table top system has the capability to fabricate functional periodic metallic nanostructures. Preliminary results and prospects for future work are also presented at the end of this thesis
OpenSeqSLAM2.0: An Open Source Toolbox for Visual Place Recognition Under Changing Conditions
No full textVisually recognising a traversed route — regardless of whether seen during the day or night, in clear or inclement conditions, or in summer or winter — is an important capability for navigating robots. Since SeqSLAM was introduced in 2012, a large body of work has followed exploring how robotic systems can use the algorithm to meet the challenges posed by navigation in changing environmental conditions. The following paper describes OpenSeqSLAM2.0, a fully open-source toolbox for visual place recognition under changing conditions. Beyond the benefits of open access to the source code, OpenSeqSLAM2.0 provides a number of tools to facilitate exploration of the visual place recognition problem and interactive parameter tuning. Using the new open source platform, it is shown for the first time how comprehensive parameter characterisations provide new insights into many of the system components previously presented in ad hoc ways and provide users with a guide to what system component options should be used under what circumstances and why.Ben Talbot, Sourav Garg, and Michael Milfor
- …
